====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:3/1218 is trying to acquire lock: ffff88805fab6e70 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff88805fab6e70 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1900 but task is already holding lock: ffff88807a44abd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2689 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+0x46/0x1b0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2689 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_single_inode+0x3cb/0x8e0 fs/fs-writeback.c:1770 write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817 iput_final fs/inode.c:1756 [inline] iput+0x5ab/0x8a0 fs/inode.c:1795 ext4_xattr_set_entry+0x34f4/0x3ea0 fs/ext4/xattr.c:1825 ext4_xattr_block_set+0x4fd/0x2d20 fs/ext4/xattr.c:1924 ext4_xattr_move_to_block fs/ext4/xattr.c:2618 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2693 [inline] ext4_expand_extra_isize_ea+0xf3f/0x19b0 fs/ext4/xattr.c:2781 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5905 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5948 [inline] __ext4_mark_inode_dirty+0x469/0x700 fs/ext4/inode.c:6026 ext4_evict_inode+0xa8d/0x1090 fs/ext4/inode.c:282 evict+0x4c9/0x8d0 fs/inode.c:647 ext4_orphan_cleanup+0xad2/0x1320 fs/ext4/orphan.c:472 ext4_fill_super+0x8e25/0x95a0 fs/ext4/super.c:5000 mount_bdev+0x287/0x3c0 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+0x24a/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 -> #0 (&ei->xattr_sem){++++}-{3:3}: 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 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+0x670/0x2df0 fs/ext4/inode.c:2735 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940 wb_writeback+0x45d/0xbe0 fs/fs-writeback.c:2114 wb_do_writeback fs/fs-writeback.c:2257 [inline] wb_workfn+0x43a/0xf20 fs/fs-writeback.c:2298 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by kworker/u4:3/1218: #0: ffff888142582138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90004b27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff88807a44abd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2689 stack backtrace: CPU: 1 PID: 1218 Comm: kworker/u4:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: writeback wb_workfn (flush-7:4) Call Trace: 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 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+0x670/0x2df0 fs/ext4/inode.c:2735 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940 wb_writeback+0x45d/0xbe0 fs/fs-writeback.c:2114 wb_do_writeback fs/fs-writeback.c:2257 [inline] wb_workfn+0x43a/0xf20 fs/fs-writeback.c:2298 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 16 with error 28 EXT4-fs (loop4): This should not happen!! Data will be lost EXT4-fs (loop4): Total free blocks count 0 EXT4-fs (loop4): Free/Dirty block details EXT4-fs (loop4): free_blocks=2415919504 EXT4-fs (loop4): dirty_blocks=16 EXT4-fs (loop4): Block reservation details EXT4-fs (loop4): i_reserved_data_blocks=1