These patches add client support for the NFS v4.2 operation READ_PLUS. This
operation is triggered by doing any kind of read on a NFS v4.2 mounted
filesystem. `
Changes since v1:
- Add support for decoding multiple segments.
These patches and the corresponding server changes are available in the
[read_plus] branch of
git://git.linux-nfs.org/projects/anna/linux-nfs.git
Questions? Comments? Thoughts?
Anna
Anna Schumaker (6):
NFS: Add READ_PLUS support for data segments
SUNRPC: Split out a function for setting current page
SUNRPC: Add the ability to expand holes in data pages
NFS: Add READ_PLUS support for hole segments
SUNRPC: Add the ability to shift data to a specific offset
NFS: Add support for decoding multiple segments
fs/nfs/nfs42xdr.c | 163 ++++++++++++++++++++++++++++++
fs/nfs/nfs4proc.c | 30 +++++-
fs/nfs/nfs4xdr.c | 1 +
include/linux/nfs4.h | 1 +
include/linux/nfs_fs_sb.h | 1 +
include/linux/nfs_xdr.h | 2 +-
include/linux/sunrpc/xdr.h | 2 +
net/sunrpc/xdr.c | 245 ++++++++++++++++++++++++++++++++++++++++++++-
8 files changed, 440 insertions(+), 5 deletions(-)
--
2.2.2
This patch adds support for decoding a single NFS4_CONTENT_DATA segment,
matching the behaviour of READ without introducing holes.
Signed-off-by: Anna Schumaker <[email protected]>
---
fs/nfs/nfs42xdr.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++
fs/nfs/nfs4proc.c | 30 ++++++++++-
fs/nfs/nfs4xdr.c | 1 +
include/linux/nfs4.h | 1 +
include/linux/nfs_fs_sb.h | 1 +
include/linux/nfs_xdr.h | 2 +-
6 files changed, 167 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 038a7e1..3d7c01b 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -13,6 +13,15 @@
#define encode_deallocate_maxsz (op_encode_hdr_maxsz + \
encode_fallocate_maxsz)
#define decode_deallocate_maxsz (op_decode_hdr_maxsz)
+#define encode_read_plus_maxsz (op_encode_hdr_maxsz + \
+ encode_stateid_maxsz + 3)
+#define decode_read_plus_maxsz (op_decode_hdr_maxsz + \
+ 1 /* rpr_eof */ + \
+ 1 /* rpr_contents count */ + \
+ 1 /* data_content4 */ + \
+ 2 /* data_info4.di_offset */ + \
+ 2 /* data_info4.di_length */)
+
#define encode_seek_maxsz (op_encode_hdr_maxsz + \
encode_stateid_maxsz + \
2 /* offset */ + \
@@ -35,6 +44,12 @@
#define NFS4_dec_deallocate_sz (compound_decode_hdr_maxsz + \
decode_putfh_maxsz + \
decode_deallocate_maxsz)
+#define NFS4_enc_read_plus_sz (compound_encode_hdr_maxsz + \
+ encode_putfh_maxsz + \
+ encode_read_plus_maxsz)
+#define NFS4_dec_read_plus_sz (compound_decode_hdr_maxsz + \
+ decode_putfh_maxsz + \
+ decode_read_plus_maxsz)
#define NFS4_enc_seek_sz (compound_encode_hdr_maxsz + \
encode_putfh_maxsz + \
encode_seek_maxsz)
@@ -67,6 +82,16 @@ static void encode_deallocate(struct xdr_stream *xdr,
encode_fallocate(xdr, args);
}
+static void encode_read_plus(struct xdr_stream *xdr,
+ struct nfs_pgio_args *args,
+ struct compound_hdr *hdr)
+{
+ encode_op_hdr(xdr, OP_READ_PLUS, decode_read_plus_maxsz, hdr);
+ encode_nfs4_stateid(xdr, &args->stateid);
+ encode_uint64(xdr, args->offset);
+ encode_uint32(xdr, args->count);
+}
+
static void encode_seek(struct xdr_stream *xdr,
struct nfs42_seek_args *args,
struct compound_hdr *hdr)
@@ -114,6 +139,28 @@ static void nfs4_xdr_enc_deallocate(struct rpc_rqst *req,
}
/*
+ * Encode READ_PLUS request
+ */
+static void nfs4_xdr_enc_read_plus(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ struct nfs_pgio_args *args)
+{
+ struct compound_hdr hdr = {
+ .minorversion = nfs4_xdr_minorversion(&args->seq_args),
+ };
+
+ encode_compound_hdr(xdr, req, &hdr);
+ encode_sequence(xdr, &args->seq_args, &hdr);
+ encode_putfh(xdr, args->fh, &hdr);
+ encode_read_plus(xdr, args, &hdr);
+
+ xdr_inline_pages(&req->rq_rcv_buf, hdr.replen << 2,
+ args->pages, args->pgbase, args->count);
+ req->rq_rcv_buf.flags |= XDRBUF_READ;
+ encode_nops(&hdr);
+}
+
+/*
* Encode SEEK request
*/
static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
@@ -141,6 +188,68 @@ static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *re
return decode_op_hdr(xdr, OP_DEALLOCATE);
}
+static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *res)
+{
+ __be32 *p;
+ uint32_t count, recvd;
+ uint64_t offset;
+
+ p = xdr_inline_decode(xdr, 8 + 4);
+ if (unlikely(!p))
+ goto out_overflow;
+
+ p = xdr_decode_hyper(p, &offset);
+ count = be32_to_cpup(p);
+
+ recvd = xdr_read_pages(xdr, count);
+ if (recvd < count)
+ res->eof = 0;
+
+ res->count = recvd;
+ return 0;
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+}
+
+static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
+{
+ __be32 *p;
+ int status, type;
+ uint32_t segments;
+
+ status = decode_op_hdr(xdr, OP_READ_PLUS);
+ if (status)
+ return status;
+
+ p = xdr_inline_decode(xdr, 4 + 4);
+ if (unlikely(!p))
+ goto out_overflow;
+
+ res->count = 0;
+ res->eof = be32_to_cpup(p++);
+ segments = be32_to_cpup(p++);
+ if (segments == 0)
+ return 0;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+
+ type = be32_to_cpup(p++);
+ if (type == NFS4_CONTENT_DATA)
+ status = decode_read_plus_data(xdr, res);
+ else
+ status = -ENOTSUPP;
+
+ if (segments > 1)
+ res->eof = 0;
+ return status;
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+}
+
static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
{
int status;
@@ -212,6 +321,32 @@ out:
}
/*
+ * Decode READ_PLUS request
+ */
+static int nfs4_xdr_dec_read_plus(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ struct nfs_pgio_res *res)
+{
+ struct compound_hdr hdr;
+ int status;
+
+ status = decode_compound_hdr(xdr, &hdr);
+ if (status)
+ goto out;
+ status = decode_sequence(xdr, &res->seq_res, rqstp);
+ if (status)
+ goto out;
+ status = decode_putfh(xdr);
+ if (status)
+ goto out;
+ status = decode_read_plus(xdr, res);
+ if (!status)
+ status = res->count;
+out:
+ return status;
+}
+
+/*
* Decode SEEK request
*/
static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0f75b92..5887340 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -68,6 +68,10 @@
#include "nfs4trace.h"
+#ifdef CONFIG_NFS_V4_2
+#include "nfs42.h"
+#endif /* CONFIG_NFS_V4_2 */
+
#define NFSDBG_FACILITY NFSDBG_PROC
#define NFS4_POLL_RETRY_MIN (HZ/10)
@@ -4150,9 +4154,15 @@ static bool nfs4_read_stateid_changed(struct rpc_task *task,
static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
{
-
+ struct nfs_server *server = NFS_SERVER(hdr->inode);
dprintk("--> %s\n", __func__);
+ if ((server->caps & NFS_CAP_READ_PLUS) && (task->tk_status == -ENOTSUPP)) {
+ server->caps &= ~NFS_CAP_READ_PLUS;
+ if (rpc_restart_call_prepare(task))
+ task->tk_status = 0;
+ return -EAGAIN;
+ }
if (!nfs4_sequence_done(task, &hdr->res.seq_res))
return -EAGAIN;
if (nfs4_read_stateid_changed(task, &hdr->args))
@@ -4161,12 +4171,27 @@ static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
nfs4_read_done_cb(task, hdr);
}
+#ifdef CONFIG_NFS_V4_2
+static void nfs42_read_plus_support(struct nfs_server *server, struct rpc_message *msg)
+{
+ if (server->caps & NFS_CAP_READ_PLUS)
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS];
+ else
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+}
+#else
+static void nfs42_read_plus_support(struct nfs_server *server, struct rpc_message *msg)
+{
+ msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+}
+#endif /* CONFIG_NFS_V4_2 */
+
static void nfs4_proc_read_setup(struct nfs_pgio_header *hdr,
struct rpc_message *msg)
{
hdr->timestamp = jiffies;
hdr->pgio_done_cb = nfs4_read_done_cb;
- msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+ nfs42_read_plus_support(NFS_SERVER(hdr->inode), msg);
nfs4_init_sequence(&hdr->args.seq_args, &hdr->res.seq_res, 0);
}
@@ -8463,6 +8488,7 @@ static const struct nfs4_minor_version_ops nfs_v4_2_minor_ops = {
| NFS_CAP_ATOMIC_OPEN_V1
| NFS_CAP_ALLOCATE
| NFS_CAP_DEALLOCATE
+ | NFS_CAP_READ_PLUS
| NFS_CAP_SEEK,
.init_client = nfs41_init_client,
.shutdown_client = nfs41_shutdown_client,
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 4125339..da01f00 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -7397,6 +7397,7 @@ struct rpc_procinfo nfs4_procedures[] = {
PROC(SEEK, enc_seek, dec_seek),
PROC(ALLOCATE, enc_allocate, dec_allocate),
PROC(DEALLOCATE, enc_deallocate, dec_deallocate),
+ PROC(READ_PLUS, enc_read_plus, dec_read_plus),
#endif /* CONFIG_NFS_V4_2 */
};
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index 022b761..41fc2f4 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -492,6 +492,7 @@ enum {
NFSPROC4_CLNT_SEEK,
NFSPROC4_CLNT_ALLOCATE,
NFSPROC4_CLNT_DEALLOCATE,
+ NFSPROC4_CLNT_READ_PLUS,
};
/* nfs41 types */
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index ddea982..95609f2 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -236,5 +236,6 @@ struct nfs_server {
#define NFS_CAP_SEEK (1U << 19)
#define NFS_CAP_ALLOCATE (1U << 20)
#define NFS_CAP_DEALLOCATE (1U << 21)
+#define NFS_CAP_READ_PLUS (1U << 22)
#endif
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index e5c3b62..f09f023 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -513,7 +513,7 @@ struct nfs_pgio_args {
struct nfs_pgio_res {
struct nfs4_sequence_res seq_res;
struct nfs_fattr * fattr;
- __u32 count;
+ __u64 count;
int eof; /* used by read */
struct nfs_writeverf * verf; /* used by write */
const struct nfs_server *server; /* used by write */
--
2.2.2
I'm going to need this bit of code in a few places for READ_PLUS
decoding, so let's make it a helper function.
Signed-off-by: Anna Schumaker <[email protected]>
---
net/sunrpc/xdr.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 4439ac4..b1c4ffb 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -759,6 +759,12 @@ static int xdr_set_page_base(struct xdr_stream *xdr,
return 0;
}
+static void xdr_set_page(struct xdr_stream *xdr, unsigned int base)
+{
+ if (xdr_set_page_base(xdr, base, PAGE_SIZE) < 0)
+ xdr_set_iov(xdr, xdr->buf->tail, xdr->buf->len);
+}
+
static void xdr_set_next_page(struct xdr_stream *xdr)
{
unsigned int newbase;
@@ -766,8 +772,7 @@ static void xdr_set_next_page(struct xdr_stream *xdr)
newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
newbase -= xdr->buf->page_base;
- if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0)
- xdr_set_iov(xdr, xdr->buf->tail, xdr->buf->len);
+ xdr_set_page(xdr, newbase);
}
static bool xdr_set_next_buffer(struct xdr_stream *xdr)
--
2.2.2
This patch adds the ability to "read a hole" into a set of XDR data
pages by taking the following steps:
1) Shift all data after the current xdr->p to the right, possibly into
the tail,
2) Zero the specified range, and
3) Update xdr->p to point beyond the hole.
Signed-off-by: Anna Schumaker <[email protected]>
---
include/linux/sunrpc/xdr.h | 1 +
net/sunrpc/xdr.c | 104 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 105 insertions(+)
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 70c6b92..81c5a3f 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -229,6 +229,7 @@ extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
+extern size_t xdr_expand_hole(struct xdr_stream *, size_t, size_t);
#endif /* __KERNEL__ */
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index b1c4ffb..f71e227 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -219,6 +219,40 @@ _shift_data_right_pages(struct page **pages, size_t pgto_base,
} while ((len -= copy) != 0);
}
+static void
+_shift_data_right_tail(struct xdr_buf *buf, size_t pgfrom_base, size_t len)
+{
+ struct kvec *tail = buf->tail;
+
+ /* Make room for new data. */
+ if (tail->iov_len > 0)
+ memmove((char *)tail->iov_base + len, tail->iov_base, len);
+
+ _copy_from_pages((char *)tail->iov_base,
+ buf->pages,
+ buf->page_base + pgfrom_base,
+ len);
+
+ tail->iov_len += len;
+}
+
+static void
+_shift_data_right(struct xdr_buf *buf, size_t to, size_t from, size_t len)
+{
+ size_t shift = len;
+
+ if ((to + len) > buf->page_len) {
+ shift = (to + len) - buf->page_len;
+ _shift_data_right_tail(buf, (from + len) - shift, shift);
+ shift = len - shift;
+ }
+
+ _shift_data_right_pages(buf->pages,
+ buf->page_base + to,
+ buf->page_base + from,
+ shift);
+}
+
/**
* _copy_to_pages
* @pages: array of pages
@@ -304,6 +338,38 @@ _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
EXPORT_SYMBOL_GPL(_copy_from_pages);
/**
+ * _zero_data_pages
+ * @pages: array of pages
+ * @pgbase: beginning page vector address
+ * @len: length
+ */
+static void
+_zero_data_pages(struct page **pages, size_t pgbase, size_t len)
+{
+ struct page **page;
+ char *vpage;
+ size_t zero;
+
+ page = pages + (pgbase >> PAGE_CACHE_SHIFT);
+ pgbase &= ~PAGE_CACHE_MASK;
+
+ do {
+ zero = len;
+ if (pgbase + zero > PAGE_SIZE)
+ zero = PAGE_SIZE - pgbase;
+
+ vpage = kmap_atomic(*page);
+ memset(vpage + pgbase, 0, zero);
+ flush_dcache_page(*page);
+ kunmap_atomic(vpage);
+
+ page++;
+ pgbase = 0;
+
+ } while ((len -= zero) != 0);
+}
+
+/**
* xdr_shrink_bufhead
* @buf: xdr_buf
* @len: bytes to remove from buf->head[0]
@@ -445,6 +511,24 @@ unsigned int xdr_stream_pos(const struct xdr_stream *xdr)
EXPORT_SYMBOL_GPL(xdr_stream_pos);
/**
+ * xdr_page_pos - Return the current offset from the start of the xdr->buf->pages
+ * @xdr: pointer to struct xdr_stream
+ */
+static size_t xdr_page_pos(const struct xdr_stream *xdr)
+{
+ unsigned int offset;
+ unsigned int base = xdr->buf->page_len;
+ void *kaddr = xdr->buf->tail->iov_base;;
+
+ if (xdr->page_ptr) {
+ base = (xdr->page_ptr - xdr->buf->pages) * PAGE_SIZE;
+ kaddr = page_address(*xdr->page_ptr);
+ }
+ offset = xdr->p - (__be32 *)kaddr;
+ return base + (offset * sizeof(__be32));
+}
+
+/**
* xdr_init_encode - Initialize a struct xdr_stream for sending data.
* @xdr: pointer to xdr_stream struct
* @buf: pointer to XDR buffer in which to encode data
@@ -976,6 +1060,26 @@ unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
}
EXPORT_SYMBOL_GPL(xdr_read_pages);
+size_t xdr_expand_hole(struct xdr_stream *xdr, size_t offset, size_t length)
+{
+ struct xdr_buf *buf = xdr->buf;
+ size_t from = 0;
+
+ if ((offset + length) > buf->page_len)
+ length = buf->page_len - offset;
+
+ if (offset == 0)
+ xdr_align_pages(xdr, xdr->nwords << 2);
+ else
+ from = xdr_page_pos(xdr);
+
+ _shift_data_right(buf, offset + length, from, xdr->nwords << 2);
+ _zero_data_pages(buf->pages, buf->page_base + offset, length);
+ xdr_set_page(xdr, offset + length);
+ return length;
+}
+EXPORT_SYMBOL_GPL(xdr_expand_hole);
+
/**
* xdr_enter_page - decode data from the XDR page
* @xdr: pointer to xdr_stream struct
--
2.2.2
This patch adds support for decoding a single hole segment returned by
the server.
Signed-off-by: Anna Schumaker <[email protected]>
---
fs/nfs/nfs42xdr.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 3d7c01b..17126e8 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -212,6 +212,30 @@ out_overflow:
return -EIO;
}
+static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *res)
+{
+ __be32 *p;
+ uint64_t offset, length;
+ size_t recvd;
+
+ p = xdr_inline_decode(xdr, 8 + 8);
+ if (unlikely(!p))
+ goto out_overflow;
+
+ p = xdr_decode_hyper(p, &offset);
+ p = xdr_decode_hyper(p, &length);
+
+ recvd = xdr_expand_hole(xdr, 0, length);
+ if (recvd < length)
+ res->eof = 0;
+
+ res->count = recvd;
+ return 0;
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return -EIO;
+}
+
static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
{
__be32 *p;
@@ -240,7 +264,7 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
if (type == NFS4_CONTENT_DATA)
status = decode_read_plus_data(xdr, res);
else
- status = -ENOTSUPP;
+ status = decode_read_plus_hole(xdr, res);
if (segments > 1)
res->eof = 0;
--
2.2.2
Expanding holes tends to put the data content a few bytes to the right
of where we want it. This patch implements a left-shift operation to
line everything up properly.
Signed-off-by: Anna Schumaker <[email protected]>
---
include/linux/sunrpc/xdr.h | 1 +
net/sunrpc/xdr.c | 132 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 133 insertions(+)
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 81c5a3f..3670bf6 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -230,6 +230,7 @@ extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
extern size_t xdr_expand_hole(struct xdr_stream *, size_t, size_t);
+extern uint64_t xdr_align_data(struct xdr_stream *, uint64_t, uint64_t);
#endif /* __KERNEL__ */
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index f71e227..372a53c 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -16,6 +16,9 @@
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/msg_prot.h>
+static void _copy_to_pages(struct page **, size_t, const char *, size_t);
+
+
/*
* XDR functions for basic NFS types
*/
@@ -253,6 +256,117 @@ _shift_data_right(struct xdr_buf *buf, size_t to, size_t from, size_t len)
shift);
}
+
+/**
+ * _shift_data_left_pages
+ * @pages: vector of pages containing both the source and dest memory area.
+ * @pgto_base: page vector address of destination
+ * @pgfrom_base: page vector address of source
+ * @len: number of bytes to copy
+ *
+ * Note: the addresses pgto_base and pgfrom_base are both calculated in
+ * the same way:
+ * if a memory area starts at byte 'base' in page 'pages[i]',
+ * then its address is given as (i << PAGE_CACHE_SHIFT) + base
+ * Alse note: pgto_base must be < pgfrom_base, but the memory areas
+ * they point to may overlap.
+ */
+static void
+_shift_data_left_pages(struct page **pages, size_t pgto_base,
+ size_t pgfrom_base, size_t len)
+{
+ struct page **pgfrom, **pgto;
+ char *vfrom, *vto;
+ size_t copy;
+
+ BUG_ON(pgfrom_base <= pgto_base);
+
+ pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT);
+ pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT);
+
+ pgto_base = pgto_base % PAGE_CACHE_SIZE;
+ pgfrom_base = pgfrom_base % PAGE_CACHE_SIZE;
+
+ do {
+ if (pgto_base >= PAGE_CACHE_SIZE) {
+ pgto_base = 0;
+ pgto++;
+ }
+ if (pgfrom_base >= PAGE_CACHE_SIZE){
+ pgfrom_base = 0;
+ pgfrom++;
+ }
+
+ copy = len;
+ if (copy > (PAGE_CACHE_SIZE - pgto_base))
+ copy = PAGE_CACHE_SIZE - pgto_base;
+ if (copy > (PAGE_CACHE_SIZE - pgfrom_base))
+ copy = PAGE_CACHE_SIZE - pgfrom_base;
+
+ if (pgto_base == 131056)
+ break;
+
+ vto = kmap_atomic(*pgto);
+ if (*pgto != *pgfrom) {
+ vfrom = kmap_atomic(*pgfrom);
+ memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
+ kunmap_atomic(vfrom);
+ } else
+ memmove(vto + pgto_base, vto + pgfrom_base, copy);
+ flush_dcache_page(*pgto);
+ kunmap_atomic(vto);
+
+ pgto_base += copy;
+ pgfrom_base += copy;
+
+ } while ((len -= copy) != 0);
+}
+
+static void
+_shift_data_left_tail(struct xdr_buf *buf, size_t pgto_base,
+ size_t tail_from, size_t len)
+{
+ struct kvec *tail = buf->tail;
+ size_t shift = len;
+
+ if (len == 0)
+ return;
+ if (pgto_base + len > buf->page_len)
+ shift = buf->page_len - pgto_base;
+
+ _copy_to_pages(buf->pages,
+ buf->page_base + pgto_base,
+ (char *)(tail->iov_base + tail_from),
+ shift);
+
+ memmove((char *)tail->iov_base, tail->iov_base + tail_from + shift, shift);
+ tail->iov_len -= (tail_from + shift);
+}
+
+static void
+_shift_data_left(struct xdr_buf *buf, size_t to, size_t from, size_t len)
+{
+ size_t shift = len;
+
+ if (from < buf->page_len) {
+ shift = min(len, buf->page_len - from);
+ _shift_data_left_pages(buf->pages,
+ buf->page_base + to,
+ buf->page_base + from,
+ shift);
+ to += shift;
+ from += shift;
+ shift = len - shift;
+ }
+
+ if (shift == 0)
+ return;
+ if (from >= buf->page_len)
+ from -= buf->page_len;
+
+ _shift_data_left_tail(buf, to, from, shift);
+}
+
/**
* _copy_to_pages
* @pages: array of pages
@@ -1080,6 +1194,24 @@ size_t xdr_expand_hole(struct xdr_stream *xdr, size_t offset, size_t length)
}
EXPORT_SYMBOL_GPL(xdr_expand_hole);
+uint64_t xdr_align_data(struct xdr_stream *xdr, uint64_t offset, uint64_t length)
+{
+ struct xdr_buf *buf = xdr->buf;
+
+ if (offset + length > buf->page_len)
+ length = buf->page_len - offset;
+
+ if (offset == 0)
+ xdr_align_pages(xdr, xdr->nwords << 2);
+ else
+ _shift_data_left(buf, offset, xdr_page_pos(xdr), xdr->nwords << 2);
+
+ xdr->nwords -= XDR_QUADLEN(length);
+ xdr_set_page(xdr, offset + length);
+ return length;
+}
+EXPORT_SYMBOL_GPL(xdr_align_data);
+
/**
* xdr_enter_page - decode data from the XDR page
* @xdr: pointer to xdr_stream struct
--
2.2.2
We now have everything we need to read holes and then shift data to
where it's supposed to be.
Signed-off-by: Anna Schumaker <[email protected]>
---
fs/nfs/nfs42xdr.c | 40 ++++++++++++++++++++++------------------
1 file changed, 22 insertions(+), 18 deletions(-)
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 17126e8..010af55 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -201,11 +201,11 @@ static int decode_read_plus_data(struct xdr_stream *xdr, struct nfs_pgio_res *re
p = xdr_decode_hyper(p, &offset);
count = be32_to_cpup(p);
- recvd = xdr_read_pages(xdr, count);
+ recvd = xdr_align_data(xdr, res->count, count);
if (recvd < count)
res->eof = 0;
- res->count = recvd;
+ res->count += recvd;
return 0;
out_overflow:
print_overflow_msg(__func__, xdr);
@@ -225,11 +225,11 @@ static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *re
p = xdr_decode_hyper(p, &offset);
p = xdr_decode_hyper(p, &length);
- recvd = xdr_expand_hole(xdr, 0, length);
+ recvd = xdr_expand_hole(xdr, res->count, length);
if (recvd < length)
res->eof = 0;
- res->count = recvd;
+ res->count += recvd;
return 0;
out_overflow:
print_overflow_msg(__func__, xdr);
@@ -240,7 +240,7 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
{
__be32 *p;
int status, type;
- uint32_t segments;
+ uint32_t i, segments;
status = decode_op_hdr(xdr, OP_READ_PLUS);
if (status)
@@ -253,20 +253,24 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
res->count = 0;
res->eof = be32_to_cpup(p++);
segments = be32_to_cpup(p++);
- if (segments == 0)
- return 0;
- p = xdr_inline_decode(xdr, 4);
- if (unlikely(!p))
- goto out_overflow;
-
- type = be32_to_cpup(p++);
- if (type == NFS4_CONTENT_DATA)
- status = decode_read_plus_data(xdr, res);
- else
- status = decode_read_plus_hole(xdr, res);
-
- if (segments > 1)
+ for (i = 0; i < segments; i++) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+
+ type = be32_to_cpup(p);
+ if (type == NFS4_CONTENT_DATA)
+ status = decode_read_plus_data(xdr, res);
+ else
+ status = decode_read_plus_hole(xdr, res);
+ if (status)
+ break;
+ if (res->count == xdr->buf->page_len)
+ break;
+ }
+
+ if (i < segments)
res->eof = 0;
return status;
out_overflow:
--
2.2.2
On Wed, Jan 28, 2015 at 03:43:45PM -0500, Anna Schumaker wrote:
> + if (type == NFS4_CONTENT_DATA)
> + status = decode_read_plus_data(xdr, res);
> + else
> + status = -ENOTSUPP;
> +
> + if (segments > 1)
> + res->eof = 0;
Given that the server can return any amount of data and hole
segments it doesn't make any sense to separate this patch from patches 4
and 6.
On 02/05/2015 09:10 AM, Christoph Hellwig wrote:
> On Wed, Jan 28, 2015 at 03:43:45PM -0500, Anna Schumaker wrote:
>> + if (type == NFS4_CONTENT_DATA)
>> + status = decode_read_plus_data(xdr, res);
>> + else
>> + status = -ENOTSUPP;
>> +
>> + if (segments > 1)
>> + res->eof = 0;
>
> Given that the server can return any amount of data and hole
> segments it doesn't make any sense to separate this patch from patches 4
> and 6.
>
I had them split up to make development easier, but I can squash them together if that would make more sense.