From: Chunguang Xu <brookxu.cn@gmail.com>
To: tytso@mit.edu, adilger.kernel@dilger.ca
Cc: linux-ext4@vger.kernel.org
Subject: [PATCH 4/8] ext4: simplify the code of mb_find_order_for_block
Date: Fri, 16 Oct 2020 11:55:48 +0800 [thread overview]
Message-ID: <1602820552-4082-4-git-send-email-brookxu@tencent.com> (raw)
In-Reply-To: <1602820552-4082-1-git-send-email-brookxu@tencent.com>
From: Chunguang Xu <brookxu@tencent.com>
The code of mb_find_order_for_block is a bit obscure, but we can
simplify it with mb_find_buddy(), make the code more concise.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
---
fs/ext4/mballoc.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 5b8ce76..2eead37 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1289,22 +1289,18 @@ static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
{
- int order = 1;
- int bb_incr = 1 << (e4b->bd_blkbits - 1);
+ int order = 1, max;
void *bb;
BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
- bb = e4b->bd_buddy;
while (order <= e4b->bd_blkbits + 1) {
- block = block >> 1;
- if (!mb_test_bit(block, bb)) {
+ bb = mb_find_buddy(e4b, order, &max);
+ if (!mb_test_bit(block >> order, bb)) {
/* this block is part of buddy of order 'order' */
return order;
}
- bb += bb_incr;
- bb_incr >>= 1;
order++;
}
return 0;
--
1.8.3.1
next prev parent reply other threads:[~2020-10-16 3:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-16 3:55 [PATCH 1/8] ext4: use ASSERT() to replace J_ASSERT() Chunguang Xu
2020-10-16 3:55 ` [PATCH 2/8] ext4: remove redundant mb_regenerate_buddy() Chunguang Xu
2020-10-16 3:55 ` [PATCH 3/8] ext4: use do_div() to calculate block offset Chunguang Xu
2020-10-17 2:23 ` kernel test robot
2020-10-16 3:55 ` Chunguang Xu [this message]
2020-10-16 3:55 ` [PATCH 5/8] ext4: add the gdt block of meta_bg to system_zone Chunguang Xu
2020-10-16 3:55 ` [PATCH 6/8] ext4: update ext4_data_block_valid related comments Chunguang Xu
2020-10-16 3:55 ` [PATCH 7/8] ext4: add a helper function to validate metadata block Chunguang Xu
2020-10-16 3:55 ` [PATCH 8/8] ext4: delete invalid code inside ext4_xattr_block_set() Chunguang Xu
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