[PATCH 6.19 15/18] Revert "f2fs: block cache/dio write during f2fs_enable_checkpoint()"

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chao Yu <chao@kernel.org>

[ Upstream commit 3996b70209f145bfcf2afc7d05dd92c27b233b48 ]

This reverts commit 196c81fdd438f7ac429d5639090a9816abb9760a.

Original patch may cause below deadlock, revert it.

write				remount
- write_begin
 - lock_page  --- lock A
 - prepare_write_begin
  - f2fs_map_lock
				- f2fs_enable_checkpoint
				 - down_write(cp_enable_rwsem)  --- lock B
				 - sync_inode_sb
				  - writepages
				   - lock_page			--- lock A
   - down_read(cp_enable_rwsem)  --- lock A

Cc: stable@kernel.org
Fixes: 196c81fdd438 ("f2fs: block cache/dio write during f2fs_enable_checkpoint()")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[ drop tracing bits ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/f2fs/data.c  |    2 --
 fs/f2fs/f2fs.h  |    3 +--
 fs/f2fs/super.c |   38 ++++++++------------------------------
 3 files changed, 9 insertions(+), 34 deletions(-)

--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1424,7 +1424,6 @@ static int __allocate_data_block(struct
 
 static void f2fs_map_lock(struct f2fs_sb_info *sbi, int flag)
 {
-	f2fs_down_read(&sbi->cp_enable_rwsem);
 	if (flag == F2FS_GET_BLOCK_PRE_AIO)
 		f2fs_down_read(&sbi->node_change);
 	else
@@ -1437,7 +1436,6 @@ static void f2fs_map_unlock(struct f2fs_
 		f2fs_up_read(&sbi->node_change);
 	else
 		f2fs_unlock_op(sbi);
-	f2fs_up_read(&sbi->cp_enable_rwsem);
 }
 
 int f2fs_get_block_locked(struct dnode_of_data *dn, pgoff_t index)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -287,7 +287,7 @@ 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		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 */
 
@@ -1720,7 +1720,6 @@ struct f2fs_sb_info {
 	long interval_time[MAX_TIME];		/* to store thresholds */
 	struct ckpt_req_control cprc_info;	/* for checkpoint request control */
 	struct cp_stats cp_stats;		/* for time stat of checkpoint */
-	struct f2fs_rwsem cp_enable_rwsem;	/* block cache/dio write */
 
 	struct inode_management im[MAX_INO_ENTRY];	/* manage inode cache */
 
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2636,11 +2636,10 @@ restore_flag:
 static int f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)
 {
 	unsigned int nr_pages = get_pages(sbi, F2FS_DIRTY_DATA) / 16;
-	long long start, writeback, lock, sync_inode, end;
+	long long start, writeback, end;
 	int ret;
 
-	f2fs_info(sbi, "%s start, meta: %lld, node: %lld, data: %lld",
-					__func__,
+	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));
@@ -2659,18 +2658,11 @@ static int f2fs_enable_checkpoint(struct
 	}
 	writeback = ktime_get();
 
-	f2fs_down_write(&sbi->cp_enable_rwsem);
-
-	lock = ktime_get();
-
-	if (get_pages(sbi, F2FS_DIRTY_DATA))
-		sync_inodes_sb(sbi->sb);
+	sync_inodes_sb(sbi->sb);
 
 	if (unlikely(get_pages(sbi, F2FS_DIRTY_DATA)))
-		f2fs_warn(sbi, "%s: has some unwritten data: %lld",
-			__func__, get_pages(sbi, F2FS_DIRTY_DATA));
-
-	sync_inode = ktime_get();
+		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);
@@ -2679,13 +2671,6 @@ static int f2fs_enable_checkpoint(struct
 	set_sbi_flag(sbi, SBI_IS_DIRTY);
 	f2fs_up_write(&sbi->gc_lock);
 
-	f2fs_info(sbi, "%s sync_fs, meta: %lld, imeta: %lld, node: %lld, dents: %lld, qdata: %lld",
-					__func__,
-					get_pages(sbi, F2FS_DIRTY_META),
-					get_pages(sbi, F2FS_DIRTY_IMETA),
-					get_pages(sbi, F2FS_DIRTY_NODES),
-					get_pages(sbi, F2FS_DIRTY_DENTS),
-					get_pages(sbi, F2FS_DIRTY_QDATA));
 	ret = f2fs_sync_fs(sbi->sb, 1);
 	if (ret)
 		f2fs_err(sbi, "%s sync_fs failed, ret: %d", __func__, ret);
@@ -2693,17 +2678,11 @@ static int f2fs_enable_checkpoint(struct
 	/* Let's ensure there's no pending checkpoint anymore */
 	f2fs_flush_ckpt_thread(sbi);
 
-	f2fs_up_write(&sbi->cp_enable_rwsem);
-
 	end = ktime_get();
 
-	f2fs_info(sbi, "%s end, writeback:%llu, "
-				"lock:%llu, sync_inode:%llu, sync_fs:%llu",
-				__func__,
-				ktime_ms_delta(writeback, start),
-				ktime_ms_delta(lock, writeback),
-				ktime_ms_delta(sync_inode, lock),
-				ktime_ms_delta(end, sync_inode));
+	f2fs_info(sbi, "f2fs_enable_checkpoint() finishes, writeback:%llu, sync:%llu",
+					ktime_ms_delta(writeback, start),
+					ktime_ms_delta(end, writeback));
 	return ret;
 }
 
@@ -4904,7 +4883,6 @@ try_onemore:
 	init_f2fs_rwsem(&sbi->node_change);
 	spin_lock_init(&sbi->stat_lock);
 	init_f2fs_rwsem(&sbi->cp_rwsem);
-	init_f2fs_rwsem(&sbi->cp_enable_rwsem);
 	init_f2fs_rwsem(&sbi->quota_sem);
 	init_waitqueue_head(&sbi->cp_wait);
 	spin_lock_init(&sbi->error_lock);