EXT4-fs (loop4): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop7): mounted filesystem without journal. Opts: ,errors=continue
======================================================
WARNING: possible circular locking dependency detected
5.10.60 #1 Not tainted
------------------------------------------------------
syz-executor.7/9514 is trying to acquire lock:
ffff88804408de68 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x4d/0x380 fs/quota/dquot.c:476

but task is already holding lock:
ffff888044080c50 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x74b/0x12a0 fs/ext4/inode.c:4258

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       down_read+0x9b/0x430 kernel/locking/rwsem.c:1504
       ext4_map_blocks+0x380/0x1760 fs/ext4/inode.c:560
       ext4_getblk+0x144/0x680 fs/ext4/inode.c:847
       ext4_bread+0x29/0x210 fs/ext4/inode.c:899
       ext4_quota_write+0x233/0x630 fs/ext4/super.c:6544
       write_blk+0x10c/0x200 fs/quota/quota_tree.c:73
       get_free_dqblk+0xff/0x2d0 fs/quota/quota_tree.c:102
       do_insert_tree+0x787/0x1140 fs/quota/quota_tree.c:309
       do_insert_tree+0xf51/0x1140 fs/quota/quota_tree.c:340
       do_insert_tree+0xf51/0x1140 fs/quota/quota_tree.c:340
       do_insert_tree+0xf51/0x1140 fs/quota/quota_tree.c:340
       dq_insert_tree fs/quota/quota_tree.c:366 [inline]
       qtree_write_dquot+0x3bf/0x580 fs/quota/quota_tree.c:385
       v2_write_dquot+0x11c/0x250 fs/quota/quota_v2.c:358
       dquot_acquire+0x2cf/0x570 fs/quota/dquot.c:443
       ext4_acquire_dquot+0x245/0x350 fs/ext4/super.c:6200
       dqget+0x61d/0xf00 fs/quota/dquot.c:901
       __dquot_initialize+0x3d7/0xbc0 fs/quota/dquot.c:1479
       ext4_setattr+0x4ac/0x24e0 fs/ext4/inode.c:5349
       notify_change+0xb9e/0x1090 fs/attr.c:336
       do_truncate+0x134/0x1f0 fs/open.c:64
       handle_truncate fs/namei.c:2905 [inline]
       do_open fs/namei.c:3247 [inline]
       path_openat+0x15d4/0x2690 fs/namei.c:3360
       do_filp_open+0x192/0x3e0 fs/namei.c:3387
       do_sys_openat2+0x16d/0x420 fs/open.c:1180
       do_sys_open fs/open.c:1196 [inline]
       __do_sys_openat fs/open.c:1212 [inline]
       __se_sys_openat fs/open.c:1207 [inline]
       __x64_sys_openat+0x13c/0x1f0 fs/open.c:1207
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x9b/0x430 kernel/locking/rwsem.c:1504
       v2_read_dquot+0x49/0x120 fs/quota/quota_v2.c:332
       dquot_acquire+0x133/0x570 fs/quota/dquot.c:434
       ext4_acquire_dquot+0x245/0x350 fs/ext4/super.c:6200
       dqget+0x61d/0xf00 fs/quota/dquot.c:901
       __dquot_initialize+0x3d7/0xbc0 fs/quota/dquot.c:1479
       ext4_setattr+0x4ac/0x24e0 fs/ext4/inode.c:5349
       notify_change+0xb9e/0x1090 fs/attr.c:336
       do_truncate+0x134/0x1f0 fs/open.c:64
       handle_truncate fs/namei.c:2905 [inline]
       do_open fs/namei.c:3247 [inline]
       path_openat+0x15d4/0x2690 fs/namei.c:3360
       do_filp_open+0x192/0x3e0 fs/namei.c:3387
       do_sys_openat2+0x16d/0x420 fs/open.c:1180
       do_sys_open fs/open.c:1196 [inline]
       __do_sys_openat fs/open.c:1212 [inline]
       __se_sys_openat fs/open.c:1207 [inline]
       __x64_sys_openat+0x13c/0x1f0 fs/open.c:1207
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2985 [inline]
       check_prevs_add kernel/locking/lockdep.c:3110 [inline]
       validate_chain kernel/locking/lockdep.c:3725 [inline]
       __lock_acquire+0x29fd/0x5b60 kernel/locking/lockdep.c:4950
       lock_acquire kernel/locking/lockdep.c:5560 [inline]
       lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5525
       __mutex_lock_common kernel/locking/mutex.c:969 [inline]
       __mutex_lock+0x158/0x12e0 kernel/locking/mutex.c:1114
       dquot_commit+0x4d/0x380 fs/quota/dquot.c:476
       ext4_write_dquot+0x243/0x2f0 fs/ext4/super.c:6184
       ext4_mark_dquot_dirty+0x111/0x1a0 fs/ext4/super.c:6235
       mark_dquot_dirty fs/quota/dquot.c:347 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:385 [inline]
       __dquot_free_space+0x73c/0xa70 fs/quota/dquot.c:1894
       dquot_free_space_nodirty include/linux/quotaops.h:376 [inline]
       dquot_free_space include/linux/quotaops.h:381 [inline]
       dquot_free_block include/linux/quotaops.h:392 [inline]
       ext4_free_blocks+0x1a81/0x20f0 fs/ext4/mballoc.c:5503
       ext4_remove_blocks fs/ext4/extents.c:2483 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2667 [inline]
       ext4_ext_remove_space+0x308a/0x40c0 fs/ext4/extents.c:2915
       ext4_ext_truncate+0x1e6/0x240 fs/ext4/extents.c:4376
       ext4_truncate+0xd56/0x12a0 fs/ext4/inode.c:4263
       ext4_setattr+0x16a0/0x24e0 fs/ext4/inode.c:5504
       notify_change+0xb9e/0x1090 fs/attr.c:336
       do_truncate+0x134/0x1f0 fs/open.c:64
       handle_truncate fs/namei.c:2905 [inline]
       do_open fs/namei.c:3247 [inline]
       path_openat+0x15d4/0x2690 fs/namei.c:3360
       do_filp_open+0x192/0x3e0 fs/namei.c:3387
       do_sys_openat2+0x16d/0x420 fs/open.c:1180
       do_sys_open fs/open.c:1196 [inline]
       __do_sys_openat fs/open.c:1212 [inline]
       __se_sys_openat fs/open.c:1207 [inline]
       __x64_sys_openat+0x13c/0x1f0 fs/open.c:1207
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

other info that might help us debug this:

Chain exists of:
  &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/2);
                               lock(&s->s_dquot.dqio_sem);
                               lock(&ei->i_data_sem/2);
  lock(&dquot->dq_lock);

 *** DEADLOCK ***

5 locks held by syz-executor.7/9514:
 #0: ffff88800964a438 (sb_writers#3){.+.+}-{0:0}, at: do_open fs/namei.c:3236 [inline]
 #0: ffff88800964a438 (sb_writers#3){.+.+}-{0:0}, at: path_openat+0x1c68/0x2690 fs/namei.c:3360
 #1: ffff888044080e60 (&sb->s_type->i_mutex_key#14){++++}-{3:3}, at: inode_lock include/linux/fs.h:774 [inline]
 #1: ffff888044080e60 (&sb->s_type->i_mutex_key#14){++++}-{3:3}, at: do_truncate+0x125/0x1f0 fs/open.c:62
 #2: ffff888044080ce8 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xf0a/0x24e0 fs/ext4/inode.c:5429
 #3: ffff888044080c50 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x74b/0x12a0 fs/ext4/inode.c:4258
 #4: ffffffff84ed2060 (dquot_srcu){....}-{0:0}, at: i_dquot fs/quota/dquot.c:926 [inline]
 #4: ffffffff84ed2060 (dquot_srcu){....}-{0:0}, at: __dquot_free_space+0x193/0xa70 fs/quota/dquot.c:1867

stack backtrace:
CPU: 0 PID: 9514 Comm: syz-executor.7 Not tainted 5.10.60 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 check_noncircular+0x268/0x310 kernel/locking/lockdep.c:2120
 check_prev_add kernel/locking/lockdep.c:2985 [inline]
 check_prevs_add kernel/locking/lockdep.c:3110 [inline]
 validate_chain kernel/locking/lockdep.c:3725 [inline]
 __lock_acquire+0x29fd/0x5b60 kernel/locking/lockdep.c:4950
 lock_acquire kernel/locking/lockdep.c:5560 [inline]
 lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5525
 __mutex_lock_common kernel/locking/mutex.c:969 [inline]
 __mutex_lock+0x158/0x12e0 kernel/locking/mutex.c:1114
 dquot_commit+0x4d/0x380 fs/quota/dquot.c:476
 ext4_write_dquot+0x243/0x2f0 fs/ext4/super.c:6184
 ext4_mark_dquot_dirty+0x111/0x1a0 fs/ext4/super.c:6235
 mark_dquot_dirty fs/quota/dquot.c:347 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:385 [inline]
 __dquot_free_space+0x73c/0xa70 fs/quota/dquot.c:1894
 dquot_free_space_nodirty include/linux/quotaops.h:376 [inline]
 dquot_free_space include/linux/quotaops.h:381 [inline]
 dquot_free_block include/linux/quotaops.h:392 [inline]
 ext4_free_blocks+0x1a81/0x20f0 fs/ext4/mballoc.c:5503
 ext4_remove_blocks fs/ext4/extents.c:2483 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2667 [inline]
 ext4_ext_remove_space+0x308a/0x40c0 fs/ext4/extents.c:2915
 ext4_ext_truncate+0x1e6/0x240 fs/ext4/extents.c:4376
 ext4_truncate+0xd56/0x12a0 fs/ext4/inode.c:4263
 ext4_setattr+0x16a0/0x24e0 fs/ext4/inode.c:5504
 notify_change+0xb9e/0x1090 fs/attr.c:336
 do_truncate+0x134/0x1f0 fs/open.c:64
 handle_truncate fs/namei.c:2905 [inline]
 do_open fs/namei.c:3247 [inline]
 path_openat+0x15d4/0x2690 fs/namei.c:3360
 do_filp_open+0x192/0x3e0 fs/namei.c:3387
 do_sys_openat2+0x16d/0x420 fs/open.c:1180
 do_sys_open fs/open.c:1196 [inline]
 __do_sys_openat fs/open.c:1212 [inline]
 __se_sys_openat fs/open.c:1207 [inline]
 __x64_sys_openat+0x13c/0x1f0 fs/open.c:1207
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x466609
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6dbc5af188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 0000000000466609
RDX: 0000000000000200 RSI: 0000000020000040 RDI: 0000000000000005
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc3a85577f R14: 00007f6dbc5af300 R15: 0000000000022000
Quota error (device loop5): v2_read_file_info: Free block number too big (0 >= 0).
EXT4-fs warning (device loop5): ext4_enable_quotas:6417: Failed to enable quota tracking (type=1, err=-117). Please run e2fsck to fix.
EXT4-fs (loop5): mount failed
EXT4-fs (loop6): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop6): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop4): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop7): mounted filesystem without journal. Opts: ,errors=continue
Quota error (device loop5): v2_read_file_info: Free block number too big (0 >= 0).
EXT4-fs warning (device loop5): ext4_enable_quotas:6417: Failed to enable quota tracking (type=1, err=-117). Please run e2fsck to fix.
EXT4-fs (loop5): mount failed
EXT4-fs (loop4): mounted filesystem without journal. Opts: ,errors=continue
EXT4-fs (loop6): mounted filesystem without journal. Opts: ,errors=continue