syzbot

EXT4-fs (loop3): Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.29/4416 is trying to acquire lock:
ffff88805d2aac58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691

but task is already holding lock:
ffff88805c606478 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:165 [inline]
ffff88805c606478 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5964 [inline]
ffff88805c606478 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3bd/0x6c0 fs/ext4/inode.c:6045

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ei->xattr_sem){++++}-{3:3}:
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline]
       ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1900
       ext4_writepages+0x599/0x2d40 fs/ext4/inode.c:2737
       do_writepages+0x493/0x700 mm/page-writeback.c:2386
       filemap_fdatawrite_wbc+0x1eb/0x240 mm/filemap.c:400
       __filemap_fdatawrite_range mm/filemap.c:433 [inline]
       file_write_and_wait_range+0x14d/0x220 mm/filemap.c:810
       ext4_sync_file+0x20e/0xb10 fs/ext4/fsync.c:151
       generic_write_sync include/linux/fs.h:2990 [inline]
       ext4_buffered_write_iter+0x323/0x3a0 fs/ext4/file.c:275
       ext4_file_write_iter+0x73f/0x1720 fs/ext4/file.c:-1
       call_write_iter include/linux/fs.h:2173 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x748/0xd70 fs/read_write.c:594
       ksys_pwrite64 fs/read_write.c:701 [inline]
       __do_sys_pwrite64 fs/read_write.c:711 [inline]
       __se_sys_pwrite64 fs/read_write.c:708 [inline]
       __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:708
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&sbi->s_writepages_rwsem){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
       ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
       do_writepages+0x493/0x700 mm/page-writeback.c:2386
       __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
       writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1770
       write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817
       iput_final fs/inode.c:1756 [inline]
       iput+0x599/0x880 fs/inode.c:1795
       ext4_xattr_set_entry+0x1d76/0x3f70 fs/ext4/xattr.c:1827
       ext4_xattr_block_set+0x4d7/0x2ce0 fs/ext4/xattr.c:1926
       ext4_xattr_move_to_block fs/ext4/xattr.c:2620 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2695 [inline]
       ext4_expand_extra_isize_ea+0xebe/0x18e0 fs/ext4/xattr.c:2783
       __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline]
       __ext4_mark_inode_dirty+0x444/0x6c0 fs/ext4/inode.c:6045
       ext4_evict_inode+0xa55/0x1050 fs/ext4/inode.c:284
       evict+0x4b6/0x8b0 fs/inode.c:647
       ext4_orphan_cleanup+0xad8/0x1320 fs/ext4/orphan.c:472
       ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006
       mount_bdev+0x28a/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x247/0xa40 fs/namespace.c:3034
       do_mount fs/namespace.c:3377 [inline]
       __do_sys_mount fs/namespace.c:3585 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by syz.3.29/4416:
 #0: ffff88805d29e0e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x200/0x970 fs/super.c:229
 #1: ffff88805d29e650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline]
 #1: ffff88805d29e650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline]
 #1: ffff88805d29e650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x41f/0x1050 fs/ext4/inode.c:245
 #2: ffff88805c606478 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:165 [inline]
 #2: ffff88805c606478 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5964 [inline]
 #2: ffff88805c606478 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x3bd/0x6c0 fs/ext4/inode.c:6045

stack backtrace:
CPU: 0 PID: 4416 Comm: syz.3.29 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 percpu_down_read+0x46/0x1b0 include/linux/percpu-rwsem.h:51
 ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691
 do_writepages+0x493/0x700 mm/page-writeback.c:2386
 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657
 writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1770
 write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817
 iput_final fs/inode.c:1756 [inline]
 iput+0x599/0x880 fs/inode.c:1795
 ext4_xattr_set_entry+0x1d76/0x3f70 fs/ext4/xattr.c:1827
 ext4_xattr_block_set+0x4d7/0x2ce0 fs/ext4/xattr.c:1926
 ext4_xattr_move_to_block fs/ext4/xattr.c:2620 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2695 [inline]
 ext4_expand_extra_isize_ea+0xebe/0x18e0 fs/ext4/xattr.c:2783
 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline]
 __ext4_mark_inode_dirty+0x444/0x6c0 fs/ext4/inode.c:6045
 ext4_evict_inode+0xa55/0x1050 fs/ext4/inode.c:284
 evict+0x4b6/0x8b0 fs/inode.c:647
 ext4_orphan_cleanup+0xad8/0x1320 fs/ext4/orphan.c:472
 ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006
 mount_bdev+0x28a/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x247/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5f4df000ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcf53eead8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcf53eeb60 RCX: 00007f5f4df000ca
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 00007ffcf53eeb20
RBP: 0000200000000180 R08: 00007ffcf53eeb60 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000000
R13: 00007ffcf53eeb20 R14: 000000000000047a R15: 00002000000001c0
 </TASK>
EXT4-fs error (device loop3): ext4_xattr_inode_iget:401: inode #11: comm syz.3.29: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop3): ext4_xattr_inode_iget:406: comm syz.3.29: error while reading EA inode 11 err=-117
EXT4-fs warning (device loop3): ext4_expand_extra_isize_ea:2809: Unable to expand inode 15. Delete some EAs or run e2fsck.
EXT4-fs error (device loop3): ext4_xattr_inode_iget:401: inode #11: comm syz.3.29: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop3): ext4_xattr_inode_iget:406: comm syz.3.29: error while reading EA inode 11 err=-117
EXT4-fs error (device loop3): ext4_xattr_inode_iget:401: inode #18: comm syz.3.29: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop3): ext4_xattr_inode_iget:406: comm syz.3.29: error while reading EA inode 18 err=-117
EXT4-fs error (device loop3): ext4_xattr_inode_iget:401: inode #18: comm syz.3.29: iget: bad extra_isize 90 (inode size 256)
EXT4-fs error (device loop3): ext4_xattr_inode_iget:406: comm syz.3.29: error while reading EA inode 18 err=-117
EXT4-fs (loop3): 1 orphan inode deleted
EXT4-fs (loop3): mounted filesystem without journal. Opts: init_itable,dioread_nolock,debug_want_extra_isize=0x000000000000005a,grpid,dioread_nolock,bsdgroups,min_batch_time=0x0000000000000003,,errors=continue. Quota mode: none.