====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.982/8827 is trying to acquire lock: ffff888057280ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xca/0x730 fs/gfs2/quota.c:682 but task is already holding lock: ffff88804b8c5d40 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x271/0x1a20 fs/gfs2/bmap.c:679 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ip->i_rw_mutex){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x155/0x13e0 fs/gfs2/bmap.c:856 gfs2_iomap_get+0xc1/0x120 fs/gfs2/bmap.c:1396 bh_get+0x241/0x730 fs/gfs2/quota.c:385 qdsb_get+0x21c/0x3c0 fs/gfs2/quota.c:522 gfs2_quota_hold+0x194/0x5d0 fs/gfs2/quota.c:608 gfs2_quota_lock+0xa0/0x7d0 fs/gfs2/quota.c:1076 gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline] alloc_dinode+0x164/0x4f0 fs/gfs2/inode.c:393 gfs2_create_inode+0xc73/0x1400 fs/gfs2/inode.c:712 gfs2_atomic_open+0xce/0x210 fs/gfs2/inode.c:1293 atomic_open fs/namei.c:3353 [inline] lookup_open fs/namei.c:3461 [inline] open_last_lookups fs/namei.c:3558 [inline] path_openat+0xe20/0x2e70 fs/namei.c:3788 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818 do_sys_openat2+0x142/0x490 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 do_qc+0xca/0x730 fs/gfs2/quota.c:682 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295 gfs2_alloc_blocks+0x18b3/0x2070 fs/gfs2/rgrp.c:2494 __gfs2_iomap_alloc+0x4d1/0x1a20 fs/gfs2/bmap.c:705 gfs2_iomap_begin_write fs/gfs2/bmap.c:1047 [inline] gfs2_iomap_begin+0xa5b/0x1340 fs/gfs2/bmap.c:1112 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91 iomap_file_buffered_write+0x1b4/0x880 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x4fe/0x880 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x42c/0xdf0 fs/gfs2/file.c:1158 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ip->i_rw_mutex); lock(&sdp->sd_quota_mutex); lock(&ip->i_rw_mutex); lock(&sdp->sd_quota_mutex); *** DEADLOCK *** 6 locks held by syz.5.982/8827: #0: ffff88802fba74e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888068e50460 (sb_writers#36){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #2: ffff88804b8c58a8 (&sb->s_type->i_mutex_key#42){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #2: ffff88804b8c58a8 (&sb->s_type->i_mutex_key#42){+.+.}-{3:3}, at: gfs2_file_write_iter+0x308/0xdf0 fs/gfs2/file.c:1115 #3: ffff888068e50650 (sb_internal#6){.+.+}-{0:0}, at: gfs2_trans_begin+0x6b/0xe0 fs/gfs2/trans.c:118 #4: ffff888057281058 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x50d/0x880 fs/gfs2/trans.c:87 #5: ffff88804b8c5d40 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x271/0x1a20 fs/gfs2/bmap.c:679 stack backtrace: CPU: 1 PID: 8827 Comm: syz.5.982 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 do_qc+0xca/0x730 fs/gfs2/quota.c:682 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295 gfs2_alloc_blocks+0x18b3/0x2070 fs/gfs2/rgrp.c:2494 __gfs2_iomap_alloc+0x4d1/0x1a20 fs/gfs2/bmap.c:705 gfs2_iomap_begin_write fs/gfs2/bmap.c:1047 [inline] gfs2_iomap_begin+0xa5b/0x1340 fs/gfs2/bmap.c:1112 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91 iomap_file_buffered_write+0x1b4/0x880 fs/iomap/buffered-io.c:846 gfs2_file_buffered_write+0x4fe/0x880 fs/gfs2/file.c:1057 gfs2_file_write_iter+0x42c/0xdf0 fs/gfs2/file.c:1158 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7e6718f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7e6804f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7e673e5fa0 RCX: 00007f7e6718f749 RDX: 000000000208e24b RSI: 0000200000000040 RDI: 0000000000000008 RBP: 00007f7e67213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7e673e6038 R14: 00007f7e673e5fa0 R15: 00007ffd4a41fa08