Commit Graph

393 Commits

Author SHA1 Message Date
Christoph Hellwig 268283244c nbd: use the atomic queue limits API in nbd_set_size
Use queue_limits_start_update / queue_limits_commit_update to update
all the limits in one go and with proper sanity checking.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240229143846.1047223-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-01 09:08:22 -07:00
Christoph Hellwig 242a49e5c8 nbd: freeze the queue for queue limits updates
nbd currently updates the logical and physical block sizes as well
as the discard_sectors on a live queue.  Freeze the queue first to
make sure there are not commands in flight that can see torn or
inconsistent limits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240229143846.1047223-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-01 09:08:22 -07:00
Christoph Hellwig 7ea201f2cc nbd: don't clear discard_sectors in nbd_config_put
nbd_config_put currently clears discard_sectors when unusing a device.
This is pretty odd behavior and different from the sector size
configuration which is simply left in places and then reconfigured when
nbd_set_size is as part of configuring the device.  Change nbd_set_size
to clear discard_sectors if discard is not supported so that all the
queue limits changes are handled in one place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240229143846.1047223-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-03-01 09:08:22 -07:00
Christoph Hellwig 9a0d497028 nbd: pass queue_limits to blk_mq_alloc_disk
Pass the few limits nbd imposes directly to blk_mq_alloc_disk instead
of setting them one at a time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240215070300.2200308-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-19 16:59:31 -07:00
Navid Emamdoost 31edf4bbe0 nbd: null check for nla_nest_start
nla_nest_start() may fail and return NULL. Insert a check and set errno
based on other call sites within the same source code.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Fixes: 47d902b90a ("nbd: add a status netlink command")
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240218042534.it.206-kees@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-18 06:01:18 -07:00
Christoph Hellwig 27e32cd23f block: pass a queue_limits argument to blk_mq_alloc_disk
Pass a queue_limits to blk_mq_alloc_disk and apply it if non-NULL.  This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-13 08:56:59 -07:00
Eric Dumazet 78fbb92af2 nbd: always initialize struct msghdr completely
syzbot complains that msg->msg_get_inq value can be uninitialized [1]

struct msghdr got many new fields recently, we should always make
sure their values is zero by default.

[1]
 BUG: KMSAN: uninit-value in tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571
  tcp_recvmsg+0x686/0xac0 net/ipv4/tcp.c:2571
  inet_recvmsg+0x131/0x580 net/ipv4/af_inet.c:879
  sock_recvmsg_nosec net/socket.c:1044 [inline]
  sock_recvmsg+0x12b/0x1e0 net/socket.c:1066
  __sock_xmit+0x236/0x5c0 drivers/block/nbd.c:538
  nbd_read_reply drivers/block/nbd.c:732 [inline]
  recv_work+0x262/0x3100 drivers/block/nbd.c:863
  process_one_work kernel/workqueue.c:2627 [inline]
  process_scheduled_works+0x104e/0x1e70 kernel/workqueue.c:2700
  worker_thread+0xf45/0x1490 kernel/workqueue.c:2781
  kthread+0x3ed/0x540 kernel/kthread.c:388
  ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Local variable msg created at:
  __sock_xmit+0x4c/0x5c0 drivers/block/nbd.c:513
  nbd_read_reply drivers/block/nbd.c:732 [inline]
  recv_work+0x262/0x3100 drivers/block/nbd.c:863

CPU: 1 PID: 7465 Comm: kworker/u5:1 Not tainted 6.7.0-rc7-syzkaller-00041-gf016f7547aee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: nbd5-recv recv_work

Fixes: f94fd25cb0 ("tcp: pass back data left in socket after receive")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: nbd@other.debian.org
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240112132657.647112-1-edumazet@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-17 08:47:46 -07:00
Christoph Hellwig 1e2ab2e8a9 nbd: use the default discard granularity
The discard granularity now defaults to a single sector, so don't set
that value explicitly.  Also don't bother clearing it as a discard
granularity without discard_sectors doesn't mean anything.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231228075545.362768-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-29 08:44:12 -07:00
Li Nan 98c598afc2 nbd: pass nbd_sock to nbd_read_reply() instead of index
If a socket is processing ioctl 'NBD_SET_SOCK', config->socks might be
krealloc in nbd_add_socket(), and a garbage request is received now, a UAF
may occurs.

  T1
  nbd_ioctl
   __nbd_ioctl
    nbd_add_socket
     blk_mq_freeze_queue
				T2
  				recv_work
  				 nbd_read_reply
  				  sock_xmit
     krealloc config->socks
				   def config->socks

Pass nbd_sock to nbd_read_reply(). And introduce a new function
sock_xmit_recv(), which differs from sock_xmit only in the way it get
socket.

==================================================================
BUG: KASAN: use-after-free in sock_xmit+0x525/0x550
Read of size 8 at addr ffff8880188ec428 by task kworker/u12:1/18779

Workqueue: knbd4-recv recv_work
Call Trace:
 __dump_stack
 dump_stack+0xbe/0xfd
 print_address_description.constprop.0+0x19/0x170
 __kasan_report.cold+0x6c/0x84
 kasan_report+0x3a/0x50
 sock_xmit+0x525/0x550
 nbd_read_reply+0xfe/0x2c0
 recv_work+0x1c2/0x750
 process_one_work+0x6b6/0xf10
 worker_thread+0xdd/0xd80
 kthread+0x30a/0x410
 ret_from_fork+0x22/0x30

Allocated by task 18784:
 kasan_save_stack+0x1b/0x40
 kasan_set_track
 set_alloc_info
 __kasan_kmalloc
 __kasan_kmalloc.constprop.0+0xf0/0x130
 slab_post_alloc_hook
 slab_alloc_node
 slab_alloc
 __kmalloc_track_caller+0x157/0x550
 __do_krealloc
 krealloc+0x37/0xb0
 nbd_add_socket
 +0x2d3/0x880
 __nbd_ioctl
 nbd_ioctl+0x584/0x8e0
 __blkdev_driver_ioctl
 blkdev_ioctl+0x2a0/0x6e0
 block_ioctl+0xee/0x130
 vfs_ioctl
 __do_sys_ioctl
 __se_sys_ioctl+0x138/0x190
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

Freed by task 18784:
 kasan_save_stack+0x1b/0x40
 kasan_set_track+0x1c/0x30
 kasan_set_free_info+0x20/0x40
 __kasan_slab_free.part.0+0x13f/0x1b0
 slab_free_hook
 slab_free_freelist_hook
 slab_free
 kfree+0xcb/0x6c0
 krealloc+0x56/0xb0
 nbd_add_socket+0x2d3/0x880
 __nbd_ioctl
 nbd_ioctl+0x584/0x8e0
 __blkdev_driver_ioctl
 blkdev_ioctl+0x2a0/0x6e0
 block_ioctl+0xee/0x130
 vfs_ioctl
 __do_sys_ioctl
 __se_sys_ioctl+0x138/0x190
 do_syscall_64+0x33/0x40
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230911023308.3467802-1-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-21 07:42:04 -07:00
Li Nan c2da049f41 nbd: fix null-ptr-dereference while accessing 'nbd->config'
Memory reordering may occur in nbd_genl_connect(), causing config_refs
to be set to 1 while nbd->config is still empty. Opening nbd at this
time will cause null-ptr-dereference.

   T1                      T2
   nbd_open
    nbd_get_config_unlocked
                 	   nbd_genl_connect
                 	    nbd_alloc_and_init_config
                 	     //memory reordered
                  	     refcount_set(&nbd->config_refs, 1)  // 2
     nbd->config
      ->null point
			     nbd->config = config  // 1

Fix it by adding smp barrier to guarantee the execution sequence.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231116162316.1740402-4-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-20 10:16:44 -07:00
Li Nan 3123ac7792 nbd: factor out a helper to get nbd_config without holding 'config_lock'
There are no functional changes, just to make code cleaner and prepare
to fix null-ptr-dereference while accessing 'nbd->config'.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231116162316.1740402-3-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-20 10:16:44 -07:00
Li Nan 1b59860540 nbd: fold nbd config initialization into nbd_alloc_config()
There are no functional changes, make the code cleaner and prepare to
fix null-ptr-dereference while accessing 'nbd->config'.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231116162316.1740402-2-linan666@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-20 10:16:44 -07:00
Li Lingfeng 327462725b nbd: fix uaf in nbd_open
Commit 4af5f2e030 ("nbd: use blk_mq_alloc_disk and
blk_cleanup_disk") cleans up disk by blk_cleanup_disk() and it won't set
disk->private_data as NULL as before. UAF may be triggered in nbd_open()
if someone tries to open nbd device right after nbd_put() since nbd has
been free in nbd_dev_remove().

Fix this by implementing ->free_disk and free private data in it.

Fixes: 4af5f2e030 ("nbd: use blk_mq_alloc_disk and blk_cleanup_disk")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231107103435.2074904-1-lilingfeng@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-07 08:14:57 -07:00
Christoph Hellwig 07a1141ff1 nbd: don't call blk_mark_disk_dead nbd_clear_sock_ioctl
blk_mark_disk_dead is the proper interface to shut down a block
device, but it also makes the disk unusable forever.

nbd_clear_sock_ioctl on the other hand wants to shut down the file
system, but allow the block device to be used again when when connected
to another socket.  Switch nbd to use disk_force_media_change and
nbd_bdev_reset to go back to a behavior of the old __invalidate_device
call, with the added benefit of incrementing the device generation
as there is no guarantee the old content comes back when the device
is reconnected.

Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 0c1c9a27ce ("nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231003153106.1331363-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-10-03 18:27:44 -06:00
Linus Torvalds 3d3dfeb3ae for-6.6/block-2023-08-28
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Merge tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:
 "Pretty quiet round for this release. This contains:

   - Add support for zoned storage to ublk (Andreas, Ming)

   - Series improving performance for drivers that mark themselves as
     needing a blocking context for issue (Bart)

   - Cleanup the flush logic (Chengming)

   - sed opal keyring support (Greg)

   - Fixes and improvements to the integrity support (Jinyoung)

   - Add some exports for bcachefs that we can hopefully delete again in
     the future (Kent)

   - deadline throttling fix (Zhiguo)

   - Series allowing building the kernel without buffer_head support
     (Christoph)

   - Sanitize the bio page adding flow (Christoph)

   - Write back cache fixes (Christoph)

   - MD updates via Song:
      - Fix perf regression for raid0 large sequential writes (Jan)
      - Fix split bio iostat for raid0 (David)
      - Various raid1 fixes (Heinz, Xueshi)
      - raid6test build fixes (WANG)
      - Deprecate bitmap file support (Christoph)
      - Fix deadlock with md sync thread (Yu)
      - Refactor md io accounting (Yu)
      - Various non-urgent fixes (Li, Yu, Jack)

   - Various fixes and cleanups (Arnd, Azeem, Chengming, Damien, Li,
     Ming, Nitesh, Ruan, Tejun, Thomas, Xu)"

* tag 'for-6.6/block-2023-08-28' of git://git.kernel.dk/linux: (113 commits)
  block: use strscpy() to instead of strncpy()
  block: sed-opal: keyring support for SED keys
  block: sed-opal: Implement IOC_OPAL_REVERT_LSP
  block: sed-opal: Implement IOC_OPAL_DISCOVERY
  blk-mq: prealloc tags when increase tagset nr_hw_queues
  blk-mq: delete redundant tagset map update when fallback
  blk-mq: fix tags leak when shrink nr_hw_queues
  ublk: zoned: support REQ_OP_ZONE_RESET_ALL
  md: raid0: account for split bio in iostat accounting
  md/raid0: Fix performance regression for large sequential writes
  md/raid0: Factor out helper for mapping and submitting a bio
  md raid1: allow writebehind to work on any leg device set WriteMostly
  md/raid1: hold the barrier until handle_read_error() finishes
  md/raid1: free the r1bio before waiting for blocked rdev
  md/raid1: call free_r1bio() before allow_barrier() in raid_end_bio_io()
  blk-cgroup: Fix NULL deref caused by blkg_policy_data being installed before init
  drivers/rnbd: restore sysfs interface to rnbd-client
  md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid()
  raid6: test: only check for Altivec if building on powerpc hosts
  raid6: test: make sure all intermediate and artifact files are .gitignored
  ...
2023-08-29 20:21:42 -07:00
Christoph Hellwig 0c1c9a27ce nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl
nbd_clear_sock_ioctl kills the socket and with that the block
device.  Instead of just invalidating file system buffers,
mark the device as dead, which will also invalidate the buffers
as part of the proper shutdown sequence.  This also includes
invalidating partitions if there are any.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Message-Id: <20230811100828.1897174-8-hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-21 14:35:30 +02:00
Thomas Weißschuh ffe357c868 nbd: automatically load module on genl access
Add a module alias to nbd.ko that allows the generic netlink core to
automatically load the module when netlink messages for nbd are
received.

This frees the user from manually having to load the module before using
nbd functionality via netlink.
If the system policy allows it this can even be used to load the nbd
module from containers which would otherwise not have access to the
necessary module files to do a normal "modprobe nbd".

For example this avoids the following error when using nbd-client:

$ nbd-client localhost 10809 /dev/nbd0
...
Error: Couldn't resolve the nbd netlink family, make sure the nbd module is loaded and your nbd driver supports the netlink interface.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Josef Bacik <josef@toxicpadna.com>
Link: https://lore.kernel.org/r/20230713-b4-nbd-genl-v3-1-226cbddba04b@weissschuh.net
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-07-17 08:18:17 -06:00
Christoph Hellwig 05bdb99653 block: replace fmode_t with a block-specific type for block open flags
The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE.  Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com>		[rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:05 -06:00
Christoph Hellwig ae220766d8 block: remove the unused mode argument to ->release
The mode argument to the ->release block_device_operation is never used,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com>			[rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:04 -06:00
Christoph Hellwig d32e2bf837 block: pass a gendisk to ->open
->open is only called on the whole device.  Make that explicit by
passing a gendisk instead of the block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com>		[rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:04 -06:00
Zhong Jinghua f12bc113ce nbd: Add the maximum limit of allocated index in nbd_dev_add
If the index allocated by idr_alloc greater than MINORMASK >> part_shift,
the device number will overflow, resulting in failure to create a block
device.

Fix it by imiting the size of the max allocation.

Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230605122159.2134384-1-zhongjinghua@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-07 07:50:48 -06:00
Ivan Orlov 4913cfcf01 nbd: Fix debugfs_create_dir error checking
The debugfs_create_dir function returns ERR_PTR in case of error, and the
only correct way to check if an error occurred is 'IS_ERR' inline function.
This patch will replace the null-comparison with IS_ERR.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Link: https://lore.kernel.org/r/20230512130533.98709-1-ivan.orlov0322@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-12 08:56:33 -06:00
Eric Blake bd9e9916c3 block nbd: use req.cookie instead of req.handle
The NBD spec was recently changed [1] to refer to the opaque client
identifier as a 'cookie' rather than a 'handle', but has for a much
longer time listed it as a 64-bit value, and declares that all values
in the NBD protocol are sent in network byte order (big-endian).

Because the value is opaque to the server, it doesn't usually matter
what endianness we send as the client - as long as we are consistent
that either we byte-swap on both write and read, or on neither, then
we can match server replies back to our requests.  That said, our
internal use of the cookie is as a 64-bit number (well, as two 32-bit
numbers concatenated together), rather than as 8 individual bytes; so
prior to this commit, we ARE leaking the native endianness of our
internals as a client out to the server.  We don't know of any server
that will actually inspect the opaque value and behave differently
depending on whether a little-endian or big-endian client is sending
requests, but since we DO log the cookie value, a wireshark capture of
the network traffic is easier to correlate back to the kernel traffic
of a big-endian host (where the u64 and char[8] representations are
the same) than of a little-endian host (where if wireshark honors the
NBD spec and displays a u64 in network byte order, it is byte-swapped
from what the kernel logged).

The fix in this patch is thus two-part: it now consistently uses
network byte order for the opaque value (no difference to a big-endian
machine, but an extra byteswap on a little-endian machine; probably in
the noise compared to the overhead of network traffic in general), and
now uses a 64-bit integer instead of char[8] as its preferred access
to the opaque value (direct assignment instead of memcpy()).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20230410180611.1051618-4-eblake@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-27 19:15:11 -06:00
Chaitanya Kulkarni 3f89ac587b block/drivers: remove dead clear of random flag
QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk",
"brd", "nbd", "zram", and "bcache" since by default we don't set
"QUEUE_FLAG_ADD_RANDOM" to MQ ops.

Remove dead clear of QUEUE_FLAG_ADD_RANDOM in above listed drivers.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> #zram
Link: https://lore.kernel.org/r/20230424234628.45544-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-25 08:02:11 -06:00
Zhong Jinghua 55793ea54d nbd: fix incomplete validation of ioctl arg
We tested and found an alarm caused by nbd_ioctl arg without verification.
The UBSAN warning calltrace like below:

UBSAN: Undefined behaviour in fs/buffer.c:1709:35
signed integer overflow:
-9223372036854775808 - 1 cannot be represented in type 'long long int'
CPU: 3 PID: 2523 Comm: syz-executor.0 Not tainted 4.19.90 #1
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x0/0x3f0 arch/arm64/kernel/time.c:78
 show_stack+0x28/0x38 arch/arm64/kernel/traps.c:158
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x170/0x1dc lib/dump_stack.c:118
 ubsan_epilogue+0x18/0xb4 lib/ubsan.c:161
 handle_overflow+0x188/0x1dc lib/ubsan.c:192
 __ubsan_handle_sub_overflow+0x34/0x44 lib/ubsan.c:206
 __block_write_full_page+0x94c/0xa20 fs/buffer.c:1709
 block_write_full_page+0x1f0/0x280 fs/buffer.c:2934
 blkdev_writepage+0x34/0x40 fs/block_dev.c:607
 __writepage+0x68/0xe8 mm/page-writeback.c:2305
 write_cache_pages+0x44c/0xc70 mm/page-writeback.c:2240
 generic_writepages+0xdc/0x148 mm/page-writeback.c:2329
 blkdev_writepages+0x2c/0x38 fs/block_dev.c:2114
 do_writepages+0xd4/0x250 mm/page-writeback.c:2344

The reason for triggering this warning is __block_write_full_page()
-> i_size_read(inode) - 1 overflow.
inode->i_size is assigned in __nbd_ioctl() -> nbd_set_size() -> bytesize.
We think it is necessary to limit the size of arg to prevent errors.

Moreover, __nbd_ioctl() -> nbd_add_socket(), arg will be cast to int.
Assuming the value of arg is 0x80000000000000001) (on a 64-bit machine),
it will become 1 after the coercion, which will return unexpected results.

Fix it by adding checks to prevent passing in too large numbers.

Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20230206145805.2645671-1-zhongjinghua@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-20 13:43:44 -06:00
Jakub Kicinski 7399b886b5 nbd: use the structured req attr check
Use the macro for checking presence of required attributes.
It has the advantage of reporting to the user which attr
was missing in a machine-readable format (extack).

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230224021301.1630703-2-kuba@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-14 14:17:13 -06:00
Jakub Kicinski 9195b317f1 nbd: allow genl access outside init_net
NBD doesn't have much to do with networking, allow users outside
init_net to access the family.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230224021301.1630703-1-kuba@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-14 14:17:13 -06:00
Benjamin Coddington 98123866fc Treewide: Stop corrupting socket's task_frag
Since moving to memalloc_nofs_save/restore, SUNRPC has stopped setting the
GFP_NOIO flag on sk_allocation which the networking system uses to decide
when it is safe to use current->task_frag.  The results of this are
unexpected corruption in task_frag when SUNRPC is involved in memory
reclaim.

The corruption can be seen in crashes, but the root cause is often
difficult to ascertain as a crashing machine's stack trace will have no
evidence of being near NFS or SUNRPC code.  I believe this problem to
be much more pervasive than reports to the community may indicate.

Fix this by having kernel users of sockets that may corrupt task_frag due
to reclaim set sk_use_task_frag = false.  Preemptively correcting this
situation for users that still set sk_allocation allows them to convert to
memalloc_nofs_save/restore without the same unexpected corruptions that are
sure to follow, unlikely to show up in testing, and difficult to bisect.

CC: Philipp Reisner <philipp.reisner@linbit.com>
CC: Lars Ellenberg <lars.ellenberg@linbit.com>
CC: "Christoph Böhmwalder" <christoph.boehmwalder@linbit.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Josef Bacik <josef@toxicpanda.com>
CC: Keith Busch <kbusch@kernel.org>
CC: Christoph Hellwig <hch@lst.de>
CC: Sagi Grimberg <sagi@grimberg.me>
CC: Lee Duncan <lduncan@suse.com>
CC: Chris Leech <cleech@redhat.com>
CC: Mike Christie <michael.christie@oracle.com>
CC: "James E.J. Bottomley" <jejb@linux.ibm.com>
CC: "Martin K. Petersen" <martin.petersen@oracle.com>
CC: Valentina Manea <valentina.manea.m@gmail.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: David Howells <dhowells@redhat.com>
CC: Marc Dionne <marc.dionne@auristor.com>
CC: Steve French <sfrench@samba.org>
CC: Christine Caulfield <ccaulfie@redhat.com>
CC: David Teigland <teigland@redhat.com>
CC: Mark Fasheh <mark@fasheh.com>
CC: Joel Becker <jlbec@evilplan.org>
CC: Joseph Qi <joseph.qi@linux.alibaba.com>
CC: Eric Van Hensbergen <ericvh@gmail.com>
CC: Latchesar Ionkov <lucho@ionkov.net>
CC: Dominique Martinet <asmadeus@codewreck.org>
CC: Ilya Dryomov <idryomov@gmail.com>
CC: Xiubo Li <xiubli@redhat.com>
CC: Chuck Lever <chuck.lever@oracle.com>
CC: Jeff Layton <jlayton@kernel.org>
CC: Trond Myklebust <trond.myklebust@hammerspace.com>
CC: Anna Schumaker <anna@kernel.org>
CC: Steffen Klassert <steffen.klassert@secunet.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-19 17:28:49 -08:00
Al Viro de4eda9de2 use less confusing names for iov_iter direction initializers
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-25 13:01:55 -05:00
Linus Torvalds e8bc52cb8d Driver core changes for 6.1-rc1
Here is the big set of driver core and debug printk changes for 6.1-rc1.
 Included in here is:
 	- dynamic debug updates for the core and the drm subsystem.  The
 	  drm changes have all been acked by the relevant maintainers.
 	- kernfs fixes for syzbot reported problems
 	- kernfs refactors and updates for cgroup requirements
 	- magic number cleanups and removals from the kernel tree (they
 	  were not being used and they really did not actually do
 	  anything.)
 	- other tiny cleanups
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the big set of driver core and debug printk changes for
  6.1-rc1. Included in here is:

   - dynamic debug updates for the core and the drm subsystem. The drm
     changes have all been acked by the relevant maintainers

   - kernfs fixes for syzbot reported problems

   - kernfs refactors and updates for cgroup requirements

   - magic number cleanups and removals from the kernel tree (they were
     not being used and they really did not actually do anything)

   - other tiny cleanups

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (74 commits)
  docs: filesystems: sysfs: Make text and code for ->show() consistent
  Documentation: NBD_REQUEST_MAGIC isn't a magic number
  a.out: restore CMAGIC
  device property: Add const qualifier to device_get_match_data() parameter
  drm_print: add _ddebug descriptor to drm_*dbg prototypes
  drm_print: prefer bare printk KERN_DEBUG on generic fn
  drm_print: optimize drm_debug_enabled for jump-label
  drm-print: add drm_dbg_driver to improve namespace symmetry
  drm-print.h: include dyndbg header
  drm_print: wrap drm_*_dbg in dyndbg descriptor factory macro
  drm_print: interpose drm_*dbg with forwarding macros
  drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.
  drm_print: condense enum drm_debug_category
  debugfs: use DEFINE_SHOW_ATTRIBUTE to define debugfs_regset32_fops
  driver core: use IS_ERR_OR_NULL() helper in device_create_groups_vargs()
  Documentation: ENI155_MAGIC isn't a magic number
  Documentation: NBD_REPLY_MAGIC isn't a magic number
  nbd: remove define-only NBD_MAGIC, previously magic number
  Documentation: FW_HEADER_MAGIC isn't a magic number
  Documentation: EEPROM_MAGIC_VALUE isn't a magic number
  ...
2022-10-07 17:04:10 -07:00
Linus Torvalds 513389809e for-6.1/block-2022-10-03
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Merge tag 'for-6.1/block-2022-10-03' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe pull requests via Christoph:
      - handle number of queue changes in the TCP and RDMA drivers
        (Daniel Wagner)
      - allow changing the number of queues in nvmet (Daniel Wagner)
      - also consider host_iface when checking ip options (Daniel
        Wagner)
      - don't map pages which can't come from HIGHMEM (Fabio M. De
        Francesco)
      - avoid unnecessary flush bios in nvmet (Guixin Liu)
      - shrink and better pack the nvme_iod structure (Keith Busch)
      - add comment for unaligned "fake" nqn (Linjun Bao)
      - print actual source IP address through sysfs "address" attr
        (Martin Belanger)
      - various cleanups (Jackie Liu, Wolfram Sang, Genjian Zhang)
      - handle effects after freeing the request (Keith Busch)
      - copy firmware_rev on each init (Keith Busch)
      - restrict management ioctls to admin (Keith Busch)
      - ensure subsystem reset is single threaded (Keith Busch)
      - report the actual number of tagset maps in nvme-pci (Keith
        Busch)
      - small fabrics authentication fixups (Christoph Hellwig)
      - add common code for tagset allocation and freeing (Christoph
        Hellwig)
      - stop using the request_queue in nvmet (Christoph Hellwig)
      - set min_align_mask before calculating max_hw_sectors (Rishabh
        Bhatnagar)
      - send a rediscover uevent when a persistent discovery controller
        reconnects (Sagi Grimberg)
      - misc nvmet-tcp fixes (Varun Prakash, zhenwei pi)

 - MD pull request via Song:
      - Various raid5 fix and clean up, by Logan Gunthorpe and David
        Sloan.
      - Raid10 performance optimization, by Yu Kuai.

 - sbitmap wakeup hang fixes (Hugh, Keith, Jan, Yu)

 - IO scheduler switching quisce fix (Keith)

 - s390/dasd block driver updates (Stefan)

 - support for recovery for the ublk driver (ZiyangZhang)

 - rnbd drivers fixes and updates (Guoqing, Santosh, ye, Christoph)

 - blk-mq and null_blk map fixes (Bart)

 - various bcache fixes (Coly, Jilin, Jules)

 - nbd signal hang fix (Shigeru)

 - block writeback throttling fix (Yu)

 - optimize the passthrough mapping handling (me)

 - prepare block cgroups to being gendisk based (Christoph)

 - get rid of an old PSI hack in the block layer, moving it to the
   callers instead where it belongs (Christoph)

 - blk-throttle fixes and cleanups (Yu)

 - misc fixes and cleanups (Liu Shixin, Liu Song, Miaohe, Pankaj,
   Ping-Xiang, Wolfram, Saurabh, Li Jinlin, Li Lei, Lin, Li zeming,
   Miaohe, Bart, Coly, Gaosheng

* tag 'for-6.1/block-2022-10-03' of git://git.kernel.dk/linux: (162 commits)
  sbitmap: fix lockup while swapping
  block: add rationale for not using blk_mq_plug() when applicable
  block: adapt blk_mq_plug() to not plug for writes that require a zone lock
  s390/dasd: use blk_mq_alloc_disk
  blk-cgroup: don't update the blkg lookup hint in blkg_conf_prep
  nvmet: don't look at the request_queue in nvmet_bdev_set_limits
  nvmet: don't look at the request_queue in nvmet_bdev_zone_mgmt_emulate_all
  blk-mq: use quiesced elevator switch when reinitializing queues
  block: replace blk_queue_nowait with bdev_nowait
  nvme: remove nvme_ctrl_init_connect_q
  nvme-loop: use the tagset alloc/free helpers
  nvme-loop: store the generic nvme_ctrl in set->driver_data
  nvme-loop: initialize sqsize later
  nvme-fc: use the tagset alloc/free helpers
  nvme-fc: store the generic nvme_ctrl in set->driver_data
  nvme-fc: keep ctrl->sqsize in sync with opts->queue_size
  nvme-rdma: use the tagset alloc/free helpers
  nvme-rdma: store the generic nvme_ctrl in set->driver_data
  nvme-tcp: use the tagset alloc/free helpers
  nvme-tcp: store the generic nvme_ctrl in set->driver_data
  ...
2022-10-07 09:19:14 -07:00
наб bd5926220f nbd: remove define-only NBD_MAGIC, previously magic number
commit f4507164e7 ("nbd: rename the nbd_device variable from lo to
nbd") renamed LO_MAGIC to NBD_MAGIC; commit 5ea8d10802 ("nbd:
separate out the config information") removed the last users of that

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Link: https://lore.kernel.org/r/10a80681c5966fed1a1afc696e3db114f481514c.1663280877.git.nabijaczleweli@nabijaczleweli.xyz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-24 14:17:19 +02:00
Shigeru Yoshida 1de7c3cf48 nbd: Fix hung when signal interrupts nbd_start_device_ioctl()
syzbot reported hung task [1].  The following program is a simplified
version of the reproducer:

int main(void)
{
	int sv[2], fd;

	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) < 0)
		return 1;
	if ((fd = open("/dev/nbd0", 0)) < 0)
		return 1;
	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, 0x81) < 0)
		return 1;
	if (ioctl(fd, NBD_SET_SOCK, sv[0]) < 0)
		return 1;
	if (ioctl(fd, NBD_DO_IT) < 0)
		return 1;
	return 0;
}

When signal interrupt nbd_start_device_ioctl() waiting the condition
atomic_read(&config->recv_threads) == 0, the task can hung because it
waits the completion of the inflight IOs.

This patch fixes the issue by clearing queue, not just shutdown, when
signal interrupt nbd_start_device_ioctl().

Link: https://syzkaller.appspot.com/bug?id=7d89a3ffacd2b83fdd39549bc4d8e0a89ef21239 [1]
Reported-by: syzbot+38e6c55d4969a14c1534@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220907163502.577561-1-syoshida@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-08 08:41:36 -06:00
Jakub Kicinski 9c5d03d362 genetlink: start to validate reserved header bytes
We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-29 12:47:15 +01:00
Yu Kuai bc9da6dd06 nbd: add missing definition of pr_fmt
commit 1243172d58 ("nbd: use pr_err to output error message") tries
to define pr_fmt and use short pr_err() to output error message,
however, the definition is missed.

This patch also remove existing "nbd:" inside pr_err().

Fixes: 1243172d58 ("nbd: use pr_err to output error message")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220723082427.3890655-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02 17:22:41 -06:00
John Garry 2dd6532e95 blk-mq: Drop 'reserved' arg of busy_tag_iter_fn
We no longer use the 'reserved' arg in busy_tag_iter_fn for any iter
function so it may be dropped.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me> #nvme
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/1657109034-206040-6-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-06 06:33:53 -06:00
John Garry 9bdb4833dd blk-mq: Drop blk_mq_ops.timeout 'reserved' arg
With new API blk_mq_is_reserved_rq() we can tell if a request is from
the reserved pool, so stop passing 'reserved' arg. There is actually
only a single user of that arg for all the callback implementations, which
can use blk_mq_is_reserved_rq() instead.

This will also allow us to stop passing the same 'reserved' around the
blk-mq iter functions next.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/1657109034-206040-4-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-06 06:33:53 -06:00
Christoph Hellwig 8b9ab62662 block: remove blk_cleanup_disk
blk_cleanup_disk is nothing but a trivial wrapper for put_disk now,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-28 06:33:15 -06:00
Yu Kuai 1243172d58 nbd: use pr_err to output error message
Instead of using the long printk(KERN_ERR "nbd: ...") to
output error message, defining pr_fmt and using
the short pr_err("") to do that. The replacemen is done
by using the following command:

  sed -i 's/printk(KERN_ERR "nbd: /pr_err("/g' \
		  drivers/block/nbd.c

This patch also rewrap to 80 columns where possible.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-7-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-27 20:39:33 -06:00
Zhang Wensheng 858f1bf65d nbd: fix possible overflow on 'first_minor' in nbd_dev_add()
When 'index' is a big numbers, it may become negative which forced
to 'int'. then 'index << part_shift' might overflow to a positive
value that is not greater than '0xfffff', then sysfs might complains
about duplicate creation. Because of this, move the 'index' judgment
to the front will fix it and be better.

Fixes: b0d9111a2d ("nbd: use an idr to keep track of nbd devices")
Fixes: 940c264984 ("nbd: fix possible overflow for 'first_minor' in nbd_dev_add()")
Signed-off-by: Zhang Wensheng <zhangwensheng5@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-6-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-27 20:39:33 -06:00
Yu Kuai 09dadb5985 nbd: fix io hung while disconnecting device
In our tests, "qemu-nbd" triggers a io hung:

INFO: task qemu-nbd:11445 blocked for more than 368 seconds.
      Not tainted 5.18.0-rc3-next-20220422-00003-g2176915513ca #884
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:qemu-nbd        state:D stack:    0 pid:11445 ppid:     1 flags:0x00000000
Call Trace:
 <TASK>
 __schedule+0x480/0x1050
 ? _raw_spin_lock_irqsave+0x3e/0xb0
 schedule+0x9c/0x1b0
 blk_mq_freeze_queue_wait+0x9d/0xf0
 ? ipi_rseq+0x70/0x70
 blk_mq_freeze_queue+0x2b/0x40
 nbd_add_socket+0x6b/0x270 [nbd]
 nbd_ioctl+0x383/0x510 [nbd]
 blkdev_ioctl+0x18e/0x3e0
 __x64_sys_ioctl+0xac/0x120
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fd8ff706577
RSP: 002b:00007fd8fcdfebf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000040000000 RCX: 00007fd8ff706577
RDX: 000000000000000d RSI: 000000000000ab00 RDI: 000000000000000f
RBP: 000000000000000f R08: 000000000000fbe8 R09: 000055fe497c62b0
R10: 00000002aff20000 R11: 0000000000000246 R12: 000000000000006d
R13: 0000000000000000 R14: 00007ffe82dc5e70 R15: 00007fd8fcdff9c0

"qemu-ndb -d" will call ioctl 'NBD_DISCONNECT' first, however, following
message was found:

block nbd0: Send disconnect failed -32

Which indicate that something is wrong with the server. Then,
"qemu-nbd -d" will call ioctl 'NBD_CLEAR_SOCK', however ioctl can't clear
requests after commit 2516ab1543fd("nbd: only clear the queue on device
teardown"). And in the meantime, request can't complete through timeout
because nbd_xmit_timeout() will always return 'BLK_EH_RESET_TIMER', which
means such request will never be completed in this situation.

Now that the flag 'NBD_CMD_INFLIGHT' can make sure requests won't
complete multiple times, switch back to call nbd_clear_sock() in
nbd_clear_sock_ioctl(), so that inflight requests can be cleared.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-5-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-27 20:39:33 -06:00
Yu Kuai 2895f1831e nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed
Otherwise io will hung because request will only be completed if the
cmd has the flag 'NBD_CMD_INFLIGHT'.

Fixes: 07175cb1ba ("nbd: make sure request completion won't concurrent")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-4-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-27 20:39:33 -06:00
Yu Kuai c55b2b983b nbd: fix race between nbd_alloc_config() and module removal
When nbd module is being removing, nbd_alloc_config() may be
called concurrently by nbd_genl_connect(), although try_module_get()
will return false, but nbd_alloc_config() doesn't handle it.

The race may lead to the leak of nbd_config and its related
resources (e.g, recv_workq) and oops in nbd_read_stat() due
to the unload of nbd module as shown below:

  BUG: kernel NULL pointer dereference, address: 0000000000000040
  Oops: 0000 [#1] SMP PTI
  CPU: 5 PID: 13840 Comm: kworker/u17:33 Not tainted 5.14.0+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  Workqueue: knbd16-recv recv_work [nbd]
  RIP: 0010:nbd_read_stat.cold+0x130/0x1a4 [nbd]
  Call Trace:
   recv_work+0x3b/0xb0 [nbd]
   process_one_work+0x1ed/0x390
   worker_thread+0x4a/0x3d0
   kthread+0x12a/0x150
   ret_from_fork+0x22/0x30

Fixing it by checking the return value of try_module_get()
in nbd_alloc_config(). As nbd_alloc_config() may return ERR_PTR(-ENODEV),
assign nbd->config only when nbd_alloc_config() succeeds to ensure
the value of nbd->config is binary (valid or NULL).

Also adding a debug message to check the reference counter
of nbd_config during module removal.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-3-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-27 20:39:33 -06:00
Yu Kuai 06c4da89c2 nbd: call genl_unregister_family() first in nbd_cleanup()
Otherwise there may be race between module removal and the handling of
netlink command, which can lead to the oops as shown below:

  BUG: kernel NULL pointer dereference, address: 0000000000000098
  Oops: 0002 [#1] SMP PTI
  CPU: 1 PID: 31299 Comm: nbd-client Tainted: G            E     5.14.0-rc4
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
  RIP: 0010:down_write+0x1a/0x50
  Call Trace:
   start_creating+0x89/0x130
   debugfs_create_dir+0x1b/0x130
   nbd_start_device+0x13d/0x390 [nbd]
   nbd_genl_connect+0x42f/0x748 [nbd]
   genl_family_rcv_msg_doit.isra.0+0xec/0x150
   genl_rcv_msg+0xe5/0x1e0
   netlink_rcv_skb+0x55/0x100
   genl_rcv+0x29/0x40
   netlink_unicast+0x1a8/0x250
   netlink_sendmsg+0x21b/0x430
   ____sys_sendmsg+0x2a4/0x2d0
   ___sys_sendmsg+0x81/0xc0
   __sys_sendmsg+0x62/0xb0
   __x64_sys_sendmsg+0x1f/0x30
   do_syscall_64+0x3b/0xc0
   entry_SYSCALL_64_after_hwframe+0x44/0xae
  Modules linked in: nbd(E-)

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220521073749.3146892-2-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-27 20:39:33 -06:00
Xie Yongji 491bf8f236 nbd: Fix hung on disconnect request if socket is closed before
When userspace closes the socket before sending a disconnect
request, the following I/O requests will be blocked in
wait_for_reconnect() until dead timeout. This will cause the
following disconnect request also hung on blk_mq_quiesce_queue().
That means we have no way to disconnect a nbd device if there
are some I/O requests waiting for reconnecting until dead timeout.
It's not expected. So let's wake up the thread waiting for
reconnecting directly when a disconnect request is sent.

Reported-by: Xu Jianhai <zero.xu@bytedance.com>
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20220322080639.142-1-xieyongji@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-16 06:19:35 -06:00
Christoph Hellwig 4a04d517c5 nbd: don't set the discard_alignment queue limit
The discard_alignment queue limit is named a bit misleading means the
offset into the block device at which the discard granularity starts.
Setting it to the discard granularity as done by nbd is mostly harmless
but also useless.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220418045314.360785-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-03 10:38:50 -06:00
Christoph Hellwig dbdc1be325 block: add a disk_openers helper
Add a helper that returns the openers for a given gendisk to avoid having
drivers poke into disk->part0 to get at this information in a somewhat
cumbersome way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18 06:54:09 -06:00
Christoph Hellwig 2a852a693f nbd: use the correct block_device in nbd_bdev_reset
The bdev parameter to ->ioctl contains the block device that the ioctl
is called on, which can be the partition.  But the openers check in
nbd_bdev_reset really needs to check use the whole device, so switch to
using that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-18 06:54:09 -06:00
Christoph Hellwig 70200574cc block: remove QUEUE_FLAG_DISCARD
Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17 19:49:59 -06:00
Jens Axboe 7198bfc201 Revert "nbd: fix possible overflow on 'first_minor' in nbd_dev_add()"
This reverts commit 6d35d04a9e.

Both Gabriel and Borislav report that this commit casues a regression
with nbd:

sysfs: cannot create duplicate filename '/dev/block/43:0'

Revert it before 5.18-rc1 and we'll investigage this separately in
due time.

Link: https://lore.kernel.org/all/YkiJTnFOt9bTv6A2@zn.tnic/
Reported-by: Gabriel L. Somlo <somlo@cmu.edu>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-02 11:40:23 -06:00