Changelog from v1:
o resend the whole filesystem into a patchset suggested by Greg;
o code is more cleaner, especially for decompression frontend.
--8<----------
Hi,
EROFS file system has been in Linux-staging for about a year.
It has been proved to be stable enough to move out of staging
by 10+ millions of HUAWEI Android mobile phones on the market
from EMUI 9.0.1, and it was promoted as one of the key features
of EMUI 9.1 [1], including P30(pro).
EROFS is a read-only file system designed to save extra storage
space with guaranteed end-to-end performance by applying
fixed-size output compression, inplace I/O and decompression
inplace technologies [2] to Linux filesystem.
In our observation, EROFS is one of the fastest Linux compression
filesystem using buffered I/O in the world. It will support
direct I/O in the future if needed. EROFS even has better read
performance in a large CR range compared with generic uncompressed
file systems with proper CPU-storage combination, which is
a reason why EROFS can be landed to speed up mobile phone
performance, and which can be probably used for other use cases
such as LiveCD and Docker image as well.
Currently EROFS supports 4k LZ4 fixed-size output compression
since LZ4 is the fastest widely-used decompression solution in
the world and 4k leads to unnoticable read amplification for
the worst case. More compression algorithms and cluster sizes
could be added later, which depends on the real requirement.
More informations about EROFS itself are available at:
Documentation/filesystems/erofs.txt
https://kccncosschn19eng.sched.com/event/Nru2/erofs-an-introduction-and-our-smartphone-practice-xiang-gao-huawei
erofs-utils (mainly mkfs.erofs now) is available at
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git
Preliminary iomap support has been pending in EROFS mailing
list by Chao Yu. The key issue is that current iomap doesn't
support tail-end packing inline data yet, it should be
resolved later.
Thanks to many contributors in the last year, the code is more
clean and improved. We hope EROFS can be used in wider use cases
so let's promote erofs out of staging and enhance it more actively.
Share comments about EROFS! We think EROFS is useful to
community as a part of Linux upstream.
Thank you very much,
Gao Xiang
[1] http://web.archive.org/web/20190627021241/https://consumer.huawei.com/en/emui/
[2] https://lore.kernel.org/lkml/[email protected]/
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: Chao Yu <[email protected]>
Cc: Miao Xie <[email protected]>
Cc: Li Guifu <[email protected]>
Cc: Fang Wei <[email protected]>
Signed-off-by: Gao Xiang <[email protected]>
Gao Xiang (24):
erofs: add on-disk layout
erofs: add erofs in-memory stuffs
erofs: add super block operations
erofs: add raw address_space operations
erofs: add inode operations
erofs: support special inode
erofs: add directory operations
erofs: add namei functions
erofs: support tracepoint
erofs: update Kconfig and Makefile
erofs: introduce xattr & posixacl support
erofs: introduce tagged pointer
erofs: add compression indexes support
erofs: introduce superblock registration
erofs: introduce erofs shrinker
erofs: introduce workstation for decompression
erofs: introduce per-CPU buffers implementation
erofs: introduce pagevec for decompression subsystem
erofs: add erofs_allocpage()
erofs: introduce generic decompression backend
erofs: introduce LZ4 decompression inplace
erofs: introduce the decompression frontend
erofs: introduce cached decompression
erofs: add document
Documentation/filesystems/erofs.txt | 211 ++++
fs/Kconfig | 1 +
fs/Makefile | 1 +
fs/erofs/Kconfig | 154 +++
fs/erofs/Makefile | 11 +
fs/erofs/compress.h | 89 ++
fs/erofs/data.c | 390 ++++++++
fs/erofs/decompressor.c | 329 ++++++
fs/erofs/dir.c | 147 +++
fs/erofs/erofs_fs.h | 317 ++++++
fs/erofs/inode.c | 326 ++++++
fs/erofs/internal.h | 566 +++++++++++
fs/erofs/namei.c | 250 +++++
fs/erofs/super.c | 616 ++++++++++++
fs/erofs/tagptr.h | 110 ++
fs/erofs/utils.c | 416 ++++++++
fs/erofs/xattr.c | 700 +++++++++++++
fs/erofs/xattr.h | 93 ++
fs/erofs/zdata.c | 1439 +++++++++++++++++++++++++++
fs/erofs/zdata.h | 201 ++++
fs/erofs/zmap.c | 462 +++++++++
fs/erofs/zpvec.h | 159 +++
include/trace/events/erofs.h | 256 +++++
23 files changed, 7244 insertions(+)
create mode 100644 Documentation/filesystems/erofs.txt
create mode 100644 fs/erofs/Kconfig
create mode 100644 fs/erofs/Makefile
create mode 100644 fs/erofs/compress.h
create mode 100644 fs/erofs/data.c
create mode 100644 fs/erofs/decompressor.c
create mode 100644 fs/erofs/dir.c
create mode 100644 fs/erofs/erofs_fs.h
create mode 100644 fs/erofs/inode.c
create mode 100644 fs/erofs/internal.h
create mode 100644 fs/erofs/namei.c
create mode 100644 fs/erofs/super.c
create mode 100644 fs/erofs/tagptr.h
create mode 100644 fs/erofs/utils.c
create mode 100644 fs/erofs/xattr.c
create mode 100644 fs/erofs/xattr.h
create mode 100644 fs/erofs/zdata.c
create mode 100644 fs/erofs/zdata.h
create mode 100644 fs/erofs/zmap.c
create mode 100644 fs/erofs/zpvec.h
create mode 100644 include/trace/events/erofs.h
--
2.17.1
This patch adds EROFS compression indexes support,
including legacy and compacted 2/4B indexes.
In addition, it introduces an iterable L2P mapping
operation called 'z_erofs_map_blocks_iter'.
Compared with 'erofs_map_blocks', it avoids a number
of redundant 'release and regrab' processes if they
request the same meta page.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/Kconfig | 9 +
fs/erofs/Makefile | 1 +
fs/erofs/inode.c | 2 +-
fs/erofs/internal.h | 35 ++-
fs/erofs/zmap.c | 460 +++++++++++++++++++++++++++++++++++
include/trace/events/erofs.h | 17 +-
6 files changed, 521 insertions(+), 3 deletions(-)
create mode 100644 fs/erofs/zmap.c
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index b6a4384936b3..f6b6eb0250b8 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -80,3 +80,12 @@ config EROFS_FS_SECURITY
If you are not using a security module, say N.
+config EROFS_FS_ZIP
+ bool "EROFS Data Compresssion Support"
+ depends on EROFS_FS
+ select LZ4_DECOMPRESS
+ help
+ Enable fixed-sized output compression for EROFS.
+
+ If you don't want to enable compression feature, say N.
+
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index fc5d1cd3345f..9ab4ccc9328e 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -7,4 +7,5 @@ ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\"
obj-$(CONFIG_EROFS_FS) += erofs.o
erofs-objs := super.o inode.o data.o namei.o dir.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += zmap.o
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 8fa5cdf6c0de..3b916008b620 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -205,7 +205,7 @@ static int fill_inode(struct inode *inode, int isdir)
}
if (is_inode_layout_compression(inode)) {
- err = -ENOTSUPP;
+ err = z_erofs_fill_inode(inode);
goto out_unlock;
}
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index ccef7f2a7cf3..f0a5fd316e09 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -171,9 +171,12 @@ static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
/* atomic flag definitions */
#define EROFS_V_EA_INITED_BIT 0
+#define EROFS_V_Z_INITED_BIT 1
/* bitlock definitions (arranged in reverse order) */
#define EROFS_V_BL_XATTR_BIT (BITS_PER_LONG - 1)
+#define EROFS_V_BL_Z_BIT (BITS_PER_LONG - 2)
+
struct erofs_vnode {
erofs_nid_t nid;
@@ -187,7 +190,17 @@ struct erofs_vnode {
unsigned xattr_shared_count;
unsigned *xattr_shared_xattrs;
- erofs_blk_t raw_blkaddr;
+ union {
+ erofs_blk_t raw_blkaddr;
+#ifdef CONFIG_EROFS_FS_ZIP
+ struct {
+ unsigned short z_advise;
+ unsigned char z_algorithmtype[2];
+ unsigned char z_logical_clusterbits;
+ unsigned char z_physical_clusterbits[2];
+ };
+#endif
+ };
/* the corresponding vfs inode */
struct inode vfs_inode;
};
@@ -260,6 +273,10 @@ enum {
#define EROFS_MAP_MAPPED (1 << BH_Mapped)
/* Located in metadata (could be copied from bd_inode) */
#define EROFS_MAP_META (1 << BH_Meta)
+/* The extent has been compressed */
+#define EROFS_MAP_ZIPPED (1 << BH_Zipped)
+/* The length of extent is full */
+#define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
struct erofs_map_blocks {
erofs_off_t m_pa, m_la;
@@ -273,6 +290,22 @@ struct erofs_map_blocks {
/* Flags used by erofs_map_blocks() */
#define EROFS_GET_BLOCKS_RAW 0x0001
+/* zmap.c */
+#ifdef CONFIG_EROFS_FS_ZIP
+int z_erofs_fill_inode(struct inode *inode);
+int z_erofs_map_blocks_iter(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags);
+#else
+static inline int z_erofs_fill_inode(struct inode *inode) { return -ENOTSUPP; }
+static inline int z_erofs_map_blocks_iter(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags)
+{
+ return -ENOTSUPP;
+}
+#endif
+
/* data.c */
static inline struct bio *erofs_grab_bio(struct super_block *sb,
erofs_blk_t blkaddr,
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
new file mode 100644
index 000000000000..006f09ce83a1
--- /dev/null
+++ b/fs/erofs/zmap.c
@@ -0,0 +1,460 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/zmap.c
+ *
+ * Copyright (C) 2018-2019 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "internal.h"
+#include <asm/unaligned.h>
+#include <trace/events/erofs.h>
+
+int z_erofs_fill_inode(struct inode *inode)
+{
+ struct erofs_vnode *const vi = EROFS_V(inode);
+
+ if (vi->datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY) {
+ vi->z_advise = 0;
+ vi->z_algorithmtype[0] = 0;
+ vi->z_algorithmtype[1] = 0;
+ vi->z_logical_clusterbits = LOG_BLOCK_SIZE;
+ vi->z_physical_clusterbits[0] = vi->z_logical_clusterbits;
+ vi->z_physical_clusterbits[1] = vi->z_logical_clusterbits;
+ set_bit(EROFS_V_Z_INITED_BIT, &vi->flags);
+ }
+ return -ENOTSUPP;
+}
+
+static int fill_inode_lazy(struct inode *inode)
+{
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ struct super_block *const sb = inode->i_sb;
+ int err;
+ erofs_off_t pos;
+ struct page *page;
+ void *kaddr;
+ struct z_erofs_map_header *h;
+
+ if (test_bit(EROFS_V_Z_INITED_BIT, &vi->flags))
+ return 0;
+
+ if (wait_on_bit_lock(&vi->flags, EROFS_V_BL_Z_BIT, TASK_KILLABLE))
+ return -ERESTARTSYS;
+
+ err = 0;
+ if (test_bit(EROFS_V_Z_INITED_BIT, &vi->flags))
+ goto out_unlock;
+
+ DBG_BUGON(vi->datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
+
+ pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
+ vi->xattr_isize, 8);
+ page = erofs_get_meta_page(sb, erofs_blknr(pos), false);
+ if (IS_ERR(page)) {
+ err = PTR_ERR(page);
+ goto out_unlock;
+ }
+
+ kaddr = kmap_atomic(page);
+
+ h = kaddr + erofs_blkoff(pos);
+ vi->z_advise = le16_to_cpu(h->h_advise);
+ vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
+ vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
+
+ if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX) {
+ errln("unknown compression format %u for nid %llu, please upgrade kernel",
+ vi->z_algorithmtype[0], vi->nid);
+ err = -ENOTSUPP;
+ goto unmap_done;
+ }
+
+ vi->z_logical_clusterbits = LOG_BLOCK_SIZE + (h->h_clusterbits & 7);
+ vi->z_physical_clusterbits[0] = vi->z_logical_clusterbits +
+ ((h->h_clusterbits >> 3) & 3);
+
+ if (vi->z_physical_clusterbits[0] != LOG_BLOCK_SIZE) {
+ errln("unsupported physical clusterbits %u for nid %llu, please upgrade kernel",
+ vi->z_physical_clusterbits[0], vi->nid);
+ err = -ENOTSUPP;
+ goto unmap_done;
+ }
+
+ vi->z_physical_clusterbits[1] = vi->z_logical_clusterbits +
+ ((h->h_clusterbits >> 5) & 7);
+unmap_done:
+ kunmap_atomic(kaddr);
+ unlock_page(page);
+ put_page(page);
+
+ set_bit(EROFS_V_Z_INITED_BIT, &vi->flags);
+out_unlock:
+ clear_and_wake_up_bit(EROFS_V_BL_Z_BIT, &vi->flags);
+ return err;
+}
+
+struct z_erofs_maprecorder {
+ struct inode *inode;
+ struct erofs_map_blocks *map;
+ void *kaddr;
+
+ unsigned long lcn;
+ /* compression extent information gathered */
+ u8 type;
+ u16 clusterofs;
+ u16 delta[2];
+ erofs_blk_t pblk;
+};
+
+static int z_erofs_reload_indexes(struct z_erofs_maprecorder *m,
+ erofs_blk_t eblk)
+{
+ struct super_block *const sb = m->inode->i_sb;
+ struct erofs_map_blocks *const map = m->map;
+ struct page *mpage = map->mpage;
+
+ if (mpage) {
+ if (mpage->index == eblk) {
+ if (!m->kaddr)
+ m->kaddr = kmap_atomic(mpage);
+ return 0;
+ }
+
+ if (m->kaddr) {
+ kunmap_atomic(m->kaddr);
+ m->kaddr = NULL;
+ }
+ put_page(mpage);
+ }
+
+ mpage = erofs_get_meta_page(sb, eblk, false);
+ if (IS_ERR(mpage)) {
+ map->mpage = NULL;
+ return PTR_ERR(mpage);
+ }
+ m->kaddr = kmap_atomic(mpage);
+ unlock_page(mpage);
+ map->mpage = mpage;
+ return 0;
+}
+
+static int vle_legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
+ unsigned long lcn)
+{
+ struct inode *const inode = m->inode;
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ const erofs_off_t ibase = iloc(EROFS_I_SB(inode), vi->nid);
+ const erofs_off_t pos =
+ Z_EROFS_VLE_LEGACY_INDEX_ALIGN(ibase + vi->inode_isize +
+ vi->xattr_isize) +
+ lcn * sizeof(struct z_erofs_vle_decompressed_index);
+ struct z_erofs_vle_decompressed_index *di;
+ unsigned int advise, type;
+ int err;
+
+ err = z_erofs_reload_indexes(m, erofs_blknr(pos));
+ if (err)
+ return err;
+
+ m->lcn = lcn;
+ di = m->kaddr + erofs_blkoff(pos);
+
+ advise = le16_to_cpu(di->di_advise);
+ type = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) &
+ ((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1);
+ switch (type) {
+ case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+ m->clusterofs = 1 << vi->z_logical_clusterbits;
+ m->delta[0] = le16_to_cpu(di->di_u.delta[0]);
+ m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
+ break;
+ case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+ m->clusterofs = le16_to_cpu(di->di_clusterofs);
+ m->pblk = le32_to_cpu(di->di_u.blkaddr);
+ break;
+ default:
+ DBG_BUGON(1);
+ return -EIO;
+ }
+ m->type = type;
+ return 0;
+}
+
+static unsigned int decode_compactedbits(unsigned int lobits,
+ unsigned int lomask,
+ u8 *in, unsigned int pos, u8 *type)
+{
+ const unsigned int v = get_unaligned_le32(in + pos / 8) >> (pos & 7);
+ const unsigned int lo = v & lomask;
+
+ *type = (v >> lobits) & 3;
+ return lo;
+}
+
+static int unpack_compacted_index(struct z_erofs_maprecorder *m,
+ unsigned int amortizedshift,
+ unsigned int eofs)
+{
+ struct erofs_vnode *const vi = EROFS_V(m->inode);
+ const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ const unsigned int lomask = (1 << lclusterbits) - 1;
+ unsigned int vcnt, base, lo, encodebits, nblk;
+ int i;
+ u8 *in, type;
+
+ if (1 << amortizedshift == 4)
+ vcnt = 2;
+ else if (1 << amortizedshift == 2 && lclusterbits == 12)
+ vcnt = 16;
+ else
+ return -ENOTSUPP;
+
+ encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
+ base = round_down(eofs, vcnt << amortizedshift);
+ in = m->kaddr + base;
+
+ i = (eofs - base) >> amortizedshift;
+
+ lo = decode_compactedbits(lclusterbits, lomask,
+ in, encodebits * i, &type);
+ m->type = type;
+ if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
+ m->clusterofs = 1 << lclusterbits;
+ if (i + 1 != vcnt) {
+ m->delta[0] = lo;
+ return 0;
+ }
+ /*
+ * since the last lcluster in the pack is special,
+ * of which lo saves delta[1] rather than delta[0].
+ * Hence, get delta[0] by the previous lcluster indirectly.
+ */
+ lo = decode_compactedbits(lclusterbits, lomask,
+ in, encodebits * (i - 1), &type);
+ if (type != Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
+ lo = 0;
+ m->delta[0] = lo + 1;
+ return 0;
+ }
+ m->clusterofs = lo;
+ m->delta[0] = 0;
+ /* figout out blkaddr (pblk) for HEAD lclusters */
+ nblk = 1;
+ while (i > 0) {
+ --i;
+ lo = decode_compactedbits(lclusterbits, lomask,
+ in, encodebits * i, &type);
+ if (type == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD)
+ i -= lo;
+
+ if (i >= 0)
+ ++nblk;
+ }
+ in += (vcnt << amortizedshift) - sizeof(__le32);
+ m->pblk = le32_to_cpu(*(__le32 *)in) + nblk;
+ return 0;
+}
+
+static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
+ unsigned long lcn)
+{
+ struct inode *const inode = m->inode;
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ const erofs_off_t ebase = ALIGN(iloc(EROFS_I_SB(inode), vi->nid) +
+ vi->inode_isize + vi->xattr_isize, 8) +
+ sizeof(struct z_erofs_map_header);
+ const unsigned int totalidx = DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+ unsigned int compacted_4b_initial, compacted_2b;
+ unsigned int amortizedshift;
+ erofs_off_t pos;
+ int err;
+
+ if (lclusterbits != 12)
+ return -ENOTSUPP;
+
+ if (lcn >= totalidx)
+ return -EINVAL;
+
+ m->lcn = lcn;
+ /* used to align to 32-byte (compacted_2b) alignment */
+ compacted_4b_initial = (32 - ebase % 32) / 4;
+ if (compacted_4b_initial == 32 / 4)
+ compacted_4b_initial = 0;
+
+ if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
+ compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
+ else
+ compacted_2b = 0;
+
+ pos = ebase;
+ if (lcn < compacted_4b_initial) {
+ amortizedshift = 2;
+ goto out;
+ }
+ pos += compacted_4b_initial * 4;
+ lcn -= compacted_4b_initial;
+
+ if (lcn < compacted_2b) {
+ amortizedshift = 1;
+ goto out;
+ }
+ pos += compacted_2b * 2;
+ lcn -= compacted_2b;
+ amortizedshift = 2;
+out:
+ pos += lcn * (1 << amortizedshift);
+ err = z_erofs_reload_indexes(m, erofs_blknr(pos));
+ if (err)
+ return err;
+ return unpack_compacted_index(m, amortizedshift, erofs_blkoff(pos));
+}
+
+static int vle_load_cluster_from_disk(struct z_erofs_maprecorder *m,
+ unsigned int lcn)
+{
+ const unsigned int datamode = EROFS_V(m->inode)->datamode;
+
+ if (datamode == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
+ return vle_legacy_load_cluster_from_disk(m, lcn);
+
+ if (datamode == EROFS_INODE_FLAT_COMPRESSION)
+ return compacted_load_cluster_from_disk(m, lcn);
+
+ return -EINVAL;
+}
+
+static int vle_extent_lookback(struct z_erofs_maprecorder *m,
+ unsigned int lookback_distance)
+{
+ struct erofs_vnode *const vi = EROFS_V(m->inode);
+ struct erofs_map_blocks *const map = m->map;
+ const unsigned int lclusterbits = vi->z_logical_clusterbits;
+ unsigned long lcn = m->lcn;
+ int err;
+
+ if (lcn < lookback_distance) {
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ /* load extent head logical cluster if needed */
+ lcn -= lookback_distance;
+ err = vle_load_cluster_from_disk(m, lcn);
+ if (err)
+ return err;
+
+ switch (m->type) {
+ case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+ return vle_extent_lookback(m, m->delta[0]);
+ case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+ map->m_flags &= ~EROFS_MAP_ZIPPED;
+ /* fallthrough */
+ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+ map->m_la = (lcn << lclusterbits) | m->clusterofs;
+ break;
+ default:
+ errln("unknown type %u at lcn %lu of nid %llu",
+ m->type, lcn, vi->nid);
+ DBG_BUGON(1);
+ return -EIO;
+ }
+ return 0;
+}
+
+int z_erofs_map_blocks_iter(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags)
+{
+ struct erofs_vnode *const vi = EROFS_V(inode);
+ struct z_erofs_maprecorder m = {
+ .inode = inode,
+ .map = map,
+ };
+ int err = 0;
+ unsigned int lclusterbits, endoff;
+ unsigned long long ofs, end;
+
+ trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
+
+ /* when trying to read beyond EOF, leave it unmapped */
+ if (unlikely(map->m_la >= inode->i_size)) {
+ map->m_llen = map->m_la + 1 - inode->i_size;
+ map->m_la = inode->i_size;
+ map->m_flags = 0;
+ goto out;
+ }
+
+ err = fill_inode_lazy(inode);
+ if (err)
+ goto out;
+
+ lclusterbits = vi->z_logical_clusterbits;
+ ofs = map->m_la;
+ m.lcn = ofs >> lclusterbits;
+ endoff = ofs & ((1 << lclusterbits) - 1);
+
+ err = vle_load_cluster_from_disk(&m, m.lcn);
+ if (err)
+ goto unmap_out;
+
+ map->m_flags = EROFS_MAP_ZIPPED; /* by default, compressed */
+ end = (m.lcn + 1ULL) << lclusterbits;
+
+ switch (m.type) {
+ case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
+ if (endoff >= m.clusterofs)
+ map->m_flags &= ~EROFS_MAP_ZIPPED;
+ /* fallthrough */
+ case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
+ if (endoff >= m.clusterofs) {
+ map->m_la = (m.lcn << lclusterbits) | m.clusterofs;
+ break;
+ }
+ /* m.lcn should be >= 1 if endoff < m.clusterofs */
+ if (unlikely(!m.lcn)) {
+ errln("invalid logical cluster 0 at nid %llu",
+ vi->nid);
+ err = -EIO;
+ goto unmap_out;
+ }
+ end = (m.lcn << lclusterbits) | m.clusterofs;
+ map->m_flags |= EROFS_MAP_FULL_MAPPED;
+ m.delta[0] = 1;
+ /* fallthrough */
+ case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+ /* get the correspoinding first chunk */
+ err = vle_extent_lookback(&m, m.delta[0]);
+ if (unlikely(err))
+ goto unmap_out;
+ break;
+ default:
+ errln("unknown type %u at offset %llu of nid %llu",
+ m.type, ofs, vi->nid);
+ err = -EIO;
+ goto unmap_out;
+ }
+
+ map->m_llen = end - map->m_la;
+ map->m_plen = 1 << lclusterbits;
+ map->m_pa = blknr_to_addr(m.pblk);
+ map->m_flags |= EROFS_MAP_MAPPED;
+
+unmap_out:
+ if (m.kaddr)
+ kunmap_atomic(m.kaddr);
+
+out:
+ debugln("%s, m_la %llu m_pa %llu m_llen %llu m_plen %llu m_flags 0%o",
+ __func__, map->m_la, map->m_pa,
+ map->m_llen, map->m_plen, map->m_flags);
+
+ trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
+
+ /* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
+ DBG_BUGON(err < 0 && err != -ENOMEM);
+ return err;
+}
+
diff --git a/include/trace/events/erofs.h b/include/trace/events/erofs.h
index 188c28e48289..660c92fc1803 100644
--- a/include/trace/events/erofs.h
+++ b/include/trace/events/erofs.h
@@ -20,7 +20,8 @@
#define show_mflags(flags) __print_flags(flags, "", \
{ EROFS_MAP_MAPPED, "M" }, \
- { EROFS_MAP_META, "I" })
+ { EROFS_MAP_META, "I" }, \
+ { EROFS_MAP_ZIPPED, "Z" })
TRACE_EVENT(erofs_lookup,
@@ -172,6 +173,13 @@ DEFINE_EVENT(erofs__map_blocks_enter, erofs_map_blocks_flatmode_enter,
TP_ARGS(inode, map, flags)
);
+DEFINE_EVENT(erofs__map_blocks_enter, z_erofs_map_blocks_iter_enter,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned int flags),
+
+ TP_ARGS(inode, map, flags)
+);
+
DECLARE_EVENT_CLASS(erofs__map_blocks_exit,
TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
unsigned int flags, int ret),
@@ -217,6 +225,13 @@ DEFINE_EVENT(erofs__map_blocks_exit, erofs_map_blocks_flatmode_exit,
TP_ARGS(inode, map, flags, ret)
);
+DEFINE_EVENT(erofs__map_blocks_exit, z_erofs_map_blocks_iter_exit,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned int flags, int ret),
+
+ TP_ARGS(inode, map, flags, ret)
+);
+
TRACE_EVENT(erofs_destroy_inode,
TP_PROTO(struct inode *inode),
--
2.17.1
- erofs_sb_info:
contains erofs-specific in-memory information.
- erofs_vnode:
contains vfs_inode and other fs-specific information.
same as super block, the only one in-memory definition exists.
- erofs_map_blocks
Logical to physical block mapping, used by erofs_map_blocks().
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/internal.h | 359 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 359 insertions(+)
create mode 100644 fs/erofs/internal.h
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
new file mode 100644
index 000000000000..03ce8420d20c
--- /dev/null
+++ b/fs/erofs/internal.h
@@ -0,0 +1,359 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * linux/fs/erofs/internal.h
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#ifndef __EROFS_INTERNAL_H
+#define __EROFS_INTERNAL_H
+
+#include <linux/fs.h>
+#include <linux/dcache.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/bio.h>
+#include <linux/buffer_head.h>
+#include <linux/cleancache.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "erofs_fs.h"
+
+/* redefine pr_fmt "erofs: " */
+#undef pr_fmt
+#define pr_fmt(fmt) "erofs: " fmt
+
+#define errln(x, ...) pr_err(x "\n", ##__VA_ARGS__)
+#define infoln(x, ...) pr_info(x "\n", ##__VA_ARGS__)
+#ifdef CONFIG_EROFS_FS_DEBUG
+#define debugln(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
+#define DBG_BUGON BUG_ON
+#else
+#define debugln(x, ...) ((void)0)
+#define DBG_BUGON(x) ((void)(x))
+#endif
+
+enum {
+ FAULT_KMALLOC,
+ FAULT_READ_IO,
+ FAULT_MAX,
+};
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+extern const char *erofs_fault_name[FAULT_MAX];
+#define IS_FAULT_SET(fi, type) ((fi)->inject_type & (1 << (type)))
+
+struct erofs_fault_info {
+ atomic_t inject_ops;
+ unsigned int inject_rate;
+ unsigned int inject_type;
+};
+#endif
+
+/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
+#define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
+
+typedef u64 erofs_nid_t;
+typedef u64 erofs_off_t;
+/* data type for filesystem-wide blocks number */
+typedef u32 erofs_blk_t;
+
+struct erofs_sb_info {
+ u32 blocks;
+ u32 meta_blkaddr;
+
+ /* inode slot unit size in bit shift */
+ unsigned char islotbits;
+ u32 build_time_nsec;
+ u64 build_time;
+
+ /* what we really care is nid, rather than ino.. */
+ erofs_nid_t root_nid;
+ /* used for statfs, f_files - f_favail */
+ u64 inos;
+
+ u8 uuid[16]; /* 128-bit uuid for volume */
+ u8 volume_name[16]; /* volume name */
+ u32 requirements;
+
+ char *dev_name;
+ unsigned int mount_opt;
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+ struct erofs_fault_info fault_info; /* For fault injection */
+#endif
+};
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+#define erofs_show_injection_info(type) \
+ infoln("inject %s in %s of %pS", erofs_fault_name[type], \
+ __func__, __builtin_return_address(0))
+
+static inline bool time_to_inject(struct erofs_sb_info *sbi, int type)
+{
+ struct erofs_fault_info *ffi = &sbi->fault_info;
+
+ if (!ffi->inject_rate)
+ return false;
+
+ if (!IS_FAULT_SET(ffi, type))
+ return false;
+
+ atomic_inc(&ffi->inject_ops);
+ if (atomic_read(&ffi->inject_ops) >= ffi->inject_rate) {
+ atomic_set(&ffi->inject_ops, 0);
+ return true;
+ }
+ return false;
+}
+#else
+static inline bool time_to_inject(struct erofs_sb_info *sbi, int type)
+{
+ return false;
+}
+
+static inline void erofs_show_injection_info(int type)
+{
+}
+#endif
+
+static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
+ size_t size, gfp_t flags)
+{
+ if (time_to_inject(sbi, FAULT_KMALLOC)) {
+ erofs_show_injection_info(FAULT_KMALLOC);
+ return NULL;
+ }
+ return kmalloc(size, flags);
+}
+
+#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
+#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
+
+/* Mount flags set via mount options or defaults */
+#define EROFS_MOUNT_FAULT_INJECTION 0x00000040
+
+#define clear_opt(sbi, option) ((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
+#define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option)
+#define test_opt(sbi, option) ((sbi)->mount_opt & EROFS_MOUNT_##option)
+
+/* we strictly follow PAGE_SIZE and no buffer head yet */
+#define LOG_BLOCK_SIZE PAGE_SHIFT
+
+#undef LOG_SECTORS_PER_BLOCK
+#define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
+
+#undef SECTORS_PER_BLOCK
+#define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
+
+#define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
+
+#if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
+#error erofs cannot be used in this platform
+#endif
+
+#define ROOT_NID(sb) ((sb)->root_nid)
+
+#define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
+#define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
+#define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
+
+static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
+{
+ return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
+}
+
+struct erofs_vnode {
+ erofs_nid_t nid;
+
+ unsigned char datamode;
+ unsigned char inode_isize;
+ unsigned short xattr_isize;
+
+ erofs_blk_t raw_blkaddr;
+ /* the corresponding vfs inode */
+ struct inode vfs_inode;
+};
+
+#define EROFS_V(ptr) \
+ container_of(ptr, struct erofs_vnode, vfs_inode)
+
+#define __inode_advise(x, bit, bits) \
+ (((x) >> (bit)) & ((1 << (bits)) - 1))
+
+#define __inode_version(advise) \
+ __inode_advise(advise, EROFS_I_VERSION_BIT, \
+ EROFS_I_VERSION_BITS)
+
+#define __inode_data_mapping(advise) \
+ __inode_advise(advise, EROFS_I_DATA_MAPPING_BIT,\
+ EROFS_I_DATA_MAPPING_BITS)
+
+static inline unsigned long inode_datablocks(struct inode *inode)
+{
+ /* since i_size cannot be changed */
+ return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
+}
+
+static inline bool is_inode_layout_compression(struct inode *inode)
+{
+ return erofs_inode_is_data_compressed(EROFS_V(inode)->datamode);
+}
+
+static inline bool is_inode_flat_inline(struct inode *inode)
+{
+ return EROFS_V(inode)->datamode == EROFS_INODE_FLAT_INLINE;
+}
+
+extern const struct super_operations erofs_sops;
+
+extern const struct address_space_operations erofs_raw_access_aops;
+
+/*
+ * Logical to physical block mapping, used by erofs_map_blocks()
+ *
+ * Different with other file systems, it is used for 2 access modes:
+ *
+ * 1) RAW access mode:
+ *
+ * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
+ * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
+ *
+ * Note that m_lblk in the RAW access mode refers to the number of
+ * the compressed ondisk block rather than the uncompressed
+ * in-memory block for the compressed file.
+ *
+ * m_pofs equals to m_lofs except for the inline data page.
+ *
+ * 2) Normal access mode:
+ *
+ * If the inode is not compressed, it has no difference with
+ * the RAW access mode. However, if the inode is compressed,
+ * users should pass a valid (m_lblk, m_lofs) pair, and get
+ * the needed m_pblk, m_pofs, m_len to get the compressed data
+ * and the updated m_lblk, m_lofs which indicates the start
+ * of the corresponding uncompressed data in the file.
+ */
+enum {
+ BH_Zipped = BH_PrivateStart,
+ BH_FullMapped,
+};
+
+/* Has a disk mapping */
+#define EROFS_MAP_MAPPED (1 << BH_Mapped)
+/* Located in metadata (could be copied from bd_inode) */
+#define EROFS_MAP_META (1 << BH_Meta)
+
+struct erofs_map_blocks {
+ erofs_off_t m_pa, m_la;
+ u64 m_plen, m_llen;
+
+ unsigned int m_flags;
+
+ struct page *mpage;
+};
+
+/* Flags used by erofs_map_blocks() */
+#define EROFS_GET_BLOCKS_RAW 0x0001
+
+/* data.c */
+static inline struct bio *erofs_grab_bio(struct super_block *sb,
+ erofs_blk_t blkaddr,
+ unsigned int nr_pages,
+ void *bi_private, bio_end_io_t endio,
+ bool nofail)
+{
+ const gfp_t gfp = GFP_NOIO;
+ struct bio *bio;
+
+ do {
+ if (nr_pages == 1) {
+ bio = bio_alloc(gfp | (nofail ? __GFP_NOFAIL : 0), 1);
+ if (unlikely(!bio)) {
+ DBG_BUGON(nofail);
+ return ERR_PTR(-ENOMEM);
+ }
+ break;
+ }
+ bio = bio_alloc(gfp, nr_pages);
+ nr_pages /= 2;
+ } while (unlikely(!bio));
+
+ bio->bi_end_io = endio;
+ bio_set_dev(bio, sb->s_bdev);
+ bio->bi_iter.bi_sector = (sector_t)blkaddr << LOG_SECTORS_PER_BLOCK;
+ bio->bi_private = bi_private;
+ return bio;
+}
+
+static inline void __submit_bio(struct bio *bio, unsigned int op,
+ unsigned int op_flags)
+{
+ bio_set_op_attrs(bio, op, op_flags);
+ submit_bio(bio);
+}
+
+#ifndef CONFIG_EROFS_FS_IO_MAX_RETRIES
+#define EROFS_IO_MAX_RETRIES_NOFAIL 0
+#else
+#define EROFS_IO_MAX_RETRIES_NOFAIL CONFIG_EROFS_FS_IO_MAX_RETRIES
+#endif
+
+struct page *__erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr,
+ bool prio, bool nofail);
+
+static inline struct page *erofs_get_meta_page(struct super_block *sb,
+ erofs_blk_t blkaddr, bool prio)
+{
+ return __erofs_get_meta_page(sb, blkaddr, prio, false);
+}
+
+int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
+
+static inline struct page *erofs_get_inline_page(struct inode *inode,
+ erofs_blk_t blkaddr)
+{
+ return erofs_get_meta_page(inode->i_sb, blkaddr,
+ S_ISDIR(inode->i_mode));
+}
+
+/* inode.c */
+static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
+{
+#if BITS_PER_LONG == 32
+ return (nid >> 32) ^ (nid & 0xffffffff);
+#else
+ return nid;
+#endif
+}
+
+extern const struct inode_operations erofs_generic_iops;
+extern const struct inode_operations erofs_symlink_iops;
+extern const struct inode_operations erofs_fast_symlink_iops;
+
+static inline void set_inode_fast_symlink(struct inode *inode)
+{
+ inode->i_op = &erofs_fast_symlink_iops;
+}
+
+static inline bool is_inode_fast_symlink(struct inode *inode)
+{
+ return inode->i_op == &erofs_fast_symlink_iops;
+}
+
+struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
+int erofs_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags);
+
+/* namei.c */
+extern const struct inode_operations erofs_dir_iops;
+
+int erofs_namei(struct inode *dir, struct qstr *name,
+ erofs_nid_t *nid, unsigned int *d_type);
+
+/* dir.c */
+extern const struct file_operations erofs_dir_fops;
+
+#endif
+
--
2.17.1
This patch introduces an temporary _on-stack_ page
pool to reuse the freed page directly as much as
it can for better performance and release all pages
at a time, it also slightly reduces the possibility of
the potential memory allocation failure.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/internal.h | 2 ++
fs/erofs/utils.c | 14 ++++++++++++++
2 files changed, 16 insertions(+)
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 5e06e2d12b5e..7e6ac4642593 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -495,6 +495,8 @@ int erofs_namei(struct inode *dir, struct qstr *name,
extern const struct file_operations erofs_dir_fops;
/* utils.c */
+struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp, bool nofail);
+
#if (EROFS_PCPUBUF_NR_PAGES > 0)
void *erofs_get_pcpubuf(unsigned int pagenr);
#define erofs_put_pcpubuf(buf) do { \
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index c430790a02e0..53ee6daa3f70 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -9,6 +9,20 @@
#include "internal.h"
#include <linux/pagevec.h>
+struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp, bool nofail)
+{
+ struct page *page;
+
+ if (!list_empty(pool)) {
+ page = lru_to_page(pool);
+ DBG_BUGON(page_ref_count(page) != 1);
+ list_del(&page->lru);
+ } else {
+ page = alloc_pages(gfp | (nofail ? __GFP_NOFAIL : 0), 0);
+ }
+ return page;
+}
+
#if (EROFS_PCPUBUF_NR_PAGES > 0)
static struct {
u8 data[PAGE_SIZE * EROFS_PCPUBUF_NR_PAGES];
--
2.17.1
This adds functions for directory, mainly readdir.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/dir.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 147 insertions(+)
create mode 100644 fs/erofs/dir.c
diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c
new file mode 100644
index 000000000000..f5bedf4e142f
--- /dev/null
+++ b/fs/erofs/dir.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/dir.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "internal.h"
+
+static const unsigned char erofs_filetype_table[EROFS_FT_MAX] = {
+ [EROFS_FT_UNKNOWN] = DT_UNKNOWN,
+ [EROFS_FT_REG_FILE] = DT_REG,
+ [EROFS_FT_DIR] = DT_DIR,
+ [EROFS_FT_CHRDEV] = DT_CHR,
+ [EROFS_FT_BLKDEV] = DT_BLK,
+ [EROFS_FT_FIFO] = DT_FIFO,
+ [EROFS_FT_SOCK] = DT_SOCK,
+ [EROFS_FT_SYMLINK] = DT_LNK,
+};
+
+static void debug_one_dentry(unsigned char d_type, const char *de_name,
+ unsigned int de_namelen)
+{
+#ifdef CONFIG_EROFS_FS_DEBUG
+ /* since the on-disk name could not have the trailing '\0' */
+ unsigned char dbg_namebuf[EROFS_NAME_LEN + 1];
+
+ memcpy(dbg_namebuf, de_name, de_namelen);
+ dbg_namebuf[de_namelen] = '\0';
+
+ debugln("found dirent %s de_len %u d_type %d", dbg_namebuf,
+ de_namelen, d_type);
+#endif
+}
+
+static int erofs_fill_dentries(struct dir_context *ctx,
+ void *dentry_blk, unsigned int *ofs,
+ unsigned int nameoff, unsigned int maxsize)
+{
+ struct erofs_dirent *de = dentry_blk + *ofs;
+ const struct erofs_dirent *end = dentry_blk + nameoff;
+
+ while (de < end) {
+ const char *de_name;
+ unsigned int de_namelen;
+ unsigned char d_type;
+
+ if (de->file_type < EROFS_FT_MAX)
+ d_type = erofs_filetype_table[de->file_type];
+ else
+ d_type = DT_UNKNOWN;
+
+ nameoff = le16_to_cpu(de->nameoff);
+ de_name = (char *)dentry_blk + nameoff;
+
+ /* the last dirent in the block? */
+ if (de + 1 >= end)
+ de_namelen = strnlen(de_name, maxsize - nameoff);
+ else
+ de_namelen = le16_to_cpu(de[1].nameoff) - nameoff;
+
+ /* a corrupted entry is found */
+ if (unlikely(nameoff + de_namelen > maxsize ||
+ de_namelen > EROFS_NAME_LEN)) {
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ debug_one_dentry(d_type, de_name, de_namelen);
+ if (!dir_emit(ctx, de_name, de_namelen,
+ le64_to_cpu(de->nid), d_type))
+ /* stopped by some reason */
+ return 1;
+ ++de;
+ *ofs += sizeof(struct erofs_dirent);
+ }
+ *ofs = maxsize;
+ return 0;
+}
+
+static int erofs_readdir(struct file *f, struct dir_context *ctx)
+{
+ struct inode *dir = file_inode(f);
+ struct address_space *mapping = dir->i_mapping;
+ const size_t dirsize = i_size_read(dir);
+ unsigned int i = ctx->pos / EROFS_BLKSIZ;
+ unsigned int ofs = ctx->pos % EROFS_BLKSIZ;
+ int err = 0;
+ bool initial = true;
+
+ while (ctx->pos < dirsize) {
+ struct page *dentry_page;
+ struct erofs_dirent *de;
+ unsigned int nameoff, maxsize;
+
+ dentry_page = read_mapping_page(mapping, i, NULL);
+ if (IS_ERR(dentry_page))
+ continue;
+
+ de = (struct erofs_dirent *)kmap(dentry_page);
+
+ nameoff = le16_to_cpu(de->nameoff);
+
+ if (unlikely(nameoff < sizeof(struct erofs_dirent) ||
+ nameoff >= PAGE_SIZE)) {
+ errln("%s, invalid de[0].nameoff %u",
+ __func__, nameoff);
+
+ err = -EIO;
+ goto skip_this;
+ }
+
+ maxsize = min_t(unsigned int,
+ dirsize - ctx->pos + ofs, PAGE_SIZE);
+
+ /* search dirents at the arbitrary position */
+ if (unlikely(initial)) {
+ initial = false;
+
+ ofs = roundup(ofs, sizeof(struct erofs_dirent));
+ if (unlikely(ofs >= nameoff))
+ goto skip_this;
+ }
+
+ err = erofs_fill_dentries(ctx, de, &ofs, nameoff, maxsize);
+skip_this:
+ kunmap(dentry_page);
+
+ put_page(dentry_page);
+
+ ctx->pos = blknr_to_addr(i) + ofs;
+
+ if (unlikely(err))
+ break;
+ ++i;
+ ofs = 0;
+ }
+ return err < 0 ? err : 0;
+}
+
+const struct file_operations erofs_dir_fops = {
+ .llseek = generic_file_llseek,
+ .read = generic_read_dir,
+ .iterate_shared = erofs_readdir,
+};
+
--
2.17.1
In order to introducing shrinker solution for erofs,
let's manage all mounted erofs instances at first.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/Makefile | 2 +-
fs/erofs/internal.h | 13 +++++++++++++
fs/erofs/super.c | 4 ++++
fs/erofs/utils.c | 32 ++++++++++++++++++++++++++++++++
4 files changed, 50 insertions(+), 1 deletion(-)
create mode 100644 fs/erofs/utils.c
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index 9ab4ccc9328e..6a63c5998980 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -5,7 +5,7 @@ EROFS_VERSION = "1.0"
ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\"
obj-$(CONFIG_EROFS_FS) += erofs.o
-erofs-objs := super.o inode.o data.o namei.o dir.o
+erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
erofs-$(CONFIG_EROFS_FS_ZIP) += zmap.o
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f0a5fd316e09..87287cd9c146 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -60,6 +60,10 @@ typedef u64 erofs_off_t;
typedef u32 erofs_blk_t;
struct erofs_sb_info {
+#ifdef CONFIG_EROFS_FS_ZIP
+ /* list for all registered superblocks, mainly for shrinker */
+ struct list_head list;
+#endif
u32 blocks;
u32 meta_blkaddr;
#ifdef CONFIG_EROFS_FS_XATTR
@@ -404,5 +408,14 @@ int erofs_namei(struct inode *dir, struct qstr *name,
/* dir.c */
extern const struct file_operations erofs_dir_fops;
+/* utils.c */
+#ifdef CONFIG_EROFS_FS_ZIP
+void erofs_shrinker_register(struct super_block *sb);
+void erofs_shrinker_unregister(struct super_block *sb);
+#else
+static inline void erofs_shrinker_register(struct super_block *sb) {}
+static inline void erofs_shrinker_unregister(struct super_block *sb) {}
+#endif
+
#endif
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index bb1ae1f416e6..60058d3c50d4 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -374,6 +374,8 @@ static int erofs_read_super(struct super_block *sb,
snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
sbi->dev_name[PATH_MAX - 1] = '\0';
+ erofs_shrinker_register(sb);
+
if (!silent)
infoln("mounted on %s with opts: %s.", dev_name,
(char *)data);
@@ -412,6 +414,8 @@ static void erofs_put_super(struct super_block *sb)
infoln("unmounted for %s", sbi->dev_name);
__putname(sbi->dev_name);
+ erofs_shrinker_unregister(sb);
+
kfree(sbi);
sb->s_fs_info = NULL;
}
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
new file mode 100644
index 000000000000..08c8752895bc
--- /dev/null
+++ b/fs/erofs/utils.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/utils.c
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "internal.h"
+
+#ifdef CONFIG_EROFS_FS_ZIP
+/* protects the mounted 'erofs_sb_list' */
+static DEFINE_SPINLOCK(erofs_sb_list_lock);
+static LIST_HEAD(erofs_sb_list);
+
+void erofs_shrinker_register(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+
+ spin_lock(&erofs_sb_list_lock);
+ list_add(&sbi->list, &erofs_sb_list);
+ spin_unlock(&erofs_sb_list_lock);
+}
+
+void erofs_shrinker_unregister(struct super_block *sb)
+{
+ spin_lock(&erofs_sb_list_lock);
+ list_del(&EROFS_SB(sb)->list);
+ spin_unlock(&erofs_sb_list_lock);
+}
+#endif
+
--
2.17.1
Currently kernel has scattered tagged pointer usages
hacked by hand in plain code, without a unique and
portable functionset to highlight the tagged pointer
itself and wrap these hacked code in order to clean up
all over meaningless magic masks.
This patch introduces simple generic methods to fold
tags into a pointer integer. Currently it supports
the last n bits of the pointer for tags, which can be
selected by users.
In addition, it will also be used for the upcoming EROFS
filesystem, which heavily uses tagged pointer pproach
to reduce extra memory allocation.
Link: https://en.wikipedia.org/wiki/Tagged_pointer
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/tagptr.h | 110 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 110 insertions(+)
create mode 100644 fs/erofs/tagptr.h
diff --git a/fs/erofs/tagptr.h b/fs/erofs/tagptr.h
new file mode 100644
index 000000000000..121403cff2a3
--- /dev/null
+++ b/fs/erofs/tagptr.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Tagged pointer implementation
+ *
+ * Copyright (C) 2018 Gao Xiang <[email protected]>
+ */
+#ifndef __EROFS_TAGPTR_H
+#define __EROFS_TAGPTR_H
+
+#include <linux/types.h>
+#include <linux/build_bug.h>
+
+/*
+ * the name of tagged pointer types are tagptr{1, 2, 3...}_t
+ * avoid directly using the internal structs __tagptr{1, 2, 3...}
+ */
+#define __MAKE_TAGPTR(n) \
+typedef struct __tagptr##n { \
+ uintptr_t v; \
+} tagptr##n##_t;
+
+__MAKE_TAGPTR(1)
+__MAKE_TAGPTR(2)
+__MAKE_TAGPTR(3)
+__MAKE_TAGPTR(4)
+
+#undef __MAKE_TAGPTR
+
+extern void __compiletime_error("bad tagptr tags")
+ __bad_tagptr_tags(void);
+
+extern void __compiletime_error("bad tagptr type")
+ __bad_tagptr_type(void);
+
+/* fix the broken usage of "#define tagptr2_t tagptr3_t" by users */
+#define __tagptr_mask_1(ptr, n) \
+ __builtin_types_compatible_p(typeof(ptr), struct __tagptr##n) ? \
+ (1UL << (n)) - 1 :
+
+#define __tagptr_mask(ptr) (\
+ __tagptr_mask_1(ptr, 1) ( \
+ __tagptr_mask_1(ptr, 2) ( \
+ __tagptr_mask_1(ptr, 3) ( \
+ __tagptr_mask_1(ptr, 4) ( \
+ __bad_tagptr_type(), 0)))))
+
+/* generate a tagged pointer from a raw value */
+#define tagptr_init(type, val) \
+ ((typeof(type)){ .v = (uintptr_t)(val) })
+
+/*
+ * directly cast a tagged pointer to the native pointer type, which
+ * could be used for backward compatibility of existing code.
+ */
+#define tagptr_cast_ptr(tptr) ((void *)(tptr).v)
+
+/* encode tagged pointers */
+#define tagptr_fold(type, ptr, _tags) ({ \
+ const typeof(_tags) tags = (_tags); \
+ if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(type))) \
+ __bad_tagptr_tags(); \
+tagptr_init(type, (uintptr_t)(ptr) | tags); })
+
+/* decode tagged pointers */
+#define tagptr_unfold_ptr(tptr) \
+ ((void *)((tptr).v & ~__tagptr_mask(tptr)))
+
+#define tagptr_unfold_tags(tptr) \
+ ((tptr).v & __tagptr_mask(tptr))
+
+/* operations for the tagger pointer */
+#define tagptr_eq(_tptr1, _tptr2) ({ \
+ typeof(_tptr1) tptr1 = (_tptr1); \
+ typeof(_tptr2) tptr2 = (_tptr2); \
+ (void)(&tptr1 == &tptr2); \
+(tptr1).v == (tptr2).v; })
+
+/* lock-free CAS operation */
+#define tagptr_cmpxchg(_ptptr, _o, _n) ({ \
+ typeof(_ptptr) ptptr = (_ptptr); \
+ typeof(_o) o = (_o); \
+ typeof(_n) n = (_n); \
+ (void)(&o == &n); \
+ (void)(&o == ptptr); \
+tagptr_init(o, cmpxchg(&ptptr->v, o.v, n.v)); })
+
+/* wrap WRITE_ONCE if atomic update is needed */
+#define tagptr_replace_tags(_ptptr, tags) ({ \
+ typeof(_ptptr) ptptr = (_ptptr); \
+ *ptptr = tagptr_fold(*ptptr, tagptr_unfold_ptr(*ptptr), tags); \
+*ptptr; })
+
+#define tagptr_set_tags(_ptptr, _tags) ({ \
+ typeof(_ptptr) ptptr = (_ptptr); \
+ const typeof(_tags) tags = (_tags); \
+ if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(*ptptr))) \
+ __bad_tagptr_tags(); \
+ ptptr->v |= tags; \
+*ptptr; })
+
+#define tagptr_clear_tags(_ptptr, _tags) ({ \
+ typeof(_ptptr) ptptr = (_ptptr); \
+ const typeof(_tags) tags = (_tags); \
+ if (__builtin_constant_p(tags) && (tags & ~__tagptr_mask(*ptptr))) \
+ __bad_tagptr_tags(); \
+ ptptr->v &= ~tags; \
+*ptptr; })
+
+#endif
+
--
2.17.1
This commit adds functions that transfer names to inodes.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/namei.c | 246 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 246 insertions(+)
create mode 100644 fs/erofs/namei.c
diff --git a/fs/erofs/namei.c b/fs/erofs/namei.c
new file mode 100644
index 000000000000..7665d3603503
--- /dev/null
+++ b/fs/erofs/namei.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/namei.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "internal.h"
+
+#include <trace/events/erofs.h>
+
+struct erofs_qstr {
+ const unsigned char *name;
+ const unsigned char *end;
+};
+
+/* based on the end of qn is accurate and it must have the trailing '\0' */
+static inline int dirnamecmp(const struct erofs_qstr *qn,
+ const struct erofs_qstr *qd,
+ unsigned int *matched)
+{
+ unsigned int i = *matched;
+
+ /*
+ * on-disk error, let's only BUG_ON in the debugging mode.
+ * otherwise, it will return 1 to just skip the invalid name
+ * and go on (in consideration of the lookup performance).
+ */
+ DBG_BUGON(qd->name > qd->end);
+
+ /* qd could not have trailing '\0' */
+ /* However it is absolutely safe if < qd->end */
+ while (qd->name + i < qd->end && qd->name[i] != '\0') {
+ if (qn->name[i] != qd->name[i]) {
+ *matched = i;
+ return qn->name[i] > qd->name[i] ? 1 : -1;
+ }
+ ++i;
+ }
+ *matched = i;
+ /* See comments in __d_alloc on the terminating NUL character */
+ return qn->name[i] == '\0' ? 0 : 1;
+}
+
+#define nameoff_from_disk(off, sz) (le16_to_cpu(off) & ((sz) - 1))
+
+static struct erofs_dirent *find_target_dirent(struct erofs_qstr *name,
+ u8 *data,
+ unsigned int dirblksize,
+ const int ndirents)
+{
+ int head, back;
+ unsigned int startprfx, endprfx;
+ struct erofs_dirent *const de = (struct erofs_dirent *)data;
+
+ /* since the 1st dirent has been evaluated previously */
+ head = 1;
+ back = ndirents - 1;
+ startprfx = endprfx = 0;
+
+ while (head <= back) {
+ const int mid = head + (back - head) / 2;
+ const int nameoff = nameoff_from_disk(de[mid].nameoff,
+ dirblksize);
+ unsigned int matched = min(startprfx, endprfx);
+ struct erofs_qstr dname = {
+ .name = data + nameoff,
+ .end = unlikely(mid >= ndirents - 1) ?
+ data + dirblksize :
+ data + nameoff_from_disk(de[mid + 1].nameoff,
+ dirblksize)
+ };
+
+ /* string comparison without already matched prefix */
+ int ret = dirnamecmp(name, &dname, &matched);
+
+ if (unlikely(!ret)) {
+ return de + mid;
+ } else if (ret > 0) {
+ head = mid + 1;
+ startprfx = matched;
+ } else {
+ back = mid - 1;
+ endprfx = matched;
+ }
+ }
+ return ERR_PTR(-ENOENT);
+}
+
+static struct page *find_target_block_classic(struct inode *dir,
+ struct erofs_qstr *name,
+ int *_ndirents)
+{
+ unsigned int startprfx, endprfx;
+ int head, back;
+ struct address_space *const mapping = dir->i_mapping;
+ struct page *candidate = ERR_PTR(-ENOENT);
+
+ startprfx = endprfx = 0;
+ head = 0;
+ back = inode_datablocks(dir) - 1;
+
+ while (head <= back) {
+ const int mid = head + (back - head) / 2;
+ struct page *page = read_mapping_page(mapping, mid, NULL);
+
+ if (!IS_ERR(page)) {
+ struct erofs_dirent *de = kmap_atomic(page);
+ const int nameoff = nameoff_from_disk(de->nameoff,
+ EROFS_BLKSIZ);
+ const int ndirents = nameoff / sizeof(*de);
+ int diff;
+ unsigned int matched;
+ struct erofs_qstr dname;
+
+ if (unlikely(!ndirents)) {
+ DBG_BUGON(1);
+ kunmap_atomic(de);
+ put_page(page);
+ page = ERR_PTR(-EIO);
+ goto out;
+ }
+
+ matched = min(startprfx, endprfx);
+
+ dname.name = (u8 *)de + nameoff;
+ if (ndirents == 1)
+ dname.end = (u8 *)de + EROFS_BLKSIZ;
+ else
+ dname.end = (u8 *)de +
+ nameoff_from_disk(de[1].nameoff,
+ EROFS_BLKSIZ);
+
+ /* string comparison without already matched prefix */
+ diff = dirnamecmp(name, &dname, &matched);
+ kunmap_atomic(de);
+
+ if (unlikely(!diff)) {
+ *_ndirents = 0;
+ goto out;
+ } else if (diff > 0) {
+ head = mid + 1;
+ startprfx = matched;
+
+ if (!IS_ERR(candidate))
+ put_page(candidate);
+ candidate = page;
+ *_ndirents = ndirents;
+ } else {
+ put_page(page);
+
+ back = mid - 1;
+ endprfx = matched;
+ }
+ continue;
+ }
+out: /* free if the candidate is valid */
+ if (!IS_ERR(candidate))
+ put_page(candidate);
+ return page;
+ }
+ return candidate;
+}
+
+int erofs_namei(struct inode *dir,
+ struct qstr *name,
+ erofs_nid_t *nid, unsigned int *d_type)
+{
+ int ndirents;
+ struct page *page;
+ void *data;
+ struct erofs_dirent *de;
+ struct erofs_qstr qn;
+
+ if (unlikely(!dir->i_size))
+ return -ENOENT;
+
+ qn.name = name->name;
+ qn.end = name->name + name->len;
+
+ ndirents = 0;
+ page = find_target_block_classic(dir, &qn, &ndirents);
+
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ data = kmap_atomic(page);
+ /* the target page has been mapped */
+ if (ndirents)
+ de = find_target_dirent(&qn, data, EROFS_BLKSIZ, ndirents);
+ else
+ de = (struct erofs_dirent *)data;
+
+ if (!IS_ERR(de)) {
+ *nid = le64_to_cpu(de->nid);
+ *d_type = de->file_type;
+ }
+
+ kunmap_atomic(data);
+ put_page(page);
+
+ return PTR_ERR_OR_ZERO(de);
+}
+
+/* NOTE: i_mutex is already held by vfs */
+static struct dentry *erofs_lookup(struct inode *dir,
+ struct dentry *dentry,
+ unsigned int flags)
+{
+ int err;
+ erofs_nid_t nid;
+ unsigned int d_type;
+ struct inode *inode;
+
+ DBG_BUGON(!d_really_is_negative(dentry));
+ /* dentry must be unhashed in lookup, no need to worry about */
+ DBG_BUGON(!d_unhashed(dentry));
+
+ trace_erofs_lookup(dir, dentry, flags);
+
+ /* file name exceeds fs limit */
+ if (unlikely(dentry->d_name.len > EROFS_NAME_LEN))
+ return ERR_PTR(-ENAMETOOLONG);
+
+ /* false uninitialized warnings on gcc 4.8.x */
+ err = erofs_namei(dir, &dentry->d_name, &nid, &d_type);
+
+ if (err == -ENOENT) {
+ /* negative dentry */
+ inode = NULL;
+ } else if (unlikely(err)) {
+ inode = ERR_PTR(err);
+ } else {
+ debugln("%s, %s (nid %llu) found, d_type %u", __func__,
+ dentry->d_name.name, nid, d_type);
+ inode = erofs_iget(dir->i_sb, nid, d_type == EROFS_FT_DIR);
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+const struct inode_operations erofs_dir_iops = {
+ .lookup = erofs_lookup,
+ .getattr = erofs_getattr,
+};
+
--
2.17.1
Add basic tracepoints for ->readpage{,s}, ->lookup,
->destroy_inode, fill_inode and map_blocks.
Signed-off-by: Gao Xiang <[email protected]>
---
include/trace/events/erofs.h | 241 +++++++++++++++++++++++++++++++++++
1 file changed, 241 insertions(+)
create mode 100644 include/trace/events/erofs.h
diff --git a/include/trace/events/erofs.h b/include/trace/events/erofs.h
new file mode 100644
index 000000000000..188c28e48289
--- /dev/null
+++ b/include/trace/events/erofs.h
@@ -0,0 +1,241 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM erofs
+
+#if !defined(_TRACE_EROFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EROFS_H
+
+#include <linux/tracepoint.h>
+
+#define show_dev(dev) MAJOR(dev), MINOR(dev)
+#define show_dev_nid(entry) show_dev(entry->dev), entry->nid
+
+#define show_file_type(type) \
+ __print_symbolic(type, \
+ { 0, "FILE" }, \
+ { 1, "DIR" })
+
+#define show_map_flags(flags) __print_flags(flags, "|", \
+ { EROFS_GET_BLOCKS_RAW, "RAW" })
+
+#define show_mflags(flags) __print_flags(flags, "", \
+ { EROFS_MAP_MAPPED, "M" }, \
+ { EROFS_MAP_META, "I" })
+
+TRACE_EVENT(erofs_lookup,
+
+ TP_PROTO(struct inode *dir, struct dentry *dentry, unsigned int flags),
+
+ TP_ARGS(dir, dentry, flags),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev )
+ __field(erofs_nid_t, nid )
+ __field(const char *, name )
+ __field(unsigned int, flags )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = dir->i_sb->s_dev;
+ __entry->nid = EROFS_V(dir)->nid;
+ __entry->name = dentry->d_name.name;
+ __entry->flags = flags;
+ ),
+
+ TP_printk("dev = (%d,%d), pnid = %llu, name:%s, flags:%x",
+ show_dev_nid(__entry),
+ __entry->name,
+ __entry->flags)
+);
+
+TRACE_EVENT(erofs_fill_inode,
+ TP_PROTO(struct inode *inode, int isdir),
+ TP_ARGS(inode, isdir),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev )
+ __field(erofs_nid_t, nid )
+ __field(erofs_blk_t, blkaddr )
+ __field(unsigned int, ofs )
+ __field(int, isdir )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->nid = EROFS_V(inode)->nid;
+ __entry->blkaddr = erofs_blknr(iloc(EROFS_I_SB(inode), __entry->nid));
+ __entry->ofs = erofs_blkoff(iloc(EROFS_I_SB(inode), __entry->nid));
+ __entry->isdir = isdir;
+ ),
+
+ TP_printk("dev = (%d,%d), nid = %llu, blkaddr %u ofs %u, isdir %d",
+ show_dev_nid(__entry),
+ __entry->blkaddr, __entry->ofs,
+ __entry->isdir)
+);
+
+TRACE_EVENT(erofs_readpage,
+
+ TP_PROTO(struct page *page, bool raw),
+
+ TP_ARGS(page, raw),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev )
+ __field(erofs_nid_t, nid )
+ __field(int, dir )
+ __field(pgoff_t, index )
+ __field(int, uptodate)
+ __field(bool, raw )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = page->mapping->host->i_sb->s_dev;
+ __entry->nid = EROFS_V(page->mapping->host)->nid;
+ __entry->dir = S_ISDIR(page->mapping->host->i_mode);
+ __entry->index = page->index;
+ __entry->uptodate = PageUptodate(page);
+ __entry->raw = raw;
+ ),
+
+ TP_printk("dev = (%d,%d), nid = %llu, %s, index = %lu, uptodate = %d "
+ "raw = %d",
+ show_dev_nid(__entry),
+ show_file_type(__entry->dir),
+ (unsigned long)__entry->index,
+ __entry->uptodate,
+ __entry->raw)
+);
+
+TRACE_EVENT(erofs_readpages,
+
+ TP_PROTO(struct inode *inode, struct page *page, unsigned int nrpage,
+ bool raw),
+
+ TP_ARGS(inode, page, nrpage, raw),
+
+ TP_STRUCT__entry(
+ __field(dev_t, dev )
+ __field(erofs_nid_t, nid )
+ __field(pgoff_t, start )
+ __field(unsigned int, nrpage )
+ __field(bool, raw )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->nid = EROFS_V(inode)->nid;
+ __entry->start = page->index;
+ __entry->nrpage = nrpage;
+ __entry->raw = raw;
+ ),
+
+ TP_printk("dev = (%d,%d), nid = %llu, start = %lu nrpage = %u raw = %d",
+ show_dev_nid(__entry),
+ (unsigned long)__entry->start,
+ __entry->nrpage,
+ __entry->raw)
+);
+
+DECLARE_EVENT_CLASS(erofs__map_blocks_enter,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned int flags),
+
+ TP_ARGS(inode, map, flags),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( erofs_nid_t, nid )
+ __field( erofs_off_t, la )
+ __field( u64, llen )
+ __field( unsigned int, flags )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->nid = EROFS_V(inode)->nid;
+ __entry->la = map->m_la;
+ __entry->llen = map->m_llen;
+ __entry->flags = flags;
+ ),
+
+ TP_printk("dev = (%d,%d), nid = %llu, la %llu llen %llu flags %s",
+ show_dev_nid(__entry),
+ __entry->la, __entry->llen,
+ __entry->flags ? show_map_flags(__entry->flags) : "NULL")
+);
+
+DEFINE_EVENT(erofs__map_blocks_enter, erofs_map_blocks_flatmode_enter,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned flags),
+
+ TP_ARGS(inode, map, flags)
+);
+
+DECLARE_EVENT_CLASS(erofs__map_blocks_exit,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned int flags, int ret),
+
+ TP_ARGS(inode, map, flags, ret),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( erofs_nid_t, nid )
+ __field( unsigned int, flags )
+ __field( erofs_off_t, la )
+ __field( erofs_off_t, pa )
+ __field( u64, llen )
+ __field( u64, plen )
+ __field( unsigned int, mflags )
+ __field( int, ret )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->nid = EROFS_V(inode)->nid;
+ __entry->flags = flags;
+ __entry->la = map->m_la;
+ __entry->pa = map->m_pa;
+ __entry->llen = map->m_llen;
+ __entry->plen = map->m_plen;
+ __entry->mflags = map->m_flags;
+ __entry->ret = ret;
+ ),
+
+ TP_printk("dev = (%d,%d), nid = %llu, flags %s "
+ "la %llu pa %llu llen %llu plen %llu mflags %s ret %d",
+ show_dev_nid(__entry),
+ __entry->flags ? show_map_flags(__entry->flags) : "NULL",
+ __entry->la, __entry->pa, __entry->llen, __entry->plen,
+ show_mflags(__entry->mflags), __entry->ret)
+);
+
+DEFINE_EVENT(erofs__map_blocks_exit, erofs_map_blocks_flatmode_exit,
+ TP_PROTO(struct inode *inode, struct erofs_map_blocks *map,
+ unsigned flags, int ret),
+
+ TP_ARGS(inode, map, flags, ret)
+);
+
+TRACE_EVENT(erofs_destroy_inode,
+ TP_PROTO(struct inode *inode),
+
+ TP_ARGS(inode),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( erofs_nid_t, nid )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->nid = EROFS_V(inode)->nid;
+ ),
+
+ TP_printk("dev = (%d,%d), nid = %llu", show_dev_nid(__entry))
+);
+
+#endif /* _TRACE_EROFS_H */
+
+ /* This part must be outside protection */
+#include <trace/define_trace.h>
--
2.17.1
This patch introduces per-CPU buffers in order for
the upcoming generic decompression framework to use.
Note that I tried to use in-kernel per-CPU buffer or
per-CPU page approaches to clean up further, however
noticeable performanace regression (about 2% for
sequential read) was observed.
Let's leave it as-is for now.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/Kconfig | 14 ++++++++++++++
fs/erofs/internal.h | 24 ++++++++++++++++++++++++
fs/erofs/utils.c | 12 ++++++++++++
3 files changed, 50 insertions(+)
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index f6b6eb0250b8..ae6c7c69ab76 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -89,3 +89,17 @@ config EROFS_FS_ZIP
If you don't want to enable compression feature, say N.
+config EROFS_FS_CLUSTER_PAGE_LIMIT
+ int "EROFS Cluster Pages Hard Limit"
+ depends on EROFS_FS_ZIP
+ range 1 256
+ default "1"
+ help
+ Indicates maximum # of pages of a compressed
+ physical cluster.
+
+ For example, if files in a image were compressed
+ into 8k-unit, hard limit should not be configured
+ less than 2. Otherwise, the image will be refused
+ to mount on this kernel.
+
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f603ae8aa9b1..5e06e2d12b5e 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -222,6 +222,15 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
return v;
}
#endif
+
+#ifdef CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT
+#define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
+#else
+#define Z_EROFS_CLUSTER_MAX_PAGES 1
+#endif
+#define EROFS_PCPUBUF_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES
+#else
+#define EROFS_PCPUBUF_NR_PAGES 0
#endif
/* we strictly follow PAGE_SIZE and no buffer head yet */
@@ -486,6 +495,21 @@ int erofs_namei(struct inode *dir, struct qstr *name,
extern const struct file_operations erofs_dir_fops;
/* utils.c */
+#if (EROFS_PCPUBUF_NR_PAGES > 0)
+void *erofs_get_pcpubuf(unsigned int pagenr);
+#define erofs_put_pcpubuf(buf) do { \
+ (void)&(buf); \
+ preempt_enable(); \
+} while (0)
+#else
+static inline void *erofs_get_pcpubuf(unsigned int pagenr)
+{
+ return ERR_PTR(-ENOTSUPP);
+}
+
+#define erofs_put_pcpubuf(buf) do {} while (0)
+#endif
+
#ifdef CONFIG_EROFS_FS_ZIP
int erofs_workgroup_put(struct erofs_workgroup *grp);
struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index 45fd780e6429..c430790a02e0 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -9,6 +9,18 @@
#include "internal.h"
#include <linux/pagevec.h>
+#if (EROFS_PCPUBUF_NR_PAGES > 0)
+static struct {
+ u8 data[PAGE_SIZE * EROFS_PCPUBUF_NR_PAGES];
+} ____cacheline_aligned_in_smp erofs_pcpubuf[NR_CPUS];
+
+void *erofs_get_pcpubuf(unsigned int pagenr)
+{
+ preempt_disable();
+ return &erofs_pcpubuf[smp_processor_id()].data[pagenr * PAGE_SIZE];
+}
+#endif
+
#ifdef CONFIG_EROFS_FS_ZIP
/* global shrink count (for all mounted EROFS instances) */
static atomic_long_t erofs_global_shrink_cnt;
--
2.17.1
This patch adds strategies which can be selected
by users in order to cache both incomplete ends of
compressed physical clusters as a complement of
in-place I/O in order to boost random read, but
it costs more memory than the in-place I/O only.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/Kconfig | 38 ++++++++++
fs/erofs/internal.h | 17 +++++
fs/erofs/super.c | 15 ++++
fs/erofs/utils.c | 104 ++++++++++++++++++++++++++-
fs/erofs/zdata.c | 171 ++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/zdata.h | 9 +++
6 files changed, 353 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 45a81ebeb023..95affb10d4d1 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -114,3 +114,41 @@ config EROFS_FS_CLUSTER_PAGE_LIMIT
less than 2. Otherwise, the image will be refused
to mount on this kernel.
+choice
+ prompt "EROFS Data Decompression mode"
+ depends on EROFS_FS_ZIP
+ default EROFS_FS_ZIP_CACHE_READAROUND
+ help
+ EROFS supports three options for decompression.
+ "In-place I/O Only" consumes the minimum memory
+ with lowest random read.
+
+ "Cached Decompression for readaround" consumes
+ the maximum memory with highest random read.
+
+ If unsure, select "Cached Decompression for readaround"
+
+config EROFS_FS_ZIP_CACHE_DISABLED
+ bool "In-place I/O Only"
+ help
+ Read compressed data into page cache and do in-place
+ I/O decompression directly.
+
+config EROFS_FS_ZIP_CACHE_READAHEAD
+ bool "Cached Decompression for readahead"
+ help
+ For each request, it caches the last compressed page
+ for further reading.
+ It still does in-place I/O for the rest compressed pages.
+
+config EROFS_FS_ZIP_CACHE_READAROUND
+ bool "Cached Decompression for readaround"
+ help
+ For each request, it caches the both end compressed pages
+ for further reading.
+ It still does in-place I/O for the rest compressed pages.
+
+ Recommended for performance priority.
+
+endchoice
+
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 73892162f494..e8b0d65db1d1 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -51,6 +51,11 @@ struct erofs_fault_info {
};
#endif
+#ifdef CONFIG_EROFS_FS_ZIP_CACHE_READAROUND
+#define EROFS_FS_HAS_MANAGED_CACHE (2)
+#elif defined(CONFIG_EROFS_FS_ZIP_CACHE_READAHEAD)
+#define EROFS_FS_HAS_MANAGED_CACHE (1)
+#endif
/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
#define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
@@ -73,6 +78,10 @@ struct erofs_sb_info {
unsigned int shrinker_run_no;
#endif
+
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ struct inode *managed_cache;
+#endif
u32 blocks;
u32 meta_blkaddr;
#ifdef CONFIG_EROFS_FS_XATTR
@@ -545,5 +554,13 @@ static inline int z_erofs_init_zip_subsystem(void) { return 0; }
static inline void z_erofs_exit_zip_subsystem(void) {}
#endif
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+struct inode *erofs_init_managed_cache(struct super_block *sb);
+int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+ struct erofs_workgroup *egrp);
+int erofs_try_to_free_cached_page(struct address_space *mapping,
+ struct page *page);
+#endif
+
#endif
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 80e1a9b6d855..643adcbb46fc 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -350,6 +350,14 @@ static int erofs_read_super(struct super_block *sb,
INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
#endif
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ sbi->managed_cache = erofs_init_managed_cache(sb);
+ if (IS_ERR(sbi->managed_cache)) {
+ err = PTR_ERR(sbi->managed_cache);
+ goto err_init_managed_cache;
+ }
+#endif
+
/* get the root inode */
inode = erofs_iget(sb, ROOT_NID(sbi), true);
if (IS_ERR(inode)) {
@@ -396,6 +404,10 @@ static int erofs_read_super(struct super_block *sb,
dput(sb->s_root);
sb->s_root = NULL;
err_iget:
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ iput(sbi->managed_cache);
+err_init_managed_cache:
+#endif
err_parseopt:
err_sbread:
sb->s_fs_info = NULL;
@@ -421,6 +433,9 @@ static void erofs_put_super(struct super_block *sb)
infoln("unmounted for %s", sbi->dev_name);
__putname(sbi->dev_name);
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ iput(sbi->managed_cache);
+#endif
erofs_shrinker_unregister(sb);
kfree(sbi);
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index 53ee6daa3f70..eb161b31b8ee 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -145,6 +145,53 @@ int erofs_workgroup_put(struct erofs_workgroup *grp)
return count;
}
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+/* for cache-managed case, customized reclaim paths exist */
+static void erofs_workgroup_unfreeze_final(struct erofs_workgroup *grp)
+{
+ erofs_workgroup_unfreeze(grp, 0);
+ __erofs_workgroup_free(grp);
+}
+
+static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
+ struct erofs_workgroup *grp,
+ bool cleanup)
+{
+ /*
+ * for managed cache enabled, the refcount of workgroups
+ * themselves could be < 0 (freezed). So there is no guarantee
+ * that all refcount > 0 if managed cache is enabled.
+ */
+ if (!erofs_workgroup_try_to_freeze(grp, 1))
+ return false;
+
+ /*
+ * note that all cached pages should be unlinked
+ * before delete it from the radix tree.
+ * Otherwise some cached pages of an orphan old workgroup
+ * could be still linked after the new one is available.
+ */
+ if (erofs_try_to_free_all_cached_pages(sbi, grp)) {
+ erofs_workgroup_unfreeze(grp, 1);
+ return false;
+ }
+
+ /*
+ * it is impossible to fail after the workgroup is freezed,
+ * however in order to avoid some race conditions, add a
+ * DBG_BUGON to observe this in advance.
+ */
+ DBG_BUGON(xa_untag_pointer(radix_tree_delete(&sbi->workstn_tree,
+ grp->index)) != grp);
+
+ /*
+ * if managed cache is enable, the last refcount
+ * should indicate the related workstation.
+ */
+ erofs_workgroup_unfreeze_final(grp);
+ return true;
+}
+#else
/* for nocache case, no customized reclaim path at all */
static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
struct erofs_workgroup *grp,
@@ -165,7 +212,7 @@ static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
erofs_workgroup_put(grp);
return true;
}
-
+#endif
unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
unsigned long nr_shrink,
@@ -312,3 +359,58 @@ void erofs_exit_shrinker(void)
#endif
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+static const struct address_space_operations managed_cache_aops;
+
+struct inode *erofs_init_managed_cache(struct super_block *sb)
+{
+ struct inode *inode = new_inode(sb);
+
+ if (unlikely(!inode))
+ return ERR_PTR(-ENOMEM);
+
+ set_nlink(inode, 1);
+ inode->i_size = OFFSET_MAX;
+
+ inode->i_mapping->a_ops = &managed_cache_aops;
+ mapping_set_gfp_mask(inode->i_mapping,
+ GFP_NOFS | __GFP_HIGHMEM | __GFP_MOVABLE);
+ return inode;
+}
+
+static int erofs_managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
+{
+ int ret = 1; /* 0 - busy */
+ struct address_space *const mapping = page->mapping;
+
+ DBG_BUGON(!PageLocked(page));
+ DBG_BUGON(mapping->a_ops != &managed_cache_aops);
+
+ if (PagePrivate(page))
+ ret = erofs_try_to_free_cached_page(mapping, page);
+
+ return ret;
+}
+
+static void erofs_managed_cache_invalidatepage(struct page *page,
+ unsigned int offset,
+ unsigned int length)
+{
+ const unsigned int stop = length + offset;
+
+ DBG_BUGON(!PageLocked(page));
+
+ /* Check for potential overflow in debug mode */
+ DBG_BUGON(stop > PAGE_SIZE || stop < length);
+
+ if (offset == 0 && stop == PAGE_SIZE)
+ while (!erofs_managed_cache_releasepage(page, GFP_NOFS))
+ cond_resched();
+}
+
+static const struct address_space_operations managed_cache_aops = {
+ .releasepage = erofs_managed_cache_releasepage,
+ .invalidatepage = erofs_managed_cache_invalidatepage,
+};
+#endif
+
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index bebbd45bf08e..591acd90fd9d 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -162,6 +162,118 @@ struct z_erofs_decompress_frontend {
static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
static DEFINE_MUTEX(z_pagemap_global_lock);
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+static void preload_compressed_pages(struct z_erofs_collector *clt,
+ struct address_space *mc,
+ enum z_erofs_cache_alloctype type,
+ struct list_head *pagepool)
+{
+ const struct z_erofs_pcluster *pcl = clt->pcl;
+ const unsigned int clusterpages = BIT(pcl->clusterbits);
+ struct page **pages = clt->compressedpages;
+ pgoff_t index = pcl->obj.index + (pages - pcl->compressed_pages);
+ bool standalone = true;
+
+ if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
+ return;
+
+ for (; pages < pcl->compressed_pages + clusterpages; ++pages) {
+ struct page *page;
+ compressed_page_t t;
+
+ /* the compressed page was loaded before */
+ if (READ_ONCE(*pages))
+ continue;
+
+ page = find_get_page(mc, index);
+
+ if (page) {
+ t = tag_compressed_page_justfound(page);
+ } else if (type == DELAYEDALLOC) {
+ t = tagptr_init(compressed_page_t, PAGE_UNALLOCATED);
+ } else { /* DONTALLOC */
+ if (standalone)
+ clt->compressedpages = pages;
+ standalone = false;
+ continue;
+ }
+
+ if (!cmpxchg_relaxed(pages, NULL, tagptr_cast_ptr(t)))
+ continue;
+
+ if (page)
+ put_page(page);
+ }
+
+ if (standalone) /* downgrade to PRIMARY_FOLLOWED_NOINPLACE */
+ clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
+}
+
+/* called by erofs_shrinker to get rid of all compressed_pages */
+int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
+ struct erofs_workgroup *grp)
+{
+ struct z_erofs_pcluster *const pcl =
+ container_of(grp, struct z_erofs_pcluster, obj);
+ struct address_space *const mapping = MNGD_MAPPING(sbi);
+ const unsigned int clusterpages = BIT(pcl->clusterbits);
+ int i;
+
+ /*
+ * refcount of workgroup is now freezed as 1,
+ * therefore no need to worry about available decompression users.
+ */
+ for (i = 0; i < clusterpages; ++i) {
+ struct page *page = pcl->compressed_pages[i];
+
+ if (!page)
+ continue;
+
+ /* block other users from reclaiming or migrating the page */
+ if (!trylock_page(page))
+ return -EBUSY;
+
+ if (unlikely(page->mapping != mapping))
+ continue;
+
+ /* barrier is implied in the following 'unlock_page' */
+ pcl->compressed_pages[i] = NULL;
+ set_page_private(page, 0);
+ ClearPagePrivate(page);
+
+ unlock_page(page);
+ put_page(page);
+ }
+ return 0;
+}
+
+int erofs_try_to_free_cached_page(struct address_space *mapping,
+ struct page *page)
+{
+ struct z_erofs_pcluster *const pcl = (void *)page_private(page);
+ const unsigned int clusterpages = BIT(pcl->clusterbits);
+ int ret = 0; /* 0 - busy */
+
+ if (erofs_workgroup_try_to_freeze(&pcl->obj, 1)) {
+ unsigned int i;
+
+ for (i = 0; i < clusterpages; ++i) {
+ if (pcl->compressed_pages[i] == page) {
+ pcl->compressed_pages[i] = NULL;
+ ret = 1;
+ break;
+ }
+ }
+ erofs_workgroup_unfreeze(&pcl->obj, 1);
+
+ if (ret) {
+ ClearPagePrivate(page);
+ put_page(page);
+ }
+ }
+ return ret;
+}
+#else
static void preload_compressed_pages(struct z_erofs_collector *clt,
struct address_space *mc,
enum z_erofs_cache_alloctype type,
@@ -169,6 +281,7 @@ static void preload_compressed_pages(struct z_erofs_collector *clt,
{
/* nowhere to load compressed pages from */
}
+#endif
/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
static inline bool try_inplace_io(struct z_erofs_collector *clt,
@@ -440,6 +553,13 @@ static inline struct page *__stagingpage_alloc(struct list_head *pagepool,
static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
erofs_off_t la)
{
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ if (fe->backmost)
+ return true;
+#if (EROFS_FS_HAS_MANAGED_CACHE >= 2)
+ return la < fe->headoffset;
+#endif
+#endif
return false;
}
@@ -1001,6 +1121,9 @@ static struct z_erofs_unzip_io *jobqueue_init(struct super_block *sb,
/* define decompression jobqueue types */
enum {
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ JQ_BYPASS,
+#endif
JQ_SUBMIT,
NR_JOBQUEUES,
};
@@ -1011,12 +1134,56 @@ static void *jobqueueset_init(struct super_block *sb,
struct z_erofs_unzip_io *fgq,
bool forcefg)
{
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ /*
+ * if managed cache is enabled, bypass jobqueue is needed,
+ * no need to read from device for all pclusters in this queue.
+ */
+ q[JQ_BYPASS] = jobqueue_init(sb, fgq + JQ_BYPASS, true);
+ qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head;
+#endif
+
q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, forcefg);
qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head;
return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], !forcefg));
}
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
+ z_erofs_next_pcluster_t qtail[],
+ z_erofs_next_pcluster_t owned_head)
+{
+ z_erofs_next_pcluster_t *const submit_qtail = qtail[JQ_SUBMIT];
+ z_erofs_next_pcluster_t *const bypass_qtail = qtail[JQ_BYPASS];
+
+ DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
+ if (owned_head == Z_EROFS_PCLUSTER_TAIL)
+ owned_head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
+
+ WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_TAIL_CLOSED);
+
+ WRITE_ONCE(*submit_qtail, owned_head);
+ WRITE_ONCE(*bypass_qtail, &pcl->next);
+
+ qtail[JQ_BYPASS] = &pcl->next;
+}
+
+static bool postsubmit_is_all_bypassed(struct z_erofs_unzip_io *q[],
+ unsigned int nr_bios,
+ bool force_fg)
+{
+ /*
+ * although background is preferred, no one is pending for submission.
+ * don't issue workqueue for decompression but drop it directly instead.
+ */
+ if (force_fg || nr_bios)
+ return false;
+
+ kvfree(container_of(q[JQ_SUBMIT], struct z_erofs_unzip_io_sb, io));
+ return true;
+}
+#else
static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
z_erofs_next_pcluster_t qtail[],
z_erofs_next_pcluster_t owned_head)
@@ -1033,6 +1200,7 @@ static bool postsubmit_is_all_bypassed(struct z_erofs_unzip_io *q[],
DBG_BUGON(!nr_bios);
return false;
}
+#endif
static bool z_erofs_vle_submit_all(struct super_block *sb,
z_erofs_next_pcluster_t owned_head,
@@ -1144,6 +1312,9 @@ static void z_erofs_submit_and_unzip(struct super_block *sb,
pagepool, io, force_fg))
return;
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+ z_erofs_vle_unzip_all(sb, &io[JQ_BYPASS], pagepool);
+#endif
if (!force_fg)
return;
diff --git a/fs/erofs/zdata.h b/fs/erofs/zdata.h
index 53297d1811dd..ab22f994506f 100644
--- a/fs/erofs/zdata.h
+++ b/fs/erofs/zdata.h
@@ -101,9 +101,18 @@ struct z_erofs_unzip_io_sb {
struct super_block *sb;
};
+#ifdef EROFS_FS_HAS_MANAGED_CACHE
+#define MNGD_MAPPING(sbi) ((sbi)->managed_cache->i_mapping)
+static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
+ struct page *page)
+{
+ return page->mapping == MNGD_MAPPING(sbi);
+}
+#else
#define MNGD_MAPPING(sbi) (NULL)
static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
struct page *page) { return false; }
+#endif
#define Z_EROFS_ONLINEPAGE_COUNT_BITS 2
#define Z_EROFS_ONLINEPAGE_COUNT_MASK ((1 << Z_EROFS_ONLINEPAGE_COUNT_BITS) - 1)
--
2.17.1
This patch adds decompression backend to EROFS, which
supports uncompressed and LZ4 compressed data.
For compressed data, it uses the following strategy:
1) If outputsize is very small (totally less than a threshold),
decompress to the per-CPU buffer and do memcpy directly
in order to avoid vmap() overhead;
2) Otherwise it will fill bounced pages if needed and vmap
all output pages into a continuous virtual memory area,
memcpy compressed data to the per-CPU buffer for inplace
I/O [1] and decompress.
Since LZ4 is a lz77-based algorithm which has a dynamically
populated ("sliding window") dictionary and the maximum
lookback distance is 65535. Therefore the number of bounced
pages could be limited by erofs based on this property.
[1] `LZ4 decompression inplace' will eliminate the extra memcpy
if iend - oend margin is safe enough, see the following patch.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/Kconfig | 10 ++
fs/erofs/Makefile | 2 +-
fs/erofs/compress.h | 89 ++++++++++++
fs/erofs/decompressor.c | 301 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 401 insertions(+), 1 deletion(-)
create mode 100644 fs/erofs/compress.h
create mode 100644 fs/erofs/decompressor.c
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index ae6c7c69ab76..9cefecec3194 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -80,6 +80,16 @@ config EROFS_FS_SECURITY
If you are not using a security module, say N.
+config EROFS_FS_USE_VM_MAP_RAM
+ bool "EROFS VM_MAP_RAM Support"
+ depends on EROFS_FS
+ default y
+ help
+ use vm_map_ram / vm_unmap_ram pair which have better performance
+ instead of vmap/vunmap pair.
+
+ If you don't know what these are, say Y.
+
config EROFS_FS_ZIP
bool "EROFS Data Compresssion Support"
depends on EROFS_FS
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index 6a63c5998980..afb7c6556bf9 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -7,5 +7,5 @@ ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\"
obj-$(CONFIG_EROFS_FS) += erofs.o
erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
-erofs-$(CONFIG_EROFS_FS_ZIP) += zmap.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o
diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
new file mode 100644
index 000000000000..dbcac48ac888
--- /dev/null
+++ b/fs/erofs/compress.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/erofs/compress.h
+ *
+ * Copyright (C) 2019 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#ifndef __EROFS_FS_COMPRESS_H
+#define __EROFS_FS_COMPRESS_H
+
+#include "internal.h"
+
+enum {
+ Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
+ Z_EROFS_COMPRESSION_RUNTIME_MAX
+};
+
+struct z_erofs_decompress_req {
+ struct super_block *sb;
+ struct page **in, **out;
+
+ unsigned short pageofs_out;
+ unsigned int inputsize, outputsize;
+
+ /* indicate the algorithm will be used for decompression */
+ unsigned int alg;
+ bool inplace_io, partial_decoding;
+};
+
+/*
+ * - 0x5A110C8D ('sallocated', Z_EROFS_MAPPING_STAGING) -
+ * used to mark temporary allocated pages from other
+ * file/cached pages and NULL mapping pages.
+ */
+#define Z_EROFS_MAPPING_STAGING ((void *)0x5A110C8D)
+
+/* check if a page is marked as staging */
+static inline bool z_erofs_page_is_staging(struct page *page)
+{
+ return page->mapping == Z_EROFS_MAPPING_STAGING;
+}
+
+static inline bool z_erofs_put_stagingpage(struct list_head *pagepool,
+ struct page *page)
+{
+ if (!z_erofs_page_is_staging(page))
+ return false;
+
+ /* staging pages should not be used by others at the same time */
+ if (page_ref_count(page) > 1)
+ put_page(page);
+ else
+ list_add(&page->lru, pagepool);
+ return true;
+}
+
+static inline void *erofs_vmap(struct page **pages, unsigned int count)
+{
+#ifdef CONFIG_EROFS_FS_USE_VM_MAP_RAM
+ int i = 0;
+
+ while (1) {
+ void *addr = vm_map_ram(pages, count, -1, PAGE_KERNEL);
+ /* retry two more times (totally 3 times) */
+ if (addr || ++i >= 3)
+ return addr;
+ vm_unmap_aliases();
+ }
+ return NULL;
+#else
+ return vmap(pages, count, VM_MAP, PAGE_KERNEL);
+#endif
+}
+
+static inline void erofs_vunmap(const void *mem, unsigned int count)
+{
+#ifdef CONFIG_EROFS_FS_USE_VM_MAP_RAM
+ vm_unmap_ram(mem, count);
+#else
+ vunmap(mem);
+#endif
+}
+
+int z_erofs_decompress(struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool);
+
+#endif
+
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
new file mode 100644
index 000000000000..2ee10bb7e440
--- /dev/null
+++ b/fs/erofs/decompressor.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/decompressor.c
+ *
+ * Copyright (C) 2019 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "compress.h"
+#include <linux/lz4.h>
+
+#ifndef LZ4_DISTANCE_MAX /* history window size */
+#define LZ4_DISTANCE_MAX 65535 /* set to maximum value by default */
+#endif
+
+#define LZ4_MAX_DISTANCE_PAGES (DIV_ROUND_UP(LZ4_DISTANCE_MAX, PAGE_SIZE) + 1)
+
+struct z_erofs_decompressor {
+ /*
+ * if destpages have sparsed pages, fill them with bounce pages.
+ * it also check whether destpages indicate continuous physical memory.
+ */
+ int (*prepare_destpages)(struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool);
+ int (*decompress)(struct z_erofs_decompress_req *rq, u8 *out);
+ char *name;
+};
+
+static int lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool)
+{
+ const unsigned int nr =
+ PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
+ struct page *availables[LZ4_MAX_DISTANCE_PAGES] = { NULL };
+ unsigned long bounced[DIV_ROUND_UP(LZ4_MAX_DISTANCE_PAGES,
+ BITS_PER_LONG)] = { 0 };
+ void *kaddr = NULL;
+ unsigned int i, j, top;
+
+ top = 0;
+ for (i = j = 0; i < nr; ++i, ++j) {
+ struct page *const page = rq->out[i];
+ struct page *victim;
+
+ if (j >= LZ4_MAX_DISTANCE_PAGES)
+ j = 0;
+
+ /* 'valid' bounced can only be tested after a complete round */
+ if (test_bit(j, bounced)) {
+ DBG_BUGON(i < LZ4_MAX_DISTANCE_PAGES);
+ DBG_BUGON(top >= LZ4_MAX_DISTANCE_PAGES);
+ availables[top++] = rq->out[i - LZ4_MAX_DISTANCE_PAGES];
+ }
+
+ if (page) {
+ __clear_bit(j, bounced);
+ if (kaddr) {
+ if (kaddr + PAGE_SIZE == page_address(page))
+ kaddr += PAGE_SIZE;
+ else
+ kaddr = NULL;
+ } else if (!i) {
+ kaddr = page_address(page);
+ }
+ continue;
+ }
+ kaddr = NULL;
+ __set_bit(j, bounced);
+
+ if (top) {
+ victim = availables[--top];
+ get_page(victim);
+ } else {
+ victim = erofs_allocpage(pagepool, GFP_KERNEL, false);
+ if (unlikely(!victim))
+ return -ENOMEM;
+ victim->mapping = Z_EROFS_MAPPING_STAGING;
+ }
+ rq->out[i] = victim;
+ }
+ return kaddr ? 1 : 0;
+}
+
+static void *generic_copy_inplace_data(struct z_erofs_decompress_req *rq,
+ u8 *src, unsigned int pageofs_in)
+{
+ /*
+ * if in-place decompression is ongoing, those decompressed
+ * pages should be copied in order to avoid being overlapped.
+ */
+ struct page **in = rq->in;
+ u8 *const tmp = erofs_get_pcpubuf(0);
+ u8 *tmpp = tmp;
+ unsigned int inlen = rq->inputsize - pageofs_in;
+ unsigned int count = min_t(uint, inlen, PAGE_SIZE - pageofs_in);
+
+ while (tmpp < tmp + inlen) {
+ if (!src)
+ src = kmap_atomic(*in);
+ memcpy(tmpp, src + pageofs_in, count);
+ kunmap_atomic(src);
+ src = NULL;
+ tmpp += count;
+ pageofs_in = 0;
+ count = PAGE_SIZE;
+ ++in;
+ }
+ return tmp;
+}
+
+static int lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
+{
+ unsigned int inputmargin, inlen;
+ u8 *src;
+ bool copied;
+ int ret;
+
+ if (rq->inputsize > PAGE_SIZE)
+ return -ENOTSUPP;
+
+ src = kmap_atomic(*rq->in);
+ inputmargin = 0;
+
+ copied = false;
+ inlen = rq->inputsize - inputmargin;
+ if (rq->inplace_io) {
+ src = generic_copy_inplace_data(rq, src, inputmargin);
+ inputmargin = 0;
+ copied = true;
+ }
+
+ ret = LZ4_decompress_safe_partial(src + inputmargin, out,
+ inlen, rq->outputsize,
+ rq->outputsize);
+ if (ret < 0) {
+ errln("%s, failed to decompress, in[%p, %u, %u] out[%p, %u]",
+ __func__, src + inputmargin, inlen, inputmargin,
+ out, rq->outputsize);
+ WARN_ON(1);
+ print_hex_dump(KERN_DEBUG, "[ in]: ", DUMP_PREFIX_OFFSET,
+ 16, 1, src + inputmargin, inlen, true);
+ print_hex_dump(KERN_DEBUG, "[out]: ", DUMP_PREFIX_OFFSET,
+ 16, 1, out, rq->outputsize, true);
+ ret = -EIO;
+ }
+
+ if (copied)
+ erofs_put_pcpubuf(src);
+ else
+ kunmap_atomic(src);
+ return ret;
+}
+
+static struct z_erofs_decompressor decompressors[] = {
+ [Z_EROFS_COMPRESSION_SHIFTED] = {
+ .name = "shifted"
+ },
+ [Z_EROFS_COMPRESSION_LZ4] = {
+ .prepare_destpages = lz4_prepare_destpages,
+ .decompress = lz4_decompress,
+ .name = "lz4"
+ },
+};
+
+static void copy_from_pcpubuf(struct page **out, const char *dst,
+ unsigned short pageofs_out,
+ unsigned int outputsize)
+{
+ const char *end = dst + outputsize;
+ const unsigned int righthalf = PAGE_SIZE - pageofs_out;
+ const char *cur = dst - pageofs_out;
+
+ while (cur < end) {
+ struct page *const page = *out++;
+
+ if (page) {
+ char *buf = kmap_atomic(page);
+
+ if (cur >= dst) {
+ memcpy(buf, cur, min_t(uint, PAGE_SIZE,
+ end - cur));
+ } else {
+ memcpy(buf + pageofs_out, cur + pageofs_out,
+ min_t(uint, righthalf, end - cur));
+ }
+ kunmap_atomic(buf);
+ }
+ cur += PAGE_SIZE;
+ }
+}
+
+static int decompress_generic(struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool)
+{
+ const unsigned int nrpages_out =
+ PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
+ const struct z_erofs_decompressor *alg = decompressors + rq->alg;
+ unsigned int dst_maptype;
+ void *dst;
+ int ret;
+
+ if (nrpages_out == 1 && !rq->inplace_io) {
+ DBG_BUGON(!*rq->out);
+ dst = kmap_atomic(*rq->out);
+ dst_maptype = 0;
+ goto dstmap_out;
+ }
+
+ /*
+ * For the case of small output size (especially much less
+ * than PAGE_SIZE), memcpy the decompressed data rather than
+ * compressed data is preferred.
+ */
+ if (rq->outputsize <= PAGE_SIZE * 7 / 8) {
+ dst = erofs_get_pcpubuf(0);
+ if (IS_ERR(dst))
+ return PTR_ERR(dst);
+
+ rq->inplace_io = false;
+ ret = alg->decompress(rq, dst);
+ if (!ret)
+ copy_from_pcpubuf(rq->out, dst, rq->pageofs_out,
+ rq->outputsize);
+
+ erofs_put_pcpubuf(dst);
+ return ret;
+ }
+
+ ret = alg->prepare_destpages(rq, pagepool);
+ if (ret < 0) {
+ return ret;
+ } else if (ret) {
+ dst = page_address(*rq->out);
+ dst_maptype = 1;
+ goto dstmap_out;
+ }
+
+ dst = erofs_vmap(rq->out, nrpages_out);
+ if (!dst)
+ return -ENOMEM;
+ dst_maptype = 2;
+
+dstmap_out:
+ ret = alg->decompress(rq, dst + rq->pageofs_out);
+
+ if (!dst_maptype)
+ kunmap_atomic(dst);
+ else if (dst_maptype == 2)
+ erofs_vunmap(dst, nrpages_out);
+ return ret;
+}
+
+static int shifted_decompress(const struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool)
+{
+ const unsigned int nrpages_out =
+ PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
+ const unsigned int righthalf = PAGE_SIZE - rq->pageofs_out;
+ unsigned char *src, *dst;
+
+ if (nrpages_out > 2) {
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ if (rq->out[0] == *rq->in) {
+ DBG_BUGON(nrpages_out != 1);
+ return 0;
+ }
+
+ src = kmap_atomic(*rq->in);
+ if (!rq->out[0]) {
+ dst = NULL;
+ } else {
+ dst = kmap_atomic(rq->out[0]);
+ memcpy(dst + rq->pageofs_out, src, righthalf);
+ }
+
+ if (rq->out[1] == *rq->in) {
+ memmove(src, src + righthalf, rq->pageofs_out);
+ } else if (nrpages_out == 2) {
+ if (dst)
+ kunmap_atomic(dst);
+ DBG_BUGON(!rq->out[1]);
+ dst = kmap_atomic(rq->out[1]);
+ memcpy(dst, src + righthalf, rq->pageofs_out);
+ }
+ if (dst)
+ kunmap_atomic(dst);
+ kunmap_atomic(src);
+ return 0;
+}
+
+int z_erofs_decompress(struct z_erofs_decompress_req *rq,
+ struct list_head *pagepool)
+{
+ if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED)
+ return shifted_decompress(rq, pagepool);
+ return decompress_generic(rq, pagepool);
+}
+
--
2.17.1
For each physical cluster, there is a straight-forward
way of allocating a fixed or variable-sized array to
record the corresponding file pages for its decompression
if we decide to decompress these pages asynchronously
(eg. read-ahead case), however it will take variable-sized
on-heap memory compared with traditional uncompressed
filesystems.
This patch introduces a pagevec solution to reuse some
allocated file page in the time-sharing approach to store
parts of the array itself in order to minimize the extra
memory overhead, thus only a small-sized constant array
used for booting the whole array itself up will be needed.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/zpvec.h | 159 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 159 insertions(+)
create mode 100644 fs/erofs/zpvec.h
diff --git a/fs/erofs/zpvec.h b/fs/erofs/zpvec.h
new file mode 100644
index 000000000000..292aee36d380
--- /dev/null
+++ b/fs/erofs/zpvec.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/erofs/zpvec.h
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#ifndef __EROFS_ZPVEC_H
+#define __EROFS_ZPVEC_H
+
+#include "tagptr.h"
+
+/* page type in pagevec for decompress subsystem */
+enum z_erofs_page_type {
+ /* including Z_EROFS_VLE_PAGE_TAIL_EXCLUSIVE */
+ Z_EROFS_PAGE_TYPE_EXCLUSIVE,
+
+ Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED,
+
+ Z_EROFS_VLE_PAGE_TYPE_HEAD,
+ Z_EROFS_VLE_PAGE_TYPE_MAX
+};
+
+extern void __compiletime_error("Z_EROFS_PAGE_TYPE_EXCLUSIVE != 0")
+ __bad_page_type_exclusive(void);
+
+/* pagevec tagged pointer */
+typedef tagptr2_t erofs_vtptr_t;
+
+/* pagevec collector */
+struct z_erofs_pagevec_ctor {
+ struct page *curr, *next;
+ erofs_vtptr_t *pages;
+
+ unsigned int nr, index;
+};
+
+static inline void z_erofs_pagevec_ctor_exit(struct z_erofs_pagevec_ctor *ctor,
+ bool atomic)
+{
+ if (!ctor->curr)
+ return;
+
+ if (atomic)
+ kunmap_atomic(ctor->pages);
+ else
+ kunmap(ctor->curr);
+}
+
+static inline struct page *
+z_erofs_pagevec_ctor_next_page(struct z_erofs_pagevec_ctor *ctor,
+ unsigned int nr)
+{
+ unsigned int index;
+
+ /* keep away from occupied pages */
+ if (ctor->next)
+ return ctor->next;
+
+ for (index = 0; index < nr; ++index) {
+ const erofs_vtptr_t t = ctor->pages[index];
+ const unsigned int tags = tagptr_unfold_tags(t);
+
+ if (tags == Z_EROFS_PAGE_TYPE_EXCLUSIVE)
+ return tagptr_unfold_ptr(t);
+ }
+ DBG_BUGON(nr >= ctor->nr);
+ return NULL;
+}
+
+static inline void
+z_erofs_pagevec_ctor_pagedown(struct z_erofs_pagevec_ctor *ctor,
+ bool atomic)
+{
+ struct page *next = z_erofs_pagevec_ctor_next_page(ctor, ctor->nr);
+
+ z_erofs_pagevec_ctor_exit(ctor, atomic);
+
+ ctor->curr = next;
+ ctor->next = NULL;
+ ctor->pages = atomic ?
+ kmap_atomic(ctor->curr) : kmap(ctor->curr);
+
+ ctor->nr = PAGE_SIZE / sizeof(struct page *);
+ ctor->index = 0;
+}
+
+static inline void z_erofs_pagevec_ctor_init(struct z_erofs_pagevec_ctor *ctor,
+ unsigned int nr,
+ erofs_vtptr_t *pages,
+ unsigned int i)
+{
+ ctor->nr = nr;
+ ctor->curr = ctor->next = NULL;
+ ctor->pages = pages;
+
+ if (i >= nr) {
+ i -= nr;
+ z_erofs_pagevec_ctor_pagedown(ctor, false);
+ while (i > ctor->nr) {
+ i -= ctor->nr;
+ z_erofs_pagevec_ctor_pagedown(ctor, false);
+ }
+ }
+ ctor->next = z_erofs_pagevec_ctor_next_page(ctor, i);
+ ctor->index = i;
+}
+
+static inline bool z_erofs_pagevec_enqueue(struct z_erofs_pagevec_ctor *ctor,
+ struct page *page,
+ enum z_erofs_page_type type,
+ bool *occupied)
+{
+ *occupied = false;
+ if (unlikely(!ctor->next && type))
+ if (ctor->index + 1 == ctor->nr)
+ return false;
+
+ if (unlikely(ctor->index >= ctor->nr))
+ z_erofs_pagevec_ctor_pagedown(ctor, false);
+
+ /* exclusive page type must be 0 */
+ if (Z_EROFS_PAGE_TYPE_EXCLUSIVE != (uintptr_t)NULL)
+ __bad_page_type_exclusive();
+
+ /* should remind that collector->next never equal to 1, 2 */
+ if (type == (uintptr_t)ctor->next) {
+ ctor->next = page;
+ *occupied = true;
+ }
+ ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, page, type);
+ return true;
+}
+
+static inline struct page *
+z_erofs_pagevec_dequeue(struct z_erofs_pagevec_ctor *ctor,
+ enum z_erofs_page_type *type)
+{
+ erofs_vtptr_t t;
+
+ if (unlikely(ctor->index >= ctor->nr)) {
+ DBG_BUGON(!ctor->next);
+ z_erofs_pagevec_ctor_pagedown(ctor, true);
+ }
+
+ t = ctor->pages[ctor->index];
+
+ *type = tagptr_unfold_tags(t);
+
+ /* should remind that collector->next never equal to 1, 2 */
+ if (*type == (uintptr_t)ctor->next)
+ ctor->next = tagptr_unfold_ptr(t);
+
+ ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, NULL, 0);
+ return tagptr_unfold_ptr(t);
+}
+#endif
+
--
2.17.1
This patch introduces the basic inplace fixed-sized
output decompression implementation for erofs
filesystem.
In constant to fixed-sized input compression, it has
fixed-sized capacity for each compressed cluster to
contain compressed data with the following advantages:
1) improved storage density;
2) decompression inplace support;
3) all data in a compressed physical cluster can be
decompressed and utilized.
The key point of inplace refers to one of all erofs
decompression strategies: Instead of allocating extra
compressed pages and data management structures, it
reuses the allocated file cache pages as much as
possible to store its compressed data (called inplace
I/O) and the corresponding pagevec in a time-sharing
approach, which is particularly useful for low memory
scenario.
In addition, decompression inplace technology is based
on inplace I/O, which eliminates page allocation and
all extra compressed data memcpy.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/Kconfig | 1 +
fs/erofs/Makefile | 2 +-
fs/erofs/internal.h | 16 +-
fs/erofs/super.c | 9 +
fs/erofs/zdata.c | 1268 +++++++++++++++++++++++++++++++++++++++++++
fs/erofs/zdata.h | 192 +++++++
fs/erofs/zmap.c | 4 +-
7 files changed, 1488 insertions(+), 4 deletions(-)
create mode 100644 fs/erofs/zdata.c
create mode 100644 fs/erofs/zdata.h
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 9cefecec3194..45a81ebeb023 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -94,6 +94,7 @@ config EROFS_FS_ZIP
bool "EROFS Data Compresssion Support"
depends on EROFS_FS
select LZ4_DECOMPRESS
+ default y
help
Enable fixed-sized output compression for EROFS.
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
index afb7c6556bf9..ac627823e6b8 100644
--- a/fs/erofs/Makefile
+++ b/fs/erofs/Makefile
@@ -7,5 +7,5 @@ ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\"
obj-$(CONFIG_EROFS_FS) += erofs.o
erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
-erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o
+erofs-$(CONFIG_EROFS_FS_ZIP) += decompressor.o zmap.o zdata.o
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 7e6ac4642593..73892162f494 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -68,6 +68,9 @@ struct erofs_sb_info {
/* the dedicated workstation for compression */
struct radix_tree_root workstn_tree;
+ /* threshold for decompression synchronously */
+ unsigned int max_sync_decompress_pages;
+
unsigned int shrinker_run_no;
#endif
u32 blocks;
@@ -223,6 +226,8 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
}
#endif
+#define DEFAULT_MAX_SYNC_DECOMPRESS_PAGES 3
+
#ifdef CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT
#define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
#else
@@ -328,6 +333,9 @@ static inline bool is_inode_flat_inline(struct inode *inode)
extern const struct super_operations erofs_sops;
extern const struct address_space_operations erofs_raw_access_aops;
+#ifdef CONFIG_EROFS_FS_ZIP
+extern const struct address_space_operations z_erofs_vle_normalaccess_aops;
+#endif
/*
* Logical to physical block mapping, used by erofs_map_blocks()
@@ -494,7 +502,7 @@ int erofs_namei(struct inode *dir, struct qstr *name,
/* dir.c */
extern const struct file_operations erofs_dir_fops;
-/* utils.c */
+/* utils.c / zdata.c */
struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp, bool nofail);
#if (EROFS_PCPUBUF_NR_PAGES > 0)
@@ -520,17 +528,21 @@ int erofs_register_workgroup(struct super_block *sb,
struct erofs_workgroup *grp, bool tag);
unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
unsigned long nr_shrink, bool cleanup);
-static inline void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) {}
+void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
void erofs_shrinker_register(struct super_block *sb);
void erofs_shrinker_unregister(struct super_block *sb);
int __init erofs_init_shrinker(void);
void erofs_exit_shrinker(void);
+int __init z_erofs_init_zip_subsystem(void);
+void z_erofs_exit_zip_subsystem(void);
#else
static inline void erofs_shrinker_register(struct super_block *sb) {}
static inline void erofs_shrinker_unregister(struct super_block *sb) {}
static inline int erofs_init_shrinker(void) { return 0; }
static inline void erofs_exit_shrinker(void) {}
+static inline int z_erofs_init_zip_subsystem(void) { return 0; }
+static inline void z_erofs_exit_zip_subsystem(void) {}
#endif
#endif
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index acb60553b586..80e1a9b6d855 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -200,6 +200,9 @@ static unsigned int erofs_get_fault_rate(struct erofs_sb_info *sbi)
/* set up default EROFS parameters */
static void default_options(struct erofs_sb_info *sbi)
{
+#ifdef CONFIG_EROFS_FS_ZIP
+ sbi->max_sync_decompress_pages = DEFAULT_MAX_SYNC_DECOMPRESS_PAGES;
+#endif
#ifdef CONFIG_EROFS_FS_XATTR
set_opt(sbi, XATTR_USER);
#endif
@@ -481,6 +484,9 @@ static int __init erofs_module_init(void)
err = erofs_init_shrinker();
if (err)
goto shrinker_err;
+ err = z_erofs_init_zip_subsystem();
+ if (err)
+ goto zip_err;
err = register_filesystem(&erofs_fs_type);
if (err)
goto fs_err;
@@ -489,6 +495,8 @@ static int __init erofs_module_init(void)
return 0;
fs_err:
+ z_erofs_exit_zip_subsystem();
+zip_err:
erofs_exit_shrinker();
shrinker_err:
erofs_exit_inode_cache();
@@ -499,6 +507,7 @@ static int __init erofs_module_init(void)
static void __exit erofs_module_exit(void)
{
unregister_filesystem(&erofs_fs_type);
+ z_erofs_exit_zip_subsystem();
erofs_exit_shrinker();
erofs_exit_inode_cache();
infoln("successfully finalize erofs");
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
new file mode 100644
index 000000000000..bebbd45bf08e
--- /dev/null
+++ b/fs/erofs/zdata.c
@@ -0,0 +1,1268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/zdata.c
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "zdata.h"
+#include "compress.h"
+#include <linux/prefetch.h>
+
+#include <trace/events/erofs.h>
+
+/*
+ * a compressed_pages[] placeholder in order to avoid
+ * being filled with file pages for in-place decompression.
+ */
+#define PAGE_UNALLOCATED ((void *)0x5F0E4B1D)
+
+/* how to allocate cached pages for a pcluster */
+enum z_erofs_cache_alloctype {
+ DONTALLOC, /* don't allocate any cached pages */
+ DELAYEDALLOC, /* delayed allocation (at the time of submitting io) */
+};
+
+/*
+ * tagged pointer with 1-bit tag for all compressed pages
+ * tag 0 - the page is just found with an extra page reference
+ */
+typedef tagptr1_t compressed_page_t;
+
+#define tag_compressed_page_justfound(page) \
+ tagptr_fold(compressed_page_t, page, 1)
+
+static struct workqueue_struct *z_erofs_workqueue __read_mostly;
+static struct kmem_cache *pcluster_cachep __read_mostly;
+
+void z_erofs_exit_zip_subsystem(void)
+{
+ destroy_workqueue(z_erofs_workqueue);
+ kmem_cache_destroy(pcluster_cachep);
+}
+
+static inline int init_unzip_workqueue(void)
+{
+ const unsigned int onlinecpus = num_possible_cpus();
+ const unsigned int flags = WQ_UNBOUND | WQ_HIGHPRI | WQ_CPU_INTENSIVE;
+
+ /*
+ * no need to spawn too many threads, limiting threads could minimum
+ * scheduling overhead, perhaps per-CPU threads should be better?
+ */
+ z_erofs_workqueue = alloc_workqueue("erofs_unzipd", flags,
+ onlinecpus + onlinecpus / 4);
+ return z_erofs_workqueue ? 0 : -ENOMEM;
+}
+
+static void init_once(void *ptr)
+{
+ struct z_erofs_pcluster *pcl = ptr;
+ struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
+ unsigned int i;
+
+ mutex_init(&cl->lock);
+ cl->nr_pages = 0;
+ cl->vcnt = 0;
+ for (i = 0; i < Z_EROFS_CLUSTER_MAX_PAGES; ++i)
+ pcl->compressed_pages[i] = NULL;
+}
+
+static void init_always(struct z_erofs_pcluster *pcl)
+{
+ struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
+
+ atomic_set(&pcl->obj.refcount, 1);
+
+ DBG_BUGON(cl->nr_pages);
+ DBG_BUGON(cl->vcnt);
+}
+
+int __init z_erofs_init_zip_subsystem(void)
+{
+ pcluster_cachep = kmem_cache_create("erofs_compress",
+ Z_EROFS_WORKGROUP_SIZE, 0,
+ SLAB_RECLAIM_ACCOUNT, init_once);
+ if (pcluster_cachep) {
+ if (!init_unzip_workqueue())
+ return 0;
+
+ kmem_cache_destroy(pcluster_cachep);
+ }
+ return -ENOMEM;
+}
+
+enum z_erofs_collectmode {
+ COLLECT_SECONDARY,
+ COLLECT_PRIMARY,
+ /*
+ * The current collection was the tail of an exist chain, in addition
+ * that the previous processed chained collections are all decided to
+ * be hooked up to it.
+ * A new chain will be created for the remaining collections which are
+ * not processed yet, therefore different from COLLECT_PRIMARY_FOLLOWED,
+ * the next collection cannot reuse the whole page safely in
+ * the following scenario:
+ * ________________________________________________________________
+ * | tail (partial) page | head (partial) page |
+ * | (belongs to the next cl) | (belongs to the current cl) |
+ * |_______PRIMARY_FOLLOWED_______|________PRIMARY_HOOKED___________|
+ */
+ COLLECT_PRIMARY_HOOKED,
+ COLLECT_PRIMARY_FOLLOWED_NOINPLACE,
+ /*
+ * The current collection has been linked with the owned chain, and
+ * could also be linked with the remaining collections, which means
+ * if the processing page is the tail page of the collection, thus
+ * the current collection can safely use the whole page (since
+ * the previous collection is under control) for in-place I/O, as
+ * illustrated below:
+ * ________________________________________________________________
+ * | tail (partial) page | head (partial) page |
+ * | (of the current cl) | (of the previous collection) |
+ * | PRIMARY_FOLLOWED or | |
+ * |_____PRIMARY_HOOKED___|____________PRIMARY_FOLLOWED____________|
+ *
+ * [ (*) the above page can be used as inplace I/O. ]
+ */
+ COLLECT_PRIMARY_FOLLOWED,
+};
+
+struct z_erofs_collector {
+ struct z_erofs_pagevec_ctor vector;
+
+ struct z_erofs_pcluster *pcl;
+ struct z_erofs_collection *cl;
+ struct page **compressedpages;
+ z_erofs_next_pcluster_t owned_head;
+
+ enum z_erofs_collectmode mode;
+};
+
+struct z_erofs_decompress_frontend {
+ struct inode *const inode;
+
+ struct z_erofs_collector clt;
+ struct erofs_map_blocks map;
+
+ /* used for applying cache strategy on the fly */
+ bool backmost;
+ erofs_off_t headoffset;
+};
+
+#define COLLECTOR_INIT() { \
+ .owned_head = Z_EROFS_PCLUSTER_TAIL, \
+ .mode = COLLECT_PRIMARY_FOLLOWED }
+
+#define DECOMPRESS_FRONTEND_INIT(__i) { \
+ .inode = __i, .clt = COLLECTOR_INIT(), \
+ .backmost = true, }
+
+static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
+static DEFINE_MUTEX(z_pagemap_global_lock);
+
+static void preload_compressed_pages(struct z_erofs_collector *clt,
+ struct address_space *mc,
+ enum z_erofs_cache_alloctype type,
+ struct list_head *pagepool)
+{
+ /* nowhere to load compressed pages from */
+}
+
+/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
+static inline bool try_inplace_io(struct z_erofs_collector *clt,
+ struct page *page)
+{
+ struct z_erofs_pcluster *const pcl = clt->pcl;
+ const unsigned int clusterpages = BIT(pcl->clusterbits);
+
+ while (clt->compressedpages < pcl->compressed_pages + clusterpages) {
+ if (!cmpxchg(clt->compressedpages++, NULL, page))
+ return true;
+ }
+ return false;
+}
+
+/* callers must be with collection lock held */
+static int z_erofs_attach_page(struct z_erofs_collector *clt,
+ struct page *page,
+ enum z_erofs_page_type type)
+{
+ int ret;
+ bool occupied;
+
+ /* give priority for inplaceio */
+ if (clt->mode >= COLLECT_PRIMARY &&
+ type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
+ try_inplace_io(clt, page))
+ return 0;
+
+ ret = z_erofs_pagevec_enqueue(&clt->vector,
+ page, type, &occupied);
+ clt->cl->vcnt += (unsigned int)ret;
+
+ return ret ? 0 : -EAGAIN;
+}
+
+static enum z_erofs_collectmode
+try_to_claim_pcluster(struct z_erofs_pcluster *pcl,
+ z_erofs_next_pcluster_t *owned_head)
+{
+ /* let's claim these following types of pclusters */
+retry:
+ if (pcl->next == Z_EROFS_PCLUSTER_NIL) {
+ /* type 1, nil pcluster */
+ if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
+ *owned_head) != Z_EROFS_PCLUSTER_NIL)
+ goto retry;
+
+ *owned_head = &pcl->next;
+ /* lucky, I am the followee :) */
+ return COLLECT_PRIMARY_FOLLOWED;
+ } else if (pcl->next == Z_EROFS_PCLUSTER_TAIL) {
+ /*
+ * type 2, link to the end of a existing open chain,
+ * be careful that its submission itself is governed
+ * by the original owned chain.
+ */
+ if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
+ *owned_head) != Z_EROFS_PCLUSTER_TAIL)
+ goto retry;
+ *owned_head = Z_EROFS_PCLUSTER_TAIL;
+ return COLLECT_PRIMARY_HOOKED;
+ }
+ return COLLECT_PRIMARY; /* :( better luck next time */
+}
+
+static struct z_erofs_collection *cllookup(struct z_erofs_collector *clt,
+ struct inode *inode,
+ struct erofs_map_blocks *map)
+{
+ struct erofs_workgroup *grp;
+ struct z_erofs_pcluster *pcl;
+ struct z_erofs_collection *cl;
+ unsigned int length;
+ bool tag;
+
+ grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT, &tag);
+ if (!grp)
+ return NULL;
+
+ pcl = container_of(grp, struct z_erofs_pcluster, obj);
+
+ cl = z_erofs_primarycollection(pcl);
+ if (unlikely(cl->pageofs != (map->m_la & ~PAGE_MASK))) {
+ DBG_BUGON(1);
+ return ERR_PTR(-EIO);
+ }
+
+ length = READ_ONCE(pcl->length);
+ if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
+ if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
+ DBG_BUGON(1);
+ return ERR_PTR(-EIO);
+ }
+ } else {
+ unsigned int llen = map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT;
+
+ if (map->m_flags & EROFS_MAP_FULL_MAPPED)
+ llen |= Z_EROFS_PCLUSTER_FULL_LENGTH;
+
+ while (llen > length &&
+ length != cmpxchg_relaxed(&pcl->length, length, llen)) {
+ cpu_relax();
+ length = READ_ONCE(pcl->length);
+ }
+ }
+ mutex_lock(&cl->lock);
+ clt->mode = try_to_claim_pcluster(pcl, &clt->owned_head);
+ clt->pcl = pcl;
+ clt->cl = cl;
+ return cl;
+}
+
+static struct z_erofs_collection *clregister(struct z_erofs_collector *clt,
+ struct inode *inode,
+ struct erofs_map_blocks *map)
+{
+ struct z_erofs_pcluster *pcl;
+ struct z_erofs_collection *cl;
+ int err;
+
+ /* no available workgroup, let's allocate one */
+ pcl = kmem_cache_alloc(pcluster_cachep, GFP_NOFS);
+ if (unlikely(!pcl))
+ return ERR_PTR(-ENOMEM);
+
+ init_always(pcl);
+ pcl->obj.index = map->m_pa >> PAGE_SHIFT;
+
+ pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
+ (map->m_flags & EROFS_MAP_FULL_MAPPED ?
+ Z_EROFS_PCLUSTER_FULL_LENGTH : 0);
+
+ if (map->m_flags & EROFS_MAP_ZIPPED)
+ pcl->algorithmformat = Z_EROFS_COMPRESSION_LZ4;
+ else
+ pcl->algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
+
+ pcl->clusterbits = EROFS_V(inode)->z_physical_clusterbits[0];
+ pcl->clusterbits -= PAGE_SHIFT;
+
+ /* new pclusters should be claimed as type 1, primary and followed */
+ pcl->next = clt->owned_head;
+ clt->mode = COLLECT_PRIMARY_FOLLOWED;
+
+ cl = z_erofs_primarycollection(pcl);
+ cl->pageofs = map->m_la & ~PAGE_MASK;
+
+ /*
+ * lock all primary followed works before visible to others
+ * and mutex_trylock *never* fails for a new pcluster.
+ */
+ mutex_trylock(&cl->lock);
+
+ err = erofs_register_workgroup(inode->i_sb, &pcl->obj, 0);
+ if (err) {
+ mutex_unlock(&cl->lock);
+ kmem_cache_free(pcluster_cachep, pcl);
+ return ERR_PTR(-EAGAIN);
+ }
+ clt->owned_head = &pcl->next;
+ clt->pcl = pcl;
+ clt->cl = cl;
+ return cl;
+}
+
+static int z_erofs_collector_begin(struct z_erofs_collector *clt,
+ struct inode *inode,
+ struct erofs_map_blocks *map)
+{
+ struct z_erofs_collection *cl;
+
+ DBG_BUGON(clt->cl);
+
+ /* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
+ DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
+ DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
+
+ if (!PAGE_ALIGNED(map->m_pa)) {
+ DBG_BUGON(1);
+ return -EINVAL;
+ }
+
+repeat:
+ cl = cllookup(clt, inode, map);
+ if (!cl) {
+ cl = clregister(clt, inode, map);
+
+ if (unlikely(cl == ERR_PTR(-EAGAIN)))
+ goto repeat;
+ }
+
+ if (IS_ERR(cl))
+ return PTR_ERR(cl);
+
+ z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
+ cl->pagevec, cl->vcnt);
+
+ clt->compressedpages = clt->pcl->compressed_pages;
+ if (clt->mode <= COLLECT_PRIMARY) /* cannot do in-place I/O */
+ clt->compressedpages += Z_EROFS_CLUSTER_MAX_PAGES;
+ return 0;
+}
+
+/*
+ * keep in mind that no referenced pclusters will be freed
+ * only after a RCU grace period.
+ */
+static void z_erofs_rcu_callback(struct rcu_head *head)
+{
+ struct z_erofs_collection *const cl =
+ container_of(head, struct z_erofs_collection, rcu);
+
+ kmem_cache_free(pcluster_cachep,
+ container_of(cl, struct z_erofs_pcluster,
+ primary_collection));
+}
+
+void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
+{
+ struct z_erofs_pcluster *const pcl =
+ container_of(grp, struct z_erofs_pcluster, obj);
+ struct z_erofs_collection *const cl = z_erofs_primarycollection(pcl);
+
+ call_rcu(&cl->rcu, z_erofs_rcu_callback);
+}
+
+static void z_erofs_collection_put(struct z_erofs_collection *cl)
+{
+ struct z_erofs_pcluster *const pcl =
+ container_of(cl, struct z_erofs_pcluster, primary_collection);
+
+ erofs_workgroup_put(&pcl->obj);
+}
+
+static bool z_erofs_collector_end(struct z_erofs_collector *clt)
+{
+ struct z_erofs_collection *cl = clt->cl;
+
+ if (!cl)
+ return false;
+
+ z_erofs_pagevec_ctor_exit(&clt->vector, false);
+ mutex_unlock(&cl->lock);
+
+ /*
+ * if all pending pages are added, don't hold its reference
+ * any longer if the pcluster isn't hosted by ourselves.
+ */
+ if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
+ z_erofs_collection_put(cl);
+
+ clt->cl = NULL;
+ return true;
+}
+
+static inline struct page *__stagingpage_alloc(struct list_head *pagepool,
+ gfp_t gfp)
+{
+ struct page *page = erofs_allocpage(pagepool, gfp, true);
+
+ if (unlikely(!page))
+ return NULL;
+
+ page->mapping = Z_EROFS_MAPPING_STAGING;
+ return page;
+}
+
+static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
+ erofs_off_t la)
+{
+ return false;
+}
+
+static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
+ struct page *page,
+ struct list_head *pagepool)
+{
+ struct inode *const inode = fe->inode;
+ struct erofs_sb_info *const sbi __maybe_unused = EROFS_I_SB(inode);
+ struct erofs_map_blocks *const map = &fe->map;
+ struct z_erofs_collector *const clt = &fe->clt;
+ const loff_t offset = page_offset(page);
+ bool tight = (clt->mode >= COLLECT_PRIMARY_HOOKED);
+
+ enum z_erofs_cache_alloctype cache_strategy;
+ enum z_erofs_page_type page_type;
+ unsigned int cur, end, spiltted, index;
+ int err = 0;
+
+ /* register locked file pages as online pages in pack */
+ z_erofs_onlinepage_init(page);
+
+ spiltted = 0;
+ end = PAGE_SIZE;
+repeat:
+ cur = end - 1;
+
+ /* lucky, within the range of the current map_blocks */
+ if (offset + cur >= map->m_la &&
+ offset + cur < map->m_la + map->m_llen) {
+ /* didn't get a valid collection previously (very rare) */
+ if (!clt->cl)
+ goto restart_now;
+ goto hitted;
+ }
+
+ /* go ahead the next map_blocks */
+ debugln("%s: [out-of-range] pos %llu", __func__, offset + cur);
+
+ if (z_erofs_collector_end(clt))
+ fe->backmost = false;
+
+ map->m_la = offset + cur;
+ map->m_llen = 0;
+ err = z_erofs_map_blocks_iter(inode, map, 0);
+ if (unlikely(err))
+ goto err_out;
+
+restart_now:
+ if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED)))
+ goto hitted;
+
+ err = z_erofs_collector_begin(clt, inode, map);
+ if (unlikely(err))
+ goto err_out;
+
+ /* preload all compressed pages (maybe downgrade role if necessary) */
+ if (should_alloc_managed_pages(fe, map->m_la))
+ cache_strategy = DELAYEDALLOC;
+ else
+ cache_strategy = DONTALLOC;
+
+ preload_compressed_pages(clt, MNGD_MAPPING(sbi),
+ cache_strategy, pagepool);
+
+ tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED);
+hitted:
+ cur = end - min_t(unsigned int, offset + end - map->m_la, end);
+ if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED))) {
+ zero_user_segment(page, cur, end);
+ goto next_part;
+ }
+
+ /* let's derive page type */
+ page_type = cur ? Z_EROFS_VLE_PAGE_TYPE_HEAD :
+ (!spiltted ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
+ (tight ? Z_EROFS_PAGE_TYPE_EXCLUSIVE :
+ Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));
+
+ if (cur)
+ tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
+
+retry:
+ err = z_erofs_attach_page(clt, page, page_type);
+ /* should allocate an additional staging page for pagevec */
+ if (err == -EAGAIN) {
+ struct page *const newpage =
+ __stagingpage_alloc(pagepool, GFP_NOFS);
+
+ err = z_erofs_attach_page(clt, newpage,
+ Z_EROFS_PAGE_TYPE_EXCLUSIVE);
+ if (likely(!err))
+ goto retry;
+ }
+
+ if (unlikely(err))
+ goto err_out;
+
+ index = page->index - (map->m_la >> PAGE_SHIFT);
+
+ z_erofs_onlinepage_fixup(page, index, true);
+
+ /* bump up the number of spiltted parts of a page */
+ ++spiltted;
+ /* also update nr_pages */
+ clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1);
+next_part:
+ /* can be used for verification */
+ map->m_llen = offset + cur - map->m_la;
+
+ end = cur;
+ if (end > 0)
+ goto repeat;
+
+out:
+ z_erofs_onlinepage_endio(page);
+
+ debugln("%s, finish page: %pK spiltted: %u map->m_llen %llu",
+ __func__, page, spiltted, map->m_llen);
+ return err;
+
+ /* if some error occurred while processing this page */
+err_out:
+ SetPageError(page);
+ goto out;
+}
+
+static void z_erofs_vle_unzip_kickoff(void *ptr, int bios)
+{
+ tagptr1_t t = tagptr_init(tagptr1_t, ptr);
+ struct z_erofs_unzip_io *io = tagptr_unfold_ptr(t);
+ bool background = tagptr_unfold_tags(t);
+
+ if (!background) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&io->u.wait.lock, flags);
+ if (!atomic_add_return(bios, &io->pending_bios))
+ wake_up_locked(&io->u.wait);
+ spin_unlock_irqrestore(&io->u.wait.lock, flags);
+ return;
+ }
+
+ if (!atomic_add_return(bios, &io->pending_bios))
+ queue_work(z_erofs_workqueue, &io->u.work);
+}
+
+static inline void z_erofs_vle_read_endio(struct bio *bio)
+{
+ struct erofs_sb_info *sbi = NULL;
+ blk_status_t err = bio->bi_status;
+ struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
+
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ struct page *page = bvec->bv_page;
+ bool cachemngd = false;
+
+ DBG_BUGON(PageUptodate(page));
+ DBG_BUGON(!page->mapping);
+
+ if (unlikely(!sbi && !z_erofs_page_is_staging(page))) {
+ sbi = EROFS_SB(page->mapping->host->i_sb);
+
+ if (time_to_inject(sbi, FAULT_READ_IO)) {
+ erofs_show_injection_info(FAULT_READ_IO);
+ err = BLK_STS_IOERR;
+ }
+ }
+
+ /* sbi should already be gotten if the page is managed */
+ if (sbi)
+ cachemngd = erofs_page_is_managed(sbi, page);
+
+ if (unlikely(err))
+ SetPageError(page);
+ else if (cachemngd)
+ SetPageUptodate(page);
+
+ if (cachemngd)
+ unlock_page(page);
+ }
+
+ z_erofs_vle_unzip_kickoff(bio->bi_private, -1);
+ bio_put(bio);
+}
+
+static int z_erofs_decompress_pcluster(struct super_block *sb,
+ struct z_erofs_pcluster *pcl,
+ struct list_head *pagepool)
+{
+ struct erofs_sb_info *const sbi = EROFS_SB(sb);
+ const unsigned int clusterpages = BIT(pcl->clusterbits);
+ struct z_erofs_pagevec_ctor ctor;
+ unsigned int i, outputsize, llen, nr_pages;
+ struct page *pages_onstack[Z_EROFS_VMAP_ONSTACK_PAGES];
+ struct page **pages, **compressed_pages, *page;
+
+ enum z_erofs_page_type page_type;
+ bool overlapped, partial;
+ struct z_erofs_collection *cl;
+ int err;
+
+ might_sleep();
+ cl = z_erofs_primarycollection(pcl);
+ DBG_BUGON(!READ_ONCE(cl->nr_pages));
+
+ mutex_lock(&cl->lock);
+ nr_pages = cl->nr_pages;
+
+ if (likely(nr_pages <= Z_EROFS_VMAP_ONSTACK_PAGES)) {
+ pages = pages_onstack;
+ } else if (nr_pages <= Z_EROFS_VMAP_GLOBAL_PAGES &&
+ mutex_trylock(&z_pagemap_global_lock)) {
+ pages = z_pagemap_global;
+ } else {
+repeat:
+ pages = kvmalloc_array(nr_pages, sizeof(struct page *),
+ GFP_KERNEL);
+
+ /* fallback to global pagemap for the lowmem scenario */
+ if (unlikely(!pages)) {
+ if (nr_pages > Z_EROFS_VMAP_GLOBAL_PAGES)
+ goto repeat;
+
+ mutex_lock(&z_pagemap_global_lock);
+ pages = z_pagemap_global;
+ }
+ }
+
+ for (i = 0; i < nr_pages; ++i)
+ pages[i] = NULL;
+
+ z_erofs_pagevec_ctor_init(&ctor, Z_EROFS_NR_INLINE_PAGEVECS,
+ cl->pagevec, 0);
+
+ for (i = 0; i < cl->vcnt; ++i) {
+ unsigned int pagenr;
+
+ page = z_erofs_pagevec_dequeue(&ctor, &page_type);
+
+ /* all pages in pagevec ought to be valid */
+ DBG_BUGON(!page);
+ DBG_BUGON(!page->mapping);
+
+ if (z_erofs_put_stagingpage(pagepool, page))
+ continue;
+
+ if (page_type == Z_EROFS_VLE_PAGE_TYPE_HEAD)
+ pagenr = 0;
+ else
+ pagenr = z_erofs_onlinepage_index(page);
+
+ DBG_BUGON(pagenr >= nr_pages);
+ DBG_BUGON(pages[pagenr]);
+
+ pages[pagenr] = page;
+ }
+ z_erofs_pagevec_ctor_exit(&ctor, true);
+
+ overlapped = false;
+ compressed_pages = pcl->compressed_pages;
+
+ err = 0;
+ for (i = 0; i < clusterpages; ++i) {
+ unsigned int pagenr;
+
+ page = compressed_pages[i];
+
+ /* all compressed pages ought to be valid */
+ DBG_BUGON(!page);
+ DBG_BUGON(!page->mapping);
+
+ if (!z_erofs_page_is_staging(page)) {
+ if (erofs_page_is_managed(sbi, page)) {
+ if (unlikely(!PageUptodate(page)))
+ err = -EIO;
+ continue;
+ }
+
+ /*
+ * only if non-head page can be selected
+ * for inplace decompression
+ */
+ pagenr = z_erofs_onlinepage_index(page);
+
+ DBG_BUGON(pagenr >= nr_pages);
+ DBG_BUGON(pages[pagenr]);
+ pages[pagenr] = page;
+
+ overlapped = true;
+ }
+
+ /* PG_error needs checking for inplaced and staging pages */
+ if (unlikely(PageError(page))) {
+ DBG_BUGON(PageUptodate(page));
+ err = -EIO;
+ }
+ }
+
+ if (unlikely(err))
+ goto out;
+
+ llen = pcl->length >> Z_EROFS_PCLUSTER_LENGTH_BIT;
+ if (nr_pages << PAGE_SHIFT >= cl->pageofs + llen) {
+ outputsize = llen;
+ partial = !(pcl->length & Z_EROFS_PCLUSTER_FULL_LENGTH);
+ } else {
+ outputsize = (nr_pages << PAGE_SHIFT) - cl->pageofs;
+ partial = true;
+ }
+
+ err = z_erofs_decompress(&(struct z_erofs_decompress_req) {
+ .sb = sb,
+ .in = compressed_pages,
+ .out = pages,
+ .pageofs_out = cl->pageofs,
+ .inputsize = PAGE_SIZE,
+ .outputsize = outputsize,
+ .alg = pcl->algorithmformat,
+ .inplace_io = overlapped,
+ .partial_decoding = partial
+ }, pagepool);
+
+out:
+ /* must handle all compressed pages before endding pages */
+ for (i = 0; i < clusterpages; ++i) {
+ page = compressed_pages[i];
+
+ if (erofs_page_is_managed(sbi, page))
+ continue;
+
+ /* recycle all individual staging pages */
+ (void)z_erofs_put_stagingpage(pagepool, page);
+
+ WRITE_ONCE(compressed_pages[i], NULL);
+ }
+
+ for (i = 0; i < nr_pages; ++i) {
+ page = pages[i];
+ if (!page)
+ continue;
+
+ DBG_BUGON(!page->mapping);
+
+ /* recycle all individual staging pages */
+ if (z_erofs_put_stagingpage(pagepool, page))
+ continue;
+
+ if (unlikely(err < 0))
+ SetPageError(page);
+
+ z_erofs_onlinepage_endio(page);
+ }
+
+ if (pages == z_pagemap_global)
+ mutex_unlock(&z_pagemap_global_lock);
+ else if (unlikely(pages != pages_onstack))
+ kvfree(pages);
+
+ cl->nr_pages = 0;
+ cl->vcnt = 0;
+
+ /* all cl locks MUST be taken before the following line */
+ WRITE_ONCE(pcl->next, Z_EROFS_PCLUSTER_NIL);
+
+ /* all cl locks SHOULD be released right now */
+ mutex_unlock(&cl->lock);
+
+ z_erofs_collection_put(cl);
+ return err;
+}
+
+static void z_erofs_vle_unzip_all(struct super_block *sb,
+ struct z_erofs_unzip_io *io,
+ struct list_head *pagepool)
+{
+ z_erofs_next_pcluster_t owned = io->head;
+
+ while (owned != Z_EROFS_PCLUSTER_TAIL_CLOSED) {
+ struct z_erofs_pcluster *pcl;
+
+ /* no possible that 'owned' equals Z_EROFS_WORK_TPTR_TAIL */
+ DBG_BUGON(owned == Z_EROFS_PCLUSTER_TAIL);
+
+ /* no possible that 'owned' equals NULL */
+ DBG_BUGON(owned == Z_EROFS_PCLUSTER_NIL);
+
+ pcl = container_of(owned, struct z_erofs_pcluster, next);
+ owned = READ_ONCE(pcl->next);
+
+ z_erofs_decompress_pcluster(sb, pcl, pagepool);
+ }
+}
+
+static void z_erofs_vle_unzip_wq(struct work_struct *work)
+{
+ struct z_erofs_unzip_io_sb *iosb =
+ container_of(work, struct z_erofs_unzip_io_sb, io.u.work);
+ LIST_HEAD(pagepool);
+
+ DBG_BUGON(iosb->io.head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
+ z_erofs_vle_unzip_all(iosb->sb, &iosb->io, &pagepool);
+
+ put_pages_list(&pagepool);
+ kvfree(iosb);
+}
+
+static struct page *pickup_page_for_submission(struct z_erofs_pcluster *pcl,
+ unsigned int nr,
+ struct list_head *pagepool,
+ struct address_space *mc,
+ gfp_t gfp)
+{
+ /* determined at compile time to avoid too many #ifdefs */
+ const bool nocache = __builtin_constant_p(mc) ? !mc : false;
+ const pgoff_t index = pcl->obj.index;
+ bool tocache = false;
+
+ struct address_space *mapping;
+ struct page *oldpage, *page;
+
+ compressed_page_t t;
+ int justfound;
+
+repeat:
+ page = READ_ONCE(pcl->compressed_pages[nr]);
+ oldpage = page;
+
+ if (!page)
+ goto out_allocpage;
+
+ /*
+ * the cached page has not been allocated and
+ * an placeholder is out there, prepare it now.
+ */
+ if (!nocache && page == PAGE_UNALLOCATED) {
+ tocache = true;
+ goto out_allocpage;
+ }
+
+ /* process the target tagged pointer */
+ t = tagptr_init(compressed_page_t, page);
+ justfound = tagptr_unfold_tags(t);
+ page = tagptr_unfold_ptr(t);
+
+ mapping = READ_ONCE(page->mapping);
+
+ /*
+ * if managed cache is disabled, it's no way to
+ * get such a cached-like page.
+ */
+ if (nocache) {
+ /* if managed cache is disabled, it is impossible `justfound' */
+ DBG_BUGON(justfound);
+
+ /* and it should be locked, not uptodate, and not truncated */
+ DBG_BUGON(!PageLocked(page));
+ DBG_BUGON(PageUptodate(page));
+ DBG_BUGON(!mapping);
+ goto out;
+ }
+
+ /*
+ * unmanaged (file) pages are all locked solidly,
+ * therefore it is impossible for `mapping' to be NULL.
+ */
+ if (mapping && mapping != mc)
+ /* ought to be unmanaged pages */
+ goto out;
+
+ lock_page(page);
+
+ /* only true if page reclaim goes wrong, should never happen */
+ DBG_BUGON(justfound && PagePrivate(page));
+
+ /* the page is still in manage cache */
+ if (page->mapping == mc) {
+ WRITE_ONCE(pcl->compressed_pages[nr], page);
+
+ ClearPageError(page);
+ if (!PagePrivate(page)) {
+ /*
+ * impossible to be !PagePrivate(page) for
+ * the current restriction as well if
+ * the page is already in compressed_pages[].
+ */
+ DBG_BUGON(!justfound);
+
+ justfound = 0;
+ set_page_private(page, (unsigned long)pcl);
+ SetPagePrivate(page);
+ }
+
+ /* no need to submit io if it is already up-to-date */
+ if (PageUptodate(page)) {
+ unlock_page(page);
+ page = NULL;
+ }
+ goto out;
+ }
+
+ /*
+ * the managed page has been truncated, it's unsafe to
+ * reuse this one, let's allocate a new cache-managed page.
+ */
+ DBG_BUGON(page->mapping);
+ DBG_BUGON(!justfound);
+
+ tocache = true;
+ unlock_page(page);
+ put_page(page);
+out_allocpage:
+ page = __stagingpage_alloc(pagepool, gfp);
+ if (oldpage != cmpxchg(&pcl->compressed_pages[nr], oldpage, page)) {
+ list_add(&page->lru, pagepool);
+ cpu_relax();
+ goto repeat;
+ }
+ if (nocache || !tocache)
+ goto out;
+ if (add_to_page_cache_lru(page, mc, index + nr, gfp)) {
+ page->mapping = Z_EROFS_MAPPING_STAGING;
+ goto out;
+ }
+
+ set_page_private(page, (unsigned long)pcl);
+ SetPagePrivate(page);
+out: /* the only exit (for tracing and debugging) */
+ return page;
+}
+
+static struct z_erofs_unzip_io *jobqueue_init(struct super_block *sb,
+ struct z_erofs_unzip_io *io,
+ bool foreground)
+{
+ struct z_erofs_unzip_io_sb *iosb;
+
+ if (foreground) {
+ /* waitqueue available for foreground io */
+ DBG_BUGON(!io);
+
+ init_waitqueue_head(&io->u.wait);
+ atomic_set(&io->pending_bios, 0);
+ goto out;
+ }
+
+ iosb = kvzalloc(sizeof(*iosb), GFP_KERNEL | __GFP_NOFAIL);
+ DBG_BUGON(!iosb);
+
+ /* initialize fields in the allocated descriptor */
+ io = &iosb->io;
+ iosb->sb = sb;
+ INIT_WORK(&io->u.work, z_erofs_vle_unzip_wq);
+out:
+ io->head = Z_EROFS_PCLUSTER_TAIL_CLOSED;
+ return io;
+}
+
+/* define decompression jobqueue types */
+enum {
+ JQ_SUBMIT,
+ NR_JOBQUEUES,
+};
+
+static void *jobqueueset_init(struct super_block *sb,
+ z_erofs_next_pcluster_t qtail[],
+ struct z_erofs_unzip_io *q[],
+ struct z_erofs_unzip_io *fgq,
+ bool forcefg)
+{
+ q[JQ_SUBMIT] = jobqueue_init(sb, fgq + JQ_SUBMIT, forcefg);
+ qtail[JQ_SUBMIT] = &q[JQ_SUBMIT]->head;
+
+ return tagptr_cast_ptr(tagptr_fold(tagptr1_t, q[JQ_SUBMIT], !forcefg));
+}
+
+static void move_to_bypass_jobqueue(struct z_erofs_pcluster *pcl,
+ z_erofs_next_pcluster_t qtail[],
+ z_erofs_next_pcluster_t owned_head)
+{
+ /* impossible to bypass submission for managed cache disabled */
+ DBG_BUGON(1);
+}
+
+static bool postsubmit_is_all_bypassed(struct z_erofs_unzip_io *q[],
+ unsigned int nr_bios,
+ bool force_fg)
+{
+ /* bios should be >0 if managed cache is disabled */
+ DBG_BUGON(!nr_bios);
+ return false;
+}
+
+static bool z_erofs_vle_submit_all(struct super_block *sb,
+ z_erofs_next_pcluster_t owned_head,
+ struct list_head *pagepool,
+ struct z_erofs_unzip_io *fgq,
+ bool force_fg)
+{
+ struct erofs_sb_info *const sbi __maybe_unused = EROFS_SB(sb);
+ z_erofs_next_pcluster_t qtail[NR_JOBQUEUES];
+ struct z_erofs_unzip_io *q[NR_JOBQUEUES];
+ struct bio *bio;
+ void *bi_private;
+ /* since bio will be NULL, no need to initialize last_index */
+ pgoff_t uninitialized_var(last_index);
+ bool force_submit = false;
+ unsigned int nr_bios;
+
+ if (unlikely(owned_head == Z_EROFS_PCLUSTER_TAIL))
+ return false;
+
+ force_submit = false;
+ bio = NULL;
+ nr_bios = 0;
+ bi_private = jobqueueset_init(sb, qtail, q, fgq, force_fg);
+
+ /* by default, all need io submission */
+ q[JQ_SUBMIT]->head = owned_head;
+
+ do {
+ struct z_erofs_pcluster *pcl;
+ unsigned int clusterpages;
+ pgoff_t first_index;
+ struct page *page;
+ unsigned int i = 0, bypass = 0;
+ int err;
+
+ /* no possible 'owned_head' equals the following */
+ DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
+ DBG_BUGON(owned_head == Z_EROFS_PCLUSTER_NIL);
+
+ pcl = container_of(owned_head, struct z_erofs_pcluster, next);
+
+ clusterpages = BIT(pcl->clusterbits);
+
+ /* close the main owned chain at first */
+ owned_head = cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
+ Z_EROFS_PCLUSTER_TAIL_CLOSED);
+
+ first_index = pcl->obj.index;
+ force_submit |= (first_index != last_index + 1);
+
+repeat:
+ page = pickup_page_for_submission(pcl, i, pagepool,
+ MNGD_MAPPING(sbi),
+ GFP_NOFS);
+ if (!page) {
+ force_submit = true;
+ ++bypass;
+ goto skippage;
+ }
+
+ if (bio && force_submit) {
+submit_bio_retry:
+ __submit_bio(bio, REQ_OP_READ, 0);
+ bio = NULL;
+ }
+
+ if (!bio) {
+ bio = erofs_grab_bio(sb, first_index + i,
+ BIO_MAX_PAGES, bi_private,
+ z_erofs_vle_read_endio, true);
+ ++nr_bios;
+ }
+
+ err = bio_add_page(bio, page, PAGE_SIZE, 0);
+ if (err < PAGE_SIZE)
+ goto submit_bio_retry;
+
+ force_submit = false;
+ last_index = first_index + i;
+skippage:
+ if (++i < clusterpages)
+ goto repeat;
+
+ if (bypass < clusterpages)
+ qtail[JQ_SUBMIT] = &pcl->next;
+ else
+ move_to_bypass_jobqueue(pcl, qtail, owned_head);
+ } while (owned_head != Z_EROFS_PCLUSTER_TAIL);
+
+ if (bio)
+ __submit_bio(bio, REQ_OP_READ, 0);
+
+ if (postsubmit_is_all_bypassed(q, nr_bios, force_fg))
+ return true;
+
+ z_erofs_vle_unzip_kickoff(bi_private, nr_bios);
+ return true;
+}
+
+static void z_erofs_submit_and_unzip(struct super_block *sb,
+ struct z_erofs_collector *clt,
+ struct list_head *pagepool,
+ bool force_fg)
+{
+ struct z_erofs_unzip_io io[NR_JOBQUEUES];
+
+ if (!z_erofs_vle_submit_all(sb, clt->owned_head,
+ pagepool, io, force_fg))
+ return;
+
+ if (!force_fg)
+ return;
+
+ /* wait until all bios are completed */
+ wait_event(io[JQ_SUBMIT].u.wait,
+ !atomic_read(&io[JQ_SUBMIT].pending_bios));
+
+ /* let's synchronous decompression */
+ z_erofs_vle_unzip_all(sb, &io[JQ_SUBMIT], pagepool);
+}
+
+static int z_erofs_vle_normalaccess_readpage(struct file *file,
+ struct page *page)
+{
+ struct inode *const inode = page->mapping->host;
+ struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
+ int err;
+ LIST_HEAD(pagepool);
+
+ trace_erofs_readpage(page, false);
+
+ f.headoffset = (erofs_off_t)page->index << PAGE_SHIFT;
+
+ err = z_erofs_do_read_page(&f, page, &pagepool);
+ (void)z_erofs_collector_end(&f.clt);
+
+ if (err) {
+ errln("%s, failed to read, err [%d]", __func__, err);
+ goto out;
+ }
+
+ z_erofs_submit_and_unzip(inode->i_sb, &f.clt, &pagepool, true);
+out:
+ if (f.map.mpage)
+ put_page(f.map.mpage);
+
+ /* clean up the remaining free pages */
+ put_pages_list(&pagepool);
+ return 0;
+}
+
+static bool should_decompress_synchronously(struct erofs_sb_info *sbi,
+ unsigned int nr)
+{
+ return nr <= sbi->max_sync_decompress_pages;
+}
+
+static int z_erofs_vle_normalaccess_readpages(struct file *filp,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned int nr_pages)
+{
+ struct inode *const inode = mapping->host;
+ struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
+
+ bool sync = should_decompress_synchronously(sbi, nr_pages);
+ struct z_erofs_decompress_frontend f = DECOMPRESS_FRONTEND_INIT(inode);
+ gfp_t gfp = mapping_gfp_constraint(mapping, GFP_KERNEL);
+ struct page *head = NULL;
+ LIST_HEAD(pagepool);
+
+ trace_erofs_readpages(mapping->host, lru_to_page(pages),
+ nr_pages, false);
+
+ f.headoffset = (erofs_off_t)lru_to_page(pages)->index << PAGE_SHIFT;
+
+ for (; nr_pages; --nr_pages) {
+ struct page *page = lru_to_page(pages);
+
+ prefetchw(&page->flags);
+ list_del(&page->lru);
+
+ /*
+ * A pure asynchronous readahead is indicated if
+ * a PG_readahead marked page is hitted at first.
+ * Let's also do asynchronous decompression for this case.
+ */
+ sync &= !(PageReadahead(page) && !head);
+
+ if (add_to_page_cache_lru(page, mapping, page->index, gfp)) {
+ list_add(&page->lru, &pagepool);
+ continue;
+ }
+
+ set_page_private(page, (unsigned long)head);
+ head = page;
+ }
+
+ while (head) {
+ struct page *page = head;
+ int err;
+
+ /* traversal in reverse order */
+ head = (void *)page_private(page);
+
+ err = z_erofs_do_read_page(&f, page, &pagepool);
+ if (err) {
+ struct erofs_vnode *vi = EROFS_V(inode);
+
+ errln("%s, readahead error at page %lu of nid %llu",
+ __func__, page->index, vi->nid);
+ }
+ put_page(page);
+ }
+
+ (void)z_erofs_collector_end(&f.clt);
+
+ z_erofs_submit_and_unzip(inode->i_sb, &f.clt, &pagepool, sync);
+
+ if (f.map.mpage)
+ put_page(f.map.mpage);
+
+ /* clean up the remaining free pages */
+ put_pages_list(&pagepool);
+ return 0;
+}
+
+const struct address_space_operations z_erofs_vle_normalaccess_aops = {
+ .readpage = z_erofs_vle_normalaccess_readpage,
+ .readpages = z_erofs_vle_normalaccess_readpages,
+};
+
diff --git a/fs/erofs/zdata.h b/fs/erofs/zdata.h
new file mode 100644
index 000000000000..53297d1811dd
--- /dev/null
+++ b/fs/erofs/zdata.h
@@ -0,0 +1,192 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/erofs/zdata.h
+ *
+ * Copyright (C) 2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#ifndef __EROFS_FS_UNZIP_VLE_H
+#define __EROFS_FS_UNZIP_VLE_H
+
+#include "internal.h"
+#include "zpvec.h"
+
+#define Z_EROFS_NR_INLINE_PAGEVECS 3
+
+/*
+ * Structure fields follow one of the following exclusion rules.
+ *
+ * I: Modifiable by initialization/destruction paths and read-only
+ * for everyone else;
+ *
+ * L: Field protected by pageset lock;
+ *
+ * A: Field accessed / updated in atomic.
+ */
+struct z_erofs_collection {
+ struct mutex lock;
+
+ /* I: page offset of start position of decompression */
+ unsigned short pageofs;
+
+ /* L: maximum relative page index in pagevec[] */
+ unsigned short nr_pages;
+
+ /* L: total number of pages in pagevec[] */
+ unsigned int vcnt;
+
+ union {
+ /* L: inline a certain number of pagevecs for bootstrap */
+ erofs_vtptr_t pagevec[Z_EROFS_NR_INLINE_PAGEVECS];
+
+ /* I: can be used to free the pcluster by RCU. */
+ struct rcu_head rcu;
+ };
+};
+
+#define Z_EROFS_PCLUSTER_FULL_LENGTH 0x00000001
+#define Z_EROFS_PCLUSTER_LENGTH_BIT 1
+
+/*
+ * let's leave a type here in case of introducing
+ * another tagged pointer later.
+ */
+typedef void *z_erofs_next_pcluster_t;
+
+struct z_erofs_pcluster {
+ struct erofs_workgroup obj;
+ struct z_erofs_collection primary_collection;
+
+ /* point to next chained pcluster or TAILs */
+ z_erofs_next_pcluster_t next;
+
+ /* compressed pages (including multi-usage pages) */
+ struct page *compressed_pages[Z_EROFS_CLUSTER_MAX_PAGES];
+
+ /* A: lower limit of decompressed length and if full length or not */
+ unsigned int length;
+
+ /* I: compression algorithm format */
+ unsigned char algorithmformat;
+ /* I: bit shift of physical cluster size */
+ unsigned char clusterbits;
+};
+
+#define z_erofs_primarycollection(pcluster) (&(pcluster)->primary_collection)
+
+/* let's avoid the valid 32-bit kernel addresses */
+
+/* the chained workgroup has't submitted io (still open) */
+#define Z_EROFS_PCLUSTER_TAIL ((void *)0x5F0ECAFE)
+/* the chained workgroup has already submitted io */
+#define Z_EROFS_PCLUSTER_TAIL_CLOSED ((void *)0x5F0EDEAD)
+
+#define Z_EROFS_PCLUSTER_NIL (NULL)
+
+#define Z_EROFS_WORKGROUP_SIZE sizeof(struct z_erofs_pcluster)
+
+struct z_erofs_unzip_io {
+ atomic_t pending_bios;
+ z_erofs_next_pcluster_t head;
+
+ union {
+ wait_queue_head_t wait;
+ struct work_struct work;
+ } u;
+};
+
+struct z_erofs_unzip_io_sb {
+ struct z_erofs_unzip_io io;
+ struct super_block *sb;
+};
+
+#define MNGD_MAPPING(sbi) (NULL)
+static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
+ struct page *page) { return false; }
+
+#define Z_EROFS_ONLINEPAGE_COUNT_BITS 2
+#define Z_EROFS_ONLINEPAGE_COUNT_MASK ((1 << Z_EROFS_ONLINEPAGE_COUNT_BITS) - 1)
+#define Z_EROFS_ONLINEPAGE_INDEX_SHIFT (Z_EROFS_ONLINEPAGE_COUNT_BITS)
+
+/*
+ * waiters (aka. ongoing_packs): # to unlock the page
+ * sub-index: 0 - for partial page, >= 1 full page sub-index
+ */
+typedef atomic_t z_erofs_onlinepage_t;
+
+/* type punning */
+union z_erofs_onlinepage_converter {
+ z_erofs_onlinepage_t *o;
+ unsigned long *v;
+};
+
+static inline unsigned z_erofs_onlinepage_index(struct page *page)
+{
+ union z_erofs_onlinepage_converter u;
+
+ DBG_BUGON(!PagePrivate(page));
+ u.v = &page_private(page);
+
+ return atomic_read(u.o) >> Z_EROFS_ONLINEPAGE_INDEX_SHIFT;
+}
+
+static inline void z_erofs_onlinepage_init(struct page *page)
+{
+ union {
+ z_erofs_onlinepage_t o;
+ unsigned long v;
+ /* keep from being unlocked in advance */
+ } u = { .o = ATOMIC_INIT(1) };
+
+ set_page_private(page, u.v);
+ smp_wmb();
+ SetPagePrivate(page);
+}
+
+static inline void z_erofs_onlinepage_fixup(struct page *page,
+ uintptr_t index, bool down)
+{
+ unsigned long *p, o, v, id;
+repeat:
+ p = &page_private(page);
+ o = READ_ONCE(*p);
+
+ id = o >> Z_EROFS_ONLINEPAGE_INDEX_SHIFT;
+ if (id) {
+ if (!index)
+ return;
+
+ DBG_BUGON(id != index);
+ }
+
+ v = (index << Z_EROFS_ONLINEPAGE_INDEX_SHIFT) |
+ ((o & Z_EROFS_ONLINEPAGE_COUNT_MASK) + (unsigned)down);
+ if (cmpxchg(p, o, v) != o)
+ goto repeat;
+}
+
+static inline void z_erofs_onlinepage_endio(struct page *page)
+{
+ union z_erofs_onlinepage_converter u;
+ unsigned v;
+
+ DBG_BUGON(!PagePrivate(page));
+ u.v = &page_private(page);
+
+ v = atomic_dec_return(u.o);
+ if (!(v & Z_EROFS_ONLINEPAGE_COUNT_MASK)) {
+ ClearPagePrivate(page);
+ if (!PageError(page))
+ SetPageUptodate(page);
+ unlock_page(page);
+ }
+ debugln("%s, page %p value %x", __func__, page, atomic_read(u.o));
+}
+
+#define Z_EROFS_VMAP_ONSTACK_PAGES \
+ min_t(unsigned int, THREAD_SIZE / 8 / sizeof(struct page *), 96U)
+#define Z_EROFS_VMAP_GLOBAL_PAGES 2048
+
+#endif
+
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 006f09ce83a1..61e18322d804 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -23,7 +23,9 @@ int z_erofs_fill_inode(struct inode *inode)
vi->z_physical_clusterbits[1] = vi->z_logical_clusterbits;
set_bit(EROFS_V_Z_INITED_BIT, &vi->flags);
}
- return -ENOTSUPP;
+
+ inode->i_mapping->a_ops = &z_erofs_vle_normalaccess_aops;
+ return 0;
}
static int fill_inode_lazy(struct inode *inode)
--
2.17.1
This patch adds to support special inode, such as
block dev, char, socket, pipe inode.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/inode.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 79ef5b38dfa3..5a95cd076fcc 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -34,7 +34,16 @@ static int read_inode(struct inode *inode, void *data)
vi->xattr_isize = ondisk_xattr_ibody_size(v2->i_xattr_icount);
inode->i_mode = le16_to_cpu(v2->i_mode);
- vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
+ if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode))
+ vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
+ else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+ inode->i_rdev =
+ new_decode_dev(le32_to_cpu(v2->i_u.rdev));
+ else if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode))
+ inode->i_rdev = 0;
+ else
+ return -EIO;
i_uid_write(inode, le32_to_cpu(v2->i_uid));
i_gid_write(inode, le32_to_cpu(v2->i_gid));
@@ -58,7 +67,16 @@ static int read_inode(struct inode *inode, void *data)
vi->xattr_isize = ondisk_xattr_ibody_size(v1->i_xattr_icount);
inode->i_mode = le16_to_cpu(v1->i_mode);
- vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
+ if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode))
+ vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
+ else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
+ inode->i_rdev =
+ new_decode_dev(le32_to_cpu(v1->i_u.rdev));
+ else if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode))
+ inode->i_rdev = 0;
+ else
+ return -EIO;
i_uid_write(inode, le16_to_cpu(v1->i_uid));
i_gid_write(inode, le16_to_cpu(v1->i_gid));
@@ -176,6 +194,11 @@ static int fill_inode(struct inode *inode, int isdir)
/* by default, page_get_link is used for symlink */
inode->i_op = &erofs_symlink_iops;
inode_nohighmem(inode);
+ } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+ S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
+ inode->i_op = &erofs_generic_iops;
+ init_special_inode(inode, inode->i_mode, inode->i_rdev);
+ goto out_unlock;
} else {
err = -EIO;
goto out_unlock;
--
2.17.1
This commit adds functions for meta and raw data, and also
provides address_space_operations for raw data access.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/data.c | 390 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 390 insertions(+)
create mode 100644 fs/erofs/data.c
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
new file mode 100644
index 000000000000..1a818abeee3d
--- /dev/null
+++ b/fs/erofs/data.c
@@ -0,0 +1,390 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/data.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "internal.h"
+#include <linux/prefetch.h>
+
+#include <trace/events/erofs.h>
+
+static inline void read_endio(struct bio *bio)
+{
+ struct super_block *const sb = bio->bi_private;
+ struct bio_vec *bvec;
+ blk_status_t err = bio->bi_status;
+ struct bvec_iter_all iter_all;
+
+ if (time_to_inject(EROFS_SB(sb), FAULT_READ_IO)) {
+ erofs_show_injection_info(FAULT_READ_IO);
+ err = BLK_STS_IOERR;
+ }
+
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ struct page *page = bvec->bv_page;
+
+ /* page is already locked */
+ DBG_BUGON(PageUptodate(page));
+
+ if (unlikely(err))
+ SetPageError(page);
+ else
+ SetPageUptodate(page);
+
+ unlock_page(page);
+ /* page could be reclaimed now */
+ }
+ bio_put(bio);
+}
+
+/* prio -- true is used for dir */
+struct page *__erofs_get_meta_page(struct super_block *sb,
+ erofs_blk_t blkaddr, bool prio, bool nofail)
+{
+ struct inode *const bd_inode = sb->s_bdev->bd_inode;
+ struct address_space *const mapping = bd_inode->i_mapping;
+ /* prefer retrying in the allocator to blindly looping below */
+ const gfp_t gfp = mapping_gfp_constraint(mapping, ~__GFP_FS) |
+ (nofail ? __GFP_NOFAIL : 0);
+ unsigned int io_retries = nofail ? EROFS_IO_MAX_RETRIES_NOFAIL : 0;
+ struct page *page;
+ int err;
+
+repeat:
+ page = find_or_create_page(mapping, blkaddr, gfp);
+ if (unlikely(!page)) {
+ DBG_BUGON(nofail);
+ return ERR_PTR(-ENOMEM);
+ }
+ DBG_BUGON(!PageLocked(page));
+
+ if (!PageUptodate(page)) {
+ struct bio *bio;
+
+ bio = erofs_grab_bio(sb, blkaddr, 1, sb, read_endio, nofail);
+ if (IS_ERR(bio)) {
+ DBG_BUGON(nofail);
+ err = PTR_ERR(bio);
+ goto err_out;
+ }
+
+ err = bio_add_page(bio, page, PAGE_SIZE, 0);
+ if (unlikely(err != PAGE_SIZE)) {
+ err = -EFAULT;
+ goto err_out;
+ }
+
+ __submit_bio(bio, REQ_OP_READ,
+ REQ_META | (prio ? REQ_PRIO : 0));
+
+ lock_page(page);
+
+ /* this page has been truncated by others */
+ if (unlikely(page->mapping != mapping)) {
+unlock_repeat:
+ unlock_page(page);
+ put_page(page);
+ goto repeat;
+ }
+
+ /* more likely a read error */
+ if (unlikely(!PageUptodate(page))) {
+ if (io_retries) {
+ --io_retries;
+ goto unlock_repeat;
+ }
+ err = -EIO;
+ goto err_out;
+ }
+ }
+ return page;
+
+err_out:
+ unlock_page(page);
+ put_page(page);
+ return ERR_PTR(err);
+}
+
+static int erofs_map_blocks_flatmode(struct inode *inode,
+ struct erofs_map_blocks *map,
+ int flags)
+{
+ int err = 0;
+ erofs_blk_t nblocks, lastblk;
+ u64 offset = map->m_la;
+ struct erofs_vnode *vi = EROFS_V(inode);
+
+ trace_erofs_map_blocks_flatmode_enter(inode, map, flags);
+
+ nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
+ lastblk = nblocks - is_inode_flat_inline(inode);
+
+ if (unlikely(offset >= inode->i_size)) {
+ /* leave out-of-bound access unmapped */
+ map->m_flags = 0;
+ map->m_plen = 0;
+ goto out;
+ }
+
+ /* there is no hole in flatmode */
+ map->m_flags = EROFS_MAP_MAPPED;
+
+ if (offset < blknr_to_addr(lastblk)) {
+ map->m_pa = blknr_to_addr(vi->raw_blkaddr) + map->m_la;
+ map->m_plen = blknr_to_addr(lastblk) - offset;
+ } else if (is_inode_flat_inline(inode)) {
+ /* 2 - inode inline B: inode, [xattrs], inline last blk... */
+ struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+
+ map->m_pa = iloc(sbi, vi->nid) + vi->inode_isize +
+ vi->xattr_isize + erofs_blkoff(map->m_la);
+ map->m_plen = inode->i_size - offset;
+
+ /* inline data should locate in one meta block */
+ if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
+ DBG_BUGON(1);
+ err = -EIO;
+ goto err_out;
+ }
+
+ map->m_flags |= EROFS_MAP_META;
+ } else {
+ errln("internal error @ nid: %llu (size %llu), m_la 0x%llx",
+ vi->nid, inode->i_size, map->m_la);
+ DBG_BUGON(1);
+ err = -EIO;
+ goto err_out;
+ }
+
+out:
+ map->m_llen = map->m_plen;
+
+err_out:
+ trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
+ return err;
+}
+
+int erofs_map_blocks(struct inode *inode,
+ struct erofs_map_blocks *map, int flags)
+{
+ if (is_inode_layout_compression(inode))
+ return -ENOTSUPP;
+
+ return erofs_map_blocks_flatmode(inode, map, flags);
+}
+
+static inline struct bio *erofs_read_raw_page(struct bio *bio,
+ struct address_space *mapping,
+ struct page *page,
+ erofs_off_t *last_block,
+ unsigned int nblocks,
+ bool ra)
+{
+ struct inode *const inode = mapping->host;
+ struct super_block *const sb = inode->i_sb;
+ erofs_off_t current_block = (erofs_off_t)page->index;
+ int err;
+
+ DBG_BUGON(!nblocks);
+
+ if (PageUptodate(page)) {
+ err = 0;
+ goto has_updated;
+ }
+
+ if (cleancache_get_page(page) == 0) {
+ err = 0;
+ SetPageUptodate(page);
+ goto has_updated;
+ }
+
+ /* note that for readpage case, bio also equals to NULL */
+ if (bio &&
+ /* not continuous */
+ *last_block + 1 != current_block) {
+submit_bio_retry:
+ __submit_bio(bio, REQ_OP_READ, 0);
+ bio = NULL;
+ }
+
+ if (!bio) {
+ struct erofs_map_blocks map = {
+ .m_la = blknr_to_addr(current_block),
+ };
+ erofs_blk_t blknr;
+ unsigned int blkoff;
+
+ err = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
+ if (unlikely(err))
+ goto err_out;
+
+ /* zero out the holed page */
+ if (unlikely(!(map.m_flags & EROFS_MAP_MAPPED))) {
+ zero_user_segment(page, 0, PAGE_SIZE);
+ SetPageUptodate(page);
+
+ /* imply err = 0, see erofs_map_blocks */
+ goto has_updated;
+ }
+
+ /* for RAW access mode, m_plen must be equal to m_llen */
+ DBG_BUGON(map.m_plen != map.m_llen);
+
+ blknr = erofs_blknr(map.m_pa);
+ blkoff = erofs_blkoff(map.m_pa);
+
+ /* deal with inline page */
+ if (map.m_flags & EROFS_MAP_META) {
+ void *vsrc, *vto;
+ struct page *ipage;
+
+ DBG_BUGON(map.m_plen > PAGE_SIZE);
+
+ ipage = erofs_get_meta_page(inode->i_sb, blknr, 0);
+
+ if (IS_ERR(ipage)) {
+ err = PTR_ERR(ipage);
+ goto err_out;
+ }
+
+ vsrc = kmap_atomic(ipage);
+ vto = kmap_atomic(page);
+ memcpy(vto, vsrc + blkoff, map.m_plen);
+ memset(vto + map.m_plen, 0, PAGE_SIZE - map.m_plen);
+ kunmap_atomic(vto);
+ kunmap_atomic(vsrc);
+ flush_dcache_page(page);
+
+ SetPageUptodate(page);
+ /* TODO: could we unlock the page earlier? */
+ unlock_page(ipage);
+ put_page(ipage);
+
+ /* imply err = 0, see erofs_map_blocks */
+ goto has_updated;
+ }
+
+ /* pa must be block-aligned for raw reading */
+ DBG_BUGON(erofs_blkoff(map.m_pa));
+
+ /* max # of continuous pages */
+ if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE))
+ nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE);
+ if (nblocks > BIO_MAX_PAGES)
+ nblocks = BIO_MAX_PAGES;
+
+ bio = erofs_grab_bio(sb, blknr, nblocks, sb,
+ read_endio, false);
+ if (IS_ERR(bio)) {
+ err = PTR_ERR(bio);
+ bio = NULL;
+ goto err_out;
+ }
+ }
+
+ err = bio_add_page(bio, page, PAGE_SIZE, 0);
+ /* out of the extent or bio is full */
+ if (err < PAGE_SIZE)
+ goto submit_bio_retry;
+
+ *last_block = current_block;
+
+ /* shift in advance in case of it followed by too many gaps */
+ if (bio->bi_iter.bi_size >= bio->bi_max_vecs * PAGE_SIZE) {
+ /* err should reassign to 0 after submitting */
+ err = 0;
+ goto submit_bio_out;
+ }
+
+ return bio;
+
+err_out:
+ /* for sync reading, set page error immediately */
+ if (!ra) {
+ SetPageError(page);
+ ClearPageUptodate(page);
+ }
+has_updated:
+ unlock_page(page);
+
+ /* if updated manually, continuous pages has a gap */
+ if (bio)
+submit_bio_out:
+ __submit_bio(bio, REQ_OP_READ, 0);
+
+ return unlikely(err) ? ERR_PTR(err) : NULL;
+}
+
+/*
+ * since we dont have write or truncate flows, so no inode
+ * locking needs to be held at the moment.
+ */
+static int erofs_raw_access_readpage(struct file *file, struct page *page)
+{
+ erofs_off_t last_block;
+ struct bio *bio;
+
+ trace_erofs_readpage(page, true);
+
+ bio = erofs_read_raw_page(NULL, page->mapping,
+ page, &last_block, 1, false);
+
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ DBG_BUGON(bio); /* since we have only one bio -- must be NULL */
+ return 0;
+}
+
+static int erofs_raw_access_readpages(struct file *filp,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned int nr_pages)
+{
+ erofs_off_t last_block;
+ struct bio *bio = NULL;
+ gfp_t gfp = readahead_gfp_mask(mapping);
+ struct page *page = list_last_entry(pages, struct page, lru);
+
+ trace_erofs_readpages(mapping->host, page, nr_pages, true);
+
+ for (; nr_pages; --nr_pages) {
+ page = list_entry(pages->prev, struct page, lru);
+
+ prefetchw(&page->flags);
+ list_del(&page->lru);
+
+ if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) {
+ bio = erofs_read_raw_page(bio, mapping, page,
+ &last_block, nr_pages, true);
+
+ /* all the page errors are ignored when readahead */
+ if (IS_ERR(bio)) {
+ pr_err("%s, readahead error at page %lu of nid %llu\n",
+ __func__, page->index,
+ EROFS_V(mapping->host)->nid);
+
+ bio = NULL;
+ }
+ }
+
+ /* pages could still be locked */
+ put_page(page);
+ }
+ DBG_BUGON(!list_empty(pages));
+
+ /* the rare case (end in gaps) */
+ if (unlikely(bio))
+ __submit_bio(bio, REQ_OP_READ, 0);
+ return 0;
+}
+
+/* for uncompressed (aligned) files and raw access for other files */
+const struct address_space_operations erofs_raw_access_aops = {
+ .readpage = erofs_raw_access_readpage,
+ .readpages = erofs_raw_access_readpages,
+};
+
--
2.17.1
This commit adds erofs super block operations, including (u)mount,
remount_fs, show_options, statfs, in addition to some private
icache management functions.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/super.c | 502 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 502 insertions(+)
create mode 100644 fs/erofs/super.c
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
new file mode 100644
index 000000000000..d83e55bdd4a8
--- /dev/null
+++ b/fs/erofs/super.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/super.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include <linux/module.h>
+#include <linux/buffer_head.h>
+#include <linux/statfs.h>
+#include <linux/parser.h>
+#include <linux/seq_file.h>
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/erofs.h>
+
+static struct kmem_cache *erofs_inode_cachep __read_mostly;
+
+static void init_once(void *ptr)
+{
+ struct erofs_vnode *vi = ptr;
+
+ inode_init_once(&vi->vfs_inode);
+}
+
+static int __init erofs_init_inode_cache(void)
+{
+ erofs_inode_cachep = kmem_cache_create("erofs_inode",
+ sizeof(struct erofs_vnode), 0,
+ SLAB_RECLAIM_ACCOUNT,
+ init_once);
+
+ return erofs_inode_cachep ? 0 : -ENOMEM;
+}
+
+static void erofs_exit_inode_cache(void)
+{
+ kmem_cache_destroy(erofs_inode_cachep);
+}
+
+static struct inode *alloc_inode(struct super_block *sb)
+{
+ struct erofs_vnode *vi =
+ kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
+
+ if (!vi)
+ return NULL;
+
+ /* zero out everything except vfs_inode */
+ memset(vi, 0, offsetof(struct erofs_vnode, vfs_inode));
+ return &vi->vfs_inode;
+}
+
+static void free_inode(struct inode *inode)
+{
+ struct erofs_vnode *vi = EROFS_V(inode);
+
+ /* be careful RCU symlink path (see ext4_inode_info->i_data)! */
+ if (is_inode_fast_symlink(inode))
+ kfree(inode->i_link);
+
+ kmem_cache_free(erofs_inode_cachep, vi);
+}
+
+static bool check_layout_compatibility(struct super_block *sb,
+ struct erofs_super_block *layout)
+{
+ const unsigned int requirements = le32_to_cpu(layout->requirements);
+
+ EROFS_SB(sb)->requirements = requirements;
+
+ /* check if current kernel meets all mandatory requirements */
+ if (requirements & (~EROFS_ALL_REQUIREMENTS)) {
+ errln("unidentified requirements %x, please upgrade kernel version",
+ requirements & ~EROFS_ALL_REQUIREMENTS);
+ return false;
+ }
+ return true;
+}
+
+static int superblock_read(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi;
+ struct buffer_head *bh;
+ struct erofs_super_block *layout;
+ unsigned int blkszbits;
+ int ret;
+
+ bh = sb_bread(sb, 0);
+
+ if (!bh) {
+ errln("cannot read erofs superblock");
+ return -EIO;
+ }
+
+ sbi = EROFS_SB(sb);
+ layout = (struct erofs_super_block *)((u8 *)bh->b_data
+ + EROFS_SUPER_OFFSET);
+
+ ret = -EINVAL;
+ if (le32_to_cpu(layout->magic) != EROFS_SUPER_MAGIC_V1) {
+ errln("cannot find valid erofs superblock");
+ goto out;
+ }
+
+ blkszbits = layout->blkszbits;
+ /* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
+ if (unlikely(blkszbits != LOG_BLOCK_SIZE)) {
+ errln("blksize %u isn't supported on this platform",
+ 1 << blkszbits);
+ goto out;
+ }
+
+ if (!check_layout_compatibility(sb, layout))
+ goto out;
+
+ sbi->blocks = le32_to_cpu(layout->blocks);
+ sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
+ sbi->islotbits = ffs(sizeof(struct erofs_inode_v1)) - 1;
+ sbi->root_nid = le16_to_cpu(layout->root_nid);
+ sbi->inos = le64_to_cpu(layout->inos);
+
+ sbi->build_time = le64_to_cpu(layout->build_time);
+ sbi->build_time_nsec = le32_to_cpu(layout->build_time_nsec);
+
+ memcpy(&sb->s_uuid, layout->uuid, sizeof(layout->uuid));
+ memcpy(sbi->volume_name, layout->volume_name,
+ sizeof(layout->volume_name));
+
+ ret = 0;
+out:
+ brelse(bh);
+ return ret;
+}
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+const char *erofs_fault_name[FAULT_MAX] = {
+ [FAULT_KMALLOC] = "kmalloc",
+ [FAULT_READ_IO] = "read IO error",
+};
+
+static void __erofs_build_fault_attr(struct erofs_sb_info *sbi,
+ unsigned int rate)
+{
+ struct erofs_fault_info *ffi = &sbi->fault_info;
+
+ if (rate) {
+ atomic_set(&ffi->inject_ops, 0);
+ ffi->inject_rate = rate;
+ ffi->inject_type = (1 << FAULT_MAX) - 1;
+ } else {
+ memset(ffi, 0, sizeof(struct erofs_fault_info));
+ }
+
+ set_opt(sbi, FAULT_INJECTION);
+}
+
+static int erofs_build_fault_attr(struct erofs_sb_info *sbi,
+ substring_t *args)
+{
+ int rate = 0;
+
+ if (args->from && match_int(args, &rate))
+ return -EINVAL;
+
+ __erofs_build_fault_attr(sbi, rate);
+ return 0;
+}
+
+static unsigned int erofs_get_fault_rate(struct erofs_sb_info *sbi)
+{
+ return sbi->fault_info.inject_rate;
+}
+#else
+static void __erofs_build_fault_attr(struct erofs_sb_info *sbi,
+ unsigned int rate)
+{
+}
+
+static int erofs_build_fault_attr(struct erofs_sb_info *sbi,
+ substring_t *args)
+{
+ infoln("fault_injection options not supported");
+ return 0;
+}
+
+static unsigned int erofs_get_fault_rate(struct erofs_sb_info *sbi)
+{
+ return 0;
+}
+#endif
+
+/* set up default EROFS parameters */
+static void default_options(struct erofs_sb_info *sbi)
+{
+}
+
+enum {
+ Opt_fault_injection,
+ Opt_err
+};
+
+static match_table_t erofs_tokens = {
+ {Opt_fault_injection, "fault_injection=%u"},
+ {Opt_err, NULL}
+};
+
+static int parse_options(struct super_block *sb, char *options)
+{
+ substring_t args[MAX_OPT_ARGS];
+ char *p;
+ int err;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ","))) {
+ int token;
+
+ if (!*p)
+ continue;
+
+ args[0].to = args[0].from = NULL;
+ token = match_token(p, erofs_tokens, args);
+
+ switch (token) {
+ case Opt_fault_injection:
+ err = erofs_build_fault_attr(EROFS_SB(sb), args);
+ if (err)
+ return err;
+ break;
+
+ default:
+ errln("Unrecognized mount option \"%s\" or missing value", p);
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static int erofs_read_super(struct super_block *sb,
+ const char *dev_name,
+ void *data, int silent)
+{
+ struct inode *inode;
+ struct erofs_sb_info *sbi;
+ int err = -EINVAL;
+
+ infoln("read_super, device -> %s", dev_name);
+ infoln("options -> %s", (char *)data);
+
+ if (unlikely(!sb_set_blocksize(sb, EROFS_BLKSIZ))) {
+ errln("failed to set erofs blksize");
+ goto err;
+ }
+
+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+ if (unlikely(!sbi)) {
+ err = -ENOMEM;
+ goto err;
+ }
+ sb->s_fs_info = sbi;
+
+ err = superblock_read(sb);
+ if (err)
+ goto err_sbread;
+
+ sb->s_magic = EROFS_SUPER_MAGIC;
+ sb->s_flags |= SB_RDONLY | SB_NOATIME;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_time_gran = 1;
+
+ sb->s_op = &erofs_sops;
+
+ /* set erofs default mount options */
+ default_options(sbi);
+
+ err = parse_options(sb, data);
+ if (err)
+ goto err_parseopt;
+
+ if (!silent)
+ infoln("root inode @ nid %llu", ROOT_NID(sbi));
+
+ /* get the root inode */
+ inode = erofs_iget(sb, ROOT_NID(sbi), true);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto err_iget;
+ }
+
+ if (!S_ISDIR(inode->i_mode)) {
+ errln("rootino(nid %llu) is not a directory(i_mode %o)",
+ ROOT_NID(sbi), inode->i_mode);
+ err = -EINVAL;
+ iput(inode);
+ goto err_iget;
+ }
+
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root) {
+ err = -ENOMEM;
+ goto err_iget;
+ }
+
+ /* save the device name to sbi */
+ sbi->dev_name = __getname();
+ if (!sbi->dev_name) {
+ err = -ENOMEM;
+ goto err_devname;
+ }
+
+ snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
+ sbi->dev_name[PATH_MAX - 1] = '\0';
+
+ if (!silent)
+ infoln("mounted on %s with opts: %s.", dev_name,
+ (char *)data);
+ return 0;
+ /*
+ * please add a label for each exit point and use
+ * the following name convention, thus new features
+ * can be integrated easily without renaming labels.
+ */
+err_devname:
+ dput(sb->s_root);
+ sb->s_root = NULL;
+err_iget:
+err_parseopt:
+err_sbread:
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+err:
+ return err;
+}
+
+/*
+ * could be triggered after deactivate_locked_super()
+ * is called, thus including umount and failed to initialize.
+ */
+static void erofs_put_super(struct super_block *sb)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+
+ /* for cases which are failed in "read_super" */
+ if (!sbi)
+ return;
+
+ WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
+
+ infoln("unmounted for %s", sbi->dev_name);
+ __putname(sbi->dev_name);
+
+ kfree(sbi);
+ sb->s_fs_info = NULL;
+}
+
+
+struct erofs_mount_private {
+ const char *dev_name;
+ char *options;
+};
+
+/* support mount_bdev() with options */
+static int erofs_fill_super(struct super_block *sb,
+ void *_priv, int silent)
+{
+ struct erofs_mount_private *priv = _priv;
+
+ return erofs_read_super(sb, priv->dev_name,
+ priv->options, silent);
+}
+
+static struct dentry *erofs_mount(
+ struct file_system_type *fs_type, int flags,
+ const char *dev_name, void *data)
+{
+ struct erofs_mount_private priv = {
+ .dev_name = dev_name,
+ .options = data
+ };
+
+ return mount_bdev(fs_type, flags, dev_name,
+ &priv, erofs_fill_super);
+}
+
+static void erofs_kill_sb(struct super_block *sb)
+{
+ kill_block_super(sb);
+}
+
+static struct file_system_type erofs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "erofs",
+ .mount = erofs_mount,
+ .kill_sb = erofs_kill_sb,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+MODULE_ALIAS_FS("erofs");
+
+static int __init erofs_module_init(void)
+{
+ int err;
+
+ erofs_check_ondisk_layout_definitions();
+ infoln("initializing erofs " EROFS_VERSION);
+
+ err = erofs_init_inode_cache();
+ if (err)
+ goto icache_err;
+
+ err = register_filesystem(&erofs_fs_type);
+ if (err)
+ goto fs_err;
+
+ infoln("successfully to initialize erofs");
+ return 0;
+
+fs_err:
+ erofs_exit_inode_cache();
+icache_err:
+ return err;
+}
+
+static void __exit erofs_module_exit(void)
+{
+ unregister_filesystem(&erofs_fs_type);
+ erofs_exit_inode_cache();
+ infoln("successfully finalize erofs");
+}
+
+/* get filesystem statistics */
+static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct super_block *sb = dentry->d_sb;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+ buf->f_type = sb->s_magic;
+ buf->f_bsize = EROFS_BLKSIZ;
+ buf->f_blocks = sbi->blocks;
+ buf->f_bfree = buf->f_bavail = 0;
+
+ buf->f_files = ULLONG_MAX;
+ buf->f_ffree = ULLONG_MAX - sbi->inos;
+
+ buf->f_namelen = EROFS_NAME_LEN;
+
+ buf->f_fsid.val[0] = (u32)id;
+ buf->f_fsid.val[1] = (u32)(id >> 32);
+ return 0;
+}
+
+static int erofs_show_options(struct seq_file *seq, struct dentry *root)
+{
+ struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb);
+
+ if (test_opt(sbi, FAULT_INJECTION))
+ seq_printf(seq, ",fault_injection=%u",
+ erofs_get_fault_rate(sbi));
+ return 0;
+}
+
+static int erofs_remount(struct super_block *sb, int *flags, char *data)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ unsigned int org_mnt_opt = sbi->mount_opt;
+ unsigned int org_inject_rate = erofs_get_fault_rate(sbi);
+ int err;
+
+ DBG_BUGON(!sb_rdonly(sb));
+ err = parse_options(sb, data);
+ if (err)
+ goto out;
+
+ *flags |= SB_RDONLY;
+ return 0;
+out:
+ __erofs_build_fault_attr(sbi, org_inject_rate);
+ sbi->mount_opt = org_mnt_opt;
+
+ return err;
+}
+
+const struct super_operations erofs_sops = {
+ .put_super = erofs_put_super,
+ .alloc_inode = alloc_inode,
+ .free_inode = free_inode,
+ .statfs = erofs_statfs,
+ .show_options = erofs_show_options,
+ .remount_fs = erofs_remount,
+};
+
+module_init(erofs_module_init);
+module_exit(erofs_module_exit);
+
+MODULE_DESCRIPTION("Enhanced ROM File System");
+MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");
+MODULE_LICENSE("GPL");
+
--
2.17.1
This adds core functions to get, read an inode.
It adds statx support as well.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/inode.c | 291 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 291 insertions(+)
create mode 100644 fs/erofs/inode.c
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
new file mode 100644
index 000000000000..79ef5b38dfa3
--- /dev/null
+++ b/fs/erofs/inode.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/erofs/inode.c
+ *
+ * Copyright (C) 2017-2018 HUAWEI, Inc.
+ * http://www.huawei.com/
+ * Created by Gao Xiang <[email protected]>
+ */
+#include "internal.h"
+
+#include <trace/events/erofs.h>
+
+/* no locking */
+static int read_inode(struct inode *inode, void *data)
+{
+ struct erofs_vnode *vi = EROFS_V(inode);
+ struct erofs_inode_v1 *v1 = data;
+ const unsigned int advise = le16_to_cpu(v1->i_advise);
+ erofs_blk_t nblks = 0;
+
+ vi->datamode = __inode_data_mapping(advise);
+
+ if (unlikely(vi->datamode >= EROFS_INODE_LAYOUT_MAX)) {
+ errln("unsupported data mapping %u of nid %llu",
+ vi->datamode, vi->nid);
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ if (__inode_version(advise) == EROFS_INODE_LAYOUT_V2) {
+ struct erofs_inode_v2 *v2 = data;
+
+ vi->inode_isize = sizeof(struct erofs_inode_v2);
+ vi->xattr_isize = ondisk_xattr_ibody_size(v2->i_xattr_icount);
+
+ inode->i_mode = le16_to_cpu(v2->i_mode);
+ vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
+
+ i_uid_write(inode, le32_to_cpu(v2->i_uid));
+ i_gid_write(inode, le32_to_cpu(v2->i_gid));
+ set_nlink(inode, le32_to_cpu(v2->i_nlink));
+
+ /* ns timestamp */
+ inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
+ le64_to_cpu(v2->i_ctime);
+ inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
+ le32_to_cpu(v2->i_ctime_nsec);
+
+ inode->i_size = le64_to_cpu(v2->i_size);
+
+ /* total blocks for compressed files */
+ if (is_inode_layout_compression(inode))
+ nblks = le32_to_cpu(v2->i_u.compressed_blocks);
+ } else if (__inode_version(advise) == EROFS_INODE_LAYOUT_V1) {
+ struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+
+ vi->inode_isize = sizeof(struct erofs_inode_v1);
+ vi->xattr_isize = ondisk_xattr_ibody_size(v1->i_xattr_icount);
+
+ inode->i_mode = le16_to_cpu(v1->i_mode);
+ vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
+
+ i_uid_write(inode, le16_to_cpu(v1->i_uid));
+ i_gid_write(inode, le16_to_cpu(v1->i_gid));
+ set_nlink(inode, le16_to_cpu(v1->i_nlink));
+
+ /* use build time to derive all file time */
+ inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
+ sbi->build_time;
+ inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
+ sbi->build_time_nsec;
+
+ inode->i_size = le32_to_cpu(v1->i_size);
+ if (is_inode_layout_compression(inode))
+ nblks = le32_to_cpu(v1->i_u.compressed_blocks);
+ } else {
+ errln("unsupported on-disk inode version %u of nid %llu",
+ __inode_version(advise), vi->nid);
+ DBG_BUGON(1);
+ return -EIO;
+ }
+
+ if (!nblks)
+ /* measure inode.i_blocks as generic filesystems */
+ inode->i_blocks = roundup(inode->i_size, EROFS_BLKSIZ) >> 9;
+ else
+ inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
+ return 0;
+}
+
+/*
+ * try_lock can be required since locking order is:
+ * file data(fs_inode)
+ * meta(bd_inode)
+ * but the majority of the callers is "iget",
+ * in that case we are pretty sure no deadlock since
+ * no data operations exist. However I tend to
+ * try_lock since it takes no much overhead and
+ * will success immediately.
+ */
+static int fill_inline_data(struct inode *inode, void *data,
+ unsigned int m_pofs)
+{
+ struct erofs_vnode *vi = EROFS_V(inode);
+ struct erofs_sb_info *sbi = EROFS_I_SB(inode);
+
+ /* should be inode inline C */
+ if (!is_inode_flat_inline(inode))
+ return 0;
+
+ /* fast symlink (following ext4) */
+ if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) {
+ char *lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL);
+
+ if (unlikely(!lnk))
+ return -ENOMEM;
+
+ m_pofs += vi->inode_isize + vi->xattr_isize;
+
+ /* inline symlink data shouldn't across page boundary as well */
+ if (unlikely(m_pofs + inode->i_size > PAGE_SIZE)) {
+ DBG_BUGON(1);
+ kfree(lnk);
+ return -EIO;
+ }
+
+ /* get in-page inline data */
+ memcpy(lnk, data + m_pofs, inode->i_size);
+ lnk[inode->i_size] = '\0';
+
+ inode->i_link = lnk;
+ set_inode_fast_symlink(inode);
+ }
+ return 0;
+}
+
+static int fill_inode(struct inode *inode, int isdir)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
+ struct erofs_vnode *vi = EROFS_V(inode);
+ struct page *page;
+ void *data;
+ int err;
+ erofs_blk_t blkaddr;
+ unsigned int ofs;
+
+ trace_erofs_fill_inode(inode, isdir);
+
+ blkaddr = erofs_blknr(iloc(sbi, vi->nid));
+ ofs = erofs_blkoff(iloc(sbi, vi->nid));
+
+ debugln("%s, reading inode nid %llu at %u of blkaddr %u",
+ __func__, vi->nid, ofs, blkaddr);
+
+ page = erofs_get_meta_page(inode->i_sb, blkaddr, isdir);
+
+ if (IS_ERR(page)) {
+ errln("failed to get inode (nid: %llu) page, err %ld",
+ vi->nid, PTR_ERR(page));
+ return PTR_ERR(page);
+ }
+
+ DBG_BUGON(!PageUptodate(page));
+ data = page_address(page);
+
+ err = read_inode(inode, data + ofs);
+ if (!err) {
+ /* setup the new inode */
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &erofs_generic_iops;
+ inode->i_fop = &generic_ro_fops;
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &erofs_dir_iops;
+ inode->i_fop = &erofs_dir_fops;
+ } else if (S_ISLNK(inode->i_mode)) {
+ /* by default, page_get_link is used for symlink */
+ inode->i_op = &erofs_symlink_iops;
+ inode_nohighmem(inode);
+ } else {
+ err = -EIO;
+ goto out_unlock;
+ }
+
+ if (is_inode_layout_compression(inode)) {
+ err = -ENOTSUPP;
+ goto out_unlock;
+ }
+
+ inode->i_mapping->a_ops = &erofs_raw_access_aops;
+
+ /* fill last page if inline data is available */
+ err = fill_inline_data(inode, data, ofs);
+ }
+
+out_unlock:
+ unlock_page(page);
+ put_page(page);
+ return err;
+}
+
+/*
+ * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
+ * we should do more for 32-bit platform to find the right inode.
+ */
+#if BITS_PER_LONG == 32
+static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
+{
+ const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+
+ return EROFS_V(inode)->nid == nid;
+}
+
+static int erofs_iget_set_actor(struct inode *inode, void *opaque)
+{
+ const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+
+ inode->i_ino = erofs_inode_hash(nid);
+ return 0;
+}
+#endif
+
+static inline struct inode *erofs_iget_locked(struct super_block *sb,
+ erofs_nid_t nid)
+{
+ const unsigned long hashval = erofs_inode_hash(nid);
+
+#if BITS_PER_LONG >= 64
+ /* it is safe to use iget_locked for >= 64-bit platform */
+ return iget_locked(sb, hashval);
+#else
+ return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
+ erofs_iget_set_actor, &nid);
+#endif
+}
+
+struct inode *erofs_iget(struct super_block *sb,
+ erofs_nid_t nid,
+ bool isdir)
+{
+ struct inode *inode = erofs_iget_locked(sb, nid);
+
+ if (unlikely(!inode))
+ return ERR_PTR(-ENOMEM);
+
+ if (inode->i_state & I_NEW) {
+ int err;
+ struct erofs_vnode *vi = EROFS_V(inode);
+
+ vi->nid = nid;
+
+ err = fill_inode(inode, isdir);
+ if (likely(!err))
+ unlock_new_inode(inode);
+ else {
+ iget_failed(inode);
+ inode = ERR_PTR(err);
+ }
+ }
+ return inode;
+}
+
+int erofs_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ struct inode *const inode = d_inode(path->dentry);
+
+ if (is_inode_layout_compression(inode))
+ stat->attributes |= STATX_ATTR_COMPRESSED;
+
+ stat->attributes |= STATX_ATTR_IMMUTABLE;
+ stat->attributes_mask |= (STATX_ATTR_COMPRESSED |
+ STATX_ATTR_IMMUTABLE);
+
+ generic_fillattr(inode, stat);
+ return 0;
+}
+
+const struct inode_operations erofs_generic_iops = {
+ .getattr = erofs_getattr,
+};
+
+const struct inode_operations erofs_symlink_iops = {
+ .get_link = page_get_link,
+ .getattr = erofs_getattr,
+};
+
+const struct inode_operations erofs_fast_symlink_iops = {
+ .get_link = simple_get_link,
+ .getattr = erofs_getattr,
+};
+
--
2.17.1
This commit adds Makefile and Kconfig for erofs, and
updates Makefile and Kconfig files in the fs directory.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/Kconfig | 1 +
fs/Makefile | 1 +
fs/erofs/Kconfig | 45 +++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/Makefile | 9 +++++++++
4 files changed, 56 insertions(+)
create mode 100644 fs/erofs/Kconfig
create mode 100644 fs/erofs/Makefile
diff --git a/fs/Kconfig b/fs/Kconfig
index f1046cf6ad85..529a174cbb9c 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -262,6 +262,7 @@ source "fs/romfs/Kconfig"
source "fs/pstore/Kconfig"
source "fs/sysv/Kconfig"
source "fs/ufs/Kconfig"
+source "fs/erofs/Kconfig"
endif # MISC_FILESYSTEMS
diff --git a/fs/Makefile b/fs/Makefile
index c9aea23aba56..6166f533abf7 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -130,3 +130,4 @@ obj-$(CONFIG_F2FS_FS) += f2fs/
obj-$(CONFIG_CEPH_FS) += ceph/
obj-$(CONFIG_PSTORE) += pstore/
obj-$(CONFIG_EFIVAR_FS) += efivarfs/
+obj-$(CONFIG_EROFS_FS) += erofs/
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
new file mode 100644
index 000000000000..bcab58d3f709
--- /dev/null
+++ b/fs/erofs/Kconfig
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config EROFS_FS
+ tristate "EROFS filesystem support"
+ depends on BLOCK
+ help
+ EROFS (Enhanced Read-Only File System) is a lightweight
+ read-only file system with modern designs (eg. page-sized
+ blocks, inline xattrs/data, etc.) for scenarios which need
+ high-performance read-only requirements, e.g. Android OS
+ for mobile phones and LIVECDs.
+
+ It also provides fixed-sized output compression support,
+ which improves storage density, keeps relatively higher
+ compression ratios, which is more useful to achieve high
+ performance for embedded devices with limited memory.
+
+ If unsure, say N.
+
+config EROFS_FS_DEBUG
+ bool "EROFS debugging feature"
+ depends on EROFS_FS
+ help
+ Print debugging messages and enable more BUG_ONs which check
+ filesystem consistency and find potential issues aggressively,
+ which can be used for Android eng build, for example.
+
+ For daily use, say N.
+
+config EROFS_FAULT_INJECTION
+ bool "EROFS fault injection facility"
+ depends on EROFS_FS
+ help
+ Test EROFS to inject faults such as ENOMEM, EIO, and so on.
+ If unsure, say N.
+
+config EROFS_FS_IO_MAX_RETRIES
+ int "EROFS IO Maximum Retries"
+ depends on EROFS_FS
+ default "5"
+ help
+ Maximum retry count of IO Errors.
+
+ If unsure, leave the default value (5 retries, 6 IOs at most).
+
diff --git a/fs/erofs/Makefile b/fs/erofs/Makefile
new file mode 100644
index 000000000000..ec2795f33dc5
--- /dev/null
+++ b/fs/erofs/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+
+EROFS_VERSION = "1.0"
+
+ccflags-y += -DEROFS_VERSION=\"$(EROFS_VERSION)\"
+
+obj-$(CONFIG_EROFS_FS) += erofs.o
+erofs-objs := super.o inode.o data.o namei.o dir.o
+
--
2.17.1
This patch introduces another concept used by decompress
subsystem called 'workstation'. It can be seen as
a sparse array that stores pointers pointed to data
structures related to the corresponding physical clusters.
All lookups are protected by RCU read lock. Besides,
reference count and spin_lock are also introduced
to manage its lifetime and serialize all update
operations.
`workstation' is currently implemented on the in-kernel
radix tree approach for backward compatibility. With the
evolution of linux kernel, it will be migrated into
new XArray implementation in the future.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/internal.h | 83 ++++++++++++++++++++++
fs/erofs/super.c | 4 ++
fs/erofs/utils.c | 168 +++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 253 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 75e82fcdee08..f603ae8aa9b1 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -65,6 +65,9 @@ struct erofs_sb_info {
struct list_head list;
struct mutex umount_mutex;
+ /* the dedicated workstation for compression */
+ struct radix_tree_root workstn_tree;
+
unsigned int shrinker_run_no;
#endif
u32 blocks;
@@ -150,6 +153,77 @@ static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
#define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option)
#define test_opt(sbi, option) ((sbi)->mount_opt & EROFS_MOUNT_##option)
+#ifdef CONFIG_EROFS_FS_ZIP
+#define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL)
+
+/* basic unit of the workstation of a super_block */
+struct erofs_workgroup {
+ /* the workgroup index in the workstation */
+ pgoff_t index;
+
+ /* overall workgroup reference count */
+ atomic_t refcount;
+};
+
+#if defined(CONFIG_SMP)
+static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
+ int val)
+{
+ preempt_disable();
+ if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
+ preempt_enable();
+ return false;
+ }
+ return true;
+}
+
+static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
+ int orig_val)
+{
+ /*
+ * other observers should notice all modifications
+ * in the freezing period.
+ */
+ smp_mb();
+ atomic_set(&grp->refcount, orig_val);
+ preempt_enable();
+}
+
+static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
+{
+ return atomic_cond_read_relaxed(&grp->refcount,
+ VAL != EROFS_LOCKED_MAGIC);
+}
+#else
+static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
+ int val)
+{
+ preempt_disable();
+ /* no need to spin on UP platforms, let's just disable preemption. */
+ if (val != atomic_read(&grp->refcount)) {
+ preempt_enable();
+ return false;
+ }
+ return true;
+}
+
+static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
+ int orig_val)
+{
+ preempt_enable();
+}
+
+static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
+{
+ int v = atomic_read(&grp->refcount);
+
+ /* workgroup is never freezed on uniprocessor systems */
+ DBG_BUGON(v == EROFS_LOCKED_MAGIC);
+ return v;
+}
+#endif
+#endif
+
/* we strictly follow PAGE_SIZE and no buffer head yet */
#define LOG_BLOCK_SIZE PAGE_SHIFT
@@ -413,6 +487,15 @@ extern const struct file_operations erofs_dir_fops;
/* utils.c */
#ifdef CONFIG_EROFS_FS_ZIP
+int erofs_workgroup_put(struct erofs_workgroup *grp);
+struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
+ pgoff_t index, bool *tag);
+int erofs_register_workgroup(struct super_block *sb,
+ struct erofs_workgroup *grp, bool tag);
+unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
+ unsigned long nr_shrink, bool cleanup);
+static inline void erofs_workgroup_free_rcu(struct erofs_workgroup *grp) {}
+
void erofs_shrinker_register(struct super_block *sb);
void erofs_shrinker_unregister(struct super_block *sb);
int __init erofs_init_shrinker(void);
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index ab9d0ad94afb..acb60553b586 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -343,6 +343,10 @@ static int erofs_read_super(struct super_block *sb,
else
sb->s_flags &= ~SB_POSIXACL;
+#ifdef CONFIG_EROFS_FS_ZIP
+ INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
+#endif
+
/* get the root inode */
inode = erofs_iget(sb, ROOT_NID(sbi), true);
if (IS_ERR(inode)) {
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index 727d3831b5c9..45fd780e6429 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -7,11 +7,175 @@
* Created by Gao Xiang <[email protected]>
*/
#include "internal.h"
+#include <linux/pagevec.h>
#ifdef CONFIG_EROFS_FS_ZIP
/* global shrink count (for all mounted EROFS instances) */
static atomic_long_t erofs_global_shrink_cnt;
+#define __erofs_workgroup_get(grp) atomic_inc(&(grp)->refcount)
+#define __erofs_workgroup_put(grp) atomic_dec(&(grp)->refcount)
+
+static int erofs_workgroup_get(struct erofs_workgroup *grp)
+{
+ int o;
+
+repeat:
+ o = erofs_wait_on_workgroup_freezed(grp);
+ if (unlikely(o <= 0))
+ return -1;
+
+ if (unlikely(atomic_cmpxchg(&grp->refcount, o, o + 1) != o))
+ goto repeat;
+
+ /* decrease refcount paired by erofs_workgroup_put */
+ if (unlikely(o == 1))
+ atomic_long_dec(&erofs_global_shrink_cnt);
+ return 0;
+}
+
+struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
+ pgoff_t index, bool *tag)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_workgroup *grp;
+
+repeat:
+ rcu_read_lock();
+ grp = radix_tree_lookup(&sbi->workstn_tree, index);
+ if (grp) {
+ *tag = xa_pointer_tag(grp);
+ grp = xa_untag_pointer(grp);
+
+ if (erofs_workgroup_get(grp)) {
+ /* prefer to relax rcu read side */
+ rcu_read_unlock();
+ goto repeat;
+ }
+
+ DBG_BUGON(index != grp->index);
+ }
+ rcu_read_unlock();
+ return grp;
+}
+
+int erofs_register_workgroup(struct super_block *sb,
+ struct erofs_workgroup *grp,
+ bool tag)
+{
+ struct erofs_sb_info *sbi;
+ int err;
+
+ /* grp shouldn't be broken or used before */
+ if (unlikely(atomic_read(&grp->refcount) != 1)) {
+ DBG_BUGON(1);
+ return -EINVAL;
+ }
+
+ err = radix_tree_preload(GFP_NOFS);
+ if (err)
+ return err;
+
+ sbi = EROFS_SB(sb);
+
+ xa_lock(&sbi->workstn_tree);
+ grp = xa_tag_pointer(grp, tag);
+
+ /*
+ * Bump up reference count before making this workgroup
+ * visible to other users in order to avoid potential UAF
+ * without serialized by erofs_workstn_lock.
+ */
+ __erofs_workgroup_get(grp);
+
+ err = radix_tree_insert(&sbi->workstn_tree,
+ grp->index, grp);
+ if (unlikely(err))
+ /*
+ * it's safe to decrease since the workgroup isn't visible
+ * and refcount >= 2 (cannot be freezed).
+ */
+ __erofs_workgroup_put(grp);
+
+ xa_unlock(&sbi->workstn_tree);
+ radix_tree_preload_end();
+ return err;
+}
+
+static void __erofs_workgroup_free(struct erofs_workgroup *grp)
+{
+ atomic_long_dec(&erofs_global_shrink_cnt);
+ erofs_workgroup_free_rcu(grp);
+}
+
+int erofs_workgroup_put(struct erofs_workgroup *grp)
+{
+ int count = atomic_dec_return(&grp->refcount);
+
+ if (count == 1)
+ atomic_long_inc(&erofs_global_shrink_cnt);
+ else if (!count)
+ __erofs_workgroup_free(grp);
+ return count;
+}
+
+/* for nocache case, no customized reclaim path at all */
+static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
+ struct erofs_workgroup *grp,
+ bool cleanup)
+{
+ int cnt = atomic_read(&grp->refcount);
+
+ DBG_BUGON(cnt <= 0);
+ DBG_BUGON(cleanup && cnt != 1);
+
+ if (cnt > 1)
+ return false;
+
+ DBG_BUGON(xa_untag_pointer(radix_tree_delete(&sbi->workstn_tree,
+ grp->index)) != grp);
+
+ /* (rarely) could be grabbed again when freeing */
+ erofs_workgroup_put(grp);
+ return true;
+}
+
+
+unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
+ unsigned long nr_shrink,
+ bool cleanup)
+{
+ pgoff_t first_index = 0;
+ void *batch[PAGEVEC_SIZE];
+ unsigned int freed = 0;
+
+ int i, found;
+repeat:
+ xa_lock(&sbi->workstn_tree);
+
+ found = radix_tree_gang_lookup(&sbi->workstn_tree,
+ batch, first_index, PAGEVEC_SIZE);
+
+ for (i = 0; i < found; ++i) {
+ struct erofs_workgroup *grp = xa_untag_pointer(batch[i]);
+
+ first_index = grp->index + 1;
+
+ /* try to shrink each valid workgroup */
+ if (!erofs_try_to_release_workgroup(sbi, grp, cleanup))
+ continue;
+
+ ++freed;
+ if (unlikely(!--nr_shrink))
+ break;
+ }
+ xa_unlock(&sbi->workstn_tree);
+
+ if (i && nr_shrink)
+ goto repeat;
+ return freed;
+}
+
/* protected by 'erofs_sb_list_lock' */
static unsigned int shrinker_run_no;
@@ -35,7 +199,7 @@ void erofs_shrinker_unregister(struct super_block *sb)
struct erofs_sb_info *const sbi = EROFS_SB(sb);
mutex_lock(&sbi->umount_mutex);
- /* will add shrink final handler here */
+ erofs_shrink_workstation(EROFS_SB(sb), ~0UL, true);
spin_lock(&erofs_sb_list_lock);
list_del(&sbi->list);
@@ -84,7 +248,7 @@ static unsigned long erofs_shrink_scan(struct shrinker *shrink,
spin_unlock(&erofs_sb_list_lock);
sbi->shrinker_run_no = run_no;
- /* will add shrink handler here */
+ freed += erofs_shrink_workstation(sbi, nr, false);
spin_lock(&erofs_sb_list_lock);
/* Get the next list element before we move this one */
--
2.17.1
This patch adds a dedicated shrinker targeting to free
unneeded memory consumed by a number of erofs in-memory
data structures.
Like F2FS and UBIFS, it also adds:
- sbi->umount_mutex to avoid races on shrinker and put_super;
- sbi->shrinker_run_no to not revisit recently scanned objects.
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/internal.h | 7 ++++
fs/erofs/super.c | 6 +++
fs/erofs/utils.c | 94 ++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 106 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 87287cd9c146..75e82fcdee08 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -63,6 +63,9 @@ struct erofs_sb_info {
#ifdef CONFIG_EROFS_FS_ZIP
/* list for all registered superblocks, mainly for shrinker */
struct list_head list;
+ struct mutex umount_mutex;
+
+ unsigned int shrinker_run_no;
#endif
u32 blocks;
u32 meta_blkaddr;
@@ -412,9 +415,13 @@ extern const struct file_operations erofs_dir_fops;
#ifdef CONFIG_EROFS_FS_ZIP
void erofs_shrinker_register(struct super_block *sb);
void erofs_shrinker_unregister(struct super_block *sb);
+int __init erofs_init_shrinker(void);
+void erofs_exit_shrinker(void);
#else
static inline void erofs_shrinker_register(struct super_block *sb) {}
static inline void erofs_shrinker_unregister(struct super_block *sb) {}
+static inline int erofs_init_shrinker(void) { return 0; }
+static inline void erofs_exit_shrinker(void) {}
#endif
#endif
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 60058d3c50d4..ab9d0ad94afb 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -474,6 +474,9 @@ static int __init erofs_module_init(void)
if (err)
goto icache_err;
+ err = erofs_init_shrinker();
+ if (err)
+ goto shrinker_err;
err = register_filesystem(&erofs_fs_type);
if (err)
goto fs_err;
@@ -482,6 +485,8 @@ static int __init erofs_module_init(void)
return 0;
fs_err:
+ erofs_exit_shrinker();
+shrinker_err:
erofs_exit_inode_cache();
icache_err:
return err;
@@ -490,6 +495,7 @@ static int __init erofs_module_init(void)
static void __exit erofs_module_exit(void)
{
unregister_filesystem(&erofs_fs_type);
+ erofs_exit_shrinker();
erofs_exit_inode_cache();
infoln("successfully finalize erofs");
}
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index 08c8752895bc..727d3831b5c9 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -9,6 +9,12 @@
#include "internal.h"
#ifdef CONFIG_EROFS_FS_ZIP
+/* global shrink count (for all mounted EROFS instances) */
+static atomic_long_t erofs_global_shrink_cnt;
+
+/* protected by 'erofs_sb_list_lock' */
+static unsigned int shrinker_run_no;
+
/* protects the mounted 'erofs_sb_list' */
static DEFINE_SPINLOCK(erofs_sb_list_lock);
static LIST_HEAD(erofs_sb_list);
@@ -17,6 +23,8 @@ void erofs_shrinker_register(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
+ mutex_init(&sbi->umount_mutex);
+
spin_lock(&erofs_sb_list_lock);
list_add(&sbi->list, &erofs_sb_list);
spin_unlock(&erofs_sb_list_lock);
@@ -24,9 +32,93 @@ void erofs_shrinker_register(struct super_block *sb)
void erofs_shrinker_unregister(struct super_block *sb)
{
+ struct erofs_sb_info *const sbi = EROFS_SB(sb);
+
+ mutex_lock(&sbi->umount_mutex);
+ /* will add shrink final handler here */
+
spin_lock(&erofs_sb_list_lock);
- list_del(&EROFS_SB(sb)->list);
+ list_del(&sbi->list);
spin_unlock(&erofs_sb_list_lock);
+ mutex_unlock(&sbi->umount_mutex);
+}
+
+static unsigned long erofs_shrink_count(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ return atomic_long_read(&erofs_global_shrink_cnt);
}
+
+static unsigned long erofs_shrink_scan(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ struct erofs_sb_info *sbi;
+ struct list_head *p;
+
+ unsigned long nr = sc->nr_to_scan;
+ unsigned int run_no;
+ unsigned long freed = 0;
+
+ spin_lock(&erofs_sb_list_lock);
+ do {
+ run_no = ++shrinker_run_no;
+ } while (run_no == 0);
+
+ /* Iterate over all mounted superblocks and try to shrink them */
+ p = erofs_sb_list.next;
+ while (p != &erofs_sb_list) {
+ sbi = list_entry(p, struct erofs_sb_info, list);
+
+ /*
+ * We move the ones we do to the end of the list, so we stop
+ * when we see one we have already done.
+ */
+ if (sbi->shrinker_run_no == run_no)
+ break;
+
+ if (!mutex_trylock(&sbi->umount_mutex)) {
+ p = p->next;
+ continue;
+ }
+
+ spin_unlock(&erofs_sb_list_lock);
+ sbi->shrinker_run_no = run_no;
+
+ /* will add shrink handler here */
+
+ spin_lock(&erofs_sb_list_lock);
+ /* Get the next list element before we move this one */
+ p = p->next;
+
+ /*
+ * Move this one to the end of the list to provide some
+ * fairness.
+ */
+ list_move_tail(&sbi->list, &erofs_sb_list);
+ mutex_unlock(&sbi->umount_mutex);
+
+ if (freed >= nr)
+ break;
+ }
+ spin_unlock(&erofs_sb_list_lock);
+ return freed;
+}
+
+static struct shrinker erofs_shrinker_info = {
+ .scan_objects = erofs_shrink_scan,
+ .count_objects = erofs_shrink_count,
+ .seeks = DEFAULT_SEEKS,
+};
+
+int __init erofs_init_shrinker(void)
+{
+ return register_shrinker(&erofs_shrinker_info);
+}
+
+void erofs_exit_shrinker(void)
+{
+ unregister_shrinker(&erofs_shrinker_info);
+}
+
#endif
--
2.17.1
On Thu 2019-07-11 22:57:31, Gao Xiang wrote:
> Changelog from v1:
> o resend the whole filesystem into a patchset suggested by Greg;
> o code is more cleaner, especially for decompression frontend.
>
> --8<----------
>
> Hi,
>
> EROFS file system has been in Linux-staging for about a year.
> It has been proved to be stable enough to move out of staging
> by 10+ millions of HUAWEI Android mobile phones on the market
> from EMUI 9.0.1, and it was promoted as one of the key features
> of EMUI 9.1 [1], including P30(pro).
Ok, maybe it is ready to be moved to kernel proper, but as git can
do moves, would it be better to do it as one commit?
Separate patches are still better for review, I guess.
Pavel
Hi Pavel,
On 2019/7/14 18:49, Pavel Machek Wrote:
> On Thu 2019-07-11 22:57:31, Gao Xiang wrote:
>> Changelog from v1:
>> o resend the whole filesystem into a patchset suggested by Greg;
>> o code is more cleaner, especially for decompression frontend.
>>
>> --8<----------
>>
>> Hi,
>>
>> EROFS file system has been in Linux-staging for about a year.
>> It has been proved to be stable enough to move out of staging
>> by 10+ millions of HUAWEI Android mobile phones on the market
>> from EMUI 9.0.1, and it was promoted as one of the key features
>> of EMUI 9.1 [1], including P30(pro).
>
> Ok, maybe it is ready to be moved to kernel proper, but as git can
> do moves, would it be better to do it as one commit?
>
> Separate patches are still better for review, I guess.
Thanks for you reply. Either form is OK for me... The first step could
be that I hope someone could kindly take some time to look into these
patches... :)
The patch v2 is slightly different for the current code in the staging
tree since I did some code cleanup these days (mainly renaming / moving,
including rename unzip_vle.{c,h} to zdata.{c,h} and some confusing
structure names and clean up internal.h...). No functional chance and I
can submit cleanup patches to staging as well if doing moves by git...
Thanks,
Gao Xiang
> Pavel
>
Hi!
> >> Changelog from v1:
> >> o resend the whole filesystem into a patchset suggested by Greg;
> >> o code is more cleaner, especially for decompression frontend.
> >>
> >> --8<----------
> >>
> >> Hi,
> >>
> >> EROFS file system has been in Linux-staging for about a year.
> >> It has been proved to be stable enough to move out of staging
> >> by 10+ millions of HUAWEI Android mobile phones on the market
> >> from EMUI 9.0.1, and it was promoted as one of the key features
> >> of EMUI 9.1 [1], including P30(pro).
> >
> > Ok, maybe it is ready to be moved to kernel proper, but as git can
> > do moves, would it be better to do it as one commit?
> >
> > Separate patches are still better for review, I guess.
>
> Thanks for you reply. Either form is OK for me... The first step could
> be that I hope someone could kindly take some time to look into these
> patches... :)
>
> The patch v2 is slightly different for the current code in the staging
> tree since I did some code cleanup these days (mainly renaming / moving,
> including rename unzip_vle.{c,h} to zdata.{c,h} and some confusing
> structure names and clean up internal.h...). No functional chance and I
> can submit cleanup patches to staging as well if doing moves by git...
I believe you should get those committed to staging/, yes. Then you
ask Al Viro to do pull the git move, I guess, and you follow his
instructions at that point...
FILESYSTEMS (VFS and infrastructure)
M: Alexander Viro <[email protected]>
L: [email protected]
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On 2019/7/15 15:56, Pavel Machek wrote:
> Hi!
>
>>>> Changelog from v1:
>>>> o resend the whole filesystem into a patchset suggested by Greg;
>>>> o code is more cleaner, especially for decompression frontend.
>>>>
>>>> --8<----------
>>>>
>>>> Hi,
>>>>
>>>> EROFS file system has been in Linux-staging for about a year.
>>>> It has been proved to be stable enough to move out of staging
>>>> by 10+ millions of HUAWEI Android mobile phones on the market
>>>> from EMUI 9.0.1, and it was promoted as one of the key features
>>>> of EMUI 9.1 [1], including P30(pro).
>>>
>>> Ok, maybe it is ready to be moved to kernel proper, but as git can
>>> do moves, would it be better to do it as one commit?
>>>
>>> Separate patches are still better for review, I guess.
>>
>> Thanks for you reply. Either form is OK for me... The first step could
>> be that I hope someone could kindly take some time to look into these
>> patches... :)
>>
>> The patch v2 is slightly different for the current code in the staging
>> tree since I did some code cleanup these days (mainly renaming / moving,
>> including rename unzip_vle.{c,h} to zdata.{c,h} and some confusing
>> structure names and clean up internal.h...). No functional chance and I
>> can submit cleanup patches to staging as well if doing moves by git...
>
> I believe you should get those committed to staging/, yes. Then you
> ask Al Viro to do pull the git move, I guess, and you follow his
> instructions at that point...
>
> FILESYSTEMS (VFS and infrastructure)
> M: Alexander Viro <[email protected]>
> L: [email protected]
OK, I will send the incremental patches as well later if the above approach
can be done in practice...
Actually I'd like to get fs people Acked-by about EROFS stuffes, e.g. Al, Ted, etc...
Hello?
It seems rare filesystems upstreamed these years, but I think EROFS is more useful
after moving out of staging. If some people really care about compression ratio,
I can add multi-block fixed-output compression support later (Not very hard, it's
already on my TODO list), although my current company HUAWEI doesn't have any
interest in that way in the near future...
In the long term, I'd like to spend my personal free time to decouple code like
fscrypt and introduce fscompr for other generic fs to compress unmodified files
as well then...
That is another stuff. Anyway, EROFS is one of optimal read-only performance
solutions for consumer electronics compared with others (Note that block storage
has been improved a lot in the past decade...)
Thank you very much,
Gao Xiang
>
> Best regards,
> Pavel
>
On Thu, Jul 11, 2019 at 10:57:34PM +0800, Gao Xiang wrote:
> This commit adds erofs super block operations, including (u)mount,
> remount_fs, show_options, statfs, in addition to some private
> icache management functions.
Could you explain what's the point of this
> + /* save the device name to sbi */
> + sbi->dev_name = __getname();
> + if (!sbi->dev_name) {
> + err = -ENOMEM;
> + goto err_devname;
> + }
> +
> + snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
> + sbi->dev_name[PATH_MAX - 1] = '\0';
... and this?
> +struct erofs_mount_private {
> + const char *dev_name;
> + char *options;
> +};
> +
> +/* support mount_bdev() with options */
> +static int erofs_fill_super(struct super_block *sb,
> + void *_priv, int silent)
> +{
> + struct erofs_mount_private *priv = _priv;
> +
> + return erofs_read_super(sb, priv->dev_name,
> + priv->options, silent);
> +}
> +
> +static struct dentry *erofs_mount(
> + struct file_system_type *fs_type, int flags,
> + const char *dev_name, void *data)
> +{
> + struct erofs_mount_private priv = {
> + .dev_name = dev_name,
> + .options = data
> + };
> +
> + return mount_bdev(fs_type, flags, dev_name,
> + &priv, erofs_fill_super);
> +}
AFAICS, the only use of sbi->dev_name is debugging printks and
all of those have sb->s_id available, with device name stored
in there. Which makes the whole thing bloody weird - what's
wrong with simply passing data to mount_bdev (instead of
&priv), folding erofs_read_super() into erofs_fill_super(),
replacing sbi->dev_name with sb->s_id and killing sbi->dev_name,
along with the associated allocation, freeing, handling of
allocation failure, etc.?
For drivers/staging location that would be (compile-tested only)
the diff below. I suspect that you could simplify fill_super
a bit further if you added ->kill_sb() along the lines of
sbi = EROFS(sb);
#ifdef EROFS_FS_HAS_MANAGED_CACHE
if (sbi && !sb->s_root)
iput(sbi->managed_cache);
#endif
kill_block_super(sb);
kfree(sbi);
and took freeing sbi out of your ->put_super(). Then fill_super()
would simply return -E... on all failure exits, leaving all cleanup
to ->kill_sb(). E.g. initialization of the same ->managed_cache
would become
#ifdef EROFS_FS_HAS_MANAGED_CACHE
inode = erofs_init_managed_cache(sb);
if (IS_ERR(inode))
return PTR_ERR(inode);
sbi->managed_cache = inode;
#endif
etc. Matter of taste, but IME if destructor parallels the cleanups on failure
exits in constructor it often makes sense to make use of that and kill the
duplication... Anyway, that's a separate store; sbi->dev_name is a lot more
obvious one.
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 382258fc124d..16bab07e69d8 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -117,8 +117,6 @@ struct erofs_sb_info {
u8 volume_name[16]; /* volume name */
u32 requirements;
- char *dev_name;
-
unsigned int mount_opt;
unsigned int shrinker_run_no;
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index cadbcc11702a..a6ee69d0ce45 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -367,15 +367,14 @@ static struct inode *erofs_init_managed_cache(struct super_block *sb)
#endif
-static int erofs_read_super(struct super_block *sb,
- const char *dev_name,
+static int erofs_fill_super(struct super_block *sb,
void *data, int silent)
{
struct inode *inode;
struct erofs_sb_info *sbi;
int err = -EINVAL;
- infoln("read_super, device -> %s", dev_name);
+ infoln("read_super, device -> %s", sb->s_id);
infoln("options -> %s", (char *)data);
if (unlikely(!sb_set_blocksize(sb, EROFS_BLKSIZ))) {
@@ -453,20 +452,10 @@ static int erofs_read_super(struct super_block *sb,
goto err_iget;
}
- /* save the device name to sbi */
- sbi->dev_name = __getname();
- if (!sbi->dev_name) {
- err = -ENOMEM;
- goto err_devname;
- }
-
- snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
- sbi->dev_name[PATH_MAX - 1] = '\0';
-
erofs_register_super(sb);
if (!silent)
- infoln("mounted on %s with opts: %s.", dev_name,
+ infoln("mounted on %s with opts: %s.", sb->s_id,
(char *)data);
return 0;
/*
@@ -474,9 +463,6 @@ static int erofs_read_super(struct super_block *sb,
* the following name convention, thus new features
* can be integrated easily without renaming labels.
*/
-err_devname:
- dput(sb->s_root);
- sb->s_root = NULL;
err_iget:
#ifdef EROFS_FS_HAS_MANAGED_CACHE
iput(sbi->managed_cache);
@@ -504,8 +490,7 @@ static void erofs_put_super(struct super_block *sb)
WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
- infoln("unmounted for %s", sbi->dev_name);
- __putname(sbi->dev_name);
+ infoln("unmounted for %s", sb->s_id);
#ifdef EROFS_FS_HAS_MANAGED_CACHE
iput(sbi->managed_cache);
@@ -525,33 +510,12 @@ static void erofs_put_super(struct super_block *sb)
sb->s_fs_info = NULL;
}
-
-struct erofs_mount_private {
- const char *dev_name;
- char *options;
-};
-
-/* support mount_bdev() with options */
-static int erofs_fill_super(struct super_block *sb,
- void *_priv, int silent)
-{
- struct erofs_mount_private *priv = _priv;
-
- return erofs_read_super(sb, priv->dev_name,
- priv->options, silent);
-}
-
static struct dentry *erofs_mount(
struct file_system_type *fs_type, int flags,
const char *dev_name, void *data)
{
- struct erofs_mount_private priv = {
- .dev_name = dev_name,
- .options = data
- };
-
return mount_bdev(fs_type, flags, dev_name,
- &priv, erofs_fill_super);
+ data, erofs_fill_super);
}
static void erofs_kill_sb(struct super_block *sb)
Hi Al,
On 2019/7/21 ????6:49, Al Viro wrote:
> On Thu, Jul 11, 2019 at 10:57:34PM +0800, Gao Xiang wrote:
>> This commit adds erofs super block operations, including (u)mount,
>> remount_fs, show_options, statfs, in addition to some private
>> icache management functions.
> Could you explain what's the point of this
>
>> + /* save the device name to sbi */
>> + sbi->dev_name = __getname();
>> + if (!sbi->dev_name) {
>> + err = -ENOMEM;
>> + goto err_devname;
>> + }
>> +
>> + snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
>> + sbi->dev_name[PATH_MAX - 1] = '\0';
> ... and this?
Thanks for your kindly reply...
Yes, I remember the above code you already mentioned months ago... The
detail is that
It is for debugging use as you said below, mainly for our internal
testers whose jobs are
to read kmsg logs and catch kernel problems. sb->s_id (device number)
maybe not
straight-forward for them compared with dev_name...
The initial purpose of erofs_mount_private was to passing multi private
data from erofs_mount
to erofs_read_super, which was written before fs_contest was introduced.
I agree with you, it seems better to just use s_id in community and
delete erofs_mount_private stuffs...
Yet I don't look into how to use new fs_context, could I keep using
legacy mount interface and fix them all?
>
>> +struct erofs_mount_private {
>> + const char *dev_name;
>> + char *options;
>> +};
>> +
>> +/* support mount_bdev() with options */
>> +static int erofs_fill_super(struct super_block *sb,
>> + void *_priv, int silent)
>> +{
>> + struct erofs_mount_private *priv = _priv;
>> +
>> + return erofs_read_super(sb, priv->dev_name,
>> + priv->options, silent);
>> +}
>> +
>> +static struct dentry *erofs_mount(
>> + struct file_system_type *fs_type, int flags,
>> + const char *dev_name, void *data)
>> +{
>> + struct erofs_mount_private priv = {
>> + .dev_name = dev_name,
>> + .options = data
>> + };
>> +
>> + return mount_bdev(fs_type, flags, dev_name,
>> + &priv, erofs_fill_super);
>> +}
> AFAICS, the only use of sbi->dev_name is debugging printks and
> all of those have sb->s_id available, with device name stored
> in there. Which makes the whole thing bloody weird - what's
> wrong with simply passing data to mount_bdev (instead of
> &priv), folding erofs_read_super() into erofs_fill_super(),
> replacing sbi->dev_name with sb->s_id and killing sbi->dev_name,
> along with the associated allocation, freeing, handling of
> allocation failure, etc.?
OK, make sense. I will do...
>
> For drivers/staging location that would be (compile-tested only)
> the diff below. I suspect that you could simplify fill_super
> a bit further if you added ->kill_sb() along the lines of
>
> sbi = EROFS(sb);
> #ifdef EROFS_FS_HAS_MANAGED_CACHE
> if (sbi && !sb->s_root)
> iput(sbi->managed_cache);
> #endif
> kill_block_super(sb);
> kfree(sbi);
> and took freeing sbi out of your ->put_super(). Then fill_super()
> would simply return -E... on all failure exits, leaving all cleanup
> to ->kill_sb(). E.g. initialization of the same ->managed_cache
> would become
> #ifdef EROFS_FS_HAS_MANAGED_CACHE
> inode = erofs_init_managed_cache(sb);
> if (IS_ERR(inode))
> return PTR_ERR(inode);
> sbi->managed_cache = inode;
> #endif
> etc. Matter of taste, but IME if destructor parallels the cleanups on failure
> exits in constructor it often makes sense to make use of that and kill the
> duplication... Anyway, that's a separate store; sbi->dev_name is a lot more
> obvious one.
I guess if I don't misunderstand, that is another suggestion -- in
short, leave all destructors to .kill_sb() and
cleanup fill_super(). I think it makes sense as well, though the reason
why the initial erofs code was is that
I just refer other filesystems such as ext4 and f2fs which handle
failure in fill_super() constructor as well.
Anyway, your suggestion is a good idea (it's more cleaner), I will play
with it.
I will kill dev_name in patch v3 at least, and try to clean up all
failure exits as you mentioned.
Thanks for your suggestions... Let me resend v3 later :)
Thanks,
Gao Xiang
>
>
> diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
> index 382258fc124d..16bab07e69d8 100644
> --- a/drivers/staging/erofs/internal.h
> +++ b/drivers/staging/erofs/internal.h
> @@ -117,8 +117,6 @@ struct erofs_sb_info {
> u8 volume_name[16]; /* volume name */
> u32 requirements;
>
> - char *dev_name;
> -
> unsigned int mount_opt;
> unsigned int shrinker_run_no;
>
> diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
> index cadbcc11702a..a6ee69d0ce45 100644
> --- a/drivers/staging/erofs/super.c
> +++ b/drivers/staging/erofs/super.c
> @@ -367,15 +367,14 @@ static struct inode *erofs_init_managed_cache(struct super_block *sb)
>
> #endif
>
> -static int erofs_read_super(struct super_block *sb,
> - const char *dev_name,
> +static int erofs_fill_super(struct super_block *sb,
> void *data, int silent)
> {
> struct inode *inode;
> struct erofs_sb_info *sbi;
> int err = -EINVAL;
>
> - infoln("read_super, device -> %s", dev_name);
> + infoln("read_super, device -> %s", sb->s_id);
> infoln("options -> %s", (char *)data);
>
> if (unlikely(!sb_set_blocksize(sb, EROFS_BLKSIZ))) {
> @@ -453,20 +452,10 @@ static int erofs_read_super(struct super_block *sb,
> goto err_iget;
> }
>
> - /* save the device name to sbi */
> - sbi->dev_name = __getname();
> - if (!sbi->dev_name) {
> - err = -ENOMEM;
> - goto err_devname;
> - }
> -
> - snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
> - sbi->dev_name[PATH_MAX - 1] = '\0';
> -
> erofs_register_super(sb);
>
> if (!silent)
> - infoln("mounted on %s with opts: %s.", dev_name,
> + infoln("mounted on %s with opts: %s.", sb->s_id,
> (char *)data);
> return 0;
> /*
> @@ -474,9 +463,6 @@ static int erofs_read_super(struct super_block *sb,
> * the following name convention, thus new features
> * can be integrated easily without renaming labels.
> */
> -err_devname:
> - dput(sb->s_root);
> - sb->s_root = NULL;
> err_iget:
> #ifdef EROFS_FS_HAS_MANAGED_CACHE
> iput(sbi->managed_cache);
> @@ -504,8 +490,7 @@ static void erofs_put_super(struct super_block *sb)
>
> WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
>
> - infoln("unmounted for %s", sbi->dev_name);
> - __putname(sbi->dev_name);
> + infoln("unmounted for %s", sb->s_id);
>
> #ifdef EROFS_FS_HAS_MANAGED_CACHE
> iput(sbi->managed_cache);
> @@ -525,33 +510,12 @@ static void erofs_put_super(struct super_block *sb)
> sb->s_fs_info = NULL;
> }
>
> -
> -struct erofs_mount_private {
> - const char *dev_name;
> - char *options;
> -};
> -
> -/* support mount_bdev() with options */
> -static int erofs_fill_super(struct super_block *sb,
> - void *_priv, int silent)
> -{
> - struct erofs_mount_private *priv = _priv;
> -
> - return erofs_read_super(sb, priv->dev_name,
> - priv->options, silent);
> -}
> -
> static struct dentry *erofs_mount(
> struct file_system_type *fs_type, int flags,
> const char *dev_name, void *data)
> {
> - struct erofs_mount_private priv = {
> - .dev_name = dev_name,
> - .options = data
> - };
> -
> return mount_bdev(fs_type, flags, dev_name,
> - &priv, erofs_fill_super);
> + data, erofs_fill_super);
> }
>
> static void erofs_kill_sb(struct super_block *sb)
On Sun, Jul 21, 2019 at 11:08:42AM +0800, Gao Xiang wrote:
> It is for debugging use as you said below, mainly for our internal
> testers whose jobs are
> to read kmsg logs and catch kernel problems. sb->s_id (device number)
> maybe not
> straight-forward for them compared with dev_name...
Huh? ->s_id is something like "sdb7" - it's bdev_name(), not a device
number...
> The initial purpose of erofs_mount_private was to passing multi private
> data from erofs_mount
> to erofs_read_super, which was written before fs_contest was introduced.
That has nothing to do with fs_context (well, other than fs_context conversions
affecting the code very close to that).
> I agree with you, it seems better to just use s_id in community and
> delete erofs_mount_private stuffs...
> Yet I don't look into how to use new fs_context, could I keep using
> legacy mount interface and fix them all?
Sure.
> I guess if I don't misunderstand, that is another suggestion -- in
> short, leave all destructors to .kill_sb() and
> cleanup fill_super().
Just be careful with that iput() there - AFAICS, if fs went live (i.e.
if ->s_root is non-NULL), you really need it done only from put_super();
OTOH, for the case of NULL ->s_root ->put_super() won't be called at all,
so in that case you need it directly in ->kill_sb().
On 2019/7/21 12:05, Al Viro wrote:
> On Sun, Jul 21, 2019 at 11:08:42AM +0800, Gao Xiang wrote:
>
>> It is for debugging use as you said below, mainly for our internal
>> testers whose jobs are
>> to read kmsg logs and catch kernel problems. sb->s_id (device number)
>> maybe not
>> straight-forward for them compared with dev_name...
>
> Huh? ->s_id is something like "sdb7" - it's bdev_name(), not a device
> number...
You are right. Forgive me, actually we use /dev/block/by-name/system
to mount fs... we have to do some lookup if using sdbX instead.
>
>> The initial purpose of erofs_mount_private was to passing multi private
>> data from erofs_mount
>> to erofs_read_super, which was written before fs_contest was introduced.
>
> That has nothing to do with fs_context (well, other than fs_context conversions
> affecting the code very close to that).
OK. That is fine.
>
>> I agree with you, it seems better to just use s_id in community and
>> delete erofs_mount_private stuffs...
>> Yet I don't look into how to use new fs_context, could I keep using
>> legacy mount interface and fix them all?
>
> Sure.
>
>> I guess if I don't misunderstand, that is another suggestion -- in
>> short, leave all destructors to .kill_sb() and
>> cleanup fill_super().
>
> Just be careful with that iput() there - AFAICS, if fs went live (i.e.
> if ->s_root is non-NULL), you really need it done only from put_super();
> OTOH, for the case of NULL ->s_root ->put_super() won't be called at all,
> so in that case you need it directly in ->kill_sb().
I got it. I will do a quick try now :) But in case of introducing issues,
I guess I need to do some fault injection by hand.....
Thanks,
Gao Xiang
>
On 2019/7/21 ??????12:12, Gao Xiang wrote:
>
>
> On 2019/7/21 12:05, Al Viro wrote:
>> On Sun, Jul 21, 2019 at 11:08:42AM +0800, Gao Xiang wrote:
>>
>>> It is for debugging use as you said below, mainly for our internal
>>> testers whose jobs are
>>> to read kmsg logs and catch kernel problems. sb->s_id (device number)
>>> maybe not
>>> straight-forward for them compared with dev_name...
>>
>> Huh? ->s_id is something like "sdb7" - it's bdev_name(), not a device
>> number...
>
> You are right. Forgive me, actually we use /dev/block/by-name/system
> to mount fs... we have to do some lookup if using sdbX instead.
>
>
>>
>>> The initial purpose of erofs_mount_private was to passing multi private
>>> data from erofs_mount
>>> to erofs_read_super, which was written before fs_contest was introduced.
>>
>> That has nothing to do with fs_context (well, other than fs_context conversions
>> affecting the code very close to that).
>
> OK. That is fine.
>
>>
>>> I agree with you, it seems better to just use s_id in community and
>>> delete erofs_mount_private stuffs...
>>> Yet I don't look into how to use new fs_context, could I keep using
>>> legacy mount interface and fix them all?
>>
>> Sure.
>>
>>> I guess if I don't misunderstand, that is another suggestion -- in
>>> short, leave all destructors to .kill_sb() and
>>> cleanup fill_super().
>>
>> Just be careful with that iput() there - AFAICS, if fs went live (i.e.
>> if ->s_root is non-NULL), you really need it done only from put_super();
>> OTOH, for the case of NULL ->s_root ->put_super() won't be called at all,
>> so in that case you need it directly in ->kill_sb().
>
> I got it. I will do a quick try now :) But in case of introducing issues,
> I guess I need to do some fault injection by hand.....
I try to fix them in
https://git.kernel.org/pub/scm/linux/kernel/git/xiang/linux.git/tree/fs/erofs/super.c?h=erofs-outofstaging
, including:
1) remove unneeded sbi->dev_name;
2) remove all destructors in fill_super()
349 /* get the root inode */
350 inode = erofs_iget(sb, ROOT_NID(sbi), true);
351 if (IS_ERR(inode))
352 return PTR_ERR(inode);
353
354 if (unlikely(!S_ISDIR(inode->i_mode))) {
355 errln("rootino(nid %llu) is not a directory(i_mode %o)",
356 ROOT_NID(sbi), inode->i_mode);
357 iput(inode);
358 return -EINVAL;
359 }
360
361 sb->s_root = d_make_root(inode);
362 if (unlikely(!sb->s_root))
363 return -ENOMEM;
364
365 erofs_shrinker_register(sb);
366 #ifdef EROFS_FS_HAS_MANAGED_CACHE
367 /* sb->s_umount is locked here, SB_BORN and SB_ACTIVE are not set */
368 mc = erofs_init_managed_cache(sb);
369 if (IS_ERR(mc))
370 return PTR_ERR(mc);
371 sbi->managed_cache = mc;
372 #endif
...
385 /*
386 * could be triggered after deactivate_locked_super()
387 * is called, thus including umount and failed to initialize.
388 */
389 static void erofs_kill_sb(struct super_block *sb)
390 {
391 struct erofs_sb_info *sbi;
392
393 WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
394 infoln("unmounting erofs for %s", sb->s_id);
395
396 kill_block_super(sb);
397
398 sbi = EROFS_SB(sb);
399 if (!sbi)
400 return;
401 kfree(sbi);
402 sb->s_fs_info = NULL;
403 }
404
405 /* called when ->s_root is non-NULL */
406 static void erofs_put_super(struct super_block *sb)
407 {
408 struct erofs_sb_info *const sbi = EROFS_SB(sb);
409
410 DBG_BUGON(!sbi);
411
412 #ifdef EROFS_FS_HAS_MANAGED_CACHE
413 iput(sbi->managed_cache);
414 sbi->managed_cache = NULL;
415 #endif
416 erofs_shrinker_unregister(sb);
417 }
...
and I injected some faults on error paths and it seems fine...
Could you kindly check whether it makes sense? (if I understand all correctly....)
The whole patchset will be resent this morning (a few hours later), I have to sleep...
Thanks,
Gao Xiang