NFS: Ensure inode is always marked I_DIRTY_DATASYNC, if it has unstable pages

Since nfs_scan_list() doesn't wait for locked pages, we have a race in
which it is possible to end up with an inode that needs to send a COMMIT,
but which does not have the I_DIRTY_DATASYNC flag set.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 704e67d392e5..e40e949598fd 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -582,6 +582,8 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, u
         ret = nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT);
         if (ret > 0)
                 nfsi->ncommit -= ret;
+        if (nfs_need_commit(NFS_I(inode)))
+                __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
         return ret;
 }
 #else