====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:3/302 is trying to acquire lock: ffff8880626d5088 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff8880626d5088 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1908 but task is already holding lock: ffff888074936c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691 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+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+0x8a7/0x2ce0 fs/ext4/xattr.c:1995 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 -> #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+0x2c66/0x7b50 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:1908 ext4_writepages+0x599/0x2d40 fs/ext4/inode.c:2737 do_writepages+0x493/0x700 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940 wb_writeback+0x44a/0xbc0 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+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/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/u4:3/302: #0: ffff8881429e8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000291fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff888074936c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2d40 fs/ext4/inode.c:2691 stack backtrace: CPU: 1 PID: 302 Comm: kworker/u4:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: writeback wb_workfn (flush-7:0) 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+0x2c66/0x7b50 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:1908 ext4_writepages+0x599/0x2d40 fs/ext4/inode.c:2737 do_writepages+0x493/0x700 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xaaa/0x1750 fs/fs-writeback.c:1940 wb_writeback+0x44a/0xbc0 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+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 EXT4-fs error (device loop0): ext4_mb_generate_buddy:1176: group 0, block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters EXT4-fs (loop0): Delayed block allocation failed for inode 18 at logical offset 0 with max blocks 1322 with error 28 EXT4-fs (loop0): This should not happen!! Data will be lost EXT4-fs (loop0): Total free blocks count 0 EXT4-fs (loop0): Free/Dirty block details EXT4-fs (loop0): free_blocks=2415919104 EXT4-fs (loop0): dirty_blocks=1328 EXT4-fs (loop0): Block reservation details EXT4-fs (loop0): i_reserved_data_blocks=83