f2fs: initialize locks earlier in f2fs_fill_super()

commit 92b4cf5 upstream.

syzbot is reporting lockdep warning at f2fs_handle_error() [1], for
spin_lock(&sbi->error_lock) is called before spin_lock_init() is called.
For safe locking in error handling, move initialization of locks (and
obvious structures) in f2fs_fill_super() to immediately after memory
allocation.

Link: https://syzkaller.appspot.com/bug?extid=40642be9b7e0bb28e0df [1]
Reported-by: syzbot <syzbot+40642be9b7e0bb28e0df@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+40642be9b7e0bb28e0df@syzkaller.appspotmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/f2fs/super.c

@@ -4095,6 +4095,24 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 
 	sbi->sb = sb;
 
+	/* initialize locks within allocated memory */
+	init_f2fs_rwsem(&sbi->gc_lock);
+	mutex_init(&sbi->writepages);
+	init_f2fs_rwsem(&sbi->cp_global_sem);
+	init_f2fs_rwsem(&sbi->node_write);
+	init_f2fs_rwsem(&sbi->node_change);
+	spin_lock_init(&sbi->stat_lock);
+	init_f2fs_rwsem(&sbi->cp_rwsem);
+	init_f2fs_rwsem(&sbi->quota_sem);
+	init_waitqueue_head(&sbi->cp_wait);
+	spin_lock_init(&sbi->error_lock);
+
+	for (i = 0; i < NR_INODE_TYPE; i++) {
+		INIT_LIST_HEAD(&sbi->inode_list[i]);
+		spin_lock_init(&sbi->inode_lock[i]);
+	}
+	mutex_init(&sbi->flush_lock);
+
 	/* Load the checksum driver */
 	sbi->s_chksum_driver = crypto_alloc_shash("crc32", 0, 0);
 	if (IS_ERR(sbi->s_chksum_driver)) {
@@ -4118,6 +4136,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_fs_info = sbi;
 	sbi->raw_super = raw_super;
 
+	memcpy(sbi->errors, raw_super->s_errors, MAX_F2FS_ERRORS);
+
 	/* precompute checksum seed for metadata */
 	if (f2fs_sb_has_inode_chksum(sbi))
 		sbi->s_chksum_seed = f2fs_chksum(sbi, ~0, raw_super->uuid,
@@ -4174,26 +4194,14 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 
 	/* init f2fs-specific super block info */
 	sbi->valid_super_block = valid_super_block;
-	init_f2fs_rwsem(&sbi->gc_lock);
-	mutex_init(&sbi->writepages);
-	init_f2fs_rwsem(&sbi->cp_global_sem);
-	init_f2fs_rwsem(&sbi->node_write);
-	init_f2fs_rwsem(&sbi->node_change);
 
 	/* disallow all the data/node/meta page writes */
 	set_sbi_flag(sbi, SBI_POR_DOING);
-	spin_lock_init(&sbi->stat_lock);
 
 	err = f2fs_init_write_merge_io(sbi);
 	if (err)
 		goto free_bio_info;
 
-	spin_lock_init(&sbi->error_lock);
-	memcpy(sbi->errors, raw_super->s_errors, MAX_F2FS_ERRORS);
-
-	init_f2fs_rwsem(&sbi->cp_rwsem);
-	init_f2fs_rwsem(&sbi->quota_sem);
-	init_waitqueue_head(&sbi->cp_wait);
 	init_sb_info(sbi);
 
 	err = f2fs_init_iostat(sbi);
@@ -4271,12 +4279,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	limit_reserve_root(sbi);
 	adjust_unusable_cap_perc(sbi);
 
-	for (i = 0; i < NR_INODE_TYPE; i++) {
-		INIT_LIST_HEAD(&sbi->inode_list[i]);
-		spin_lock_init(&sbi->inode_lock[i]);
-	}
-	mutex_init(&sbi->flush_lock);
-
 	f2fs_init_extent_cache_info(sbi);
 
 	f2fs_init_ino_entry_info(sbi);