Kernel bug: INFO: task hung in dbAlloc
Subsystem: jfs
Status: open

Crash report:
INFO: task syz.2.19:6128 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D
 stack:24856 pid:6128  tgid:6127  ppid:5976   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5254 [inline]
 __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
 __schedule_loop kernel/sched/core.c:6944 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6959
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read_nested+0x9a/0x2f0 kernel/locking/rwsem.c:1663
 dbAlloc+0x3a7/0xba0 fs/jfs/jfs_dmap.c:790
 diNewExt+0x9af/0x3150 fs/jfs/jfs_imap.c:2261
 diAllocExt fs/jfs/jfs_imap.c:1952 [inline]
 diAllocAG+0xe86/0x1df0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8f0 fs/jfs/jfs_inode.c:56
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 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
RIP: 0033:0x7fa65298efc9
RSP: 002b:00007fa6538ef038 EFLAGS: 00000246
 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fa652be5fa0 RCX: 00007fa65298efc9
RDX: 0000000000000408 RSI: 0000200000000300 RDI: 0000000000000004
RBP: 00007fa652a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa652be6038 R14: 00007fa652be5fa0 R15: 00007ffd16b4c6d8
 </TASK>
INFO: task syz.4.21:6134 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21        state:D
 stack:25704 pid:6134  tgid:6133  ppid:5980   task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5254 [inline]
 __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
 __schedule_loop kernel/sched/core.c:6944 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6959
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 dbAlloc+0x3a7/0xba0 fs/jfs/jfs_dmap.c:790
 diNewExt+0x9af/0x3150 fs/jfs/jfs_imap.c:2261
 diAllocExt fs/jfs/jfs_imap.c:1952 [inline]
 diAllocAG+0xe86/0x1df0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
 jfs_mkdir+0x193/0xa70 fs/jfs/namei.c:225
 vfs_mkdir+0x306/0x510 fs/namei.c:4453
 do_mkdirat+0x247/0x590 fs/namei.c:4486
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 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
RIP: 0033:0x7fbe3ed8efc9
RSP: 002b:00007fbe3fcc9038 EFLAGS: 00000246
 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fbe3efe5fa0 RCX: 00007fbe3ed8efc9