1 files changed, 142 insertions, 41 deletions

diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 09783cc444ac..25ea2408118f 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -877,12 +877,11 @@ xfsaild(
 {
         struct xfs_ail  *ailp = data;
         xfs_lsn_t       last_pushed_lsn = 0;
-        long            tout = 0;
+        long            tout = 0; /* milliseconds */
 
         while (!kthread_should_stop()) {
-                if (tout)
-                        schedule_timeout_interruptible(msecs_to_jiffies(tout));
-                tout = 1000;
+                schedule_timeout_interruptible(tout ?
+                                msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT);
 
                 /* swsusp */
                 try_to_freeze();
@@ -954,16 +953,14 @@ xfs_fs_destroy_inode(
         ASSERT_ALWAYS(!xfs_iflags_test(ip, XFS_IRECLAIM));
 
         /*
-         * If we have nothing to flush with this inode then complete the
-         * teardown now, otherwise delay the flush operation.
+         * We always use background reclaim here because even if the
+         * inode is clean, it still may be under IO and hence we have
+         * to take the flush lock. The background reclaim path handles
+         * this more efficiently than we can here, so simply let background
+         * reclaim tear down all inodes.
          */
-        if (!xfs_inode_clean(ip)) {
-                xfs_inode_set_reclaim_tag(ip);
-                return;
-        }
-
 out_reclaim:
-        xfs_ireclaim(ip);
+        xfs_inode_set_reclaim_tag(ip);
 }
 
 /*
@@ -1024,12 +1021,45 @@ xfs_fs_dirty_inode(
         XFS_I(inode)->i_update_core = 1;
 }
 
-/*
- * Attempt to flush the inode, this will actually fail
- * if the inode is pinned, but we dirty the inode again
- * at the point when it is unpinned after a log write,
- * since this is when the inode itself becomes flushable.
- */
+STATIC int
+xfs_log_inode(
+        struct xfs_inode        *ip)
+{
+        struct xfs_mount        *mp = ip->i_mount;
+        struct xfs_trans        *tp;
+        int                     error;
+
+        xfs_iunlock(ip, XFS_ILOCK_SHARED);
+        tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
+        error = xfs_trans_reserve(tp, 0, XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0);
+
+        if (error) {
+                xfs_trans_cancel(tp, 0);
+                /* we need to return with the lock hold shared */
+                xfs_ilock(ip, XFS_ILOCK_SHARED);
+                return error;
+        }
+
+        xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+        /*
+         * Note - it's possible that we might have pushed ourselves out of the
+         * way during trans_reserve which would flush the inode.  But there's
+         * no guarantee that the inode buffer has actually gone out yet (it's
+         * delwri).  Plus the buffer could be pinned anyway if it's part of
+         * an inode in another recent transaction.  So we play it safe and
+         * fire off the transaction anyway.
+         */
+        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+        xfs_trans_ihold(tp, ip);
+        xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+        xfs_trans_set_sync(tp);
+        error = xfs_trans_commit(tp, 0);
+        xfs_ilock_demote(ip, XFS_ILOCK_EXCL);
+
+        return error;
+}
+
 STATIC int
 xfs_fs_write_inode(
         struct inode            *inode,
@@ -1037,7 +1067,7 @@ xfs_fs_write_inode(
 {
         struct xfs_inode        *ip = XFS_I(inode);
         struct xfs_mount        *mp = ip->i_mount;
-        int                     error = 0;
+        int                     error = EAGAIN;
 
         xfs_itrace_entry(ip);
 
@@ -1048,35 +1078,55 @@ xfs_fs_write_inode(
                 error = xfs_wait_on_pages(ip, 0, -1);
                 if (error)
                         goto out;
-        }
 
-        /*
-         * Bypass inodes which have already been cleaned by
-         * the inode flush clustering code inside xfs_iflush
-         */
-        if (xfs_inode_clean(ip))
-                goto out;
-
-        /*
-         * We make this non-blocking if the inode is contended, return
-         * EAGAIN to indicate to the caller that they did not succeed.
-         * This prevents the flush path from blocking on inodes inside
-         * another operation right now, they get caught later by xfs_sync.
-         */
-        if (sync) {
+                /*
+                 * Make sure the inode has hit stable storage.  By using the
+                 * log and the fsync transactions we reduce the IOs we have
+                 * to do here from two (log and inode) to just the log.
+                 *
+                 * Note: We still need to do a delwri write of the inode after
+                 * this to flush it to the backing buffer so that bulkstat
+                 * works properly if this is the first time the inode has been
+                 * written.  Because we hold the ilock atomically over the
+                 * transaction commit and the inode flush we are guaranteed
+                 * that the inode is not pinned when it returns. If the flush
+                 * lock is already held, then the inode has already been
+                 * flushed once and we don't need to flush it again.  Hence
+                 * the code will only flush the inode if it isn't already
+                 * being flushed.
+                 */
                 xfs_ilock(ip, XFS_ILOCK_SHARED);
-                xfs_iflock(ip);
-
-                error = xfs_iflush(ip, XFS_IFLUSH_SYNC);
+                if (ip->i_update_core) {
+                        error = xfs_log_inode(ip);
+                        if (error)
+                                goto out_unlock;
+                }
         } else {
-                error = EAGAIN;
+                /*
+                 * We make this non-blocking if the inode is contended, return
+                 * EAGAIN to indicate to the caller that they did not succeed.
+                 * This prevents the flush path from blocking on inodes inside
+                 * another operation right now, they get caught later by xfs_sync.
+                 */
                 if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED))
                         goto out;
-                if (xfs_ipincount(ip) || !xfs_iflock_nowait(ip))
-                        goto out_unlock;
+        }
+
+        if (xfs_ipincount(ip) || !xfs_iflock_nowait(ip))
+                goto out_unlock;
 
-                error = xfs_iflush(ip, XFS_IFLUSH_ASYNC_NOBLOCK);
+        /*
+         * Now we have the flush lock and the inode is not pinned, we can check
+         * if the inode is really clean as we know that there are no pending
+         * transaction completions, it is not waiting on the delayed write
+         * queue and there is no IO in progress.
+         */
+        if (xfs_inode_clean(ip)) {
+                xfs_ifunlock(ip);
+                error = 0;
+                goto out_unlock;
         }
+        error = xfs_iflush(ip, 0);
 
  out_unlock:
         xfs_iunlock(ip, XFS_ILOCK_SHARED);
@@ -1259,6 +1309,29 @@ xfs_fs_statfs(
         return 0;
 }
 
+STATIC void
+xfs_save_resvblks(struct xfs_mount *mp)
+{
+        __uint64_t resblks = 0;
+
+        mp->m_resblks_save = mp->m_resblks;
+        xfs_reserve_blocks(mp, &resblks, NULL);
+}
+
+STATIC void
+xfs_restore_resvblks(struct xfs_mount *mp)
+{
+        __uint64_t resblks;
+
+        if (mp->m_resblks_save) {
+                resblks = mp->m_resblks_save;
+                mp->m_resblks_save = 0;
+        } else
+                resblks = xfs_default_resblks(mp);
+
+        xfs_reserve_blocks(mp, &resblks, NULL);
+}
+
 STATIC int
 xfs_fs_remount(
         struct super_block      *sb,
@@ -1338,11 +1411,27 @@ xfs_fs_remount(
                         }
                         mp->m_update_flags = 0;
                 }
+
+                /*
+                 * Fill out the reserve pool if it is empty. Use the stashed
+                 * value if it is non-zero, otherwise go with the default.
+                 */
+                xfs_restore_resvblks(mp);
         }
 
         /* rw -> ro */
         if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) {
+                /*
+                 * After we have synced the data but before we sync the
+                 * metadata, we need to free up the reserve block pool so that
+                 * the used block count in the superblock on disk is correct at
+                 * the end of the remount. Stash the current reserve pool size
+                 * so that if we get remounted rw, we can return it to the same
+                 * size.
+                 */
+
                 xfs_quiesce_data(mp);
+                xfs_save_resvblks(mp);
                 xfs_quiesce_attr(mp);
                 mp->m_flags |= XFS_MOUNT_RDONLY;
         }
@@ -1361,11 +1450,22 @@ xfs_fs_freeze(
 {
         struct xfs_mount        *mp = XFS_M(sb);
 
+        xfs_save_resvblks(mp);
         xfs_quiesce_attr(mp);
         return -xfs_fs_log_dummy(mp);
 }
 
 STATIC int
+xfs_fs_unfreeze(
+        struct super_block      *sb)
+{
+        struct xfs_mount        *mp = XFS_M(sb);
+
+        xfs_restore_resvblks(mp);
+        return 0;
+}
+
+STATIC int
 xfs_fs_show_options(
         struct seq_file         *m,
         struct vfsmount         *mnt)
@@ -1587,6 +1687,7 @@ static const struct super_operations xfs_super_operations = {
         .put_super              = xfs_fs_put_super,
         .sync_fs                = xfs_fs_sync_fs,
         .freeze_fs              = xfs_fs_freeze,
+        .unfreeze_fs            = xfs_fs_unfreeze,
         .statfs                 = xfs_fs_statfs,
         .remount_fs             = xfs_fs_remount,
         .show_options           = xfs_fs_show_options,