loop_set_status doesn't change anything relevant to the discard and
write_zeroes setting, so don't bother calling loop_config_discard.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231227082020.249427-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Use the queue wide write back cache tracking insted of duplicating the
value in strut rq_wb.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231226090747.204969-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

submit_bio_noacct allows completely invalid operations, or operations
that are not supported in the bio path.  Extent the existing switch
statement to rejcect all invalid types.

Move the code point for REQ_OP_ZONE_APPEND so that it's not right in the
middle of the zone management operations and the switch statement can
follow the numerical order of the operations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231221070538.1112446-1-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Fix all kernel-doc warnings in drbd_actlog.c:

drbd_actlog.c:963: warning: No description found for return value of 'drbd_rs_begin_io'
drbd_actlog.c:1015: warning: Function parameter or member 'peer_device' not described in 'drbd_try_rs_begin_io'
drbd_actlog.c:1015: warning: Excess function parameter 'device' description in 'drbd_try_rs_begin_io'
drbd_actlog.c:1015: warning: No description found for return value of 'drbd_try_rs_begin_io'
drbd_actlog.c:1197: warning: No description found for return value of 'drbd_rs_del_all'

Fix one spelling error (s/ore/or/).
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc:  <drbd-dev@lists.linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc:  <linux-block@vger.kernel.org>
Link: https://lore.kernel.org/r/20231222061909.8791-1-rdunlap@infradead.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

commit 41fa7222 ("blk-mq: do not include passthrough requests in I/O
accounting")' disables I/O accounting for passthrough requests. Since tools
like 'iostat' do not show anything useful for passthrough I/O, it's
wasteful to do start/end time-stamping. So do away with that.

Avoiding the time-stamping improves the I/O performance by ~7%
Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20231222101707.6921-1-kundan.kumar@samsung.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe updates from Keith:

"nvme updates for Linux 6.8

 - nvme fabrics spec updates (Guixin, Max)
 - nvme target udpates (Guixin, Evan)
 - nvme attribute refactoring (Daniel)
 - nvme-fc numa fix (Keith)"

* tag 'nvme-6.8-2023-12-21' of git://git.infradead.org/nvme:
  nvme-fc: set numa_node after nvme_init_ctrl
  nvme-fabrics: don't check discovery ioccsz/iorcsz
  nvmet: configfs: use ctrl->instance to track passthru subsystems
  nvme: repack struct nvme_ns_head
  nvme: add csi, ms and nuse to sysfs
  nvme: rename ns attribute group
  nvme: refactor ns info setup function
  nvme: refactor ns info helpers
  nvme: move ns id info to struct nvme_ns_head
  nvmet: remove cntlid_min and cntlid_max check in nvmet_alloc_ctrl
  nvmet: allow identical cntlid_min and cntlid_max settings
  nvme-fabrics: check ioccsz and iorcsz
  nvme: introduce nvme_check_ctrl_fabric_info helper

nvme_init_ctrl() resets numa_node to NUMA_NO_NODE, so be sure to set the
desired value after that function call so it won't be overwritten.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

IOCCSZ and IORCSZ are reserved for discovery controllers. Avoid checking
their values during identify controller phase.

Fixes: 2fcd3ab3 ("nvme-fabrics: check ioccsz and iorcsz")
Reported-by: Daniel Wagner <dwagner@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

A previous commit split disk_set_zoned(..., bool) into not taking an
argument for whether to set or clear, and instead added
disk_clear_zoned() as the counterpart. However, that commit neglected
to export the new symbol, causing failures for modular drivers that
used it.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: d73e93b4 ("block: simplify disk_set_zoned")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

disk_clear_zoned only needs to be called when a device reported zone
managed mode first and we clear it.  Add a check so that disk_clear_zoned
isn't called on devices that were never zoned.

This avoids a fairly expensive queue freezing when revalidating
conventional devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Only use disk_set_zoned to actually enable zoned device support.
For clearing it, call disk_clear_zoned, which is renamed from
disk_clear_zone_settings and now directly clears the zoned flag as
well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

When zones were first added the SCSI and ATA specs, two different
models were supported (in addition to the drive managed one that
is invisible to the host):

 - host managed where non-conventional zones there is strict requirement
   to write at the write pointer, or else an error is returned
 - host aware where a write point is maintained if writes always happen
   at it, otherwise it is left in an under-defined state and the
   sequential write preferred zones behave like conventional zones
   (probably very badly performing ones, though)

Not surprisingly this lukewarm model didn't prove to be very useful and
was finally removed from the ZBC and SBC specs (NVMe never implemented
it).  Due to to the easily disappearing write pointer host software
could never rely on the write pointer to actually be useful for say
recovery.

Fortunately only a few HDD prototypes shipped using this model which
never made it to mass production.  Drop the support before it is too
late.  Note that any such host aware prototype HDD can still be used
with Linux as we'll now treat it as a conventional HDD.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

virtblk_revalidate_zones is called unconditionally from
virtblk_config_changed_work from the virtio config_changed callback.

virtblk_revalidate_zones is a bit odd in that it re-clears the zoned
state for host aware or non-zoned devices, which isn't needed unless the
zoned mode changed - but a zone mode change to a host managed model isn't
handled at all, and virtio_blk also doesn't handle any other config
change except for a capacity change is handled (and even if it was
the upper layers above virtio_blk wouldn't handle it very well).

But even the useful case of a size change that would add or remove
zones isn't handled properly as blk_revalidate_disk_zones expects the
device capacity to cover all zones, but the capacity is only updated
after virtblk_revalidate_zones.

As this code appears to be entirely untested and is getting in the way
remove it for now, but it can be readded in a fixed version with
proper test coverage if needed.

Fixes: 95bfec41 ("virtio-blk: add support for zoned block devices")
Fixes: f1ba4e67 ("virtio-blk: fix to match virtio spec")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Move reading and checking the zoned model from virtblk_probe_zoned_device
into the caller, leaving only the code to perform the actual setup for
host managed zoned devices in virtblk_probe_zoned_device.

This allows to share the model reading and sharing between builds with
and without CONFIG_BLK_DEV_ZONED, and improve it for the
!CONFIG_BLK_DEV_ZONED case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'md-next-20231219' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into for-6.8/block

Pull MD updates from Song:

"1. Remove deprecated flavors, by Song Liu;
 2. raid1 read error check support, by Li Nan;
 3. Better handle events off-by-1 case, by Alex Lyakas."

* tag 'md-next-20231219' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: Remove deprecated CONFIG_MD_FAULTY
  md: Remove deprecated CONFIG_MD_MULTIPATH
  md: Remove deprecated CONFIG_MD_LINEAR
  md/raid1: support read error check
  md: factor out a helper exceed_read_errors() to check read_errors
  md: Whenassemble the array, consult the superblock of the freshest device
  md/raid1: remove unnecessary null checking

md-faulty has been marked as deprecated for 2.5 years. Remove it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231214222107.2016042-4-song@kernel.org

md-multipath has been marked as deprecated for 2.5 years. Remove it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231214222107.2016042-3-song@kernel.org

md-linear has been marked as deprecated for 2.5 years. Remove it.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231214222107.2016042-2-song@kernel.org

To prevent enabling more than one passthrough subsystem per NVMe
controller, passthru.c maintains an xarray indexed by cntlid values.
Passthrough for a given nvmet subsystem cannot be enabled by configfs
if the subsystem's passthru_ctrl->cntlid value is already accounted
for in the xarray.

However, according to the NVMe spec (rev 2.0c, p.145), "The Controller
ID (CNTLID) value returned in the Identify Controller data structure
may be used to uniquely identify a controller within an NVM subsystem,"
meaning that cntlid values are not guaranteed to be globally unique
across multiple subsystems. Instead, the cntlid only uniquely
identifies multiple controllers _within_ a subsystem.

As a result, multiple unique & valid NVMe targets can be blocked from
enabling passthrough at the same time if their controllers share cntlid
values, a behavior allowed by the spec. Fix this by indexing the xarray
with passthru_ctrl->instance values, which are allocated per
controller by IDA and thus should be truly unique.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Evan Burgess <evan.burgess@seagate.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

ns_id, lba_shift and ms are always accessed for every read/write I/O in
nvme_setup_rw. By grouping these variables into one cacheline we can
safe some cycles.

4k sequential reads:

           baseline   patched
Bandwidth: 1620       1634
IOPs       66345579   66910939
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

libnvme is using the sysfs for enumarating the nvme resources. Though
there are few missing attritbutes in the sysfs. For these libnvme issues
commands during discovering.

As the kernel already knows all these attributes and we would like to
avoid libnvme to issue commands all the time, expose these missing
attributes.

The nuse value is updated on request because the nuse is a volatile
value. Since any user can read the sysfs attribute, a very simple rate
limit is added (update once every 5 seconds). A more sophisticated
update strategy can be added later if there is actually a need for it.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Drop the 'id' part of the attribute group name because we want to expose
non 'id' related attributes via the ns attribute group.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Use nvme_ns_head instead of nvme_ns where possible. This reduces the
coupling between the different data structures.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Pass in the nvme_ns_head pointer directly. This reduces the necessity on
the caller side have the nvme_ns data structure present. Thus we can
refactor the caller side in the next step as well.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Move the namesapce info to struct nvme_ns_head, because it's the same
for all associated namespaces.

Note: with multipathing enabled the PI information is shared between all
paths. If a path is using a different PI configuration it will overwrite
the previous settings. This is obviously not correct and such
configuration will be rejected in future. For the time being we expect
a correctly configured storage.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

'first_minor' represents the starting minor number of disks, and
'minors' represents the number of partitions in the device. Neither
of them can be greater than MINORMASK + 1.

Commit e338924b ("block: check minor range in device_add_disk()")
only added the check of 'first_minor + minors'. However, their sum might
be less than MINORMASK but their values are wrong. Complete the checks now.

Fixes: e338924b ("block: check minor range in device_add_disk()")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231219075942.840255-1-linan666@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Even if BLK_CGROUP is enabled, it does not work for passthrough io.
So skip setting up blkg for passthrough bio.

Reduced processing gives ~5% hike in peak-performance workload.
Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20231218152722.1768-1-joshi.k@samsung.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

After commit 1e50915f ("raid: improve MD/raid10 handling of correctable
read errors."), rdev will be set to faulty if it reads data error to many
times in raid10. Add this mechanism to raid1 now.
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231215023852.3478228-3-linan666@huaweicloud.com

Move check_decay_read_errors() to raid1-10.c and factor out a helper
exceed_read_errors() to check if read_errors exceeds the limit, so that
raid1 can also use it. There are no functional changes.
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231215023852.3478228-2-linan666@huaweicloud.com

Upon assembling the array, both kernel and mdadm allow the devices to have event
counter difference of 1, and still consider them as up-to-date.
However, a device whose event count is behind by 1, may in fact not be up-to-date,
and array resync with such a device may cause data corruption.
To avoid this, consult the superblock of the freshest device about the status
of a device, whose event counter is behind by 1.
Signed-off-by: Alex Lyakas <alex.lyakas@zadara.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com

It's clearly been a while since someone looked at this, so I gave it a
quick shot. There are few issues in here:

- Random bundling of members that are mostly read-only and often written
- Random holes that need not be there

This moves the most frequently used bits into cacheline 1 and 2, with
the 2nd one being more write intensive than the first one, which is
basically read-only.

Outside of making this work a bit more efficiently, it also reduces the
size of struct request_queue for my test setup from 864 bytes (spanning
14 cachelines!) to 832 bytes and 13 cachelines.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/d2b7b61c-4868-45c0-9060-4f9c73de9d7e@kernel.dkSigned-off-by: Jens Axboe <axboe@kernel.dk>

bio_add_hw_page currently always fails or succeeds.  This is fine for
the existing callers that always add PAGE_SIZE worth given that the
max_segment_size and max_sectors must always allow at least a page
worth of data.  But when we want to add it for bigger amounts of data
this means it can also fail when adding the data to a bio, and creating
a fallback for that becomes really annoying in the callers.

Make use of the existing API design that allows to return a smaller
length than the one passed in and add up to max_segment_size worth
of data from a larger input.  All the existing callers are fine with
this - not because they handle this return correctly, but because they
never pass more than a page in.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20231204173419.782378-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Reordered a check to avoid a possible overflow when adding len to bv_len.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20231204173419.782378-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

If %__GFP_DIRECT_RECLAIM is set then bio_alloc_bioset will always
be able to allocate a bio. See comment of bio_alloc_bioset.
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231214151458.28970-1-gouhao@uniontech.com

Switch to the modern style of printing kernel messages. Use %u instead
of %d to print unsigned integers.
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20231213194702.90381-1-bvanassche@acm.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

The cntlid_min and cntlid_max are checked in configfs, don't check
again in nvmet_alloc_ctrl().
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

When the user wants to restrict to only creating one controller,
they can set cntlid_min and cntlid_max to the same value.
Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Before calling add partition or resize partition, there is no check
on whether the length is aligned with the logical block size.
If the logical block size of the disk is larger than 512 bytes,
then the partition size maybe not the multiple of the logical block size,
and when the last sector is read, bio_truncate() will adjust the bio size,
resulting in an IO error if the size of the read command is smaller than
the logical block size.If integrity data is supported, this will also
result in a null pointer dereference when calling bio_integrity_free.

Cc:  <stable@vger.kernel.org>
Signed-off-by: Min Li <min15.li@samsung.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230629142517.121241-1-min15.li@samsung.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

On the error path of device_add_disk(), device's memalloc_noio flag was
set but not cleared. As the comment of pm_runtime_set_memalloc_noio(),
"The function should be called between device_add() and device_del()".
Clear this flag before device_del() now.

Fixes: 25e823c8 ("block/genhd.c: apply pm_runtime_set_memalloc_noio on block devices")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231211075356.1839282-1-linan666@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since "dev_search_path" can technically be as large as PATH_MAX,
there was a risk of truncation when copying it and a second string
into "full_path" since it was also PATH_MAX sized. The W=1 builds were
reporting this warning:

drivers/block/rnbd/rnbd-srv.c: In function 'process_msg_open.isra':
drivers/block/rnbd/rnbd-srv.c:616:51: warning: '%s' directive output may be truncated writing up to 254 bytes into a region of size between 0 and 4095 [-Wformat-truncation=]
  616 |                 snprintf(full_path, PATH_MAX, "%s/%s",
      |                                                   ^~
In function 'rnbd_srv_get_full_path',
    inlined from 'process_msg_open.isra' at drivers/block/rnbd/rnbd-srv.c:721:14: drivers/block/rnbd/rnbd-srv.c:616:17: note: 'snprintf' output between 2 and 4351 bytes into a destination of size 4096
  616 |                 snprintf(full_path, PATH_MAX, "%s/%s",
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  617 |                          dev_search_path, dev_name);
      |                          ~~~~~~~~~~~~~~~~~~~~~~~~~~

To fix this, unconditionally check for truncation (as was already done
for the case where "%SESSNAME%" was present).
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312100355.lHoJPgKy-lkp@intel.com/
Cc: Md. Haris Iqbal <haris.iqbal@ionos.com>
Cc: Jack Wang <jinpu.wang@ionos.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc:  <linux-block@vger.kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20231212214738.work.169-kees@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>