syzbot

ffff8880a1aef360: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
ffff8880a1aef370: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
XFS (loop0): metadata I/O error: block 0x5 ("xfs_trans_read_buf_map") error 117 numblks 1
=====================================
WARNING: bad unlock balance detected!
4.14.300-syzkaller #0 Not tainted
-------------------------------------
syz-executor163/7965 is trying to release lock (&xfs_nondir_ilock_class) at:
[<ffffffff825c248f>] mrunlock_excl fs/xfs/mrlock.h:74 [inline]
[<ffffffff825c248f>] xfs_iunlock+0x29f/0x3b0 fs/xfs/xfs_inode.c:327
but there are no more locks to release!

other info that might help us debug this:
2 locks held by syz-executor163/7965:
 #0:  (&type->s_umount_key#46/1){+.+.}, at: [<ffffffff81878e26>] alloc_super fs/super.c:251 [inline]
 #0:  (&type->s_umount_key#46/1){+.+.}, at: [<ffffffff81878e26>] sget_userns+0x556/0xc10 fs/super.c:516
 #1:  (sb_internal#2){.+.+}, at: [<ffffffff825f02f9>] sb_start_intwrite include/linux/fs.h:1598 [inline]
 #1:  (sb_internal#2){.+.+}, at: [<ffffffff825f02f9>] xfs_trans_alloc+0x259/0x320 fs/xfs/xfs_trans.c:242

stack backtrace:
CPU: 1 PID: 7965 Comm: syz-executor163 Not tainted 4.14.300-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_unlock_imbalance_bug include/trace/events/lock.h:58 [inline]
 __lock_release kernel/locking/lockdep.c:3769 [inline]
 lock_release.cold+0x70/0xbf kernel/locking/lockdep.c:4017
 up_write+0x17/0x60 kernel/locking/rwsem.c:115
 mrunlock_excl fs/xfs/mrlock.h:74 [inline]
 xfs_iunlock+0x29f/0x3b0 fs/xfs/xfs_inode.c:327
 xfs_inode_item_unlock+0x83/0xa0 fs/xfs/xfs_inode_item.c:613
 xfs_trans_free_items+0x172/0x230 fs/xfs/xfs_trans.c:768
 xfs_trans_cancel+0x1ae/0x250 fs/xfs/xfs_trans.c:1025
 xfs_qm_dqread+0x9c2/0xe50 fs/xfs/xfs_dquot.c:684
 xfs_qm_dqget+0x4f4/0x19a0 fs/xfs/xfs_dquot.c:837
 xfs_qm_quotacheck_dqadjust+0x96/0x5c0 fs/xfs/xfs_qm.c:1077
 xfs_qm_dqusage_adjust+0x428/0xc20 fs/xfs/xfs_qm.c:1192
 xfs_bulkstat_ag_ichunk fs/xfs/xfs_itable.c:313 [inline]
 xfs_bulkstat+0x72a/0xf60 fs/xfs/xfs_itable.c:498
 xfs_qm_quotacheck+0x223/0x790 fs/xfs/xfs_qm.c:1338
 xfs_qm_mount_quotas+0xe9/0x570 fs/xfs/xfs_qm.c:1457
 xfs_mountfs+0x18be/0x1f40 fs/xfs/xfs_mount.c:979
 xfs_fs_fill_super+0xb7a/0x1380 fs/xfs/xfs_super.c:1688
 mount_bdev+0x2b3/0x360 fs/super.c:1134
 mount_fs+0x92/0x2a0 fs/super.c:1237
 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2572 [inline]
 do_mount+0xe65/0x2a30 fs/namespace.c:2905