lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230615111200.11949-1-changfengnan@bytedance.com>
Date:   Thu, 15 Jun 2023 19:12:00 +0800
From:   Fengnan Chang <changfengnan@...edance.com>
To:     daeho.jeong@...sung.com, wangjianchao@...ishou.com, tytso@....edu
Cc:     linux-ext4@...r.kernel.org,
        Fengnan Chang <changfengnan@...edance.com>
Subject: [RFC PATCH] ext4: improve discard efficiency

In commit a015434480dc("ext4: send parallel discards on commit
completions"), issue all discard commands in parallel make all
bios could merged into one request, so lowlevel drive can issue
multi segments in one time which is more efficiency, but commit
55cdd0af2bc5 ("ext4: get discard out of jbd2 commit kthread contex")
seems broke this way, let's fix it.
In my test, the time of fstrim fs with multi big sparse file
reduce from 6.7s to 1.3s.

Signed-off-by: Fengnan Chang <changfengnan@...edance.com>
---
 fs/ext4/mballoc.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index a2475b8c9fb5..e5a27fd2e959 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -6790,7 +6790,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
  * be called with under the group lock.
  */
 static int ext4_trim_extent(struct super_block *sb,
-		int start, int count, struct ext4_buddy *e4b)
+		int start, int count, struct ext4_buddy *e4b, struct bio **biop)
 __releases(bitlock)
 __acquires(bitlock)
 {
@@ -6812,7 +6812,7 @@ __acquires(bitlock)
 	 */
 	mb_mark_used(e4b, &ex);
 	ext4_unlock_group(sb, group);
-	ret = ext4_issue_discard(sb, group, start, count, NULL);
+	ret = ext4_issue_discard(sb, group, start, count, biop);
 	ext4_lock_group(sb, group);
 	mb_free_blocks(NULL, e4b, start, ex.fe_len);
 	return ret;
@@ -6826,12 +6826,15 @@ __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
 {
 	ext4_grpblk_t next, count, free_count;
 	void *bitmap;
+	struct bio *discard_bio = NULL;
+	struct blk_plug plug;
 
 	bitmap = e4b->bd_bitmap;
 	start = (e4b->bd_info->bb_first_free > start) ?
 		e4b->bd_info->bb_first_free : start;
 	count = 0;
 	free_count = 0;
+	blk_start_plug(&plug);
 
 	while (start <= max) {
 		start = mb_find_next_zero_bit(bitmap, max + 1, start);
@@ -6840,7 +6843,7 @@ __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
 		next = mb_find_next_bit(bitmap, max + 1, start);
 
 		if ((next - start) >= minblocks) {
-			int ret = ext4_trim_extent(sb, start, next - start, e4b);
+			int ret = ext4_trim_extent(sb, start, next - start, e4b, &discard_bio);
 
 			if (ret && ret != -EOPNOTSUPP)
 				break;
@@ -6864,6 +6867,14 @@ __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
 			break;
 	}
 
+	if (discard_bio) {
+		ext4_unlock_group(sb, e4b->bd_group);
+		submit_bio_wait(discard_bio);
+		bio_put(discard_bio);
+		ext4_lock_group(sb, e4b->bd_group);
+	}
+	blk_finish_plug(&plug);
+
 	return count;
 }
 
-- 
2.37.1 (Apple Git-137.1)

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ