diff options
| author | Peng Tao <tao.peng@primarydata.com> | 2015-01-19 04:41:16 (GMT) |
|---|---|---|
| committer | Tom Haynes <loghyr@primarydata.com> | 2015-02-03 19:06:52 (GMT) |
| commit | 5fadeb47dcc5c30d4b6cf481b4a78689eab59443 (patch) | |
| tree | 61144dbb7c04d5ddae49174c122ef1c686712b06 | |
| parent | aa8a45ee974dfe3ffe290daaf5db457afae56fde (diff) | |
| download | linux-5fadeb47dcc5c30d4b6cf481b4a78689eab59443.tar.xz | |
nfs: count DIO good bytes correctly with mirroring
When resending to MDS, we might resend multiple mirroring
requests to MDS. As a result, nfs_direct_good_bytes() ends
up counting bytes multiple times, causing application to
get wrong return results in read/write syscalls.
Fix it by tracking start of a dreq and checking the range of
pgio header.
Cc: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
| -rw-r--r-- | fs/nfs/direct.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 4fad6b7..3715b49 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -88,6 +88,7 @@ struct nfs_direct_req { ssize_t count, /* bytes actually processed */ bytes_left, /* bytes left to be sent */ + io_start, /* start of IO */ error; /* any reported error */ struct completion completion; /* wait for i/o completion */ @@ -130,10 +131,11 @@ nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr) WARN_ON_ONCE(hdr->pgio_mirror_idx >= dreq->mirror_count); - dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes; - - if (hdr->pgio_mirror_idx == 0) - dreq->count += hdr->good_bytes; + count = dreq->mirrors[hdr->pgio_mirror_idx].count; + if (count + dreq->io_start < hdr->io_start + hdr->good_bytes) { + count = hdr->io_start + hdr->good_bytes - dreq->io_start; + dreq->mirrors[hdr->pgio_mirror_idx].count = count; + } /* update the dreq->count by finding the minimum agreed count from all * mirrors */ @@ -594,6 +596,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter, dreq->inode = inode; dreq->bytes_left = count; + dreq->io_start = pos; dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); l_ctx = nfs_get_lock_context(dreq->ctx); if (IS_ERR(l_ctx)) { @@ -1002,6 +1005,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, dreq->inode = inode; dreq->bytes_left = count; + dreq->io_start = pos; dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp)); l_ctx = nfs_get_lock_context(dreq->ctx); if (IS_ERR(l_ctx)) { |