[PATCH 1/2] f2fs: add timeout in f2fs_enable_checkpoint()

[PATCH 1/2] f2fs: add timeout in f2fs_enable_checkpoint()

[Chao Yu]

During f2fs_enable_checkpoint() in remount(), if we flush a large
amount of dirty pages into slow device, it may take long time which
will block write IO, let's add a timeout machanism during dirty
pages flush to avoid long time block in f2fs_enable_checkpoint().

Signed-off-by: Chao Yu <chao@kernel.org>
---
 fs/f2fs/f2fs.h  |  2 ++
 fs/f2fs/super.c | 21 +++++++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 464dcbf5c32e..df4466e652cf 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -275,6 +275,7 @@ enum {
 #define DEF_CP_INTERVAL			60	/* 60 secs */
 #define DEF_IDLE_INTERVAL		5	/* 5 secs */
 #define DEF_DISABLE_INTERVAL		5	/* 5 secs */
+#define DEF_ENABLE_INTERVAL		16	/* 16 secs */
 #define DEF_DISABLE_QUICK_INTERVAL	1	/* 1 secs */
 #define DEF_UMOUNT_DISCARD_TIMEOUT	5	/* 5 secs */
 
@@ -1406,6 +1407,7 @@ enum {
 	DISCARD_TIME,
 	GC_TIME,
 	DISABLE_TIME,
+	ENABLE_TIME,
 	UMOUNT_DISCARD_TIMEOUT,
 	MAX_TIME,
 };
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c1f45df9efec..411265c75698 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2623,16 +2623,24 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
 
 static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 {
-	int retry = DEFAULT_RETRY_IO_COUNT;
+	unsigned int nr_pages = get_pages(sbi, F2FS_DIRTY_DATA) / 16;
+
+	f2fs_update_time(sbi, ENABLE_TIME);
 
 	/* we should flush all the data to keep data consistency */
-	do {
-		sync_inodes_sb(sbi->sb);
+	while (get_pages(sbi, F2FS_DIRTY_DATA)) {
+		writeback_inodes_sb_nr(sbi->sb, nr_pages, WB_REASON_SYNC);
 		f2fs_io_schedule_timeout(DEFAULT_IO_TIMEOUT);
-	} while (get_pages(sbi, F2FS_DIRTY_DATA) && retry--);
 
-	if (unlikely(retry < 0))
-		f2fs_warn(sbi, "checkpoint=enable has some unwritten data.");
+		if (f2fs_time_over(sbi, ENABLE_TIME))
+			break;
+	}
+
+	sync_inodes_sb(sbi->sb);
+
+	if (unlikely(get_pages(sbi, F2FS_DIRTY_DATA)))
+		f2fs_warn(sbi, "checkpoint=enable has some unwritten data: %lld",
+					get_pages(sbi, F2FS_DIRTY_DATA));
 
 	f2fs_down_write(&sbi->gc_lock);
 	f2fs_dirty_to_prefree(sbi);
@@ -4229,6 +4237,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
 	sbi->interval_time[DISCARD_TIME] = DEF_IDLE_INTERVAL;
 	sbi->interval_time[GC_TIME] = DEF_IDLE_INTERVAL;
 	sbi->interval_time[DISABLE_TIME] = DEF_DISABLE_INTERVAL;
+	sbi->interval_time[ENABLE_TIME] = DEF_ENABLE_INTERVAL;
 	sbi->interval_time[UMOUNT_DISCARD_TIMEOUT] =
 				DEF_UMOUNT_DISCARD_TIMEOUT;
 	clear_sbi_flag(sbi, SBI_NEED_FSCK);
-- 
2.49.0

[PATCH 2/2] f2fs: dump more information for f2fs_{enable,disable}_checkpoint()

[Chao Yu]

Changes as below:
- print more logs for f2fs_{enable,disable}_checkpoint()
- account and dump time stats for f2fs_enable_checkpoint()

Signed-off-by: Chao Yu <chao@kernel.org>
---
 fs/f2fs/super.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 411265c75698..67788177c75b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2618,15 +2618,24 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)
 restore_flag:
 	sbi->gc_mode = gc_mode;
 	sbi->sb->s_flags = s_flags;	/* Restore SB_RDONLY status */
+	f2fs_info(sbi, "f2fs_disable_checkpoint() finish, err:%d", err);
 	return err;
 }
 
 static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 {
 	unsigned int nr_pages = get_pages(sbi, F2FS_DIRTY_DATA) / 16;
+	long long start, writeback, end;
+
+	f2fs_info(sbi, "f2fs_enable_checkpoint() starts, meta: %lld, node: %lld, data: %lld",
+					get_pages(sbi, F2FS_DIRTY_META),
+					get_pages(sbi, F2FS_DIRTY_NODES),
+					get_pages(sbi, F2FS_DIRTY_DATA));
 
 	f2fs_update_time(sbi, ENABLE_TIME);
 
+	start = ktime_get();
+
 	/* we should flush all the data to keep data consistency */
 	while (get_pages(sbi, F2FS_DIRTY_DATA)) {
 		writeback_inodes_sb_nr(sbi->sb, nr_pages, WB_REASON_SYNC);
@@ -2635,6 +2644,7 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 		if (f2fs_time_over(sbi, ENABLE_TIME))
 			break;
 	}
+	writeback = ktime_get();
 
 	sync_inodes_sb(sbi->sb);
 
@@ -2653,6 +2663,12 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 
 	/* Let's ensure there's no pending checkpoint anymore */
 	f2fs_flush_ckpt_thread(sbi);
+
+	end = ktime_get();
+
+	f2fs_info(sbi, "f2fs_enable_checkpoint() finishes, writeback:%llu, sync:%llu",
+					ktime_ms_delta(writeback, start),
+					ktime_ms_delta(end, writeback));
 }
 
 static int __f2fs_remount(struct fs_context *fc, struct super_block *sb)
-- 
2.49.0

Re: [f2fs-dev] [PATCH 1/2] f2fs: add timeout in f2fs_enable_checkpoint()

[patchwork-bot+f2fs]

Hello:

This series was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <jaegeuk@kernel.org>:

On Thu,  7 Aug 2025 12:00:25 +0800 you wrote:
> During f2fs_enable_checkpoint() in remount(), if we flush a large
> amount of dirty pages into slow device, it may take long time which
> will block write IO, let's add a timeout machanism during dirty
> pages flush to avoid long time block in f2fs_enable_checkpoint().
> 
> Signed-off-by: Chao Yu <chao@kernel.org>
> 
> [...]

Here is the summary with links:
  - [f2fs-dev,1/2] f2fs: add timeout in f2fs_enable_checkpoint()
    https://git.kernel.org/jaegeuk/f2fs/c/da63f609094d
  - [f2fs-dev,2/2] f2fs: dump more information for f2fs_{enable, disable}_checkpoint()
    https://git.kernel.org/jaegeuk/f2fs/c/347ff7d828c0

You are awesome, thank you!
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