[PATCH] per-mountpoint noatime/nodiratime

Turn noatime and nodiratime into per-mount instead of per-sb flags.

After all the preparations this is a rather trivial patch.  The mount code
needs to treat the two options as per-mount instead of per-superblock, and
touch_atime needs to be changed to check the new MNT_ flags in addition to
the MS_ flags that are kept for filesystems that are always
noatime/nodiratime but not user settable anymore.  Besides that core code
only nfs needed an update because it's leaving atime updates to the server
and thus sets the S_NOATIME flag on every inode, but needs to know whether
it's a real noatime mount for an getattr optimization.

While we're at it I've killed the IS_NOATIME/IS_NODIRATIME macros that were
only used by touch_atime.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 3e4ba9cb7f80..a77ee95b7efb 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -950,11 +950,20 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 
         /* Flush out writes to the server in order to update c/mtime */
         nfs_sync_inode(inode, 0, 0, FLUSH_WAIT|FLUSH_NOCOMMIT);
-        if (__IS_FLG(inode, MS_NOATIME))
-                need_atime = 0;
-        else if (__IS_FLG(inode, MS_NODIRATIME) && S_ISDIR(inode->i_mode))
+
+        /*
+         * We may force a getattr if the user cares about atime.
+         *
+         * Note that we only have to check the vfsmount flags here:
+         *  - NFS always sets S_NOATIME by so checking it would give a
+         *    bogus result
+         *  - NFS never sets MS_NOATIME or MS_NODIRATIME so there is
+         *    no point in checking those.
+         */
+        if ((mnt->mnt_flags & MNT_NOATIME) ||
+            ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
                 need_atime = 0;
-        /* We may force a getattr if the user cares about atime */
+
         if (need_atime)
                 err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
         else