syzbot

BUG: sleeping function called from invalid context at mm/slab.h:565
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 11179, name: syz-executor391
1 lock held by syz-executor391/11179:
 #0: ffffffff89c774f8 (sb_lock){+.+.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #0: ffffffff89c774f8 (sb_lock){+.+.}, at: sget_fc+0xde/0x810 fs/super.c:521
Preemption disabled at:
[<ffffffff81bf9f1e>] spin_lock include/linux/spinlock.h:338 [inline]
[<ffffffff81bf9f1e>] sget_fc+0xde/0x810 fs/super.c:521
CPU: 0 PID: 11179 Comm: syz-executor391 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 ___might_sleep.cold+0x1fb/0x23e kernel/sched/core.c:6800
 __might_sleep+0x95/0x190 kernel/sched/core.c:6753
 slab_pre_alloc_hook mm/slab.h:565 [inline]
 slab_alloc mm/slab.c:3306 [inline]
 __do_kmalloc mm/slab.c:3654 [inline]
 __kmalloc+0x2d5/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 path_remove_extra_slash.part.0+0xd3/0x2e0 fs/ceph/super.c:489
 path_remove_extra_slash fs/ceph/super.c:476 [inline]
 compare_mount_options fs/ceph/super.c:547 [inline]
 ceph_compare_super+0x248/0x610 fs/ceph/super.c:1046
 sget_fc+0x207/0x810 fs/super.c:524
 ceph_get_tree+0x633/0x16c0 fs/ceph/super.c:1121
 vfs_get_tree+0x8e/0x300 fs/super.c:1547
 do_new_mount fs/namespace.c:2822 [inline]
 do_mount+0x135a/0x1b50 fs/namespace.c:3107
 __do_sys_mount fs/namespace.c:3316 [inline]
 __se_sys_mount fs/namespace.c:3293 [inline]
 __x64_sys_mount+0x192/0x230 fs/namespace.c:3293
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441289
Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffeeea10138 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441289
RDX: 0000000020000140 RSI: 00000000200000c0 RDI: 0000000020000040
RBP: 00000000006cb018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402000
R13: 0000000000402090 R14: 0000000000000000 R15: 0000000000000000
ceph: No mds server is up or the cluster is laggy