[XFS] refactor xfs_btree_readahead

From: Dave Chinner <dgc@sgi.com>

Refactor xfs_btree_readahead to make it more readable:

(a) remove the inline xfs_btree_readahead wrapper and move all checks out

of line into the main routine.

(b) factor out helpers for short/long form btrees

(c) move check for root in inodes from the callers into
xfs_btree_readahead

[hch: split out from a big patch and minor cleanups]

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32182a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 1ec494e111b5..519249e20536 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -1721,8 +1721,9 @@ xfs_bmbt_decrement(
         XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
         XFS_BMBT_TRACE_ARGI(cur, level);
         ASSERT(level < cur->bc_nlevels);
-        if (level < cur->bc_nlevels - 1)
-                xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
+
+        xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
+
         if (--cur->bc_ptrs[level] > 0) {
                 XFS_BMBT_TRACE_CURSOR(cur, EXIT);
                 *stat = 1;
@@ -1743,8 +1744,7 @@ xfs_bmbt_decrement(
         for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
                 if (--cur->bc_ptrs[lev] > 0)
                         break;
-                if (lev < cur->bc_nlevels - 1)
-                        xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
+                xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
         }
         if (lev == cur->bc_nlevels) {
                 XFS_BMBT_TRACE_CURSOR(cur, EXIT);
@@ -1995,8 +1995,8 @@ xfs_bmbt_increment(
         XFS_BMBT_TRACE_CURSOR(cur, ENTRY);
         XFS_BMBT_TRACE_ARGI(cur, level);
         ASSERT(level < cur->bc_nlevels);
-        if (level < cur->bc_nlevels - 1)
-                xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
+
+        xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
         block = xfs_bmbt_get_block(cur, level, &bp);
 #ifdef DEBUG
         if ((error = xfs_btree_check_lblock(cur, block, level, bp))) {
@@ -2024,8 +2024,7 @@ xfs_bmbt_increment(
 #endif
                 if (++cur->bc_ptrs[lev] <= be16_to_cpu(block->bb_numrecs))
                         break;
-                if (lev < cur->bc_nlevels - 1)
-                        xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
+                xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
         }
         if (lev == cur->bc_nlevels) {
                 XFS_BMBT_TRACE_CURSOR(cur, EXIT);