Commit 8769918b authored by Sahitya Tummala's avatar Sahitya Tummala Committed by Jaegeuk Kim
Browse files

f2fs: change to use rwsem for cp_mutex 



Use rwsem to ensure serialization of the callers and to avoid
starvation of high priority tasks, when the system is under
heavy IO workload.

Signed-off-by: default avatarSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 7ad08a58

fs/f2fs/checkpoint.c

+4 −4
Original line number Diff line number Diff line
@@ -348,13 +348,13 @@ static int f2fs_write_meta_pages(struct address_space *mapping, 
		goto skip_write;



	/* if locked failed, cp will flush dirty pages instead */

	if (!mutex_trylock(&sbi->cp_mutex))

	if (!down_write_trylock(&sbi->cp_global_sem))

		goto skip_write;



	trace_f2fs_writepages(mapping->host, wbc, META);

	diff = nr_pages_to_write(sbi, META, wbc);

	written = f2fs_sync_meta_pages(sbi, META, wbc->nr_to_write, FS_META_IO);

	mutex_unlock(&sbi->cp_mutex);

	up_write(&sbi->cp_global_sem);

	wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);

	return 0;
@@ -1572,7 +1572,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) 
		f2fs_warn(sbi, "Start checkpoint disabled!");

	}

	if (cpc->reason != CP_RESIZE)

		mutex_lock(&sbi->cp_mutex);

		down_write(&sbi->cp_global_sem);



	if (!is_sbi_flag_set(sbi, SBI_IS_DIRTY) &&

		((cpc->reason & CP_FASTBOOT) || (cpc->reason & CP_SYNC) ||
@@ -1647,7 +1647,7 @@ int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) 
	trace_f2fs_write_checkpoint(sbi->sb, cpc->reason, "finish checkpoint");

out:

	if (cpc->reason != CP_RESIZE)

		mutex_unlock(&sbi->cp_mutex);

		up_write(&sbi->cp_global_sem);

	return err;

}

fs/f2fs/f2fs.h

+1 −1
Original line number Diff line number Diff line
@@ -1369,7 +1369,7 @@ struct f2fs_sb_info { 
	int cur_cp_pack;			/* remain current cp pack */

	spinlock_t cp_lock;			/* for flag in ckpt */

	struct inode *meta_inode;		/* cache meta blocks */

	struct mutex cp_mutex;			/* checkpoint procedure lock */

	struct rw_semaphore cp_global_sem;	/* checkpoint procedure lock */

	struct rw_semaphore cp_rwsem;		/* blocking FS operations */

	struct rw_semaphore node_write;		/* locking node writes */

	struct rw_semaphore node_change;	/* locking node change */

fs/f2fs/gc.c

+2 −2
Original line number Diff line number Diff line
@@ -1986,7 +1986,7 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) 


	freeze_super(sbi->sb);

	down_write(&sbi->gc_lock);

	mutex_lock(&sbi->cp_mutex);

	down_write(&sbi->cp_global_sem);



	spin_lock(&sbi->stat_lock);

	if (shrunk_blocks + valid_user_blocks(sbi) +
@@ -2031,7 +2031,7 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count) 
		spin_unlock(&sbi->stat_lock);

	}

out_err:

	mutex_unlock(&sbi->cp_mutex);

	up_write(&sbi->cp_global_sem);

	up_write(&sbi->gc_lock);

	thaw_super(sbi->sb);

	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);

fs/f2fs/recovery.c

+2 −2
Original line number Diff line number Diff line
@@ -799,7 +799,7 @@ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only) 
	INIT_LIST_HEAD(&dir_list);



	/* prevent checkpoint */

	mutex_lock(&sbi->cp_mutex);

	down_write(&sbi->cp_global_sem);



	/* step #1: find fsynced inode numbers */

	err = find_fsync_dnodes(sbi, &inode_list, check_only);
@@ -850,7 +850,7 @@ int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only) 
	if (!err)

		clear_sbi_flag(sbi, SBI_POR_DOING);



	mutex_unlock(&sbi->cp_mutex);

	up_write(&sbi->cp_global_sem);



	/* let's drop all the directory inodes for clean checkpoint */

	destroy_fsync_dnodes(&dir_list, err);

fs/f2fs/super.c

+1 −1
Original line number Diff line number Diff line
@@ -3551,7 +3551,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) 
	sbi->valid_super_block = valid_super_block;

	init_rwsem(&sbi->gc_lock);

	mutex_init(&sbi->writepages);

	mutex_init(&sbi->cp_mutex);

	init_rwsem(&sbi->cp_global_sem);

	init_rwsem(&sbi->node_write);

	init_rwsem(&sbi->node_change);