======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.7.5771/16573 is trying to acquire lock:
ffff8881079530c0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0

but task is already holding lock:
ffff88816e060b98 (&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+0x133/0x11a0
       writeback_single_inode+0x4ac/0xdc0
       write_inode_now+0x1c2/0x290
       iput+0x8c1/0xe80
       ext4_xattr_block_set+0x1fd4/0x2ad0
       ext4_expand_extra_isize_ea+0x12cf/0x1ea0
       __ext4_expand_extra_isize+0x30d/0x400
       __ext4_mark_inode_dirty+0x45c/0x730
       ext4_evict_inode+0x7a1/0xeb0
       evict+0x61e/0xb10
       ext4_orphan_cleanup+0xc38/0x1470
       ext4_fill_super+0x59ff/0x6320
       get_tree_bdev_flags+0x431/0x4f0
       vfs_get_tree+0x92/0x2a0
       do_new_mount+0x341/0xd30
       __se_sys_mount+0x31d/0x420
       do_syscall_64+0x14d/0xf80
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&ei->xattr_sem){++++}-{4:4}:
       __lock_acquire+0x15a5/0x2cf0
       lock_acquire+0xf0/0x2e0
       down_write+0x96/0x200
       ext4_destroy_inline_data+0x28/0xe0
       ext4_do_writepages+0x51e/0x46e0
       ext4_writepages+0x241/0x3b0
       do_writepages+0x32e/0x550
       filemap_flush+0x1e1/0x2e0
       ext4_convert_inline_data+0x18e/0x600
       ext4_page_mkwrite+0x247/0x1150
       do_page_mkwrite+0x14d/0x310
       do_wp_page+0x19ba/0x4cd0
       handle_mm_fault+0x151d/0x3170
       do_user_addr_fault+0xa73/0x1340
       exc_page_fault+0x6a/0xc0
       asm_exc_page_fault+0x26/0x30

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 ***

4 locks held by syz.7.5771/16573:
 #0: ffff888118163e88 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500
 #1: ffff888172ddc518 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1150
 #2: ffff888107953578 (mapping.invalidate_lock#2){++++}-{4:4}, at: ext4_page_mkwrite+0x23a/0x1150
 #3: ffff88816e060b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0

stack backtrace:
CPU: 0 UID: 0 PID: 16573 Comm: syz.7.5771 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+0xf0/0x2e0
 down_write+0x96/0x200
 ext4_destroy_inline_data+0x28/0xe0
 ext4_do_writepages+0x51e/0x46e0
 ext4_writepages+0x241/0x3b0
 do_writepages+0x32e/0x550
 filemap_flush+0x1e1/0x2e0
 ext4_convert_inline_data+0x18e/0x600
 ext4_page_mkwrite+0x247/0x1150
 do_page_mkwrite+0x14d/0x310
 do_wp_page+0x19ba/0x4cd0
 handle_mm_fault+0x151d/0x3170
 do_user_addr_fault+0xa73/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fc920265ea5
Code: 48 8b 04 24 48 85 c0 74 17 48 8b 74 24 10 48 0f ce 48 89 74 24 10 48 83 f8 01 0f 85 f0 02 00 00 48 8b 44 24 18 48 8b 54 24 10 <48> 89 10 e9 5a fe ff ff 48 8b 44 24 20 48 0b 44 24 28 75 30 48 8b
RSP: 002b:00007ffe2e31c720 EFLAGS: 00010246
RAX: 0000200000000080 RBX: 0000000000000008 RCX: 0000000000000000
RDX: 0000000000000009 RSI: 0000000000000000 RDI: 00005555830163d8
RBP: 00007ffe2e31c840 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000009 R11: 0000000000000000 R12: 00007ffe2e31c880
R13: 00007fc92061609c R14: 000000000012d22e R15: 00007ffe2e31c860
 </TASK>
EXT4-fs error (device loop7): ext4_validate_block_bitmap:432: comm syz.7.5771: bg 0: block 5: invalid block bitmap
EXT4-fs (loop7): Delayed block allocation failed for inode 15 at logical offset 0 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=0
EXT4-fs (loop7): dirty_blocks=2
EXT4-fs (loop7): Block reservation details
EXT4-fs (loop7): i_reserved_data_blocks=2
