[XFS] Add xfs_map_buffer helper, use it in a couple of places.

SGI-PV: 950211
SGI-Modid: xfs-linux-melb:xfs-kern:25312a

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

1 files changed, 25 insertions, 24 deletions

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 58fc7ade90b5..4b6bfdb8251c 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -487,28 +487,37 @@ xfs_add_to_ioend(
 }
 
 STATIC void
+xfs_map_buffer(
+        struct buffer_head      *bh,
+        xfs_iomap_t             *mp,
+        xfs_off_t               offset,
+        uint                    block_bits)
+{
+        sector_t                bn;
+
+        ASSERT(mp->iomap_bn != IOMAP_DADDR_NULL);
+
+        bn = (mp->iomap_bn >> (block_bits - BBSHIFT)) +
+              ((offset - mp->iomap_offset) >> block_bits);
+
+        ASSERT(bn || (mp->iomap_flags & IOMAP_REALTIME));
+
+        bh->b_blocknr = bn;
+        set_buffer_mapped(bh);
+}
+
+STATIC void
 xfs_map_at_offset(
         struct buffer_head      *bh,
         loff_t                  offset,
         int                     block_bits,
         xfs_iomap_t             *iomapp)
 {
-        xfs_daddr_t             bn;
-        int                     sector_shift;
-
         ASSERT(!(iomapp->iomap_flags & IOMAP_HOLE));
         ASSERT(!(iomapp->iomap_flags & IOMAP_DELAY));
-        ASSERT(iomapp->iomap_bn != IOMAP_DADDR_NULL);
-
-        sector_shift = block_bits - BBSHIFT;
-        bn = (iomapp->iomap_bn >> sector_shift) +
-              ((offset - iomapp->iomap_offset) >> block_bits);
-
-        ASSERT(bn || (iomapp->iomap_flags & IOMAP_REALTIME));
-        ASSERT((bn << sector_shift) >= iomapp->iomap_bn);
 
         lock_buffer(bh);
-        bh->b_blocknr = bn;
+        xfs_map_buffer(bh, iomapp, offset, block_bits);
         bh->b_bdev = iomapp->iomap_target->bt_bdev;
         set_buffer_mapped(bh);
         clear_buffer_delay(bh);
@@ -1246,21 +1255,13 @@ __linvfs_get_block(
                 return 0;
 
         if (iomap.iomap_bn != IOMAP_DADDR_NULL) {
-                xfs_daddr_t     bn;
-                xfs_off_t       delta;
-
-                /* For unwritten extents do not report a disk address on
+                /*
+                 * For unwritten extents do not report a disk address on
                  * the read case (treat as if we're reading into a hole).
                  */
                 if (create || !(iomap.iomap_flags & IOMAP_UNWRITTEN)) {
-                        delta = offset - iomap.iomap_offset;
-                        delta >>= inode->i_blkbits;
-
-                        bn = iomap.iomap_bn >> (inode->i_blkbits - BBSHIFT);
-                        bn += delta;
-                        BUG_ON(!bn && !(iomap.iomap_flags & IOMAP_REALTIME));
-                        bh_result->b_blocknr = bn;
-                        set_buffer_mapped(bh_result);
+                        xfs_map_buffer(bh_result, &iomap, offset,
+                                       inode->i_blkbits);
                 }
                 if (create && (iomap.iomap_flags & IOMAP_UNWRITTEN)) {
                         if (direct)