Re: [PATCH] Fix race bug in nvme_poll_irqdisable()

[Sungwoo Kim]

Also, this can permanently disable the first IRQ, preventing future
NVMe completions delivery.
Thus, bdev_open() and bdev_release() may stuck.

The task hung detector can detect this:

INFO: task syz-executor.2:15754 is blocked on a mutex likely owned by
task systemd-udevd:136.
task:systemd-udevd   state:D stack:0     pid:136   tgid:136   ppid:1
   task_flags:0x400100 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0xc92/0x54e0 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0x87/0x300 kernel/sched/core.c:6964
 io_schedule+0xce/0x150 kernel/sched/core.c:7791
 folio_wait_bit_common+0x367/0x8b0 mm/filemap.c:1323
 folio_wait_bit_killable mm/filemap.c:1468 [inline]
 folio_wait_locked_killable include/linux/pagemap.h:1252 [inline]
 folio_wait_locked_killable include/linux/pagemap.h:1248 [inline]
 filemap_read_folio+0x175/0x2a0 mm/filemap.c:2502
 do_read_cache_folio+0x258/0x480 mm/filemap.c:4096
 read_cache_folio+0x5e/0x80 mm/filemap.c:4128
 read_mapping_folio include/linux/pagemap.h:1028 [inline]
 read_part_sector+0xd8/0x320 block/partitions/core.c:722
 read_lba+0x1cb/0x370 block/partitions/efi.c:247
 find_valid_gpt block/partitions/efi.c:602 [inline]
 efi_partition+0x285/0x2b10 block/partitions/efi.c:719
 check_partition block/partitions/core.c:141 [inline]
 blk_add_partitions block/partitions/core.c:589 [inline]
 bdev_disk_changed block/partitions/core.c:693 [inline]
 bdev_disk_changed+0x8dc/0x1710 block/partitions/core.c:642
 blkdev_get_whole+0x194/0x2a0 block/bdev.c:765
 bdev_open+0x4ba/0xeb0 block/bdev.c:974
 bdev_file_open_by_dev block/bdev.c:1076 [inline]
 bdev_file_open_by_dev+0x1b4/0x250 block/bdev.c:1051
 disk_scan_partitions+0x1f5/0x320 block/genhd.c:387
 blkdev_common_ioctl+0x3fb/0x29b0 block/ioctl.c:707
 blkdev_ioctl+0x299/0x700 block/ioctl.c:786
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x1bf/0x220 fs/ioctl.c:583
 x64_sys_call+0x1280/0x21b0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x71/0x330 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f16e1d2e277
RSP: 002b:00007ffe72978038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe72978150 RCX: 00007f16e1d2e277
RDX: 0000000000000000 RSI: 000000000000125f RDI: 000000000000000e
RBP: 00007ffe729781d0 R08: 000055ed818ee543 R09: 00007f16e1e0bbe0
R10: 0000000000000000 R11: 0000000000000246 R12: 000055ed818f4071
R13: 000055ed818ee89f R14: 00007ffe72978090 R15: 000055edb8a23bd0
 </TASK>