xfs: split inode data writeback from xfs_sync_inodes_ag

In many cases we only want to sync inode data. Start spliting the inode sync
into data sync and inode sync by factoring out the inode data flush.

[hch: minor cleanups]

Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index b06b95c..7adc62d 100644 (file)
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -48,6 +48,35 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 
+
+STATIC int
+xfs_sync_inode_data(
+       struct xfs_inode        *ip,
+       int                     flags)
+{
+       struct inode            *inode = VFS_I(ip);
+       struct address_space *mapping = inode->i_mapping;
+       int                     error = 0;
+
+       if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+               goto out_wait;
+
+       if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
+               if (flags & SYNC_TRYLOCK)
+                       goto out_wait;
+               xfs_ilock(ip, XFS_IOLOCK_SHARED);
+       }
+
+       error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
+                               0 : XFS_B_ASYNC, FI_NONE);
+       xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+
+ out_wait:
+       if (flags & SYNC_IOWAIT)
+               xfs_ioend_wait(ip);
+       return error;
+}
+
 /*
  * Sync all the inodes in the given AG according to the
  * direction given by the flags.
@@ -123,27 +152,10 @@ xfs_sync_inodes_ag(
                 * If we have to flush data or wait for I/O completion
                 * we need to hold the iolock.
                 */
-               if (flags & SYNC_DELWRI) {
-                       if (VN_DIRTY(inode)) {
-                               if (flags & SYNC_TRYLOCK) {
-                                       if (xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
-                                               lock_flags |= XFS_IOLOCK_SHARED;
-                               } else {
-                                       xfs_ilock(ip, XFS_IOLOCK_SHARED);
-                                       lock_flags |= XFS_IOLOCK_SHARED;
-                               }
-                               if (lock_flags & XFS_IOLOCK_SHARED) {
-                                       error = xfs_flush_pages(ip, 0, -1,
-                                                       (flags & SYNC_WAIT) ? 0
-                                                               : XFS_B_ASYNC,
-                                                       FI_NONE);
-                               }
-                       }
-                       if (VN_CACHED(inode) && (flags & SYNC_IOWAIT))
-                               xfs_ioend_wait(ip);
-               }
-               xfs_ilock(ip, XFS_ILOCK_SHARED);
+               if (flags & SYNC_DELWRI)
+                       error = xfs_sync_inode_data(ip, flags);
 
+               xfs_ilock(ip, XFS_ILOCK_SHARED);
                if ((flags & SYNC_ATTR) && !xfs_inode_clean(ip)) {
                        if (flags & SYNC_WAIT) {
                                xfs_iflock(ip);