diff options
| author | Miao Xie <miaox@cn.fujitsu.com> | 2012-10-18 10:18:01 +0200 |
|---|---|---|
| committer | Josef Bacik <jbacik@fusionio.com> | 2012-12-11 19:31:33 +0100 |
| commit | de6c4115a297d4bbf178aca9948c3539f89c9caa (patch) | |
| tree | 673e3a6f97931dbed42b0dc8fca2e2a44c3808cc /fs/btrfs/free-space-cache.c | |
| parent | Btrfs: recheck bio against block device when we map the bio (diff) | |
| download | linux-de6c4115a297d4bbf178aca9948c3539f89c9caa.tar.xz linux-de6c4115a297d4bbf178aca9948c3539f89c9caa.zip | |
Btrfs: fix unnecessary while loop when search the free space, cache
When we find a bitmap free space entry, we may check the previous extent
entry covers the offset or not. But if we find this entry is also a bitmap
entry, we will continue to check the previous entry of the current one by
a while loop. It is unnecessary because it is impossible that the extent
entry which is in front of a bitmap entry can cover the offset of the entry
after that bitmap entry.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs/free-space-cache.c')
| -rw-r--r-- | fs/btrfs/free-space-cache.c | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 1027b854b90c..557502ca1a2a 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1250,18 +1250,13 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, * if previous extent entry covers the offset, * we should return it instead of the bitmap entry */ - n = &entry->offset_index; - while (1) { - n = rb_prev(n); - if (!n) - break; + n = rb_prev(&entry->offset_index); + if (n) { prev = rb_entry(n, struct btrfs_free_space, offset_index); - if (!prev->bitmap) { - if (prev->offset + prev->bytes > offset) - entry = prev; - break; - } + if (!prev->bitmap && + prev->offset + prev->bytes > offset) + entry = prev; } } return entry; @@ -1287,18 +1282,13 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, } if (entry->bitmap) { - n = &entry->offset_index; - while (1) { - n = rb_prev(n); - if (!n) - break; + n = rb_prev(&entry->offset_index); + if (n) { prev = rb_entry(n, struct btrfs_free_space, offset_index); - if (!prev->bitmap) { - if (prev->offset + prev->bytes > offset) - return prev; - break; - } + if (!prev->bitmap && + prev->offset + prev->bytes > offset) + return prev; } if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset) return entry; |