3.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Scott Mayhew <smay...@redhat.com>
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 <smay...@redhat.com>
Signed-off-by: Trond Myklebust <trond.mykleb...@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/nfs/write.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -913,12 +913,14 @@ static bool nfs_write_pageuptodate(struc
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;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
