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nfs: Fix cache_validity check in nfs_write_pageuptodate()

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commit 18dd78c427 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Scott Mayhew
2014-06-20 08:44:42 -04:00
committed by Greg Kroah-Hartman
parent ff177fb44d
commit 716f02ac00
1 changed files with 3 additions and 1 deletions
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4
fs/nfs/write.c
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@@ -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;
}