[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>

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 58fc7ade90b53047bb467d95791ec0e7445bd671..4b6bfdb8251c6771253476bbea652171794c85f0 100644 (file)
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -486,6 +486,26 @@ xfs_add_to_ioend(
        ioend->io_size += bh->b_size;
 }
 
+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,
@@ -493,22 +513,11 @@ xfs_map_at_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)