From: Anna Schumaker <[email protected]>
We now take a 2-step process that allows us to place data and hole
segments directly at their final position in the xdr_stream without
needing to do a bunch of redundant copies to expand holes. Due to the
variable lengths of each segment, the xdr metadata might cross page
boundaries which I account for by setting a small scratch buffer so
xdr_inline_decode() won't fail.
Signed-off-by: Anna Schumaker <[email protected]>
---
fs/nfs/nfs42xdr.c | 168 ++++++++++++++++++++++++----------------------
1 file changed, 87 insertions(+), 81 deletions(-)
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 271e5f92ed01..5aedc4bf5313 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -1025,73 +1025,84 @@ 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_args *args,
- struct nfs_pgio_res *res)
-{
- uint32_t count, recvd;
+struct read_plus_segment {
+ enum data_content4 type;
uint64_t offset;
+ union {
+ struct {
+ uint64_t length;
+ } hole;
+
+ struct {
+ uint32_t length;
+ unsigned int from;
+ } data;
+ };
+};
+
+static inline uint64_t read_plus_segment_length(struct read_plus_segment *seg)
+{
+ return seg->type == NFS4_CONTENT_DATA ? seg->data.length : seg->hole.length;
+}
+
+static int decode_read_plus_segment(struct xdr_stream *xdr,
+ struct read_plus_segment *seg)
+{
__be32 *p;
- p = xdr_inline_decode(xdr, 8 + 4);
+ p = xdr_inline_decode(xdr, 4);
if (!p)
- return 1;
-
- p = xdr_decode_hyper(p, &offset);
- count = be32_to_cpup(p);
- recvd = xdr_align_data(xdr, res->count, xdr_align_size(count));
- if (recvd > count)
- recvd = count;
- if (res->count + recvd > args->count) {
- if (args->count > res->count)
- res->count += args->count - res->count;
- return 1;
- }
- res->count += recvd;
- if (count > recvd)
- return 1;
+ return -EIO;
+ seg->type = be32_to_cpup(p++);
+
+ p = xdr_inline_decode(xdr, seg->type == NFS4_CONTENT_DATA ? 12 : 16);
+ if (!p)
+ return -EIO;
+ p = xdr_decode_hyper(p, &seg->offset);
+
+ if (seg->type == NFS4_CONTENT_DATA) {
+ struct xdr_buf buf;
+ uint32_t len = be32_to_cpup(p);
+
+ seg->data.length = len;
+ seg->data.from = xdr_stream_pos(xdr);
+
+ if (!xdr_stream_subsegment(xdr, &buf, xdr_align_size(len)))
+ return -EIO;
+ } else if (seg->type == NFS4_CONTENT_HOLE) {
+ xdr_decode_hyper(p, &seg->hole.length);
+ } else
+ return -EINVAL;
return 0;
}
-static int decode_read_plus_hole(struct xdr_stream *xdr,
- struct nfs_pgio_args *args,
- struct nfs_pgio_res *res, uint32_t *eof)
+static int process_read_plus_segment(struct xdr_stream *xdr,
+ struct nfs_pgio_args *args,
+ struct nfs_pgio_res *res,
+ struct read_plus_segment *seg)
{
- uint64_t offset, length, recvd;
- __be32 *p;
+ unsigned long offset = seg->offset;
+ unsigned long length = read_plus_segment_length(seg);
+ unsigned int bufpos;
- p = xdr_inline_decode(xdr, 8 + 8);
- if (!p)
- return 1;
-
- p = xdr_decode_hyper(p, &offset);
- p = xdr_decode_hyper(p, &length);
- if (offset != args->offset + res->count) {
- /* Server returned an out-of-sequence extent */
- if (offset > args->offset + res->count ||
- offset + length < args->offset + res->count) {
- dprintk("NFS: server returned out of sequence extent: "
- "offset/size = %llu/%llu != expected %llu\n",
- (unsigned long long)offset,
- (unsigned long long)length,
- (unsigned long long)(args->offset +
- res->count));
- return 1;
- }
- length -= args->offset + res->count - offset;
+ if (offset + length < args->offset)
+ return 0;
+ else if (offset > args->offset + args->count) {
+ res->eof = 0;
+ return 0;
+ } else if (offset < args->offset) {
+ length -= (args->offset - offset);
+ offset = args->offset;
+ } else if (offset + length > args->offset + args->count) {
+ length = (args->offset + args->count) - offset;
+ res->eof = 0;
}
- if (length + res->count > args->count) {
- *eof = 0;
- if (unlikely(res->count >= args->count))
- return 1;
- length = args->count - res->count;
- }
- recvd = xdr_expand_hole(xdr, res->count, length);
- res->count += recvd;
- if (recvd < length)
- return 1;
- return 0;
+ bufpos = xdr->buf->head[0].iov_len + (offset - args->offset);
+ if (seg->type == NFS4_CONTENT_HOLE)
+ return xdr_stream_zero(xdr, bufpos, length);
+ else
+ return xdr_stream_move_segment(xdr, seg->data.from, bufpos, length);
}
static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
@@ -1099,8 +1110,10 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
struct nfs_pgio_header *hdr =
container_of(res, struct nfs_pgio_header, res);
struct nfs_pgio_args *args = &hdr->args;
- uint32_t eof, segments, type;
+ uint32_t segments;
+ struct read_plus_segment *segs;
int status, i;
+ char scratch_buf[16];
__be32 *p;
status = decode_op_hdr(xdr, OP_READ_PLUS);
@@ -1112,38 +1125,31 @@ static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
return -EIO;
res->count = 0;
- eof = be32_to_cpup(p++);
+ res->eof = be32_to_cpup(p++);
segments = be32_to_cpup(p++);
if (segments == 0)
- goto out;
+ return status;
+ segs = kmalloc_array(segments, sizeof(*segs), GFP_KERNEL);
+ if (!segs)
+ return -ENOMEM;
+
+ xdr_set_scratch_buffer(xdr, &scratch_buf, 32);
+ status = -EIO;
for (i = 0; i < segments; i++) {
- p = xdr_inline_decode(xdr, 4);
- if (!p)
- goto early_out;
-
- type = be32_to_cpup(p++);
- if (type == NFS4_CONTENT_DATA)
- status = decode_read_plus_data(xdr, args, res);
- else if (type == NFS4_CONTENT_HOLE)
- status = decode_read_plus_hole(xdr, args, res, &eof);
- else
- return -EINVAL;
-
+ status = decode_read_plus_segment(xdr, &segs[i]);
if (status < 0)
- return status;
- if (status > 0)
- goto early_out;
+ goto out;
}
+ xdr_set_pagelen(xdr, xdr_align_size(args->count));
+ for (i = segments; i > 0; i--)
+ res->count += process_read_plus_segment(xdr, args, res, &segs[i-1]);
+ status = 0;
+
out:
- res->eof = eof;
- return 0;
-early_out:
- if (unlikely(!i))
- return -EIO;
- res->eof = 0;
- return 0;
+ kfree(segs);
+ return status;
}
static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
--
2.36.1