Commit c9c8ed50 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: fix to avoid potential race on sbi->unusable_block_count access/update 



Use sbi.stat_lock to protect sbi->unusable_block_count accesss/udpate, in
order to avoid potential race on it.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent d7648343

fs/f2fs/checkpoint.c

+4 −0
Original line number Diff line number Diff line
@@ -1536,7 +1536,11 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) 
	clear_sbi_flag(sbi, SBI_IS_DIRTY);

	clear_sbi_flag(sbi, SBI_NEED_CP);

	clear_sbi_flag(sbi, SBI_QUOTA_SKIP_FLUSH);



	spin_lock(&sbi->stat_lock);

	sbi->unusable_block_count = 0;

	spin_unlock(&sbi->stat_lock);



	__set_cp_next_pack(sbi);



	/*

fs/f2fs/segment.c

+4 −1
Original line number Diff line number Diff line
@@ -2169,8 +2169,11 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) 
			 * before, we must track that to know how much space we

			 * really have.

			 */

			if (f2fs_test_bit(offset, se->ckpt_valid_map))

			if (f2fs_test_bit(offset, se->ckpt_valid_map)) {

				spin_lock(&sbi->stat_lock);

				sbi->unusable_block_count++;

				spin_unlock(&sbi->stat_lock);

			}

		}



		if (f2fs_test_and_clear_bit(offset, se->discard_map))

fs/f2fs/super.c

+6 −0
Original line number Diff line number Diff line
@@ -1226,10 +1226,13 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf) 
	buf->f_blocks = total_count - start_count;

	buf->f_bfree = user_block_count - valid_user_blocks(sbi) -

						sbi->current_reserved_blocks;



	spin_lock(&sbi->stat_lock);

	if (unlikely(buf->f_bfree <= sbi->unusable_block_count))

		buf->f_bfree = 0;

	else

		buf->f_bfree -= sbi->unusable_block_count;

	spin_unlock(&sbi->stat_lock);



	if (buf->f_bfree > F2FS_OPTION(sbi).root_reserved_blocks)

		buf->f_bavail = buf->f_bfree -
@@ -1508,7 +1511,10 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) 
	if (err)

		goto out_unlock;



	spin_lock(&sbi->stat_lock);

	sbi->unusable_block_count = 0;

	spin_unlock(&sbi->stat_lock);



out_unlock:

	mutex_unlock(&sbi->gc_mutex);

restore_flag: