[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>

8 files changed, 49 insertions, 54 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;
diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index c73d3c18882c..563cb9e975d2 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -281,9 +281,6 @@ xfs_read(
 
         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 
-        if (likely(!(ioflags & IO_INVIS)))
-                xfs_ichgtime_fast(ip, inode, XFS_ICHGTIME_ACC);
-
 unlock_isem:
         if (unlikely(ioflags & IO_ISDIRECT))
                 mutex_unlock(&inode->i_mutex);
@@ -346,9 +343,6 @@ xfs_sendfile(
         if (ret > 0)
                 XFS_STATS_ADD(xs_read_bytes, ret);
 
-        if (likely(!(ioflags & IO_INVIS)))
-                xfs_ichgtime_fast(ip, LINVFS_GET_IP(vp), XFS_ICHGTIME_ACC);
-
         return ret;
 }
 
diff --git a/fs/xfs/linux-2.6/xfs_vnode.c b/fs/xfs/linux-2.6/xfs_vnode.c
index e9bbcb4d6243..260dd8415dd7 100644
--- a/fs/xfs/linux-2.6/xfs_vnode.c
+++ b/fs/xfs/linux-2.6/xfs_vnode.c
@@ -106,7 +106,6 @@ vn_revalidate_core(
         inode->i_blocks     = vap->va_nblocks;
         inode->i_mtime      = vap->va_mtime;
         inode->i_ctime      = vap->va_ctime;
-        inode->i_atime      = vap->va_atime;
         inode->i_blksize    = vap->va_blocksize;
         if (vap->va_xflags & XFS_XFLAG_IMMUTABLE)
                 inode->i_flags |= S_IMMUTABLE;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 0063437f291a..6b7ac8bdcac2 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3364,6 +3364,11 @@ xfs_iflush_int(
         ip->i_update_core = 0;
         SYNCHRONIZE();
 
+        /*
+         * Make sure to get the latest atime from the Linux inode.
+         */
+        xfs_synchronize_atime(ip);
+
         if (XFS_TEST_ERROR(INT_GET(dip->di_core.di_magic,ARCH_CONVERT) != XFS_DINODE_MAGIC,
                                mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
                 xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 124d30e6143b..c4c1d9bce82e 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -436,6 +436,8 @@ void		xfs_ichgtime(xfs_inode_t *, int);
 xfs_fsize_t     xfs_file_last_byte(xfs_inode_t *);
 void            xfs_lock_inodes(xfs_inode_t **, int, int, uint);
 
+void            xfs_synchronize_atime(xfs_inode_t *);
+
 #define xfs_ipincount(ip)       ((unsigned int) atomic_read(&ip->i_pincount))
 
 #ifdef DEBUG
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 7f3363c621e1..9369010f3f16 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -271,6 +271,11 @@ xfs_inode_item_format(
         if (ip->i_update_size)
                 ip->i_update_size = 0;
 
+        /*
+         * Make sure to get the latest atime from the Linux inode.
+         */
+        xfs_synchronize_atime(ip);
+
         vecp->i_addr = (xfs_caddr_t)&ip->i_d;
         vecp->i_len  = sizeof(xfs_dinode_core_t);
         XLOG_VEC_SET_TYPE(vecp, XLOG_REG_TYPE_ICORE);
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index f63646ead816..41f50e7d1c32 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -56,6 +56,7 @@ xfs_bulkstat_one_iget(
 {
         xfs_dinode_core_t *dic;         /* dinode core info pointer */
         xfs_inode_t     *ip;            /* incore inode pointer */
+        vnode_t         *vp;
         int             error;
 
         error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, bno);
@@ -72,6 +73,7 @@ xfs_bulkstat_one_iget(
                 goto out_iput;
         }
 
+        vp = XFS_ITOV(ip);
         dic = &ip->i_d;
 
         /* xfs_iget returns the following without needing
@@ -84,8 +86,9 @@ xfs_bulkstat_one_iget(
         buf->bs_uid = dic->di_uid;
         buf->bs_gid = dic->di_gid;
         buf->bs_size = dic->di_size;
-        buf->bs_atime.tv_sec = dic->di_atime.t_sec;
-        buf->bs_atime.tv_nsec = dic->di_atime.t_nsec;
+        /* atime is only kept uptodate in the Linux inode */
+        buf->bs_atime.tv_sec = vp->v_inode.i_atime.tv_sec;
+        buf->bs_atime.tv_nsec = vp->v_inode.i_atime.tv_nsec;
         buf->bs_mtime.tv_sec = dic->di_mtime.t_sec;
         buf->bs_mtime.tv_nsec = dic->di_mtime.t_nsec;
         buf->bs_ctime.tv_sec = dic->di_ctime.t_sec;
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 15734c54952e..688fc2cb4b8d 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -182,8 +182,8 @@ xfs_getattr(
                 break;
         }
 
-        vap->va_atime.tv_sec = ip->i_d.di_atime.t_sec;
-        vap->va_atime.tv_nsec = ip->i_d.di_atime.t_nsec;
+        /* atime is only kept uptodate in the Linux inode */
+        vap->va_atime = vp->v_inode.i_atime;
         vap->va_mtime.tv_sec = ip->i_d.di_mtime.t_sec;
         vap->va_mtime.tv_nsec = ip->i_d.di_mtime.t_nsec;
         vap->va_ctime.tv_sec = ip->i_d.di_ctime.t_sec;
@@ -982,10 +982,6 @@ xfs_readlink(
                 goto error_return;
         }
 
-        if (!(ioflags & IO_INVIS)) {
-                xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
-        }
-
         /*
          * See if the symlink is stored inline.
          */
@@ -3226,7 +3222,6 @@ xfs_readdir(
         xfs_trans_t     *tp = NULL;
         int             error = 0;
         uint            lock_mode;
-        xfs_off_t       start_offset;
 
         vn_trace_entry(BHV_TO_VNODE(dir_bdp), __FUNCTION__,
                                                (inst_t *)__return_address);
@@ -3237,11 +3232,7 @@ xfs_readdir(
         }
 
         lock_mode = xfs_ilock_map_shared(dp);
-        start_offset = uiop->uio_offset;
         error = XFS_DIR_GETDENTS(dp->i_mount, tp, dp, uiop, eofp);
-        if (start_offset != uiop->uio_offset) {
-                xfs_ichgtime(dp, XFS_ICHGTIME_ACC);
-        }
         xfs_iunlock_map_shared(dp, lock_mode);
         return error;
 }
@@ -3819,6 +3810,12 @@ xfs_reclaim(
 
         ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0);
 
+        /*
+         * Make sure the atime in the XFS inode is correct before freeing the
+         * Linux inode.
+         */
+        xfs_synchronize_atime(ip);
+
         /* If we have nothing to flush with this inode then complete the
          * teardown now, otherwise break the link between the xfs inode
          * and the linux inode and clean up the xfs inode later. This