| Message ID | 20211122151646.14235-1-nborisov@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: get next entry in tree_search_offset before doing checks | expand |
On Mon, Nov 22, 2021 at 05:16:46PM +0200, Nikolay Borisov wrote: > This is a small optimisation since the currenty 'entry' is already > checked in the if () {} else if {} construct above the loop. In essence > the first iteration of the final while loop is redundant. To eliminate > this extra check simply get the next entry at the beginning of the loop. You forgot your signed-off-by, but you can add my Reviewed-by: Josef Bacik <josef@toxicpanda.com> Thanks, Josef
On Mon, Nov 22, 2021 at 05:16:46PM +0200, Nikolay Borisov wrote: > This is a small optimisation since the currenty 'entry' is already > checked in the if () {} else if {} construct above the loop. In essence > the first iteration of the final while loop is redundant. To eliminate > this extra check simply get the next entry at the beginning of the loop. > --- Added to misc-next, thanks.
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index f3fee88c8ee0..145a07b19359 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1686,6 +1686,10 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, return NULL; while (1) { + n = rb_next(&entry->offset_index); + if (!n) + return NULL; + entry = rb_entry(n, struct btrfs_free_space, offset_index); if (entry->bitmap) { if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset) @@ -1694,11 +1698,6 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, if (entry->offset + entry->bytes > offset) break; } - - n = rb_next(&entry->offset_index); - if (!n) - return NULL; - entry = rb_entry(n, struct btrfs_free_space, offset_index); } return entry; }
This is a small optimisation since the currenty 'entry' is already checked in the if () {} else if {} construct above the loop. In essence the first iteration of the final while loop is redundant. To eliminate this extra check simply get the next entry at the beginning of the loop. --- fs/btrfs/free-space-cache.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)