====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:9/1151 is trying to acquire lock: ffff8880497513e8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff8880497513e8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787 but task is already holding lock: ffff888041a00b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff888041a00b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] ffff888041a00b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{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 include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_single_inode+0x1f9/0x6a0 fs/fs-writeback.c:1840 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2903 iput_final fs/inode.c:1901 [inline] iput+0x830/0xc50 fs/inode.c:1966 ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2199 ext4_xattr_move_to_block fs/ext4/xattr.c:2664 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline] ext4_expand_extra_isize_ea+0x12da/0x1ea0 fs/ext4/xattr.c:2827 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6364 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6407 [inline] __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6485 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:470 __ext4_fill_super fs/ext4/super.c:5617 [inline] ext4_fill_super+0x5920/0x61e0 fs/ext4/super.c:5736 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ei->xattr_sem){++++}-{4:4}: 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 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787 ext4_do_writepages+0x526/0x4610 fs/ext4/inode.c:2810 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195 wb_do_writeback fs/fs-writeback.c:2342 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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/u8:9/1151: #0: ffff88801c69f948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801c69f948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000395fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000395fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888041a00b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #2: ffff888041a00b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] #2: ffff888041a00b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 stack backtrace: CPU: 1 UID: 0 PID: 1151 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: 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 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787 ext4_do_writepages+0x526/0x4610 fs/ext4/inode.c:2810 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2195 wb_do_writeback fs/fs-writeback.c:2342 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 EXT4-fs error (device loop3): ext4_mb_generate_buddy:1289: group 0, block bitmap and bg descriptor inconsistent: 25 vs 4128793 free clusters EXT4-fs (loop3): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop3): This should not happen!! Data will be lost EXT4-fs (loop3): Total free blocks count 0 EXT4-fs (loop3): Free/Dirty block details EXT4-fs (loop3): free_blocks=66060288 EXT4-fs (loop3): dirty_blocks=64 EXT4-fs (loop3): Block reservation details EXT4-fs (loop3): i_reserved_data_blocks=4