If the header object gets deleted (perhaps along with the entire pool),
there is no point in attempting to reregister the watch. Treat this
the same as blacklisting: fail all pending and new I/Os requiring the
lock.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
-EBLACKLISTED from __rbd_register_watch() means that our ceph_client
got blacklisted - we won't be able to restore the watch and reacquire
the lock. Wake up and fail all outstanding requests waiting for the
lock and arrange for all new requests that require the lock to fail
immediately.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Mike Christie <mchristi@redhat.com>
A good practice is to prefix the names of functions by the name
of the subsystem.
The kthread worker API is a mix of classic kthreads and workqueues. Each
worker has a dedicated kthread. It runs a generic function that process
queued works. It is implemented as part of the kthread subsystem.
This patch renames the existing kthread worker API to use
the corresponding name from the workqueues API prefixed by
kthread_:
__init_kthread_worker() -> __kthread_init_worker()
init_kthread_worker() -> kthread_init_worker()
init_kthread_work() -> kthread_init_work()
insert_kthread_work() -> kthread_insert_work()
queue_kthread_work() -> kthread_queue_work()
flush_kthread_work() -> kthread_flush_work()
flush_kthread_worker() -> kthread_flush_worker()
Note that the names of DEFINE_KTHREAD_WORK*() macros stay
as they are. It is common that the "DEFINE_" prefix has
precedence over the subsystem names.
Note that INIT() macros and init() functions use different
naming scheme. There is no good solution. There are several
reasons for this solution:
+ "init" in the function names stands for the verb "initialize"
aka "initialize worker". While "INIT" in the macro names
stands for the noun "INITIALIZER" aka "worker initializer".
+ INIT() macros are used only in DEFINE() macros
+ init() functions are used close to the other kthread()
functions. It looks much better if all the functions
use the same scheme.
+ There will be also kthread_destroy_worker() that will
be used close to kthread_cancel_work(). It is related
to the init() function. Again it looks better if all
functions use the same naming scheme.
+ there are several precedents for such init() function
names, e.g. amd_iommu_init_device(), free_area_init_node(),
jump_label_init_type(), regmap_init_mmio_clk(),
+ It is not an argument but it was inconsistent even before.
[arnd@arndb.de: fix linux-next merge conflict]
Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
with maintenance operations offloaded to userspace (Douglas Fuller,
Mike Christie and myself). Another block device bullet is a series
fixing up layering error paths (myself).
On the filesystem side, we've got patches that improve our handling of
buffered vs dio write races (Neil Brown) and a few assorted fixes from
Zheng. Also included a couple of random cleanups and a minor CRUSH
update.
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Merge tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client
Pull Ceph updates from Ilya Dryomov:
"The big ticket item here is support for rbd exclusive-lock feature,
with maintenance operations offloaded to userspace (Douglas Fuller,
Mike Christie and myself). Another block device bullet is a series
fixing up layering error paths (myself).
On the filesystem side, we've got patches that improve our handling of
buffered vs dio write races (Neil Brown) and a few assorted fixes from
Zheng. Also included a couple of random cleanups and a minor CRUSH
update"
* tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client: (39 commits)
crush: remove redundant local variable
crush: don't normalize input of crush_ln iteratively
libceph: ceph_build_auth() doesn't need ceph_auth_build_hello()
libceph: use CEPH_AUTH_UNKNOWN in ceph_auth_build_hello()
ceph: fix description for rsize and rasize mount options
rbd: use kmalloc_array() in rbd_header_from_disk()
ceph: use list_move instead of list_del/list_add
ceph: handle CEPH_SESSION_REJECT message
ceph: avoid accessing / when mounting a subpath
ceph: fix mandatory flock check
ceph: remove warning when ceph_releasepage() is called on dirty page
ceph: ignore error from invalidate_inode_pages2_range() in direct write
ceph: fix error handling of start_read()
rbd: add rbd_obj_request_error() helper
rbd: img_data requests don't own their page array
rbd: don't call rbd_osd_req_format_read() for !img_data requests
rbd: rework rbd_img_obj_exists_submit() error paths
rbd: don't crash or leak on errors in rbd_img_obj_parent_read_full_callback()
rbd: move bumping img_request refcount into rbd_obj_request_submit()
rbd: mark the original request as done if stat request fails
...
Pull blk-mq irq/cpu mapping updates from Jens Axboe:
"This is the block-irq topic branch for 4.9-rc. It's mostly from
Christoph, and it allows drivers to specify their own mappings, and
more importantly, to share the blk-mq mappings with the IRQ affinity
mappings. It's a good step towards making this work better out of the
box"
* 'for-4.9/block-irq' of git://git.kernel.dk/linux-block:
blk_mq: linux/blk-mq.h does not include all the headers it depends on
blk-mq: kill unused blk_mq_create_mq_map()
blk-mq: get rid of the cpumask in struct blk_mq_tags
nvme: remove the post_scan callout
nvme: switch to use pci_alloc_irq_vectors
blk-mq: provide a default queue mapping for PCI device
blk-mq: allow the driver to pass in a queue mapping
blk-mq: remove ->map_queue
blk-mq: only allocate a single mq_map per tag_set
blk-mq: don't redistribute hardware queues on a CPU hotplug event
* A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus use the corresponding function "kmalloc_array".
This issue was detected by using the Coccinelle software.
* Delete the local variable "size" which became unnecessary with
this refactoring.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Pull setting an error and marking a request done code into a new
helper. obj_request_img_data_test() check isn't strictly needed right
now, but makes it applicable to !img_data requests and a bit safer.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Move the check into rbd_obj_request_destroy() to avoid use-after-free
on errors in rbd_img_request_fill(..., OBJ_REQUEST_PAGES, ...), where
pages, owned by the caller, gets freed in rbd_img_request_fill().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Accessing obj_request->img_request union field is only valid for object
requests associated with an image (i.e. if obj_request_img_data_test()
returns true). rbd_osd_req_format_read() used to do more, but now it
just sets osd_req->snap_id. Standalone and stat object requests always
go to the HEAD revision and are fine with CEPH_NOSNAP set by libceph,
so get around the invalid union field use by simply not calling
rbd_osd_req_format_read() in those places.
Reported-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: David Disseldorp <ddiss@suse.de>
- don't put obj_request before rbd_obj_request_get() if
rbd_obj_request_create() fails
- don't leak pages if rbd_obj_request_create() fails
- don't leak stat_request if rbd_osd_req_create() fails
Reported-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: David Disseldorp <ddiss@suse.de>
- fix parent_length == img_request->xferred assert to not fire on
copyup read failures
- don't leak pages if copyup read fails or we can't allocate a new osd
request
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Commit 0f2d5be792 ("rbd: use reference counts for image requests")
added rbd_img_request_get(), which rbd_img_request_fill() calls for
each obj_request added to img_request. It was an urgent band-aid for
the uglyness that is rbd_img_obj_callback() and none of the error paths
were updated.
Given that this img_request reference is meant to represent an
obj_request that hasn't passed through rbd_img_obj_callback() yet,
proper cleanup in appropriate destructors is a challenge. However,
noting that if we don't get a chance to call rbd_obj_request_complete(),
there is not going to be a call to rbd_img_obj_callback(), we can move
rbd_img_request_get() into rbd_obj_request_submit() and fixup the two
places that call rbd_obj_request_complete() directly and not through
rbd_obj_request_submit() to temporarily bump img_request, so that
rbd_img_obj_callback() can put as usual.
This takes care of img_request leaks on errors on the submit side.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
If stat request fails with something other than -ENOENT (which just
means that we need to copyup), the original object request is never
marked as done and therefore never completed. Fix this by moving the
mark done + complete snippet from rbd_img_obj_parent_read_full() into
rbd_img_obj_exists_callback(). The former remains covered, as the
latter is its only caller (through rbd_img_obj_request_submit()).
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Assert once in rbd_img_obj_request_submit().
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: David Disseldorp <ddiss@suse.de>
Add a per-device option to acquire exclusive lock on reads (in addition
to writes and discards). The use case is iSCSI, where it will be used
to prevent execution of stale writes after the implicit failover.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Mike Christie <mchristi@redhat.com>
We take a mutex when sending commands and send stuff over the network, we need
to have queue_rq called asynchronously.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Fixes: fd8383fd88 ("nbd: convert to blkmq")
Signed-off-by: Jens Axboe <axboe@fb.com>
LightNVM compatible device drivers does not have a method to expose
LightNVM specific sysfs entries.
To enable LightNVM sysfs entries to be exposed, lightnvm device
drivers require a struct device to attach it to. To allow both the
actual device driver and lightnvm sysfs entries to coexist, the device
driver tracks the lifetime of the nvm_dev structure.
This patch refactors NVMe and null_blk to handle the lifetime of struct
nvm_dev, which eliminates the need for struct gendisk when a lightnvm
compatible device is provided.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
With LightNVM enabled devices, the gendisk structure is not exposed
to the user. This hides the device driver specific sysfs entries, and
prevents binding of LightNVM geometry information to the device.
Refactor the device registration process, so that gendisk and
non-gendisk devices are easily managed.
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
All drivers use the default, so provide an inline version of it. If we
ever need other queue mapping we can add an optional method back,
although supporting will also require major changes to the queue setup
code.
This provides better code generation, and better debugability as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Instead of rolling our own timer, just utilize the blk mq req timeout and do the
disconnect if any of our commands timeout.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In preparation for some future changes, change a few of the state bools over to
normal bits to set/clear properly.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We hit a warning when shutting down the nbd connection because we have irq's
disabled. We don't really need to do the shutdown under the lock, just clear
the nbd->sock. So do the shutdown outside of the irq. This gets rid of the
warning.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This moves NBD over to using blkmq, which allows us to get rid of the NBD
wide queue lock and the async submit kthread. We will start with 1 hw
queue for now, but I plan to add multiple tcp connection support in the
future and we'll fix how we set the hwqueue's.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We get 1 warning when biuld kernel with W=1:
drivers/block/mtip32xx/mtip32xx.c:3689:6: warning: no previous prototype for
'mtip_block_release' [-Wmissing-prototypes]
In fact, this function is only used in the file in which it is declared
and don't need a declaration, but can be made static.
so this patch marks it 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
This adds a force close option, so we can force the unmapping
of a rbd device that is open. If a path/device is blacklisted, apps
like multipathd can map a new device and then unmap the old one.
The unmapping cleanup would then be handled by the generic hotunplug
code paths in multipahd like is done for iSCSI, FC/FCOE, SAS, etc.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Export the info used to setup the rbd image, so it can be used to remap
the image.
Signed-off-by: Mike Christie <mchristi@redhat.com>
[idryomov@gmail.com: do_rbd_add() EH]
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Export snap id in sysfs, so tools like multipathd can use it in a uuid.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Export the cluster fsid, so tools like udev and multipath-tools can use
it for part of the uuid.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Export client addr/nonce, so userspace can check if a image is being
blacklisted.
Signed-off-by: Mike Christie <mchristi@redhat.com>
[idryomov@gmail.com: ceph_client_addr(), endianess fix]
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
With exclusive-lock added and more to come, print features into dmesg.
Change capacity to decimal while at it.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Add basic support for RBD_FEATURE_EXCLUSIVE_LOCK feature. Maintenance
operations (resize, snapshot create, etc) are offloaded to librbd via
returning -EOPNOTSUPP - librbd should request the lock and execute the
operation.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Tested-by: Mike Christie <mchristi@redhat.com>
Revamp watch code to support retrying watch re-registration:
- add rbd_dev->watch_state for more robust errcb handling
- store watch cookie separately to avoid dereferencing watch_handle
which is set to NULL on unwatch
- move re-register code into a delayed work and retry re-registration
every second, unless the client is blacklisted
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Tested-by: Mike Christie <mchristi@redhat.com>
This is going to be used for re-registering watch requests and
exclusive-lock tasks: acquire/request lock, notify-acquired, release
lock, notify-released. Some refactoring in the map/unmap paths was
necessary to give this workqueue a meaningful name: "rbdX-tasks".
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
It's gid / global_id in other places.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Current code forgets to free resources in the failure path of
xlvbd_alloc_gendisk(), this patch fix it.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
blk_mq_update_nr_hw_queues() reset all queue limits to default which it's
not as xen-blkfront expected, introducing blkif_set_queue_limits() to reset
limits with initial correct values.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Two places didn't get updated when 64KB page granularity was introduced,
this patch fix them.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
- Misc fixes and cleanups all over the place.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
"Misc fixes and cleanups all over the place"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio/s390: deprecate old transport
virtio/s390: keep early_put_chars
virtio_blk: Fix a slient kernel panic
virtio-vsock: fix include guard typo
vhost/vsock: fix vhost virtio_vsock_pkt use-after-free
9p/trans_virtio: use kvfree() for iov_iter_get_pages_alloc()
virtio: fix error handling for debug builds
virtio: fix memory leak in virtqueue_add()
ceph_file_layout::pool_id is now s64. rbd_add_get_pool_id() and
ceph_pg_poolid_by_name() both return an int, so it's bogus anyway.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
We do a lot of memory allocation in function init_vq, and don't handle
the allocation failure properly. Then this function will return 0,
although initialization fails due to lacking memory. At that moment,
kernel will panic in guest machine, if virtio is used to drive disk.
To fix this bug, we should take care of allocation failure, and return
correct value to let caller know what happen.
Tested-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Minfei Huang <minfei.hmf@alibaba-inc.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Purely cosmetic at this point, as rbd doesn't use RADOS namespaces and
hence rbd_dev->header_oloc->pool_ns is always NULL.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Since commit 63a4cc2486, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.
No intended functional changes in this commit.
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit abf545484d changed it from an 'rw' flags type to the
newer ops based interface, but now we're effectively leaking
some bdev internals to the rest of the kernel. Since we only
care about whether it's a read or a write at that level, just
pass in a bool 'is_write' parameter instead.
Then we can also move op_is_write() and friends back under
CONFIG_BLOCK protection.
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The rw_page users were not converted to use bio/req ops. As a result
bdev_write_page is not passing down REQ_OP_WRITE and the IOs will
be sent down as reads.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Fixes: 4e1b2d52a8 ("block, fs, drivers: remove REQ_OP compat defs and related code")
Modified by me to:
1) Drop op_flags passing into ->rw_page(), as we don't use it.
2) Make op_is_write() and friends safe to use for !CONFIG_BLOCK
Signed-off-by: Jens Axboe <axboe@fb.com>
Fix a fat-fingered conversion to the req_op accessors, and also
use a switch statement to make it more obvious what is being checked.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Dave Chinner <david@fromorbit.com>
Fixes: c2df40 ("drivers: use req op accessor");
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Quentin ran into this bug:
WARNING: CPU: 64 PID: 10085 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x65/0x80
sysfs: cannot create duplicate filename '/devices/virtual/block/nbd3/pid'
Modules linked in: nbd
CPU: 64 PID: 10085 Comm: qemu-nbd Tainted: G D 4.6.0+ #7
0000000000000000 ffff8820330bba68 ffffffff814b8791 ffff8820330bbac8
0000000000000000 ffff8820330bbab8 ffffffff810d04ab ffff8820330bbaa8
0000001f00000296 0000000000017681 ffff8810380bf000 ffffffffa0001790
Call Trace:
[<ffffffff814b8791>] dump_stack+0x4d/0x6c
[<ffffffff810d04ab>] __warn+0xdb/0x100
[<ffffffff810d0574>] warn_slowpath_fmt+0x44/0x50
[<ffffffff81218c65>] sysfs_warn_dup+0x65/0x80
[<ffffffff81218a02>] sysfs_add_file_mode_ns+0x172/0x180
[<ffffffff81218a35>] sysfs_create_file_ns+0x25/0x30
[<ffffffff81594a76>] device_create_file+0x36/0x90
[<ffffffffa0000e8d>] __nbd_ioctl+0x32d/0x9b0 [nbd]
[<ffffffff814cc8e8>] ? find_next_bit+0x18/0x20
[<ffffffff810f7c29>] ? select_idle_sibling+0xe9/0x120
[<ffffffff810f6cd7>] ? __enqueue_entity+0x67/0x70
[<ffffffff810f9bf0>] ? enqueue_task_fair+0x630/0xe20
[<ffffffff810efa76>] ? resched_curr+0x36/0x70
[<ffffffff810f0078>] ? check_preempt_curr+0x78/0x90
[<ffffffff810f00a2>] ? ttwu_do_wakeup+0x12/0x80
[<ffffffff810f01b1>] ? ttwu_do_activate.constprop.86+0x61/0x70
[<ffffffff810f0c15>] ? try_to_wake_up+0x185/0x2d0
[<ffffffff810f0d6d>] ? default_wake_function+0xd/0x10
[<ffffffff81105471>] ? autoremove_wake_function+0x11/0x40
[<ffffffffa0001577>] nbd_ioctl+0x67/0x94 [nbd]
[<ffffffff814ac0fd>] blkdev_ioctl+0x14d/0x940
[<ffffffff811b0da2>] ? put_pipe_info+0x22/0x60
[<ffffffff811d96cc>] block_ioctl+0x3c/0x40
[<ffffffff811ba08d>] do_vfs_ioctl+0x8d/0x5e0
[<ffffffff811aa329>] ? ____fput+0x9/0x10
[<ffffffff810e9092>] ? task_work_run+0x72/0x90
[<ffffffff811ba627>] SyS_ioctl+0x47/0x80
[<ffffffff8185f5df>] entry_SYSCALL_64_fastpath+0x17/0x93
---[ end trace 7899b295e4f850c8 ]---
It seems fairly obvious that device_create_file() is not being protected
from being run concurrently on the same nbd.
Quentin found the following relevant commits:
1a2ad21 nbd: add locking to nbd_ioctl
90b8f28 [PATCH] end of methods switch: remove the old ones
d4430d6 [PATCH] beginning of methods conversion
08f8585 [PATCH] move block_device_operations to blkdev.h
It would seem that the race was introduced in the process of moving nbd
from BKL to unlocked ioctls.
By setting nbd->task_recv while the mutex is held, we can prevent other
processes from running concurrently (since nbd->task_recv is also checked
while the mutex is held).
Reported-and-tested-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Pavel Machek <pavel@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
