[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>

4 files changed, 38 insertions, 11 deletions

diff --git a/fs/inode.c b/fs/inode.c
index 76980a9c92e7..108138d4e909 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -22,6 +22,7 @@
 #include <linux/cdev.h>
 #include <linux/bootmem.h>
 #include <linux/inotify.h>
+#include <linux/mount.h>
 
 /*
  * This is needed for the following functions:
@@ -1189,12 +1190,20 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
         struct inode *inode = dentry->d_inode;
         struct timespec now;
 
-        /* per-mountpoint checks will go here */
-        if (IS_NOATIME(inode))
+        if (IS_RDONLY(inode))
                 return;
-        if (IS_NODIRATIME(inode) && S_ISDIR(inode->i_mode))
+
+        if ((inode->i_flags & S_NOATIME) ||
+            (inode->i_sb->s_flags & MS_NOATIME) ||
+            ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode)))
                 return;
-        if (IS_RDONLY(inode))
+
+        /*
+         * We may have a NULL vfsmount when coming from NFSD
+         */
+        if (mnt &&
+            ((mnt->mnt_flags & MNT_NOATIME) ||
+             ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))))
                 return;
 
         now = current_fs_time(inode->i_sb);
diff --git a/fs/namespace.c b/fs/namespace.c
index f0e353f5bc30..2ca6145f43d6 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -355,14 +355,14 @@ static int show_vfsmnt(struct seq_file *m, void *v)
                 { MS_SYNCHRONOUS, ",sync" },
                 { MS_DIRSYNC, ",dirsync" },
                 { MS_MANDLOCK, ",mand" },
-                { MS_NOATIME, ",noatime" },
-                { MS_NODIRATIME, ",nodiratime" },
                 { 0, NULL }
         };
         static struct proc_fs_info mnt_info[] = {
                 { MNT_NOSUID, ",nosuid" },
                 { MNT_NODEV, ",nodev" },
                 { MNT_NOEXEC, ",noexec" },
+                { MNT_NOATIME, ",noatime" },
+                { MNT_NODIRATIME, ",nodiratime" },
                 { 0, NULL }
         };
         struct proc_fs_info *fs_infop;
@@ -1286,7 +1286,13 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
                 mnt_flags |= MNT_NODEV;
         if (flags & MS_NOEXEC)
                 mnt_flags |= MNT_NOEXEC;
-        flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE);
+        if (flags & MS_NOATIME)
+                mnt_flags |= MNT_NOATIME;
+        if (flags & MS_NODIRATIME)
+                mnt_flags |= MNT_NODIRATIME;
+
+        flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE |
+                   MS_NOATIME | MS_NODIRATIME);
 
         /* ... and get the mountpoint */
         retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd);
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
diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 41c478bb1ffc..97fb1470cf28 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -54,6 +54,9 @@
 #include <linux/xattr.h>
 #include <linux/namei.h>
 
+#define IS_NOATIME(inode) ((inode->i_sb->s_flags & MS_NOATIME) ||       \
+        (S_ISDIR(inode->i_mode) && inode->i_sb->s_flags & MS_NODIRATIME))
+
 /*
  * Change the requested timestamp in the given inode.
  * We don't lock across timestamp updates, and we don't log them but