linux-kernel - [PATCH 2/4] badblocks: optimize _badblocks

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Date: Sat, 23 Dec 2023 14:37:26 +0800
From: linan666@...weicloud.com
To: axboe@...nel.dk,
	geliang.tang@...e.com,
	xni@...hat.com,
	colyli@...e.de
Cc: ira.weiny@...el.com,
	linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linan666@...weicloud.com,
	yukuai3@...wei.com,
	yi.zhang@...wei.com,
	houtao1@...wei.com,
	yangerkun@...wei.com
Subject: [PATCH 2/4] badblocks: optimize _badblocks_check()

From: Li Nan <linan122@...wei.com>

Check badblocks_empty earlier, and goto out if check range starts after
all badblocks or badblocks is empty since no badblocks intersect with
check range.

Clean up redundant check '(prev + 1) < bb->count'. If it is true, it
will enter the earlier branch.

Signed-off-by: Li Nan <linan122@...wei.com>
---
 block/badblocks.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/block/badblocks.c b/block/badblocks.c
index ebf17a54851a..054d05b93641 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -1296,6 +1296,11 @@ static int _badblocks_check(struct badblocks *bb, sector_t s, int sectors,
 retry:
 	seq = read_seqbegin(&bb->lock);
 
+	if (badblocks_empty(bb)) {
+		len = sectors;
+		goto out;
+	}
+
 	p = bb->page;
 	acked_badblocks = 0;
 
@@ -1303,17 +1308,12 @@ static int _badblocks_check(struct badblocks *bb, sector_t s, int sectors,
 	bad.start = s;
 	bad.len = sectors;
 
-	if (badblocks_empty(bb)) {
-		len = sectors;
-		goto update_sectors;
-	}
-
 	prev = prev_badblocks(bb, &bad, hint);
 
 	/* start after all badblocks */
 	if ((prev + 1) >= bb->count && !overlap_front(bb, prev, &bad)) {
 		len = sectors;
-		goto update_sectors;
+		goto out;
 	}
 
 	if (overlap_front(bb, prev, &bad)) {
@@ -1339,7 +1339,7 @@ static int _badblocks_check(struct badblocks *bb, sector_t s, int sectors,
 	}
 
 	/* Not front overlap, but behind overlap */
-	if ((prev + 1) < bb->count && overlap_behind(bb, &bad, prev + 1)) {
+	if (overlap_behind(bb, &bad, prev + 1)) {
 		len = BB_OFFSET(p[prev + 1]) - bad.start;
 		hint = prev + 1;
 		goto update_sectors;
-- 
2.39.2