From: Scott Mayhew Date: Fri, 20 Jun 2014 12:44:42 +0000 (-0400) Subject: nfs: Fix cache_validity check in nfs_write_pageuptodate() X-Git-Tag: firefly_0821_release~176^2~3407^2~64 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=18dd78c427513fb0f89365138be66e6ee8700d1b;p=firefly-linux-kernel-4.4.55.git nfs: Fix cache_validity check in nfs_write_pageuptodate() 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 Cc: # v3.11+ Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 3ee5af4e738e..98ff061ccaf3 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -934,12 +934,14 @@ 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; }