====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kswapd0/73 is trying to acquire lock: ffff888033678610 (sb_internal#2){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 but task is already holding lock: ffffffff8e247c40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline] ffffffff8e247c40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4269 [inline] fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4283 might_alloc include/linux/sched/mm.h:318 [inline] prepare_alloc_pages+0x153/0x610 mm/page_alloc.c:4951 __alloc_frozen_pages_noprof+0x123/0x370 mm/page_alloc.c:5172 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2517 filemap_alloc_folio_noprof+0xdf/0x470 mm/filemap.c:1020 __filemap_get_folio+0x3f2/0xaf0 mm/filemap.c:2012 filemap_grab_folio include/linux/pagemap.h:838 [inline] gfs2_unstuff_dinode+0xe8/0x1320 fs/gfs2/bmap.c:162 do_grow fs/gfs2/bmap.c:2097 [inline] gfs2_setattr_size+0x64c/0x1050 fs/gfs2/bmap.c:2153 gfs2_setattr+0x243/0x3f0 fs/gfs2/inode.c:2097 notify_change+0xc1a/0xf40 fs/attr.c:546 do_truncate+0x1a4/0x220 fs/open.c:68 do_ftruncate+0x489/0x540 fs/open.c:195 do_sys_ftruncate fs/open.c:210 [inline] __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213 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 -> #2 (&ip->i_rw_mutex){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 gfs2_unstuff_dinode+0x9d/0x1320 fs/gfs2/bmap.c:161 do_grow fs/gfs2/bmap.c:2097 [inline] gfs2_setattr_size+0x64c/0x1050 fs/gfs2/bmap.c:2153 gfs2_setattr+0x243/0x3f0 fs/gfs2/inode.c:2097 notify_change+0xc1a/0xf40 fs/attr.c:546 do_truncate+0x1a4/0x220 fs/open.c:68 do_ftruncate+0x489/0x540 fs/open.c:195 do_sys_ftruncate fs/open.c:210 [inline] __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:213 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 -> #1 (&sdp->sd_log_flush_lock){.+.+}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 __gfs2_trans_begin+0x515/0x890 fs/gfs2/trans.c:87 gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 ea_alloc_skeleton+0x2bd/0x540 fs/gfs2/xattr.c:760 ea_init+0x17c/0x1f0 fs/gfs2/xattr.c:821 __gfs2_xattr_set+0x498/0xae0 fs/gfs2/xattr.c:1199 __gfs2_set_acl+0x106/0x190 fs/gfs2/acl.c:103 gfs2_set_acl+0x410/0x5f0 fs/gfs2/acl.c:143 set_posix_acl fs/posix_acl.c:954 [inline] vfs_set_acl+0x887/0xb00 fs/posix_acl.c:1133 do_set_acl+0xf6/0x190 fs/posix_acl.c:1278 do_setxattr fs/xattr.c:633 [inline] filename_setxattr+0x2e0/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750 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 (sb_internal#2){.+.+}-{0:0}: 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 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1916 [inline] sb_start_intwrite include/linux/fs.h:2099 [inline] __gfs2_trans_begin+0x42a/0x890 fs/gfs2/trans.c:76 gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 gfs2_dirty_inode+0x3cb/0x600 fs/gfs2/super.c:508 __mark_inode_dirty+0x2ec/0xe10 fs/fs-writeback.c:2566 mark_inode_dirty_sync include/linux/fs.h:2619 [inline] iput+0x381/0xc50 fs/inode.c:1947 __dentry_kill+0x209/0x660 fs/dcache.c:669 shrink_kill+0xa9/0x2c0 fs/dcache.c:1114 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1141 prune_dcache_sb+0x10e/0x180 fs/dcache.c:1222 super_cache_scan+0x369/0x4b0 fs/super.c:222 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955 shrink_many mm/vmscan.c:5016 [inline] lru_gen_shrink_node mm/vmscan.c:5094 [inline] shrink_node+0x315d/0x3780 mm/vmscan.c:6081 kswapd_shrink_node mm/vmscan.c:6941 [inline] balance_pgdat mm/vmscan.c:7124 [inline] kswapd+0x147c/0x2800 mm/vmscan.c:7389 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: Chain exists of: sb_internal#2 --> &ip->i_rw_mutex --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&ip->i_rw_mutex); lock(fs_reclaim); rlock(sb_internal#2); *** DEADLOCK *** 2 locks held by kswapd0/73: #0: ffffffff8e247c40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline] #0: ffffffff8e247c40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389 #1: ffff8880336780e0 (&type->s_umount_key#51){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline] #1: ffff8880336780e0 (&type->s_umount_key#51){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197 stack backtrace: CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 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 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1916 [inline] sb_start_intwrite include/linux/fs.h:2099 [inline] __gfs2_trans_begin+0x42a/0x890 fs/gfs2/trans.c:76 gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 gfs2_dirty_inode+0x3cb/0x600 fs/gfs2/super.c:508 __mark_inode_dirty+0x2ec/0xe10 fs/fs-writeback.c:2566 mark_inode_dirty_sync include/linux/fs.h:2619 [inline] iput+0x381/0xc50 fs/inode.c:1947 __dentry_kill+0x209/0x660 fs/dcache.c:669 shrink_kill+0xa9/0x2c0 fs/dcache.c:1114 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1141 prune_dcache_sb+0x10e/0x180 fs/dcache.c:1222 super_cache_scan+0x369/0x4b0 fs/super.c:222 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955 shrink_many mm/vmscan.c:5016 [inline] lru_gen_shrink_node mm/vmscan.c:5094 [inline] shrink_node+0x315d/0x3780 mm/vmscan.c:6081 kswapd_shrink_node mm/vmscan.c:6941 [inline] balance_pgdat mm/vmscan.c:7124 [inline] kswapd+0x147c/0x2800 mm/vmscan.c:7389 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