loop7: detected capacity change from 0 to 2048
EXT4-fs (loop7): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.7.8740/29919 is trying to acquire lock:
ffff888167ce9380 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0

but task is already holding lock:
ffff8881afbf6c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       percpu_down_read_internal+0x48/0x1c0
       ext4_writepages+0x205/0x3b0
       do_writepages+0x32e/0x550
       __writeback_single_inode+0x133/0x10e0
       writeback_single_inode+0x4ac/0xdc0
       write_inode_now+0x1c2/0x290
       iput+0x8c1/0xe80
       ext4_xattr_block_set+0x2359/0x2ad0
       ext4_expand_extra_isize_ea+0x12cf/0x1ea0
       __ext4_expand_extra_isize+0x30d/0x400
       __ext4_mark_inode_dirty+0x45c/0x710
       ext4_evict_inode+0x986/0x10e0
       evict+0x61e/0xb10
       ext4_orphan_cleanup+0xc38/0x1470
       ext4_fill_super+0x5a19/0x6330
       get_tree_bdev_flags+0x431/0x4f0
       vfs_get_tree+0x92/0x2a0
       do_new_mount+0x341/0xd30
       __se_sys_mount+0x31d/0x420
       do_syscall_64+0x15f/0xf80
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ei->xattr_sem){++++}-{4:4}:
       __lock_acquire+0x15a5/0x2cf0
       lock_acquire+0x106/0x350
       down_write+0x96/0x200
       ext4_destroy_inline_data+0x28/0xe0
       ext4_do_writepages+0x51e/0x4670
       ext4_writepages+0x241/0x3b0
       do_writepages+0x32e/0x550
       file_write_and_wait_range+0x36e/0x440
       mmb_fsync_noflush+0x76/0x1c0
       ext4_sync_file+0x437/0xd50
       ext4_buffered_write_iter+0x2ca/0x3a0
       ext4_file_write_iter+0x298/0x1bf0
       iter_file_splice_write+0x9a1/0x10f0
       direct_splice_actor+0x101/0x160
       splice_direct_to_actor+0x53a/0xc70
       do_splice_direct+0x195/0x290
       vfs_copy_file_range+0xb02/0x1370
       __se_sys_copy_file_range+0x2fb/0x480
       do_syscall_64+0x15f/0xf80
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&sbi->s_writepages_rwsem);
                               lock(&ei->xattr_sem);
                               lock(&sbi->s_writepages_rwsem);
  lock(&ei->xattr_sem);

 *** DEADLOCK ***

2 locks held by syz.7.8740/29919:
 #0: ffff8881aaf00410 (sb_writers#4){++++}-{0:0}, at: direct_splice_actor+0x49/0x160
 #1: ffff8881afbf6c18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0

stack backtrace:
CPU: 1 UID: 0 PID: 29919 Comm: syz.7.8740 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e1/0x300
 check_noncircular+0x12e/0x150
 __lock_acquire+0x15a5/0x2cf0
 lock_acquire+0x106/0x350
 down_write+0x96/0x200
 ext4_destroy_inline_data+0x28/0xe0
 ext4_do_writepages+0x51e/0x4670
 ext4_writepages+0x241/0x3b0
 do_writepages+0x32e/0x550
 file_write_and_wait_range+0x36e/0x440
 mmb_fsync_noflush+0x76/0x1c0
 ext4_sync_file+0x437/0xd50
 ext4_buffered_write_iter+0x2ca/0x3a0
 ext4_file_write_iter+0x298/0x1bf0
 iter_file_splice_write+0x9a1/0x10f0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x53a/0xc70
 do_splice_direct+0x195/0x290
 vfs_copy_file_range+0xb02/0x1370
 __se_sys_copy_file_range+0x2fb/0x480
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa09af9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa09bdcc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
RAX: ffffffffffffffda RBX: 00007fa09b215fa0 RCX: 00007fa09af9cdd9
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007fa09b032d69 R08: 0000000000000863 R09: 0000000000000000
R10: 00002000000000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa09b216038 R14: 00007fa09b215fa0 R15: 00007ffcc6ddf198
 </TASK>
EXT4-fs error (device loop7): ext4_mb_generate_buddy:1317: group 0, block bitmap and bg descriptor inconsistent: 25 vs 4128793 free clusters
EXT4-fs (loop7): Delayed block allocation failed for inode 15 at logical offset 30 with max blocks 1 with error 28
EXT4-fs (loop7): This should not happen!! Data will be lost

EXT4-fs (loop7): Total free blocks count 0
EXT4-fs (loop7): Free/Dirty block details
EXT4-fs (loop7): free_blocks=66060288
