[XFS] fix, speedup and simplify atime handling let the VFS handle atime

updates and only sync back to the xfs inode when nessecary

SGI-PV: 946679
SGI-Modid: xfs-linux-melb:xfs-kern:203362a

Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

1 files changed, 24 insertions, 34 deletions

diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 97fb1470cf28..8fd274fc26d5 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -58,6 +58,24 @@
         (S_ISDIR(inode->i_mode) && inode->i_sb->s_flags & MS_NODIRATIME))
 
 /*
+ * Bring the atime in the XFS inode uptodate.
+ * Used before logging the inode to disk or when the Linux inode goes away.
+ */
+void
+xfs_synchronize_atime(
+        xfs_inode_t     *ip)
+{
+        vnode_t         *vp;
+
+        vp = XFS_ITOV_NULL(ip);
+        if (vp) {
+                struct inode *inode = &vp->v_inode;
+                ip->i_d.di_atime.t_sec = (__int32_t)inode->i_atime.tv_sec;
+                ip->i_d.di_atime.t_nsec = (__int32_t)inode->i_atime.tv_nsec;
+        }
+}
+
+/*
  * Change the requested timestamp in the given inode.
  * We don't lock across timestamp updates, and we don't log them but
  * we do record the fact that there is dirty information in core.
@@ -76,23 +94,6 @@ xfs_ichgtime(
         struct inode    *inode = LINVFS_GET_IP(XFS_ITOV(ip));
         timespec_t      tv;
 
-        /*
-         * We're not supposed to change timestamps in readonly-mounted
-         * filesystems.  Throw it away if anyone asks us.
-         */
-        if (unlikely(IS_RDONLY(inode)))
-                return;
-
-        /*
-         * Don't update access timestamps on reads if mounted "noatime".
-         * Throw it away if anyone asks us.
-         */
-        if (unlikely(
-            (ip->i_mount->m_flags & XFS_MOUNT_NOATIME || IS_NOATIME(inode)) &&
-            (flags & (XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD|XFS_ICHGTIME_CHG)) ==
-                        XFS_ICHGTIME_ACC))
-                return;
-
         nanotime(&tv);
         if (flags & XFS_ICHGTIME_MOD) {
                 inode->i_mtime = tv;
@@ -129,8 +130,6 @@ xfs_ichgtime(
  * Variant on the above which avoids querying the system clock
  * in situations where we know the Linux inode timestamps have
  * just been updated (and so we can update our inode cheaply).
- * We also skip the readonly and noatime checks here, they are
- * also catered for already.
  */
 void
 xfs_ichgtime_fast(
@@ -141,20 +140,16 @@ xfs_ichgtime_fast(
         timespec_t      *tvp;
 
         /*
-         * We're not supposed to change timestamps in readonly-mounted
-         * filesystems.  Throw it away if anyone asks us.
+         * Atime updates for read() & friends are handled lazily now, and
+         * explicit updates must go through xfs_ichgtime()
          */
-        if (unlikely(IS_RDONLY(inode)))
-                return;
+        ASSERT((flags & XFS_ICHGTIME_ACC) == 0);
 
         /*
-         * Don't update access timestamps on reads if mounted "noatime".
-         * Throw it away if anyone asks us.
+         * We're not supposed to change timestamps in readonly-mounted
+         * filesystems.  Throw it away if anyone asks us.
          */
-        if (unlikely(
-            (ip->i_mount->m_flags & XFS_MOUNT_NOATIME || IS_NOATIME(inode)) &&
-            ((flags & (XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD|XFS_ICHGTIME_CHG)) ==
-                        XFS_ICHGTIME_ACC)))
+        if (unlikely(IS_RDONLY(inode)))
                 return;
 
         if (flags & XFS_ICHGTIME_MOD) {
@@ -162,11 +157,6 @@ xfs_ichgtime_fast(
                 ip->i_d.di_mtime.t_sec = (__int32_t)tvp->tv_sec;
                 ip->i_d.di_mtime.t_nsec = (__int32_t)tvp->tv_nsec;
         }
-        if (flags & XFS_ICHGTIME_ACC) {
-                tvp = &inode->i_atime;
-                ip->i_d.di_atime.t_sec = (__int32_t)tvp->tv_sec;
-                ip->i_d.di_atime.t_nsec = (__int32_t)tvp->tv_nsec;
-        }
         if (flags & XFS_ICHGTIME_CHG) {
                 tvp = &inode->i_ctime;
                 ip->i_d.di_ctime.t_sec = (__int32_t)tvp->tv_sec;