29 Sep, 2020
1 commit
-
Add support for user space to set a max open zone and a max active zone
limit via configfs. By default, the default values are 0 == no limit.Call the block layer API functions used for exposing the configured
limits to sysfs.Add accounting in null_blk_zoned so that these new limits are respected.
Performing an operation that would exceed these limits results in a
standard I/O error.A max open zone limit exists in the ZBC standard.
While null_blk_zoned is used to test the Zoned Block Device model in
Linux, when it comes to differences between ZBC and ZNS, null_blk_zoned
mostly follows ZBC.Therefore, implement the manage open zone resources function from ZBC,
but additionally add support for max active zones.
This enables user space not only to test against a device with an open
zone limit, but also to test against a device with an active zone limit.Signed-off-by: Niklas Cassel
Reviewed-by: Damien Le Moal
Reviewed-by: Johannes Thumshirn
Signed-off-by: Jens Axboe
25 Sep, 2020
1 commit
-
Support a shared tag bitmap, whereby request tags are unique over all
submission queues, and not just per submission queue.As such, per device total queue depth is normally hw_queue_depth *
submit_queues, but hw_queue_depth when set. And a similar story for when
shared_tags is set, where that is the queue depth over all null blk
devices.Signed-off-by: John Garry
Tested-by: Douglas Gilbert
Signed-off-by: Jens Axboe
22 Aug, 2020
1 commit
-
REQ_FUA should be checked using rq->cmd_flags instead of req_op().
Fixes: deb78b419dfda ("nullb: emulate cache")
Signed-off-by: Hou Pu
Signed-off-by: Jens Axboe
08 Jul, 2020
1 commit
-
Allow emulation of a zoned device with a per zone capacity smaller than
the zone size as as defined in the Zoned Namespace (ZNS) Command Set
specification. The zone capacity defaults to the zone size if not
specified and must be smaller than the zone size otherwise.Reviewed-by: Matias Bjørling
Reviewed-by: Chaitanya Kulkarni
Reviewed-by: Himanshu Madhani
Reviewed-by: Martin K. Petersen
Reviewed-by: Hannes Reinecke
Reviewed-by: Johannes Thumshirn
Reviewed-by: Daniel Wagner
Signed-off-by: Aravind Ramesh
Signed-off-by: Christoph Hellwig
01 Jul, 2020
2 commits
-
The make_request_fn is a little weird in that it sits directly in
struct request_queue instead of an operation vector. Replace it with
a block_device_operations method called submit_bio (which describes much
better what it does). Also remove the request_queue argument to it, as
the queue can be derived pretty trivially from the bio.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Instead of setting up the queuedata as well just use one private data
field.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
24 Jun, 2020
1 commit
-
Move the call to blk_should_fake_timeout out of blk_mq_complete_request
and into the drivers, skipping call sites that are obvious error
handlers, and remove the now superflous blk_mq_force_complete_rq helper.
This ensures we don't keep injecting errors into completions that just
terminate the Linux request after the hardware has been reset or the
command has been aborted.Reviewed-by: Daniel Wagner
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
03 Jun, 2020
1 commit
-
Pull block updates from Jens Axboe:
"Core block changes that have been queued up for this release:- Remove dead blk-throttle and blk-wbt code (Guoqing)
- Include pid in blktrace note traces (Jan)
- Don't spew I/O errors on wouldblock termination (me)
- Zone append addition (Johannes, Keith, Damien)
- IO accounting improvements (Konstantin, Christoph)
- blk-mq hardware map update improvements (Ming)
- Scheduler dispatch improvement (Salman)
- Inline block encryption support (Satya)
- Request map fixes and improvements (Weiping)
- blk-iocost tweaks (Tejun)
- Fix for timeout failing with error injection (Keith)
- Queue re-run fixes (Douglas)
- CPU hotplug improvements (Christoph)
- Queue entry/exit improvements (Christoph)
- Move DMA drain handling to the few drivers that use it (Christoph)
- Partition handling cleanups (Christoph)"
* tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits)
block: mark bio_wouldblock_error() bio with BIO_QUIET
blk-wbt: rename __wbt_update_limits to wbt_update_limits
blk-wbt: remove wbt_update_limits
blk-throttle: remove tg_drain_bios
blk-throttle: remove blk_throtl_drain
null_blk: force complete for timeout request
blk-mq: drain I/O when all CPUs in a hctx are offline
blk-mq: add blk_mq_all_tag_iter
blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
blk-mq: use BLK_MQ_NO_TAG in more places
blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
blk-mq: move more request initialization to blk_mq_rq_ctx_init
blk-mq: simplify the blk_mq_get_request calling convention
blk-mq: remove the bio argument to ->prepare_request
nvme: force complete cancelled requests
blk-mq: blk-mq: provide forced completion method
block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds
block: blk-crypto-fallback: remove redundant initialization of variable err
block: reduce part_stat_lock() scope
block: use __this_cpu_add() instead of access by smp_processor_id()
...
30 May, 2020
1 commit
-
The commit 7b11eab041da ("blk-mq: blk-mq: provide forced completion
method") exports new API to force a request to complete without error
injection.There should be no error injection when completing a request by timeout
handler.Otherwise, the below would hang because timeout handler is failed.
echo 100 > /sys/kernel/debug/fail_io_timeout/probability
echo 1000 > /sys/kernel/debug/fail_io_timeout/times
echo 1 > /sys/block/nullb0/io-timeout-fail
dd if=/dev/zero of=/dev/nullb0 bs=512 count=1 oflag=directWith this patch, the timeout handler is able to complete the IO.
Signed-off-by: Dongli Zhang
Signed-off-by: Jens Axboe
21 May, 2020
1 commit
-
Zoned block device specification do not define the behavior of
discard/trim command as this command is generally replaced by the reset
write pointer (zone reset) command. Emulate this in null_blk by making
zoned and discard options mutually exclusive.Suggested-by: Damien Le Moal
Signed-off-by: Chaitanya Kulkarni
Signed-off-by: Jens Axboe
19 May, 2020
1 commit
-
This patch suppresses an uninteresting KMSAN complaint without affecting
performance of the null_blk driver if CONFIG_KMSAN is disabled.Reported-by: Alexander Potapenko
Signed-off-by: Bart Van Assche
Tested-by: Alexander Potapenko
Cc: Christoph Hellwig
Cc: Ming Lei
Cc: Damien Le Moal
Cc: Chaitanya Kulkarni
Cc: Alexander Potapenko
Signed-off-by: Jens Axboe
23 Apr, 2020
2 commits
-
Move all zoned mode related code from null_blk_main.c to
null_blk_zoned.c, avoiding an ugly #ifdef in the process.
Rename null_zone_init() into null_init_zoned_dev(), null_zone_exit()
into null_free_zoned_dev() and add the new function
null_register_zoned_dev() to finalize the zoned dev setup before
add_disk().Signed-off-by: Damien Le Moal
Reviewed-by: Christoph Hellwig
Reviewed-by: Johannes Thumshirn
Signed-off-by: Jens Axboe -
For write operations issued to a null_blk device with zoned mode
enabled, the state and write pointer position of the zone targeted by
the command should be checked before badblocks and memory backing
are handled as the write may be first failed due to, for instance, a
sector position not aligned with the zone write pointer. This order of
checking for errors reflects more accuratly the behavior of physical
zoned devices.Furthermore, the write pointer position of the target zone should be
incremented only and only if no errors are reported by badblocks and
memory backing handling.To fix this, introduce the small helper function null_process_cmd()
which execute null_handle_badblocks() and null_handle_memory_backed()
and use this function in null_zone_write() to correctly handle write
requests to zoned null devices depending on the type and state of the
write target zone. Also call this function in null_handle_zoned() to
process read requests to zoned null devices.null_process_cmd() is called directly from null_handle_cmd() for
regular null devices, resulting in no functional change for these type
of devices. To have symmetric names, the function null_handle_zoned()
is renamed to null_process_zoned_cmd().Signed-off-by: Damien Le Moal
Reviewed-by: Chaitanya Kulkarni
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
31 Mar, 2020
1 commit
-
Pull block driver updates from Jens Axboe:
- floppy driver cleanup series from Willy
- NVMe updates and fixes (Various)
- null_blk trace improvements (Chaitanya)
- bcache fixes (Coly)
- md fixes (via Song)
- loop block size change optimizations (Martijn)
- scnprintf() use (Takashi)
* tag 'for-5.7/drivers-2020-03-29' of git://git.kernel.dk/linux-block: (81 commits)
null_blk: add trace in null_blk_zoned.c
null_blk: add tracepoint helpers for zoned mode
block: add a zone condition debug helper
nvme: cleanup namespace identifier reporting in nvme_init_ns_head
nvme: rename __nvme_find_ns_head to nvme_find_ns_head
nvme: refactor nvme_identify_ns_descs error handling
nvme-tcp: Add warning on state change failure at nvme_tcp_setup_ctrl
nvme-rdma: Add warning on state change failure at nvme_rdma_setup_ctrl
nvme: Fix controller creation races with teardown flow
nvme: Make nvme_uninit_ctrl symmetric to nvme_init_ctrl
nvme: Fix ctrl use-after-free during sysfs deletion
nvme-pci: Re-order nvme_pci_free_ctrl
nvme: Remove unused return code from nvme_delete_ctrl_sync
nvme: Use nvme_state_terminal helper
nvme: release ida resources
nvme: Add compat_ioctl handler for NVME_IOCTL_SUBMIT_IO
nvmet-tcp: optimize tcp stack TX when data digest is used
nvme-fabrics: Use scnprintf() for avoiding potential buffer overflow
nvme-multipath: do not reset on unknown status
nvmet-rdma: allocate RW ctxs according to mdts
...
28 Mar, 2020
2 commits
-
Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper. Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Use the new blk_mq_init_queue_data instead of open coding the queue
allocation and initialization.Reviewed-by: Johannes Thumshirn
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
13 Mar, 2020
1 commit
-
As null_blk is a very good start point to test block layer, this patch
adds description and comments to 'timeout', 'requeue' and 'init_hctx' to
explain how to use fault injection with null_blk.The nvme has similar with nvme_core.fail_request in the form of comment.
Reviewed-by: Chaitanya Kulkarni
Signed-off-by: Dongli Zhang
Signed-off-by: Jens Axboe
12 Mar, 2020
1 commit
-
Steps to reproduce:
BLKRESETZONE zone 0
// force EIO
pwrite(fd, buf, 4096, 4096);[issue more IO including zone ioctls]
It will start failing randomly including IO to unrelated zones because of
->error "reuse". Trigger can be partition detection as well if test is not
run immediately which is even more entertaining.The fix is of course to clear ->error where necessary.
Reviewed-by: Christoph Hellwig
Signed-off-by: Alexey Dobriyan (SK hynix)
Signed-off-by: Jens Axboe
10 Mar, 2020
5 commits
-
This makes it possible to test the error path in blk_mq_realloc_hw_ctxs()
and also several error paths in null_blk.Signed-off-by: Bart Van Assche
Cc: Johannes Thumshirn
Cc: Hannes Reinecke
Cc: Ming Lei
Cc: Christoph Hellwig
Signed-off-by: Jens Axboe -
If null_add_dev() fails then null_del_dev() is called with a NULL argument.
Make null_del_dev() handle this scenario correctly. This patch fixes the
following KASAN complaint:null-ptr-deref in null_del_dev+0x28/0x280 [null_blk]
Read of size 8 at addr 0000000000000000 by task find/1062Call Trace:
dump_stack+0xa5/0xe6
__kasan_report.cold+0x65/0x99
kasan_report+0x16/0x20
__asan_load8+0x58/0x90
null_del_dev+0x28/0x280 [null_blk]
nullb_group_drop_item+0x7e/0xa0 [null_blk]
client_drop_item+0x53/0x80 [configfs]
configfs_rmdir+0x395/0x4e0 [configfs]
vfs_rmdir+0xb6/0x220
do_rmdir+0x238/0x2c0
__x64_sys_unlinkat+0x75/0x90
do_syscall_64+0x6f/0x2f0
entry_SYSCALL_64_after_hwframe+0x49/0xbeSigned-off-by: Bart Van Assche
Reviewed-by: Chaitanya Kulkarni
Cc: Johannes Thumshirn
Cc: Hannes Reinecke
Cc: Ming Lei
Cc: Christoph Hellwig
Signed-off-by: Jens Axboe -
If null_add_dev() fails, clear dev->nullb.
This patch fixes the following KASAN complaint:
BUG: KASAN: use-after-free in nullb_device_submit_queues_store+0xcf/0x160 [null_blk]
Read of size 8 at addr ffff88803280fc30 by task check/8409Call Trace:
dump_stack+0xa5/0xe6
print_address_description.constprop.0+0x26/0x260
__kasan_report.cold+0x7b/0x99
kasan_report+0x16/0x20
__asan_load8+0x58/0x90
nullb_device_submit_queues_store+0xcf/0x160 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x145/0x2c0
ksys_write+0xd7/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x2f0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff370926317
Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff2dd2da48 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007ff370926317
RDX: 0000000000000002 RSI: 0000559437ef23f0 RDI: 0000000000000001
RBP: 0000559437ef23f0 R08: 000000000000000a R09: 0000000000000001
R10: 0000559436703471 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ff370a006a0 R14: 00007ff370a014a0 R15: 00007ff370a008a0Allocated by task 8409:
save_stack+0x23/0x90
__kasan_kmalloc.constprop.0+0xcf/0xe0
kasan_kmalloc+0xd/0x10
kmem_cache_alloc_node_trace+0x129/0x4c0
null_add_dev+0x24a/0xe90 [null_blk]
nullb_device_power_store+0x1b6/0x270 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x145/0x2c0
ksys_write+0xd7/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x2f0
entry_SYSCALL_64_after_hwframe+0x49/0xbeFreed by task 8409:
save_stack+0x23/0x90
__kasan_slab_free+0x112/0x160
kasan_slab_free+0x12/0x20
kfree+0xdf/0x250
null_add_dev+0xaf3/0xe90 [null_blk]
nullb_device_power_store+0x1b6/0x270 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x145/0x2c0
ksys_write+0xd7/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x2f0
entry_SYSCALL_64_after_hwframe+0x49/0xbeFixes: 2984c8684f96 ("nullb: factor disk parameters")
Signed-off-by: Bart Van Assche
Reviewed-by: Chaitanya Kulkarni
Cc: Johannes Thumshirn
Cc: Hannes Reinecke
Cc: Ming Lei
Cc: Christoph Hellwig
Signed-off-by: Jens Axboe -
Instead of initializing null_blk hardware queues explicitly after the
request queue has been created, provide .init_hctx() and .exit_hctx()
callback functions. The latter functions are not only called during
request queue allocation but also when the number of hardware queues
changes. Allocate nr_cpu_ids queues during initialization to support
increasing the number of hardware queues above the initial hardware
queue count.This change fixes increasing the number of hardware queues above the
initial number of hardware queues and also keeps nullb->nr_queues in
sync with the number of hardware queues.Fixes: 45919fbfe1c4 ("null_blk: Enable modifying 'submit_queues' after an instance has been configured")
Signed-off-by: Bart Van Assche
Cc: Johannes Thumshirn
Cc: Hannes Reinecke
Cc: Ming Lei
Cc: Christoph Hellwig
Signed-off-by: Jens Axboe -
Although it is not clear to me why UBSAN complains when 'memory_backed'
is set, this patch suppresses the UBSAN complaint that is triggered when
setting that configfs attribute.UBSAN: Undefined behaviour in drivers/block/null_blk_main.c:327:1
load of value 16 is not a valid value for type '_Bool'
CPU: 2 PID: 8396 Comm: check Not tainted 5.6.0-rc1-dbg+ #14
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0xa5/0xe6
ubsan_epilogue+0x9/0x26
__ubsan_handle_load_invalid_value+0x6d/0x76
nullb_device_memory_backed_store.cold+0x2c/0x38 [null_blk]
configfs_write_file+0x1c4/0x250 [configfs]
__vfs_write+0x4c/0x90
vfs_write+0x145/0x2c0
ksys_write+0xd7/0x180
__x64_sys_write+0x47/0x50
do_syscall_64+0x6f/0x2f0
entry_SYSCALL_64_after_hwframe+0x49/0xbeSigned-off-by: Bart Van Assche
Reviewed-by: Chaitanya Kulkarni
Cc: Johannes Thumshirn
Cc: Hannes Reinecke
Cc: Ming Lei
Cc: Christoph Hellwig
Signed-off-by: Jens Axboe
26 Feb, 2020
1 commit
-
'list', 'll_list' and 'csd' are no longer used.
The 'list' is not used since it was introduced by commit f2298c0403b0
("null_blk: multi queue aware block test driver").The 'll_list' is no longer used since commit 3c395a969acc ("null_blk: set a
separate timer for each command").The 'csd' is no longer used since commit ce2c350b2cfe ("null_blk: use
blk_complete_request and blk_mq_complete_request").Reviewed-by: Bart Van Assche
Signed-off-by: Dongli Zhang
Signed-off-by: Jens Axboe
04 Feb, 2020
2 commits
-
With gcc-7.2, many instances of
drivers/block/null_blk_main.c: In function ‘nullb_device_zone_nr_conv_store’:
drivers/block/null_blk_main.c:291:12: warning: ‘new_value’ may be used uninitialized in this function [-Wmaybe-uninitialized]
dev->NAME = new_value; \
^
drivers/block/null_blk_main.c:279:7: note: ‘new_value’ was declared here
TYPE new_value; \
^Presumably notabug, so use uninitialized_var() to suppress them.
Cc: Shaohua Li
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Each line here overflows 80 cols by exactly one character. Delete one tab
per line to fix.Cc: Shaohua Li
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Dec, 2019
1 commit
-
If BLK_DEV_ZONED isn't set, 'ret' isn't used. This makes gcc complain,
rightfully. Move ret where it is used.Fixes: 979d54475e0b ("null_blk: cleanup null_gendisk_register")
Signed-off-by: Jens Axboe
04 Dec, 2019
1 commit
-
The current zone revalidation code has a major problem in that it
doesn't update the zone size and q->nr_zones atomically, leading
to a short window where an out of bounds access to the zone arrays
is possible.To fix this move the setting of the zone size into the crticial
sections blk_revalidate_disk_zones so that it gets updated together
with the zone bitmaps and q->nr_zones. This also slightly simplifies
the caller as it deducts the zone size from the report_zones.This change also allows to check for a power of two zone size in generic
code.Reported-by: Hans Holmberg
Reviewed-by: Javier González
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
03 Dec, 2019
3 commits
-
bio based drivers only need to update q->nr_zones. Do that manually
instead of overloading blk_revalidate_disk_zones to keep that function
simpler for the next round of changes that will rely even more on the
request based functionality.Reviewed-by: Javier González
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
Use a saner size calculation, and do a trivial cleanup on the zone
revalidation to prepare to future changes.Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe -
For zoned=1 mode, the zone size must be a power of 2. Check this not
only when the zone size is specified during modprobe, but also when
creating a zoned null_blk device using configfs.Signed-off-by: Damien Le Moal
Signed-off-by: Christoph Hellwig
Signed-off-by: Jens Axboe
13 Nov, 2019
3 commits
-
For a null_blk device with zoned mode enabled, the number of
conventional zones can be configured through configfs with the
zone_nr_conv parameter. Add this missing parameter in the features
string.Signed-off-by: Damien Le Moal
Reviewed-by: Hannes Reinecke
Reviewed-by: Chaitanya Kulkarni
Signed-off-by: Jens Axboe -
Make the instance name match the method name and define the name to NULL
instead of providing an inline stub, which is rather pointless for a
method call.Signed-off-by: Christoph Hellwig
Signed-off-by: Damien Le Moal
Reviewed-by: Hannes Reinecke
Reviewed-by: Chaitanya Kulkarni
Signed-off-by: Jens Axboe -
Remove the pointless stub open and release methods, give the operations
vector a slightly less confusing name, and use normal alignment for the
assignment operators.Signed-off-by: Christoph Hellwig
Signed-off-by: Damien Le Moal
Reviewed-by: Hannes Reinecke
Reviewed-by: Chaitanya Kulkarni
Signed-off-by: Jens Axboe
18 Oct, 2019
1 commit
-
A zoned block device maintains a write pointer within a zone, and reads
beyond the write pointer are undefined. Fill data buffer returned above
the write pointer with 0xFF.Signed-off-by: Ajay Joshi
Reviewed-by: Damien Le Moal
Reviewed-by: Matias Bjørling
Signed-off-by: Chaitanya Kulkarni
Signed-off-by: Jens Axboe
07 Oct, 2019
2 commits
-
This patch makes it possible to test blk_mq_update_nr_hw_queues() from
inside a VM.Cc: Christoph Hellwig
Cc: Ming Lei
Cc: Hannes Reinecke
Cc: Johannes Thumshirn
Signed-off-by: Bart Van Assche
Signed-off-by: Jens Axboe -
Introduce a local variable to make the code easier to read. This patch
does not change any functionality but makes the next patch in this
series easier to read.Cc: Christoph Hellwig
Cc: Ming Lei
Cc: Hannes Reinecke
Cc: Johannes Thumshirn
Signed-off-by: Bart Van Assche
Signed-off-by: Jens Axboe
16 Sep, 2019
3 commits
-
Instead of writing "null_blk: " at the beginning of each
pr_err/info/warn log message, format messages using pr_fmt() macro.Reviewed-by: Chaitanya Kulkarni
Signed-off-by: André Almeida
Signed-off-by: Jens Axboe -
Since the variable nr_devices is an unsigned int, the module_param()
should also use this type. Change the type so they can match.Fixes: f7c4ce890dd2 ("null_blk: validate the number of devices")
Reviewed-by: Chaitanya Kulkarni
Signed-off-by: André Almeida
Signed-off-by: Jens Axboe -
The module load should fail only if there is something wrong with the
configuration or if an error prevents it to work properly. The module
should be able to be loaded with (nr_device == 0), since it will not
trigger errors or be in malfunction state. Preventing loading with zero
devices also breaks applications that configures this module using
configfs API. Remove the nr_device check to fix this.Fixes: f7c4ce890dd2 ("null_blk: validate the number of devices")
Reviewed-by: Chaitanya Kulkarni
Signed-off-by: André Almeida
Signed-off-by: Jens Axboe
