nvme-multipath: fix bogus request queue reference put
The mpath disk node takes a reference on the request mpath
request queue when adding live path to the mpath gendisk.
However if we connected to an inaccessible path device_add_disk
is not called, so if we disconnect and remove the mpath gendisk
we endup putting an reference on the request queue that was
never taken [1].
Fix that to check if we ever added a live path (using
NVME_NS_HEAD_HAS_DISK flag) and if not, clear the disk->queue
reference.
[1]:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 1372 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0
CPU: 1 PID: 1372 Comm: nvme Tainted: G O 5.7.0-rc2+ #3
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:refcount_warn_saturate+0xa6/0xf0
RSP: 0018:
ffffb29e8053bdc0 EFLAGS:
00010282
RAX:
0000000000000000 RBX:
ffff8b7a2f4fc060 RCX:
0000000000000007
RDX:
0000000000000007 RSI:
0000000000000092 RDI:
ffff8b7a3ec99980
RBP:
ffff8b7a2f4fc000 R08:
00000000000002e1 R09:
0000000000000004
R10:
0000000000000000 R11:
0000000000000001 R12:
0000000000000000
R13:
fffffffffffffff2 R14:
ffffb29e8053bf08 R15:
ffff8b7a320e2da0
FS:
00007f135d4ca800(0000) GS:
ffff8b7a3ec80000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00005651178c0c30 CR3:
000000003b650005 CR4:
0000000000360ee0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
Call Trace:
disk_release+0xa2/0xc0
device_release+0x28/0x80
kobject_put+0xa5/0x1b0
nvme_put_ns_head+0x26/0x70 [nvme_core]
nvme_put_ns+0x30/0x60 [nvme_core]
nvme_remove_namespaces+0x9b/0xe0 [nvme_core]
nvme_do_delete_ctrl+0x43/0x5c [nvme_core]
nvme_sysfs_delete.cold+0x8/0xd [nvme_core]
kernfs_fop_write+0xc1/0x1a0
vfs_write+0xb6/0x1a0
ksys_write+0x5f/0xe0
do_syscall_64+0x52/0x1a0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported-by: Anton Eidelman <anton@lightbitslabs.com>
Tested-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>