loop3: detected capacity change from 0 to 512
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.1003/8605 is trying to acquire lock:
ffff88802ee02b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
ffff88802ee02b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1786 [inline]
ffff88802ee02b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024

but task is already holding lock:
ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1799 [inline]
ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1982 [inline]
ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2d6/0xee0 fs/ext4/inode.c:215

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_internal){.+.+}-{0:0}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53
       percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
       __sb_start_write include/linux/fs.h:1799 [inline]
       sb_start_intwrite include/linux/fs.h:1982 [inline]
       ext4_evict_inode+0x2d6/0xee0 fs/ext4/inode.c:215
       evict+0x504/0x9c0 fs/inode.c:810
       ext4_ext_migrate+0xd23/0x1010 fs/ext4/migrate.c:588
       __ext4_ioctl fs/ext4/ioctl.c:1402 [inline]
       ext4_ioctl+0x1b1a/0x3510 fs/ext4/ioctl.c:1626
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:598 [inline]
       __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&sbi->s_writepages_rwsem){++++}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
       __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53
       percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
       ext4_writepages_down_read fs/ext4/ext4.h:1786 [inline]
       ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024
       do_writepages+0x32e/0x550 mm/page-writeback.c:2634
       __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
       writeback_single_inode+0x1f3/0x6a0 fs/fs-writeback.c:1801
       write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2864
       iput_final fs/inode.c:1884 [inline]
       iput+0x5b9/0x9d0 fs/inode.c:1923
       ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2194
       ext4_xattr_move_to_block fs/ext4/xattr.c:2659 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2734 [inline]
       ext4_expand_extra_isize_ea+0x12d5/0x1ea0 fs/ext4/xattr.c:2822
       __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6385
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6428 [inline]
       __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6506
       ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254
       evict+0x504/0x9c0 fs/inode.c:810
       ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5609 [inline]
       ext4_fill_super+0x57df/0x6090 fs/ext4/super.c:5728
       get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
       vfs_get_tree+0x92/0x2b0 fs/super.c:1815
       do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
       do_mount fs/namespace.c:4136 [inline]
       __do_sys_mount fs/namespace.c:4347 [inline]
       __se_sys_mount+0x317/0x410 fs/namespace.c:4324
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by syz.3.1003/8605:
 #0: ffff88802ee000e0 (&type->s_umount_key#28/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
 #1: ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 #1: ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1799 [inline]
 #1: ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1982 [inline]
 #1: ffff88802ee00618 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x2d6/0xee0 fs/ext4/inode.c:215
 #2: ffff888057cdd6d8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline]
 #2: ffff888057cdd6d8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6425 [inline]
 #2: ffff888057cdd6d8 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3eb/0x700 fs/ext4/inode.c:6506

stack backtrace:
CPU: 0 UID: 0 PID: 8605 Comm: syz.3.1003 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53
 percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
 ext4_writepages_down_read fs/ext4/ext4.h:1786 [inline]
 ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024
 do_writepages+0x32e/0x550 mm/page-writeback.c:2634
 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
 writeback_single_inode+0x1f3/0x6a0 fs/fs-writeback.c:1801
 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2864
 iput_final fs/inode.c:1884 [inline]
 iput+0x5b9/0x9d0 fs/inode.c:1923
 ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2194
 ext4_xattr_move_to_block fs/ext4/xattr.c:2659 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2734 [inline]
 ext4_expand_extra_isize_ea+0x12d5/0x1ea0 fs/ext4/xattr.c:2822
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6385
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6428 [inline]
 __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6506
 ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254
 evict+0x504/0x9c0 fs/inode.c:810
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5609 [inline]
 ext4_fill_super+0x57df/0x6090 fs/ext4/super.c:5728
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
 vfs_get_tree+0x92/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff1e059034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff1e1468e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff1e1468ef0 RCX: 00007ff1e059034a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007ff1e1468eb0
RBP: 0000200000000180 R08: 00007ff1e1468ef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007ff1e1468eb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>
------------[ cut here ]------------
EA inode 11 i_nlink=2
WARNING: CPU: 1 PID: 8605 at fs/ext4/xattr.c:1053 ext4_xattr_inode_update_ref+0x534/0x5d0 fs/ext4/xattr.c:1051
Modules linked in:
CPU: 1 UID: 0 PID: 8605 Comm: syz.3.1003 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ext4_xattr_inode_update_ref+0x534/0x5d0 fs/ext4/xattr.c:1051
Code: 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 0f 85 86 00 00 00 41 8b 14 24 48 c7 c7 60 e3 9f 8b 4c 89 fe e8 6d 5d fd fe 90 <0f> 0b 90 90 48 bb 00 00 00 00 00 fc ff df e9 bb fd ff ff e8 e4 39
RSP: 0018:ffffc900044ff1a0 EFLAGS: 00010246
RAX: ad20ffb4ff87a100 RBX: dffffc0000000000 RCX: 0000000000080000
RDX: ffffc9000c4eb000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900044ff298 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1f4 R12: ffff888057e12920
R13: 1ffff1100afc2524 R14: 00000000ffffffff R15: 000000000000000b
FS:  00007ff1e14696c0(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000056f15000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ext4_xattr_inode_dec_ref fs/ext4/xattr.c:1076 [inline]
 ext4_xattr_set_entry+0xabb/0x1e20 fs/ext4/xattr.c:1714
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2263
 ext4_xattr_move_to_block fs/ext4/xattr.c:2666 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2734 [inline]
 ext4_expand_extra_isize_ea+0x13a8/0x1ea0 fs/ext4/xattr.c:2822
 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6385
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6428 [inline]
 __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6506
 ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254
 evict+0x504/0x9c0 fs/inode.c:810
 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5609 [inline]
 ext4_fill_super+0x57df/0x6090 fs/ext4/super.c:5728
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
 vfs_get_tree+0x92/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff1e059034a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff1e1468e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff1e1468ef0 RCX: 00007ff1e059034a
RDX: 0000200000000180 RSI: 00002000000001c0 RDI: 00007ff1e1468eb0
RBP: 0000200000000180 R08: 00007ff1e1468ef0 R09: 0000000000800700
R10: 0000000000800700 R11: 0000000000000246 R12: 00002000000001c0
R13: 00007ff1e1468eb0 R14: 0000000000000473 R15: 0000200000000680
 </TASK>