[PATCH 1/2] f2fs: flush pending checkpoints when freezing super

From: Jaegeuk Kim
Date: Fri Aug 19 2022 - 19:15:41 EST


This avoids -EINVAL when trying to freeze f2fs.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/checkpoint.c | 27 +++++++++++++++++++++------
fs/f2fs/f2fs.h | 1 +
fs/f2fs/super.c | 5 ++---
3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 8259e0fa97e1..37f7a9ea4746 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -1892,15 +1892,30 @@ int f2fs_start_ckpt_thread(struct f2fs_sb_info *sbi)
void f2fs_stop_ckpt_thread(struct f2fs_sb_info *sbi)
{
struct ckpt_req_control *cprc = &sbi->cprc_info;
+ struct task_struct *ckpt_task;

- if (cprc->f2fs_issue_ckpt) {
- struct task_struct *ckpt_task = cprc->f2fs_issue_ckpt;
+ if (!cprc->f2fs_issue_ckpt)
+ return;

- cprc->f2fs_issue_ckpt = NULL;
- kthread_stop(ckpt_task);
+ ckpt_task = cprc->f2fs_issue_ckpt;
+ cprc->f2fs_issue_ckpt = NULL;
+ kthread_stop(ckpt_task);

- flush_remained_ckpt_reqs(sbi, NULL);
- }
+ f2fs_flush_ckpt_thread(sbi);
+}
+
+void f2fs_flush_ckpt_thread(struct f2fs_sb_info *sbi)
+{
+ struct ckpt_req_control *cprc = &sbi->cprc_info;
+
+ if (!cprc->f2fs_issue_ckpt)
+ return;
+
+ flush_remained_ckpt_reqs(sbi, NULL);
+
+ /* Let's wait for the previous dispatched checkpoint. */
+ while (atomic_read(&cprc->queued_ckpt))
+ io_schedule_timeout(DEFAULT_IO_TIMEOUT);
}

void f2fs_init_ckpt_req_control(struct f2fs_sb_info *sbi)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 3c7cdb70fe2e..2a83fc34b372 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3707,6 +3707,7 @@ static inline bool f2fs_need_rand_seg(struct f2fs_sb_info *sbi)
* checkpoint.c
*/
void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io);
+void f2fs_flush_ckpt_thread(struct f2fs_sb_info *sbi);
struct page *f2fs_grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index);
struct page *f2fs_get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index);
struct page *f2fs_get_meta_page_retry(struct f2fs_sb_info *sbi, pgoff_t index);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 212ec2b4926b..48ac3de4a533 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1670,9 +1670,8 @@ static int f2fs_freeze(struct super_block *sb)
if (is_sbi_flag_set(F2FS_SB(sb), SBI_IS_DIRTY))
return -EINVAL;

- /* ensure no checkpoint required */
- if (!llist_empty(&F2FS_SB(sb)->cprc_info.issue_list))
- return -EINVAL;
+ /* Let's flush checkpoints and stop the thread. */
+ f2fs_flush_ckpt_thread(F2FS_SB(sb));

/* to avoid deadlock on f2fs_evict_inode->SB_FREEZE_FS */
set_sbi_flag(F2FS_SB(sb), SBI_IS_FREEZING);
--
2.37.1.595.g718a3a8f04-goog