====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:10/4816 is trying to acquire lock: ffff8880469300c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff8880469300c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1902 but task is already holding lock: ffff88807d128c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline] ffff88807d128c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2808 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+0x44/0x1a0 include/linux/percpu-rwsem.h:51 ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline] ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2808 do_writepages+0x351/0x590 mm/page-writeback.c:2575 __writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1635 writeback_single_inode+0x21f/0x760 fs/fs-writeback.c:1756 write_inode_now+0x183/0x210 fs/fs-writeback.c:2808 iput_final fs/inode.c:1807 [inline] iput+0x58f/0x900 fs/inode.c:1846 ext4_xattr_block_set+0x248b/0x2fe0 fs/ext4/xattr.c:2201 ext4_xattr_move_to_block fs/ext4/xattr.c:2666 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2741 [inline] ext4_expand_extra_isize_ea+0x128f/0x1e70 fs/ext4/xattr.c:2829 __ext4_expand_extra_isize+0x306/0x400 fs/ext4/inode.c:5990 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6033 [inline] __ext4_mark_inode_dirty+0x458/0x6d0 fs/ext4/inode.c:6111 ext4_evict_inode+0x7dd/0xe70 fs/ext4/inode.c:254 evict+0x4b7/0x8a0 fs/inode.c:705 ext4_orphan_cleanup+0xc33/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5621 [inline] ext4_fill_super+0x5fb5/0x6870 fs/ext4/super.c:5744 get_tree_bdev+0x3e5/0x520 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 down_write+0x97/0x200 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1902 ext4_do_writepages+0x4f2/0x3990 fs/ext4/inode.c:2606 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2809 do_writepages+0x351/0x590 mm/page-writeback.c:2575 __writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1635 writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1926 wb_writeback+0x45e/0xbe0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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 *** 3 locks held by kworker/u4:10/4816: #0: ffff88801e27a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801e27a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc9000fc27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000fc27d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffff88807d128c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline] #2: ffff88807d128c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2808 stack backtrace: CPU: 1 PID: 4816 Comm: kworker/u4:10 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: writeback wb_workfn (flush-7:8) Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 down_write+0x97/0x200 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1902 ext4_do_writepages+0x4f2/0x3990 fs/ext4/inode.c:2606 ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2809 do_writepages+0x351/0x590 mm/page-writeback.c:2575 __writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1635 writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1926 wb_writeback+0x45e/0xbe0 fs/fs-writeback.c:2105 wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0x400/0xe60 fs/fs-writeback.c:2292 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 EXT4-fs error (device loop8): ext4_mb_generate_buddy:1244: group 0, block bitmap and bg descriptor inconsistent: 0 vs 150994969 free clusters EXT4-fs (loop8): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 34 with error 28 EXT4-fs (loop8): This should not happen!! Data will be lost EXT4-fs (loop8): Total free blocks count 0 EXT4-fs (loop8): Free/Dirty block details EXT4-fs (loop8): free_blocks=2415919504 EXT4-fs (loop8): dirty_blocks=48 EXT4-fs (loop8): Block reservation details EXT4-fs (loop8): i_reserved_data_blocks=3