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| author | NeilBrown <neilb@suse.com> | 2017-08-25 17:34:41 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-05 11:20:47 +0100 |
| commit | 9ea40d143494705b074688a4330b7085f06d3942 (patch) | |
| tree | 8541e2c3a9f5aa772b8e68533bf1d07b63e23970 /fs | |
| parent | 72427ea588e3eaf0170f87c0ad4b8a568979771d (diff) | |
| download | linux-stable-9ea40d143494705b074688a4330b7085f06d3942.tar.gz linux-stable-9ea40d143494705b074688a4330b7085f06d3942.tar.bz2 linux-stable-9ea40d143494705b074688a4330b7085f06d3942.zip | |
NFS: revalidate "." etc correctly on "open".
commit b688741cb06695312f18b730653d6611e1bad28d upstream.
For correct close-to-open semantics, NFS must validate
the change attribute of a directory (or file) on open.
Since commit ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a
d_weak_revalidate dentry op"), open() of "." or a path ending ".." is
not revalidated reliably (except when that direct is a mount point).
Prior to that commit, "." was revalidated using nfs_lookup_revalidate()
which checks the LOOKUP_OPEN flag and forces revalidation if the flag is
set.
Since that commit, nfs_weak_revalidate() is used for NFSv3 (which
ignores the flags) and nothing is used for NFSv4.
This is fixed by using nfs_lookup_verify_inode() in
nfs_weak_revalidate(). This does the revalidation exactly when needed.
Also, add a definition of .d_weak_revalidate for NFSv4.
The incorrect behavior is easily demonstrated by running "echo *" in
some non-mountpoint NFS directory while watching network traffic.
Without this patch, "echo *" sometimes doesn't produce any traffic.
With the patch it always does.
Fixes: ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op")
cc: stable@vger.kernel.org (3.9+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfs/dir.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 43d63a4d9a92..90526b2148f0 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1266,7 +1266,7 @@ static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags) return 0; } - error = nfs_revalidate_inode(NFS_SERVER(inode), inode); + error = nfs_lookup_verify_inode(inode, flags); dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n", __func__, inode->i_ino, error ? "invalid" : "valid"); return !error; @@ -1426,6 +1426,7 @@ static int nfs4_lookup_revalidate(struct dentry *, unsigned int); const struct dentry_operations nfs4_dentry_operations = { .d_revalidate = nfs4_lookup_revalidate, + .d_weak_revalidate = nfs_weak_revalidate, .d_delete = nfs_dentry_delete, .d_iput = nfs_dentry_iput, .d_automount = nfs_d_automount, |