diff options
author | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2022-07-21 21:21:34 +0300 |
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committer | Trond Myklebust <trond.myklebust@hammerspace.com> | 2022-07-23 22:38:29 +0300 |
commit | d3b00a802c845a6021148ce2e669b5a0b5729959 (patch) | |
tree | 40759c2ecc0d53abbfb404571bb71d214f109fc7 | |
parent | e1bd87608d4b6f87813f79b91e834de610f1049b (diff) | |
download | linux-d3b00a802c845a6021148ce2e669b5a0b5729959.tar.xz |
NFS: Replace the READ_PLUS decoding code
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 <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
-rw-r--r-- | fs/nfs/nfs42xdr.c | 170 |
1 files changed, 88 insertions, 82 deletions
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c index 271e5f92ed01..b56f05113d36 100644 --- a/fs/nfs/nfs42xdr.c +++ b/fs/nfs/nfs42xdr.c @@ -1025,82 +1025,95 @@ 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; - __be32 *p; - - p = xdr_inline_decode(xdr, 8 + 4); - if (!p) - return 1; + union { + struct { + uint64_t length; + } hole; + + struct { + uint32_t length; + unsigned int from; + } data; + }; +}; - 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 0; +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_hole(struct xdr_stream *xdr, - struct nfs_pgio_args *args, - struct nfs_pgio_res *res, uint32_t *eof) +static int decode_read_plus_segment(struct xdr_stream *xdr, + struct read_plus_segment *seg) { - uint64_t offset, length, recvd; __be32 *p; - p = xdr_inline_decode(xdr, 8 + 8); + p = xdr_inline_decode(xdr, 4); 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 (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; + 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 (recvd < length) - return 1; + 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 process_read_plus_segment(struct xdr_stream *xdr, + struct nfs_pgio_args *args, + struct nfs_pgio_res *res, + struct read_plus_segment *seg) +{ + unsigned long offset = seg->offset; + unsigned long length = read_plus_segment_length(seg); + unsigned int bufpos; + + 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; + } + + 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_subsegment(xdr, seg->data.from, bufpos, length); +} + 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; - - for (i = 0; i < segments; i++) { - p = xdr_inline_decode(xdr, 4); - if (!p) - goto early_out; + return status; - 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; + 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++) { + 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) |