2022-09-23 02:40:26

by Yue Hu

[permalink] [raw]
Subject: [PATCH v6 1/2] erofs: support interlaced uncompressed data for compressed files

From: Yue Hu <[email protected]>

Currently, uncompressed data is all handled in the shifted way, which
means we have to shift the whole on-disk plain pcluster to get the
logical data. However, since we are also using in-place I/O for
uncompressed data, data copy will be reduced a lot if pcluster is
recorded in the interlaced way as illustrated below:
_______________________________________________________________
| | | |_ tail part |_ head part _|
|<- blk0 ->| .. |<- blkn-2 ->|<- blkn-1 ->|

The logical data then becomes:
________________________________________________________
|_ head part _|_ blk0 _| .. |_ blkn-2 _|_ tail part _|

In addition, non-4k plain pclusters are also survived by the
interlaced way, which can be used for non-4k lclusters as well.

However, it's almost impossible to de-duplicate uncompressed data
in the interlaced way, therefore shifted uncompressed data is still
useful.

Signed-off-by: Yue Hu <[email protected]>
Reviewed-by: Gao Xiang <[email protected]>
---
fs/erofs/decompressor.c | 47 ++++++++++++++++++++++++-----------------
fs/erofs/erofs_fs.h | 2 ++
fs/erofs/internal.h | 1 +
fs/erofs/zmap.c | 14 ++++++++----
4 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 2d55569f96ac..51b7ac7166d9 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -317,52 +317,61 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
return ret;
}

-static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,
- struct page **pagepool)
+static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
+ struct page **pagepool)
{
- const unsigned int nrpages_out =
+ const unsigned int inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT;
+ const unsigned int outpages =
PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
const unsigned int righthalf = min_t(unsigned int, rq->outputsize,
PAGE_SIZE - rq->pageofs_out);
const unsigned int lefthalf = rq->outputsize - righthalf;
+ const unsigned int interlaced_offset =
+ rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
unsigned char *src, *dst;

- if (nrpages_out > 2) {
+ if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
DBG_BUGON(1);
- return -EIO;
+ return -EFSCORRUPTED;
}

if (rq->out[0] == *rq->in) {
- DBG_BUGON(nrpages_out != 1);
+ DBG_BUGON(rq->pageofs_out);
return 0;
}

- src = kmap_atomic(*rq->in) + rq->pageofs_in;
+ src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
if (rq->out[0]) {
- dst = kmap_atomic(rq->out[0]);
- memcpy(dst + rq->pageofs_out, src, righthalf);
- kunmap_atomic(dst);
+ dst = kmap_local_page(rq->out[0]);
+ memcpy(dst + rq->pageofs_out, src + interlaced_offset,
+ righthalf);
+ kunmap_local(dst);
}

- if (nrpages_out == 2) {
- DBG_BUGON(!rq->out[1]);
- if (rq->out[1] == *rq->in) {
+ if (outpages > inpages) {
+ DBG_BUGON(!rq->out[outpages - 1]);
+ if (rq->out[outpages - 1] != rq->in[inpages - 1]) {
+ dst = kmap_local_page(rq->out[outpages - 1]);
+ memcpy(dst, interlaced_offset ? src :
+ (src + righthalf), lefthalf);
+ kunmap_local(dst);
+ } else if (!interlaced_offset) {
memmove(src, src + righthalf, lefthalf);
- } else {
- dst = kmap_atomic(rq->out[1]);
- memcpy(dst, src + righthalf, lefthalf);
- kunmap_atomic(dst);
}
}
- kunmap_atomic(src);
+ kunmap_local(src);
return 0;
}

static struct z_erofs_decompressor decompressors[] = {
[Z_EROFS_COMPRESSION_SHIFTED] = {
- .decompress = z_erofs_shifted_transform,
+ .decompress = z_erofs_transform_plain,
.name = "shifted"
},
+ [Z_EROFS_COMPRESSION_INTERLACED] = {
+ .decompress = z_erofs_transform_plain,
+ .name = "interlaced"
+ },
[Z_EROFS_COMPRESSION_LZ4] = {
.decompress = z_erofs_lz4_decompress,
.name = "lz4"
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 2b48373f690b..5c1de6d7ad71 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -295,11 +295,13 @@ struct z_erofs_lzma_cfgs {
* bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
* bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
* bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
+ * bit 4 : interlaced plain pcluster (0 - off; 1 - on)
*/
#define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
#define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
#define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
#define Z_EROFS_ADVISE_INLINE_PCLUSTER 0x0008
+#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER 0x0010

struct z_erofs_map_header {
__le16 h_reserved1;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index cfee49d33b95..f3ed36445d73 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -436,6 +436,7 @@ struct erofs_map_blocks {

enum {
Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
+ Z_EROFS_COMPRESSION_INTERLACED,
Z_EROFS_COMPRESSION_RUNTIME_MAX
};

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index d58549ca1df9..7196235a441c 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -679,12 +679,18 @@ static int z_erofs_do_map_blocks(struct inode *inode,
goto out;
}

- if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN)
- map->m_algorithmformat = Z_EROFS_COMPRESSION_SHIFTED;
- else if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2)
+ if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_PLAIN) {
+ if (vi->z_advise & Z_EROFS_ADVISE_INTERLACED_PCLUSTER)
+ map->m_algorithmformat =
+ Z_EROFS_COMPRESSION_INTERLACED;
+ else
+ map->m_algorithmformat =
+ Z_EROFS_COMPRESSION_SHIFTED;
+ } else if (m.headtype == Z_EROFS_VLE_CLUSTER_TYPE_HEAD2) {
map->m_algorithmformat = vi->z_algorithmtype[1];
- else
+ } else {
map->m_algorithmformat = vi->z_algorithmtype[0];
+ }

if ((flags & EROFS_GET_BLOCKS_FIEMAP) ||
((flags & EROFS_GET_BLOCKS_READMORE) &&
--
2.17.1


2022-09-23 02:41:38

by Yue Hu

[permalink] [raw]
Subject: [PATCH v6 2/2] erofs: support on-disk compressed fragments data

From: Yue Hu <[email protected]>

Introduce on-disk compressed fragments data feature.

This approach adds a new field called `h_fragmentoff' in the per-file
compression header to indicate the fragment offset of each tail pcluster
or the whole file in the special packed inode.

Similar to ztailpacking, it will also find and record the 'headlcn'
of the tail pcluster when initializing per-inode zmap for making
follow-on requests more easy.

Signed-off-by: Yue Hu <[email protected]>
---
fs/erofs/erofs_fs.h | 33 ++++++++++++++++++++++++------
fs/erofs/internal.h | 16 ++++++++++++---
fs/erofs/super.c | 15 ++++++++++++++
fs/erofs/sysfs.c | 2 ++
fs/erofs/zdata.c | 50 ++++++++++++++++++++++++++++++++++++++++++++-
fs/erofs/zmap.c | 48 +++++++++++++++++++++++++++++++++++++++++--
6 files changed, 152 insertions(+), 12 deletions(-)

diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 5c1de6d7ad71..5d8fefd8b3fb 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -25,6 +25,7 @@
#define EROFS_FEATURE_INCOMPAT_DEVICE_TABLE 0x00000008
#define EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 0x00000008
#define EROFS_FEATURE_INCOMPAT_ZTAILPACKING 0x00000010
+#define EROFS_FEATURE_INCOMPAT_FRAGMENTS 0x00000020
#define EROFS_ALL_FEATURE_INCOMPAT \
(EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
@@ -32,7 +33,8 @@
EROFS_FEATURE_INCOMPAT_CHUNKED_FILE | \
EROFS_FEATURE_INCOMPAT_DEVICE_TABLE | \
EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 | \
- EROFS_FEATURE_INCOMPAT_ZTAILPACKING)
+ EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
+ EROFS_FEATURE_INCOMPAT_FRAGMENTS)

#define EROFS_SB_EXTSLOT_SIZE 16

@@ -71,7 +73,9 @@ struct erofs_super_block {
} __packed u1;
__le16 extra_devices; /* # of devices besides the primary device */
__le16 devt_slotoff; /* startoff = devt_slotoff * devt_slotsize */
- __u8 reserved2[38];
+ __u8 reserved[6];
+ __le64 packed_nid; /* nid of the special packed inode */
+ __u8 reserved2[24];
};

/*
@@ -296,17 +300,26 @@ struct z_erofs_lzma_cfgs {
* bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
* bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
* bit 4 : interlaced plain pcluster (0 - off; 1 - on)
+ * bit 5 : fragment pcluster (0 - off; 1 - on)
*/
#define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
#define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
#define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
#define Z_EROFS_ADVISE_INLINE_PCLUSTER 0x0008
#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER 0x0010
+#define Z_EROFS_ADVISE_FRAGMENT_PCLUSTER 0x0020

+#define Z_EROFS_FRAGMENT_INODE_BIT 7
struct z_erofs_map_header {
- __le16 h_reserved1;
- /* indicates the encoded size of tailpacking data */
- __le16 h_idata_size;
+ union {
+ /* fragment data offset in the packed inode */
+ __le32 h_fragmentoff;
+ struct {
+ __le16 h_reserved1;
+ /* indicates the encoded size of tailpacking data */
+ __le16 h_idata_size;
+ };
+ };
__le16 h_advise;
/*
* bit 0-3 : algorithm type of head 1 (logical cluster type 01);
@@ -315,7 +328,8 @@ struct z_erofs_map_header {
__u8 h_algorithmtype;
/*
* bit 0-2 : logical cluster bits - 12, e.g. 0 for 4096;
- * bit 3-7 : reserved.
+ * bit 3-6 : reserved;
+ * bit 7 : move the whole file into packed inode or not.
*/
__u8 h_clusterbits;
};
@@ -404,6 +418,10 @@ struct erofs_dirent {
/* check the EROFS on-disk layout strictly at compile time */
static inline void erofs_check_ondisk_layout_definitions(void)
{
+ const __le64 fmh = *(__le64 *)&(struct z_erofs_map_header) {
+ .h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
+ };
+
BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64);
@@ -421,6 +439,9 @@ static inline void erofs_check_ondisk_layout_definitions(void)

BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
+ /* exclude old compiler versions like gcc 7.5.0 */
+ BUILD_BUG_ON(__builtin_constant_p(fmh) ?
+ fmh != cpu_to_le64(1ULL << 63) : 0);
}

#endif
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f3ed36445d73..b133664b4ad2 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -120,6 +120,7 @@ struct erofs_sb_info {
struct inode *managed_cache;

struct erofs_sb_lz4_info lz4;
+ struct inode *packed_inode;
#endif /* CONFIG_EROFS_FS_ZIP */
struct erofs_dev_context *devs;
struct dax_device *dax_dev;
@@ -306,6 +307,7 @@ EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
EROFS_FEATURE_FUNCS(compr_head2, incompat, INCOMPAT_COMPR_HEAD2)
EROFS_FEATURE_FUNCS(ztailpacking, incompat, INCOMPAT_ZTAILPACKING)
+EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS)
EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)

/* atomic flag definitions */
@@ -341,8 +343,13 @@ struct erofs_inode {
unsigned char z_algorithmtype[2];
unsigned char z_logical_clusterbits;
unsigned long z_tailextent_headlcn;
- erofs_off_t z_idataoff;
- unsigned short z_idata_size;
+ union {
+ struct {
+ erofs_off_t z_idataoff;
+ unsigned short z_idata_size;
+ };
+ erofs_off_t z_fragmentoff;
+ };
};
#endif /* CONFIG_EROFS_FS_ZIP */
};
@@ -400,6 +407,7 @@ extern const struct address_space_operations z_erofs_aops;
enum {
BH_Encoded = BH_PrivateStart,
BH_FullMapped,
+ BH_Fragment,
};

/* Has a disk mapping */
@@ -410,6 +418,8 @@ enum {
#define EROFS_MAP_ENCODED (1 << BH_Encoded)
/* The length of extent is full */
#define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
+/* Located in the special packed inode */
+#define EROFS_MAP_FRAGMENT (1 << BH_Fragment)

struct erofs_map_blocks {
struct erofs_buf buf;
@@ -431,7 +441,7 @@ struct erofs_map_blocks {
#define EROFS_GET_BLOCKS_FIEMAP 0x0002
/* Used to map the whole extent if non-negligible data is requested for LZMA */
#define EROFS_GET_BLOCKS_READMORE 0x0004
-/* Used to map tail extent for tailpacking inline pcluster */
+/* Used to map tail extent for tailpacking inline or fragment pcluster */
#define EROFS_GET_BLOCKS_FINDTAIL 0x0008

enum {
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 3173debeaa5a..8170c0d8ab92 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -381,6 +381,17 @@ static int erofs_read_superblock(struct super_block *sb)
#endif
sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
sbi->root_nid = le16_to_cpu(dsb->root_nid);
+#ifdef CONFIG_EROFS_FS_ZIP
+ sbi->packed_inode = NULL;
+ if (erofs_sb_has_fragments(sbi)) {
+ sbi->packed_inode =
+ erofs_iget(sb, le64_to_cpu(dsb->packed_nid), false);
+ if (IS_ERR(sbi->packed_inode)) {
+ ret = PTR_ERR(sbi->packed_inode);
+ goto out;
+ }
+ }
+#endif
sbi->inos = le64_to_cpu(dsb->inos);

sbi->build_time = le64_to_cpu(dsb->build_time);
@@ -411,6 +422,8 @@ static int erofs_read_superblock(struct super_block *sb)
erofs_info(sb, "EXPERIMENTAL compressed inline data feature in use. Use at your own risk!");
if (erofs_is_fscache_mode(sb))
erofs_info(sb, "EXPERIMENTAL fscache-based on-demand read feature in use. Use at your own risk!");
+ if (erofs_sb_has_fragments(sbi))
+ erofs_info(sb, "EXPERIMENTAL compressed fragments feature in use. Use at your own risk!");
out:
erofs_put_metabuf(&buf);
return ret;
@@ -908,6 +921,8 @@ static void erofs_put_super(struct super_block *sb)
#ifdef CONFIG_EROFS_FS_ZIP
iput(sbi->managed_cache);
sbi->managed_cache = NULL;
+ iput(sbi->packed_inode);
+ sbi->packed_inode = NULL;
#endif
erofs_fscache_unregister_cookie(&sbi->s_fscache);
}
diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index c1383e508bbe..1b52395be82a 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -76,6 +76,7 @@ EROFS_ATTR_FEATURE(device_table);
EROFS_ATTR_FEATURE(compr_head2);
EROFS_ATTR_FEATURE(sb_chksum);
EROFS_ATTR_FEATURE(ztailpacking);
+EROFS_ATTR_FEATURE(fragments);

static struct attribute *erofs_feat_attrs[] = {
ATTR_LIST(zero_padding),
@@ -86,6 +87,7 @@ static struct attribute *erofs_feat_attrs[] = {
ATTR_LIST(compr_head2),
ATTR_LIST(sb_chksum),
ATTR_LIST(ztailpacking),
+ ATTR_LIST(fragments),
NULL,
};
ATTRIBUTE_GROUPS(erofs_feat);
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 5792ca9e0d5e..c92a72f5bca6 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -650,6 +650,35 @@ static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
la < fe->headoffset;
}

+static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos,
+ struct page *page, unsigned int pageofs,
+ unsigned int len)
+{
+ struct inode *packed_inode = EROFS_I_SB(inode)->packed_inode;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ u8 *src, *dst;
+ unsigned int i, cnt;
+
+ pos += EROFS_I(inode)->z_fragmentoff;
+ for (i = 0; i < len; i += cnt) {
+ cnt = min_t(unsigned int, len - i,
+ EROFS_BLKSIZ - erofs_blkoff(pos));
+ src = erofs_bread(&buf, packed_inode,
+ erofs_blknr(pos), EROFS_KMAP);
+ if (IS_ERR(src)) {
+ erofs_put_metabuf(&buf);
+ return PTR_ERR(src);
+ }
+
+ dst = kmap_local_page(page);
+ memcpy(dst + pageofs + i, src + erofs_blkoff(pos), cnt);
+ kunmap_local(dst);
+ pos += cnt;
+ }
+ erofs_put_metabuf(&buf);
+ return 0;
+}
+
static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
struct page *page, struct page **pagepool)
{
@@ -688,7 +717,8 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
/* didn't get a valid pcluster previously (very rare) */
}

- if (!(map->m_flags & EROFS_MAP_MAPPED))
+ if (!(map->m_flags & EROFS_MAP_MAPPED) ||
+ map->m_flags & EROFS_MAP_FRAGMENT)
goto hitted;

err = z_erofs_collector_begin(fe);
@@ -735,6 +765,24 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
zero_user_segment(page, cur, end);
goto next_part;
}
+ if (map->m_flags & EROFS_MAP_FRAGMENT) {
+ unsigned int pageofs, skip, len;
+
+ if (offset > map->m_la) {
+ pageofs = 0;
+ skip = offset - map->m_la;
+ } else {
+ pageofs = map->m_la & ~PAGE_MASK;
+ skip = 0;
+ }
+ len = min_t(unsigned int, map->m_llen - skip, end - cur);
+ err = z_erofs_read_fragment(inode, skip, page, pageofs, len);
+ if (err)
+ goto out;
+ ++spiltted;
+ tight = false;
+ goto next_part;
+ }

exclusive = (!cur && (!spiltted || tight));
if (cur)
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 7196235a441c..6830999529d7 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -69,6 +69,16 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
}

h = kaddr + erofs_blkoff(pos);
+ /*
+ * if the highest bit of the 8-byte map header is set, the whole file
+ * is stored in the packed inode. The rest bits keeps z_fragmentoff.
+ */
+ if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) {
+ vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
+ vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
+ vi->z_tailextent_headlcn = 0;
+ goto unmap_done;
+ }
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;
@@ -123,6 +133,20 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
if (err < 0)
goto out_unlock;
}
+
+ if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
+ !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) {
+ struct erofs_map_blocks map = {
+ .buf = __EROFS_BUF_INITIALIZER
+ };
+
+ vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
+ err = z_erofs_do_map_blocks(inode, &map,
+ EROFS_GET_BLOCKS_FINDTAIL);
+ erofs_put_metabuf(&map.buf);
+ if (err < 0)
+ goto out_unlock;
+ }
/* paired with smp_mb() at the beginning of the function */
smp_mb();
set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
@@ -598,6 +622,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
{
struct erofs_inode *const vi = EROFS_I(inode);
bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
+ bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
struct z_erofs_maprecorder m = {
.inode = inode,
.map = map,
@@ -666,12 +691,20 @@ static int z_erofs_do_map_blocks(struct inode *inode,

map->m_llen = end - map->m_la;

- if (flags & EROFS_GET_BLOCKS_FINDTAIL)
+ if (flags & EROFS_GET_BLOCKS_FINDTAIL) {
vi->z_tailextent_headlcn = m.lcn;
+ /* for non-compact indexes, fragmentoff is 64 bits */
+ if (fragment &&
+ vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
+ vi->z_fragmentoff |= (u64)m.pblk << 32;
+ }
if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
map->m_flags |= EROFS_MAP_META;
map->m_pa = vi->z_idataoff;
map->m_plen = vi->z_idata_size;
+ } else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
+ map->m_flags |= EROFS_MAP_FRAGMENT;
+ DBG_BUGON(!map->m_la);
} else {
map->m_pa = blknr_to_addr(m.pblk);
err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
@@ -715,6 +748,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
struct erofs_map_blocks *map,
int flags)
{
+ struct erofs_inode *const vi = EROFS_I(inode);
int err = 0;

trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
@@ -731,6 +765,15 @@ int z_erofs_map_blocks_iter(struct inode *inode,
if (err)
goto out;

+ if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) &&
+ !vi->z_tailextent_headlcn) {
+ map->m_la = 0;
+ map->m_llen = inode->i_size;
+ map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_FULL_MAPPED |
+ EROFS_MAP_FRAGMENT;
+ goto out;
+ }
+
err = z_erofs_do_map_blocks(inode, map, flags);
out:
trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
@@ -757,7 +800,8 @@ static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
iomap->length = map.m_llen;
if (map.m_flags & EROFS_MAP_MAPPED) {
iomap->type = IOMAP_MAPPED;
- iomap->addr = map.m_pa;
+ iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ?
+ IOMAP_NULL_ADDR : map.m_pa;
} else {
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
--
2.17.1

2022-09-26 17:18:45

by Gao Xiang

[permalink] [raw]
Subject: Re: [PATCH v6 2/2] erofs: support on-disk compressed fragments data

On Fri, Sep 23, 2022 at 10:11:22AM +0800, Yue Hu wrote:
> From: Yue Hu <[email protected]>
>
> Introduce on-disk compressed fragments data feature.
>
> This approach adds a new field called `h_fragmentoff' in the per-file
> compression header to indicate the fragment offset of each tail pcluster
> or the whole file in the special packed inode.
>
> Similar to ztailpacking, it will also find and record the 'headlcn'
> of the tail pcluster when initializing per-inode zmap for making
> follow-on requests more easy.
>
> Signed-off-by: Yue Hu <[email protected]>

The patchset overall looks good to me,

However, there are some conflicts and userspace adaption with data dedupe
feature, so I applied the following patch to -next.

If you have some update then, please help follow the following update
as well.

Thanks,
Gao Xiang

From 08a0c9ef3e7e119c96de4a1b6fbdabdadb38b2f9 Mon Sep 17 00:00:00 2001
From: Yue Hu <[email protected]>
Date: Fri, 23 Sep 2022 10:11:22 +0800
Subject: erofs: support on-disk compressed fragments data

Introduce on-disk compressed fragments data feature.

This approach adds a new field called `h_fragmentoff' in the per-file
compression header to indicate the fragment offset of each tail pcluster
or the whole file in the special packed inode.

Similar to ztailpacking, it will also find and record the 'headlcn'
of the tail pcluster when initializing per-inode zmap for making
follow-on requests more easy.

Signed-off-by: Yue Hu <[email protected]>
Reviewed-by: Gao Xiang <[email protected]>
Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/erofs_fs.h | 33 +++++++++++++++++++++++++++------
fs/erofs/internal.h | 16 +++++++++++++---
fs/erofs/super.c | 15 +++++++++++++++
fs/erofs/sysfs.c | 2 ++
fs/erofs/zdata.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
fs/erofs/zmap.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++-------
6 files changed, 152 insertions(+), 17 deletions(-)

diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
index 5c1de6d7ad71f..b5d763aa8ff03 100644
--- a/fs/erofs/erofs_fs.h
+++ b/fs/erofs/erofs_fs.h
@@ -25,6 +25,7 @@
#define EROFS_FEATURE_INCOMPAT_DEVICE_TABLE 0x00000008
#define EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 0x00000008
#define EROFS_FEATURE_INCOMPAT_ZTAILPACKING 0x00000010
+#define EROFS_FEATURE_INCOMPAT_FRAGMENTS 0x00000020
#define EROFS_ALL_FEATURE_INCOMPAT \
(EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
@@ -32,7 +33,8 @@
EROFS_FEATURE_INCOMPAT_CHUNKED_FILE | \
EROFS_FEATURE_INCOMPAT_DEVICE_TABLE | \
EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 | \
- EROFS_FEATURE_INCOMPAT_ZTAILPACKING)
+ EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
+ EROFS_FEATURE_INCOMPAT_FRAGMENTS)

#define EROFS_SB_EXTSLOT_SIZE 16

@@ -71,7 +73,9 @@ struct erofs_super_block {
} __packed u1;
__le16 extra_devices; /* # of devices besides the primary device */
__le16 devt_slotoff; /* startoff = devt_slotoff * devt_slotsize */
- __u8 reserved2[38];
+ __u8 reserved[6];
+ __le64 packed_nid; /* nid of the special packed inode */
+ __u8 reserved2[24];
};

/*
@@ -296,17 +300,26 @@ struct z_erofs_lzma_cfgs {
* bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
* bit 3 : tailpacking inline pcluster (0 - off; 1 - on)
* bit 4 : interlaced plain pcluster (0 - off; 1 - on)
+ * bit 5 : fragment pcluster (0 - off; 1 - on)
*/
#define Z_EROFS_ADVISE_COMPACTED_2B 0x0001
#define Z_EROFS_ADVISE_BIG_PCLUSTER_1 0x0002
#define Z_EROFS_ADVISE_BIG_PCLUSTER_2 0x0004
#define Z_EROFS_ADVISE_INLINE_PCLUSTER 0x0008
#define Z_EROFS_ADVISE_INTERLACED_PCLUSTER 0x0010
+#define Z_EROFS_ADVISE_FRAGMENT_PCLUSTER 0x0020

+#define Z_EROFS_FRAGMENT_INODE_BIT 7
struct z_erofs_map_header {
- __le16 h_reserved1;
- /* indicates the encoded size of tailpacking data */
- __le16 h_idata_size;
+ union {
+ /* fragment data offset in the packed inode */
+ __le32 h_fragmentoff;
+ struct {
+ __le16 h_reserved1;
+ /* indicates the encoded size of tailpacking data */
+ __le16 h_idata_size;
+ };
+ };
__le16 h_advise;
/*
* bit 0-3 : algorithm type of head 1 (logical cluster type 01);
@@ -315,7 +328,8 @@ struct z_erofs_map_header {
__u8 h_algorithmtype;
/*
* bit 0-2 : logical cluster bits - 12, e.g. 0 for 4096;
- * bit 3-7 : reserved.
+ * bit 3-6 : reserved;
+ * bit 7 : move the whole file into packed inode or not.
*/
__u8 h_clusterbits;
};
@@ -404,6 +418,10 @@ struct erofs_dirent {
/* check the EROFS on-disk layout strictly at compile time */
static inline void erofs_check_ondisk_layout_definitions(void)
{
+ const __le64 fmh = *(__le64 *)&(struct z_erofs_map_header) {
+ .h_clusterbits = 1 << Z_EROFS_FRAGMENT_INODE_BIT
+ };
+
BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
BUILD_BUG_ON(sizeof(struct erofs_inode_compact) != 32);
BUILD_BUG_ON(sizeof(struct erofs_inode_extended) != 64);
@@ -421,6 +439,9 @@ static inline void erofs_check_ondisk_layout_definitions(void)

BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
+ /* exclude old compiler versions like gcc 7.5.0 */
+ BUILD_BUG_ON(__builtin_constant_p(fmh) ?
+ fmh != cpu_to_le64(1ULL << 63) : 0);
}

#endif
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 8dbfeb5f4f844..9f89c1da6229a 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -131,6 +131,7 @@ struct erofs_sb_info {
struct inode *managed_cache;

struct erofs_sb_lz4_info lz4;
+ struct inode *packed_inode;
#endif /* CONFIG_EROFS_FS_ZIP */
struct erofs_dev_context *devs;
struct dax_device *dax_dev;
@@ -289,6 +290,7 @@ EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
EROFS_FEATURE_FUNCS(compr_head2, incompat, INCOMPAT_COMPR_HEAD2)
EROFS_FEATURE_FUNCS(ztailpacking, incompat, INCOMPAT_ZTAILPACKING)
+EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS)
EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)

/* atomic flag definitions */
@@ -324,8 +326,13 @@ struct erofs_inode {
unsigned char z_algorithmtype[2];
unsigned char z_logical_clusterbits;
unsigned long z_tailextent_headlcn;
- erofs_off_t z_idataoff;
- unsigned short z_idata_size;
+ union {
+ struct {
+ erofs_off_t z_idataoff;
+ unsigned short z_idata_size;
+ };
+ erofs_off_t z_fragmentoff;
+ };
};
#endif /* CONFIG_EROFS_FS_ZIP */
};
@@ -384,6 +391,7 @@ extern const struct address_space_operations z_erofs_aops;
enum {
BH_Encoded = BH_PrivateStart,
BH_FullMapped,
+ BH_Fragment,
};

/* Has a disk mapping */
@@ -394,6 +402,8 @@ enum {
#define EROFS_MAP_ENCODED (1 << BH_Encoded)
/* The length of extent is full */
#define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
+/* Located in the special packed inode */
+#define EROFS_MAP_FRAGMENT (1 << BH_Fragment)

struct erofs_map_blocks {
struct erofs_buf buf;
@@ -415,7 +425,7 @@ struct erofs_map_blocks {
#define EROFS_GET_BLOCKS_FIEMAP 0x0002
/* Used to map the whole extent if non-negligible data is requested for LZMA */
#define EROFS_GET_BLOCKS_READMORE 0x0004
-/* Used to map tail extent for tailpacking inline pcluster */
+/* Used to map tail extent for tailpacking inline or fragment pcluster */
#define EROFS_GET_BLOCKS_FINDTAIL 0x0008

enum {
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 9f7fe6c04e654..ce20562ca91f4 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -381,6 +381,17 @@ static int erofs_read_superblock(struct super_block *sb)
#endif
sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
sbi->root_nid = le16_to_cpu(dsb->root_nid);
+#ifdef CONFIG_EROFS_FS_ZIP
+ sbi->packed_inode = NULL;
+ if (erofs_sb_has_fragments(sbi) && dsb->packed_nid) {
+ sbi->packed_inode =
+ erofs_iget(sb, le64_to_cpu(dsb->packed_nid), false);
+ if (IS_ERR(sbi->packed_inode)) {
+ ret = PTR_ERR(sbi->packed_inode);
+ goto out;
+ }
+ }
+#endif
sbi->inos = le64_to_cpu(dsb->inos);

sbi->build_time = le64_to_cpu(dsb->build_time);
@@ -411,6 +422,8 @@ static int erofs_read_superblock(struct super_block *sb)
erofs_info(sb, "EXPERIMENTAL compressed inline data feature in use. Use at your own risk!");
if (erofs_is_fscache_mode(sb))
erofs_info(sb, "EXPERIMENTAL fscache-based on-demand read feature in use. Use at your own risk!");
+ if (erofs_sb_has_fragments(sbi))
+ erofs_info(sb, "EXPERIMENTAL compressed fragments feature in use. Use at your own risk!");
out:
erofs_put_metabuf(&buf);
return ret;
@@ -947,6 +960,8 @@ static void erofs_put_super(struct super_block *sb)
#ifdef CONFIG_EROFS_FS_ZIP
iput(sbi->managed_cache);
sbi->managed_cache = NULL;
+ iput(sbi->packed_inode);
+ sbi->packed_inode = NULL;
#endif
erofs_fscache_unregister_fs(sb);
}
diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index 341fb43ad5874..dd6eb7eccf9a2 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -76,6 +76,7 @@ EROFS_ATTR_FEATURE(device_table);
EROFS_ATTR_FEATURE(compr_head2);
EROFS_ATTR_FEATURE(sb_chksum);
EROFS_ATTR_FEATURE(ztailpacking);
+EROFS_ATTR_FEATURE(fragments);

static struct attribute *erofs_feat_attrs[] = {
ATTR_LIST(zero_padding),
@@ -86,6 +87,7 @@ static struct attribute *erofs_feat_attrs[] = {
ATTR_LIST(compr_head2),
ATTR_LIST(sb_chksum),
ATTR_LIST(ztailpacking),
+ ATTR_LIST(fragments),
NULL,
};
ATTRIBUTE_GROUPS(erofs_feat);
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 5792ca9e0d5ef..c92a72f5bca65 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -650,6 +650,35 @@ static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
la < fe->headoffset;
}

+static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos,
+ struct page *page, unsigned int pageofs,
+ unsigned int len)
+{
+ struct inode *packed_inode = EROFS_I_SB(inode)->packed_inode;
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ u8 *src, *dst;
+ unsigned int i, cnt;
+
+ pos += EROFS_I(inode)->z_fragmentoff;
+ for (i = 0; i < len; i += cnt) {
+ cnt = min_t(unsigned int, len - i,
+ EROFS_BLKSIZ - erofs_blkoff(pos));
+ src = erofs_bread(&buf, packed_inode,
+ erofs_blknr(pos), EROFS_KMAP);
+ if (IS_ERR(src)) {
+ erofs_put_metabuf(&buf);
+ return PTR_ERR(src);
+ }
+
+ dst = kmap_local_page(page);
+ memcpy(dst + pageofs + i, src + erofs_blkoff(pos), cnt);
+ kunmap_local(dst);
+ pos += cnt;
+ }
+ erofs_put_metabuf(&buf);
+ return 0;
+}
+
static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
struct page *page, struct page **pagepool)
{
@@ -688,7 +717,8 @@ repeat:
/* didn't get a valid pcluster previously (very rare) */
}

- if (!(map->m_flags & EROFS_MAP_MAPPED))
+ if (!(map->m_flags & EROFS_MAP_MAPPED) ||
+ map->m_flags & EROFS_MAP_FRAGMENT)
goto hitted;

err = z_erofs_collector_begin(fe);
@@ -735,6 +765,24 @@ hitted:
zero_user_segment(page, cur, end);
goto next_part;
}
+ if (map->m_flags & EROFS_MAP_FRAGMENT) {
+ unsigned int pageofs, skip, len;
+
+ if (offset > map->m_la) {
+ pageofs = 0;
+ skip = offset - map->m_la;
+ } else {
+ pageofs = map->m_la & ~PAGE_MASK;
+ skip = 0;
+ }
+ len = min_t(unsigned int, map->m_llen - skip, end - cur);
+ err = z_erofs_read_fragment(inode, skip, page, pageofs, len);
+ if (err)
+ goto out;
+ ++spiltted;
+ tight = false;
+ goto next_part;
+ }

exclusive = (!cur && (!spiltted || tight));
if (cur)
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 7196235a441c1..d1723910251cc 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -17,7 +17,7 @@ int z_erofs_fill_inode(struct inode *inode)
struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);

if (!erofs_sb_has_big_pcluster(sbi) &&
- !erofs_sb_has_ztailpacking(sbi) &&
+ !erofs_sb_has_ztailpacking(sbi) && !erofs_sb_has_fragments(sbi) &&
vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY) {
vi->z_advise = 0;
vi->z_algorithmtype[0] = 0;
@@ -55,10 +55,6 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags))
goto out_unlock;

- DBG_BUGON(!erofs_sb_has_big_pcluster(EROFS_SB(sb)) &&
- !erofs_sb_has_ztailpacking(EROFS_SB(sb)) &&
- vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY);
-
pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
vi->xattr_isize, 8);
kaddr = erofs_read_metabuf(&buf, sb, erofs_blknr(pos),
@@ -69,6 +65,16 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
}

h = kaddr + erofs_blkoff(pos);
+ /*
+ * if the highest bit of the 8-byte map header is set, the whole file
+ * is stored in the packed inode. The rest bits keeps z_fragmentoff.
+ */
+ if (h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT) {
+ vi->z_advise = Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
+ vi->z_fragmentoff = le64_to_cpu(*(__le64 *)h) ^ (1ULL << 63);
+ vi->z_tailextent_headlcn = 0;
+ goto unmap_done;
+ }
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;
@@ -123,6 +129,20 @@ unmap_done:
if (err < 0)
goto out_unlock;
}
+
+ if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
+ !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) {
+ struct erofs_map_blocks map = {
+ .buf = __EROFS_BUF_INITIALIZER
+ };
+
+ vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
+ err = z_erofs_do_map_blocks(inode, &map,
+ EROFS_GET_BLOCKS_FINDTAIL);
+ erofs_put_metabuf(&map.buf);
+ if (err < 0)
+ goto out_unlock;
+ }
/* paired with smp_mb() at the beginning of the function */
smp_mb();
set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
@@ -598,6 +618,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
{
struct erofs_inode *const vi = EROFS_I(inode);
bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
+ bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
struct z_erofs_maprecorder m = {
.inode = inode,
.map = map,
@@ -666,12 +687,19 @@ static int z_erofs_do_map_blocks(struct inode *inode,

map->m_llen = end - map->m_la;

- if (flags & EROFS_GET_BLOCKS_FINDTAIL)
+ if (flags & EROFS_GET_BLOCKS_FINDTAIL) {
vi->z_tailextent_headlcn = m.lcn;
+ /* for non-compact indexes, fragmentoff is 64 bits */
+ if (fragment &&
+ vi->datalayout == EROFS_INODE_FLAT_COMPRESSION_LEGACY)
+ vi->z_fragmentoff |= (u64)m.pblk << 32;
+ }
if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
map->m_flags |= EROFS_MAP_META;
map->m_pa = vi->z_idataoff;
map->m_plen = vi->z_idata_size;
+ } else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
+ map->m_flags |= EROFS_MAP_FRAGMENT;
} else {
map->m_pa = blknr_to_addr(m.pblk);
err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
@@ -715,6 +743,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
struct erofs_map_blocks *map,
int flags)
{
+ struct erofs_inode *const vi = EROFS_I(inode);
int err = 0;

trace_z_erofs_map_blocks_iter_enter(inode, map, flags);
@@ -731,6 +760,15 @@ int z_erofs_map_blocks_iter(struct inode *inode,
if (err)
goto out;

+ if ((vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER) &&
+ !vi->z_tailextent_headlcn) {
+ map->m_la = 0;
+ map->m_llen = inode->i_size;
+ map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_FULL_MAPPED |
+ EROFS_MAP_FRAGMENT;
+ goto out;
+ }
+
err = z_erofs_do_map_blocks(inode, map, flags);
out:
trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
@@ -757,7 +795,8 @@ static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
iomap->length = map.m_llen;
if (map.m_flags & EROFS_MAP_MAPPED) {
iomap->type = IOMAP_MAPPED;
- iomap->addr = map.m_pa;
+ iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ?
+ IOMAP_NULL_ADDR : map.m_pa;
} else {
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
--
cgit