Hi Trond, 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 The resulting data looks something like this: XXXXXXXXXXXXXXX XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@XXXXXXXXXXXXXXX YYYYYYYYYYYYYYY YYYYYYYYYYYYYYY 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. The attached patch fixes the issue by calling nfs_revalidate_mapping() whenever we attach a delegation to an nfs_inode. However, I'm not entirely sure that calling nfs_revalidate_inode() in those places won't cause some other issues. I tested the change with all of the stock workloads in nfsometer except for bonnie++. An alternative would be to just revert c7559663 (NFS: Allow nfs_updatepage to extend a write under additional circumstances), but then we'd lose the performance benefits of that patch... which I'd like to avoid if possible. -Scott Scott Mayhew (1): nfs: ensure cached data is correct before using delegation fs/nfs/delegation.c | 1 + fs/nfs/inode.c | 1 + fs/nfs/nfs4proc.c | 5 +++-- 3 files changed, 5 insertions(+), 2 deletions(-) -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
