This is a note to let you know that I've just added the patch titled
nfs: Fix cache_validity check in nfs_write_pageuptodate()
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfs-fix-cache_validity-check-in-nfs_write_pageuptodate.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 18dd78c427513fb0f89365138be66e6ee8700d1b Mon Sep 17 00:00:00 2001
From: Scott Mayhew <smayhew@xxxxxxxxxx>
Date: Fri, 20 Jun 2014 08:44:42 -0400
Subject: nfs: Fix cache_validity check in nfs_write_pageuptodate()
From: Scott Mayhew <smayhew@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}
Patches currently in stable-queue which might be from smayhew@xxxxxxxxxx are
queue-3.14/nfs-fix-cache_validity-check-in-nfs_write_pageuptodate.patch
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