ext4: optimize block allocation on grow indepth

It is reasonable to prepend newly created index to older one.

[ Dropped no longer used function parameter newext. -tytso ]

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 8170b3254767e3b0f570bd076f4a79676a142347..c3ed9af20d20bb680868633158941f5a007b824f 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1263,16 +1263,24 @@ cleanup:
  *   just created block
  */
 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
-                                unsigned int flags,
-                                struct ext4_extent *newext)
+                                unsigned int flags)
 {
        struct ext4_extent_header *neh;
        struct buffer_head *bh;
-       ext4_fsblk_t newblock;
+       ext4_fsblk_t newblock, goal = 0;
+       struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
        int err = 0;
 
-       newblock = ext4_ext_new_meta_block(handle, inode, NULL,
-               newext, &err, flags);
+       /* Try to prepend new index to old one */
+       if (ext_depth(inode))
+               goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
+       if (goal > le32_to_cpu(es->s_first_data_block)) {
+               flags |= EXT4_MB_HINT_TRY_GOAL;
+               goal--;
+       } else
+               goal = ext4_inode_to_goal_block(inode);
+       newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
+                                       NULL, &err);
        if (newblock == 0)
                return err;
 
@@ -1373,7 +1381,7 @@ repeat:
                        err = PTR_ERR(path);
        } else {
                /* tree is full, time to grow in depth */
-               err = ext4_ext_grow_indepth(handle, inode, mb_flags, newext);
+               err = ext4_ext_grow_indepth(handle, inode, mb_flags);
                if (err)
                        goto out;