After first execution of mb_find_order_for_block():
'fe_start' is the value of 'block' passed in mb_find_extent().
'fe_len' is the difference between the length of order-chunk and
remainder of the block divided by order-chunk.
And 'next' does not require initialization after above modifications.
Signed-off-by: Gou Hao <gouhao@xxxxxxxxxxxxx>
---
fs/ext4/mballoc.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 454d5612641e..d3f985f7cab8 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1958,8 +1958,7 @@ static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
static int mb_find_extent(struct ext4_buddy *e4b, int block,
int needed, struct ext4_free_extent *ex)
{
- int next = block;
- int max, order;
+ int max, order, next;
void *buddy;
assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
@@ -1977,16 +1976,12 @@ static int mb_find_extent(struct ext4_buddy *e4b, int block,
/* find actual order */
order = mb_find_order_for_block(e4b, block);
- block = block >> order;
- ex->fe_len = 1 << order;
- ex->fe_start = block << order;
+ ex->fe_len = (1 << order) - (block & ((1 << order) - 1));
+ ex->fe_start = block;
ex->fe_group = e4b->bd_group;
- /* calc difference from given start */
- next = next - ex->fe_start;
- ex->fe_len -= next;
- ex->fe_start += next;
+ block = block >> order;
while (needed > ex->fe_len &&
mb_find_buddy(e4b, order, &max)) {
--
2.20.1
