diff options
| author | Josef Bacik | 2013-06-17 13:44:48 -0400 |
|---|---|---|
| committer | Josef Bacik | 2013-07-01 08:52:32 -0400 |
| commit | bdf7c00e8f56386dd1df545b37cf59d55ce4216d (patch) | |
| tree | f8fbe2f4b5c5dbd9c6b9a4d79bd3e729a874e7ec | |
| parent | fdf8e2ea3cba9ef03087482b11258d844d6cbea3 (diff) | |
Btrfs: optimize read_block_for_search
This patch does two things, first it only does one call to
btrfs_buffer_uptodate() with the gen specified instead of once with 0 and then
again with gen specified. The other thing is to call btrfs_read_buffer() on the
buffer we've found instead of dropping it and then calling read_tree_block().
This will keep us from doing yet another radix tree lookup for a buffer we've
already found. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
| -rw-r--r-- | fs/btrfs/ctree.c | 47 |
1 files changed, 20 insertions, 27 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 1c9dc71089ce..c85cde761248 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2359,35 +2359,28 @@ read_block_for_search(struct btrfs_trans_handle *trans, tmp = btrfs_find_tree_block(root, blocknr, blocksize); if (tmp) { /* first we do an atomic uptodate check */ - if (btrfs_buffer_uptodate(tmp, 0, 1) > 0) { - if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { - /* - * we found an up to date block without - * sleeping, return - * right away - */ - *eb_ret = tmp; - return 0; - } - /* the pages were up to date, but we failed - * the generation number check. Do a full - * read for the generation number that is correct. - * We must do this without dropping locks so - * we can trust our generation number - */ - free_extent_buffer(tmp); - btrfs_set_path_blocking(p); + if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { + *eb_ret = tmp; + return 0; + } - /* now we're allowed to do a blocking uptodate check */ - tmp = read_tree_block(root, blocknr, blocksize, gen); - if (tmp && btrfs_buffer_uptodate(tmp, gen, 0) > 0) { - *eb_ret = tmp; - return 0; - } - free_extent_buffer(tmp); - btrfs_release_path(p); - return -EIO; + /* the pages were up to date, but we failed + * the generation number check. Do a full + * read for the generation number that is correct. + * We must do this without dropping locks so + * we can trust our generation number + */ + btrfs_set_path_blocking(p); + + /* now we're allowed to do a blocking uptodate check */ + ret = btrfs_read_buffer(tmp, gen); + if (!ret) { + *eb_ret = tmp; + return 0; } + free_extent_buffer(tmp); + btrfs_release_path(p); + return -EIO; } /* |