path: root/fs
diff options
authorNeil Brown <neilb@suse.de>2010-08-10 10:20:05 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2010-08-10 10:20:05 -0400
commitf5a73672d1811f2fb1dcb62ca90ceb12b2050ae7 (patch)
treef9d8798abbcbb6df399dea3d718ded7b2b2b5270 /fs
parent669502ff31d7dba1849aec7ee2450a3c61f57d39 (diff)
NFS: allow close-to-open cache semantics to apply to root of NFS filesystem
To obey NFS cache semantics, the client must verify the cached attributes when a file is opened. In most cases this is done by a call to d_validate as one of the last steps in path_walk. However for the root of a filesystem, d_validate is only ever called on the mounted-on filesystem (except when the path ends '.' or '..'). So NFS has no chance to validate the attributes. So, in nfs_opendir, we revalidate the attributes if the opened directory is the mountpoint. This may cause double-validation for "." and ".." lookups, but that is better than missing regular /path/name lookups completely. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs')
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 29539ceeb74..bd91b277831 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -140,6 +140,13 @@ nfs_opendir(struct inode *inode, struct file *filp)
/* Call generic open code in order to cache credentials */
res = nfs_open(inode, filp);
+ if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
+ /* This is a mountpoint, so d_revalidate will never
+ * have been called, so we need to refresh the
+ * inode (for close-open consistency) ourselves.
+ */
+ __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+ }
return res;