| From | Jiri Slaby <> | Subject | [PATCH 3.12 038/170] nfs: Fix cache_validity check in nfs_write_pageuptodate() | Date | Fri, 18 Jul 2014 14:10:43 +0200 |
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From: Scott Mayhew <smayhew@redhat.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 18dd78c427513fb0f89365138be66e6ee8700d1b upstream.
NFS_INO_INVALID_DATA cannot be ignored, even if we have a delegation.
We're still having some problems with data corruption when multiple clients are appending to a file and those clients are being granted write delegations on open.
To reproduce:
Client A: vi /mnt/`hostname -s` while :; do echo "XXXXXXXXXXXXXXX" >>/mnt/file; sleep $(( $RANDOM % 5 )); done
Client B: vi /mnt/`hostname -s` while :; do echo "YYYYYYYYYYYYYYY" >>/mnt/file; sleep $(( $RANDOM % 5 )); done
What's happening is that in nfs_update_inode() we're recognizing that the file size has changed and we're setting NFS_INO_INVALID_DATA accordingly, but then we ignore the cache_validity flags in nfs_write_pageuptodate() because we have a delegation. As a result, in nfs_updatepage() we're extending the write to cover the full page even though we've not read in the data to begin with.
Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- fs/nfs/write.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index c6aa89f92558..3a1b1d1a27ce 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -913,12 +913,14 @@ static bool nfs_write_pageuptodate(struct page *page, struct inode *inode) if (nfs_have_delegated_attributes(inode)) goto out; - if (nfsi->cache_validity & (NFS_INO_INVALID_DATA|NFS_INO_REVAL_PAGECACHE)) + if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) return false; smp_rmb(); if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags)) return false; out: + if (nfsi->cache_validity & NFS_INO_INVALID_DATA) + return false; return PageUptodate(page) != 0; } -- 2.0.0
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