Split out a helper that adds one single partition, and another one
calling that dealing with the parsed_partitions state.  This makes
it much more obvious how we clean up all state and start again when
using the rescan label.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Avoid the need to allocate a potentially large array of struct blk_zone
in the block layer by switching the ->report_zones method interface to
a callback model. Now the caller simply supplies a callback that is
executed on each reported zone, and private data for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There is no need to arbitrarily limit the size of a report zone to the
number of zones defined by SD_ZBC_REPORT_MAX_ZONES. Rather, simply
calculate the report buffer size needed for the requested number of
zones without exceeding the device total number of zones. This buffer
size limitation to the hardware maximum transfer size and page mapping
capabilities is kept unchanged. Starting with this initial buffer size,
the allocation is optimized by iterating over decreasing buffer size
until the allocation succeeds (each iteration is allowed to fail fast
using the __GFP_NORETRY flag). This ensures forward progress for zone
reports and avoids failures of zones revalidation under memory pressure.

While at it, also replace the hard coded 512 B sector size with the
SECTOR_SIZE macro.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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 <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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 <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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 <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

No known partitioning tool supports zoned block devices, especially the
host managed flavor with strong sequential write constraints.
Furthermore, there are also no known user nor use cases for partitioned
zoned block devices.

This patch removes partition device creation for zoned block devices,
which allows simplifying the processing of zone commands for zoned
block devices. A warning is added if a partition table is found on the
device.

For report zones operations no zone sector information remapping is
necessary anymore, simplifying the code. Of note is that remapping of
zone reports for DM targets is still necessary as done by
dm_remap_zone_report().

Similarly, remaping of a zone reset bio is not necessary anymore.
Testing for the applicability of the zone reset all request also becomes
simpler and only needs to check that the number of sectors of the
requested zone range is equal to the disk capacity.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

All kernel users of blkdev_report_zones() as well as applications use
through ioctl(BLKZONEREPORT) expect to potentially get less zone
descriptors than requested. As such, the use of the internal report
zones command execution loop implemented by blk_report_zones() is
not necessary and can even be harmful to performance by causing the
execution of inefficient small zones report command to service the
reminder of a requested zone array.

This patch removes blk_report_zones(), simplifying the code. Also
remove a now incorrect comment in dm_blk_report_zones().
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Javier Gonzalez <javier@javigon.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk_revalidate_disk_zones is never called for non-zoned devices.  Just
return early and warn instead of trying to handle this case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

For ZBC and ZAC zoned devices, the scsi driver revalidation processing
implemented by sd_revalidate_disk() includes a call to
sd_zbc_read_zones() which executes a full disk zone report used to
check that all zones of the disk are the same size. This processing is
followed by a call to blk_revalidate_disk_zones(), used to initialize
the device request queue zone bitmaps (zone type and zone write lock
bitmaps). To do so, blk_revalidate_disk_zones() also executes a full
device zone report to obtain zone types. As a result, the entire
zoned block device revalidation process includes two full device zone
report.

By moving the zone size checks into blk_revalidate_disk_zones(), this
process can be optimized to a single full device zone report, leading to
shorter device scan and revalidation times. This patch implements this
optimization, reducing the original full device zone report implemented
in sd_zbc_check_zones() to a single, small, report zones command
execution to obtain the size of the first zone of the device. Checks
whether all zones of the device are the same size as the first zone
size are moved to the generic blk_check_zone() function called from
blk_revalidate_disk_zones().

This optimization also has the following benefits:
1) fewer memory allocations in the scsi layer during disk revalidation
   as the potentailly large buffer for zone report execution is not
   needed.
2) Implement zone checks in a generic manner, reducing the burden on
   device driver which only need to obtain the zone size and check that
   this size is a power of 2 number of LBAs. Any new type of zoned
   block device will benefit from this.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

* for-5.5/drivers-post:
  scsi: sd_zbc: add zone open, close, and finish support
  scsi: core: Handle drivers which set sg_tablesize to zero
  scsi: qla2xxx: fix NPIV tear down process
  scsi: sd_zbc: Fix sd_zbc_complete()
  scsi: qla2xxx: stop timer in shutdown path
  scsi: sd: define variable dif as unsigned int instead of bool
  scsi: target: cxgbit: Fix cxgbit_fw4_ack()
  scsi: qla2xxx: Fix partial flash write of MBI
  scsi: qla2xxx: Initialized mailbox to prevent driver load failure
  scsi: lpfc: Honor module parameter lpfc_use_adisc
  scsi: ufs-bsg: Wake the device before sending raw upiu commands
  scsi: lpfc: Check queue pointer before use
  scsi: qla2xxx: fixup incorrect usage of host_byte

* for-5.5/drivers: (38 commits)
  null_blk: add zone open, close, and finish support
  dm: add zone open, close and finish support
  nvme: Fix parsing of ANA log page
  nvmet: stop using bio_set_op_attrs
  nvmet: add plugging for read/write when ns is bdev
  nvmet: clean up command parsing a bit
  nvme-pci: Spelling s/resdicovered/rediscovered/
  nvmet: fill discovery controller sn, fr and mn correctly
  nvmet: Open code nvmet_req_execute()
  nvmet: Remove the data_len field from the nvmet_req struct
  nvmet: Introduce nvmet_dsm_len() helper
  nvmet: Cleanup discovery execute handlers
  nvmet: Introduce common execute function for get_log_page and identify
  nvmet-tcp: Don't set the request's data_len
  nvmet-tcp: Don't check data_len in nvmet_tcp_map_data()
  nvme: Introduce nvme_lba_to_sect()
  nvme: Cleanup and rename nvme_block_nr()
  nvme: resync include/linux/nvme.h with nvmecli
  nvme: move common call to nvme_cleanup_cmd to core layer
  nvme: introduce "Command Aborted By host" status code
  ...

64K PAGE_SIZE is popular on ARM64 or other ARCHs, and 64K has been big
enough to break some devices probably, so change the logic to split bio
if the only bvec's length is > SZ_4K instead of PAGE_SIZE.

Fixes: fa532287 (block: avoid blk_bio_segment_split for small I/O operations)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Some device may set segment boundary as PAGE_SIZE - 1. If the bvec
crosses pages, and meantime its length is <= PAGE_SIZE, we still need
to split the bvec into 2 segments.

Fixes this issue by still splitting bio if the single bvec crosses
pages.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: fa532287 (block: avoid blk_bio_segment_split for small I/O operations)
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blkg_rwstat is now only used by bfq-iosched and blk-throtl when on
cgroup1.  Let's move it into its own files and gate it behind a config
option.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-cgroup has been using blkg_rwstat to track basic IO stats.
Unfortunately, reading recursive stats scales badly as itinvolves
walking all descendants.  On systems with a huge number of cgroups
(dead or alive), this can lead to substantial CPU cost when reading IO
stats.

This patch reimplements basic IO stats using cgroup rstat which uses
more memory but makes recursive stat reading O(# descendants which
have been active since last reading) instead of O(# descendants).

* blk-cgroup core no longer uses sync/async stats.  Introduce new stat
  enums - BLKG_IOSTAT_{READ|WRITE|DISCARD}.

* Add blkg_iostat[_set] which encapsulates byte and io stats, last
  values for propagation delta calculation and u64_stats_sync for
  correctness on 32bit archs.

* Update the new percpu stat counters directly and implement
  blkcg_rstat_flush() to implement propagation.

* blkg_print_stat() can now bring the stats up to date by calling
  cgroup_rstat_flush() and print them instead of directly summing up
  all descendants.

* It now allocates 96 bytes per cpu.  It used to be 40 bytes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Dan Schatzberg <dschatzberg@fb.com>
Cc: Daniel Xu <dlxu@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

These don't have users anymore.  Remove them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When used on cgroup1, blk-throtl uses the blkg->stat_bytes and
->stat_ios from blk-cgroup core to populate four stat knobs.
blk-cgroup core is moving away from blkg_rwstat to improve scalability
and won't be able to support this usage.

It isn't like the sharing gains all that much.  Let's break them out
to dedicated rwstat counters which are updated when on cgroup1.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

When used on cgroup1, bfq uses the blkg->stat_bytes and ->stat_ios
from blk-cgroup core to populate six stat knobs.  blk-cgroup core is
moving away from blkg_rwstat to improve scalability and won't be able
to support this usage.

It isn't like the sharing gains all that much.  Let's break it out to
dedicated rwstat counters which are updated when on cgroup1.  This
makes use of bfqg_*rwstat*() helpers outside of
CONFIG_BFQ_CGROUP_DEBUG.  Move them out.

v2: Compile fix when !CONFIG_BFQ_CGROUP_DEBUG.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Collect them right under #ifdef CONFIG_BFQ_CGROUP_DEBUG.  The next
patch will use them from !DEBUG path and this makes it easy to move
them out of the ifdef block.

This is pure code reorganization.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull on for-linus to resolve what otherwise would have been a conflict
with the cgroups rstat patchset from Tejun.

* for-linus: (942 commits)
  blkcg: make blkcg_print_stat() print stats only for online blkgs
  nvme: change nvme_passthru_cmd64 to explicitly mark rsvd
  nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths
  nvme-rdma: fix a segmentation fault during module unload
  iocost: don't nest spin_lock_irq in ioc_weight_write()
  io_uring: ensure we clear io_kiocb->result before each issue
  um-ubd: Entrust re-queue to the upper layers
  nvme-multipath: remove unused groups_only mode in ana log
  nvme-multipath: fix possible io hang after ctrl reconnect
  io_uring: don't touch ctx in setup after ring fd install
  io_uring: Fix leaked shadow_req
  Linux 5.4-rc5
  riscv: cleanup do_trap_break
  nbd: verify socket is supported during setup
  ata: libahci_platform: Fix regulator_get_optional() misuse
  nbd: handle racing with error'ed out commands
  nbd: protect cmd->status with cmd->lock
  io_uring: fix bad inflight accounting for SETUP_IOPOLL|SETUP_SQTHREAD
  io_uring: used cached copies of sq->dropped and cq->overflow
  ARM: dts: stm32: relax qspi pins slew-rate for stm32mp157
  ...

Implement REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH
support to allow explicit control of zone states.

Contains contributions from Matias Bjorling, Hans Holmberg,
Keith Busch and Damien Le Moal.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi into for-5.5/drivers-post

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi:
  scsi: core: Handle drivers which set sg_tablesize to zero
  scsi: qla2xxx: fix NPIV tear down process
  scsi: sd_zbc: Fix sd_zbc_complete()

Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi into for-5.5/drivers-post

SCSI fixes on 20191101

Nine changes, eight in drivers [ufs, target, lpfc x 2, qla2xxx x 4]
and one core change in sd that fixes an I/O failure on DIF type 3
devices.
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (23 commits)
  scsi: qla2xxx: stop timer in shutdown path
  scsi: sd: define variable dif as unsigned int instead of bool
  scsi: target: cxgbit: Fix cxgbit_fw4_ack()
  scsi: qla2xxx: Fix partial flash write of MBI
  scsi: qla2xxx: Initialized mailbox to prevent driver load failure
  scsi: lpfc: Honor module parameter lpfc_use_adisc
  scsi: ufs-bsg: Wake the device before sending raw upiu commands
  scsi: lpfc: Check queue pointer before use
  scsi: qla2xxx: fixup incorrect usage of host_byte
  scsi: lpfc: remove left-over BUILD_NVME defines
  scsi: core: try to get module before removing device
  scsi: hpsa: add missing hunks in reset-patch
  scsi: target: core: Do not overwrite CDB byte 1
  scsi: ch: Make it possible to open a ch device multiple times again
  scsi: fix kconfig dependency warning related to 53C700_LE_ON_BE
  scsi: sni_53c710: fix compilation error
  scsi: scsi_dh_alua: handle RTPG sense code correctly during state transitions
  scsi: qla2xxx: fix a potential NULL pointer dereference
  scsi: MAINTAINERS: Update qla2xxx driver
  scsi: zfcp: fix reaction on bit error threshold notification
  ...

Implement REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH
support to allow explicit control of zone states.

Contains contributions from Matias Bjorling, Hans Holmberg,
Keith Busch and Damien Le Moal.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Implement REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH
support to allow explicit control of zone states.

Contains contributions from Matias Bjorling, Hans Holmberg and
Damien Le Moal.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull in dependencies for the new zoned open/close/finish support.

* for-5.5/block: (32 commits)
  block: add zone open, close and finish ioctl support
  block: add zone open, close and finish operations
  block: Simplify REQ_OP_ZONE_RESET_ALL handling
  block: Remove REQ_OP_ZONE_RESET plugging
  block: Warn if elevator= parameter is used
  block: avoid blk_bio_segment_split for small I/O operations
  blk-mq: make sure that line break can be printed
  block: sed-opal: Introduce Opal Datastore UID
  block: sed-opal: Add support to read/write opal tables generically
  block: sed-opal: Generalizing write data to any opal table
  bdev: Refresh bdev size for disks without partitioning
  bdev: Factor out bdev revalidation into a common helper
  blk-mq: avoid sysfs buffer overflow with too many CPU cores
  blk-mq: Make blk_mq_run_hw_queue() return void
  fcntl: fix typo in RWH_WRITE_LIFE_NOT_SET r/w hint name
  blk-mq: fill header with kernel-doc
  blk-mq: remove needless goto from blk_mq_get_driver_tag
  block: reorder bio::__bi_remaining for better packing
  block: Reduce the amount of memory used for tag sets
  block: Reduce the amount of memory required per request queue
  ...

Introduce three new ioctl commands BLKOPENZONE, BLKCLOSEZONE and
BLKFINISHZONE to allow applications to control the condition of zones
on a zoned block device through the execution of the REQ_OP_ZONE_OPEN,
REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH operations.

Contains contributions from Matias Bjorling, Hans Holmberg,
Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig.
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Zoned block devices (ZBC and ZAC devices) allow an explicit control
over the condition (state) of zones. The operations allowed are:
* Open a zone: Transition to open condition to indicate that a zone will
  actively be written
* Close a zone: Transition to closed condition to release the drive
  resources used for writing to a zone
* Finish a zone: Transition an open or closed zone to the full
  condition to prevent write operations

To enable this control for in-kernel zoned block device users, define
the new request operations REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE
and REQ_OP_ZONE_FINISH as well as the generic function
blkdev_zone_mgmt() for submitting these operations on a range of zones.
This results in blkdev_reset_zones() removal and replacement with this
new zone magement function. Users of blkdev_reset_zones() (f2fs and
dm-zoned) are updated accordingly.

Contains contributions from Matias Bjorling, Hans Holmberg,
Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig.
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There is no need for the function __blkdev_reset_all_zones() as
REQ_OP_ZONE_RESET_ALL can be handled directly in blkdev_reset_zones()
bio loop with an early break from the loop. This patch removes this
function and modifies blkdev_reset_zones(), simplifying the code.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

REQ_OP_ZONE_RESET operations cannot be merged as these bios and requests
do not have a size and are never sequential due to the zone start sector
position required for their execution. As a result, there is no point in
using a plug around blkdev_reset_zones() bio issuing loop. This patch
removes this unnecessary plugging.
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blkcg_print_stat() iterates blkgs under RCU and doesn't test whether
the blkg is online.  This can call into pd_stat_fn() on a pd which is
still being initialized leading to an oops.

The heaviest operation - recursively summing up rwstat counters - is
already done while holding the queue_lock.  Expand queue_lock to cover
the other operations and skip the blkg if it isn't online yet.  The
online state is protected by both blkcg and queue locks, so this
guarantees that only online blkgs are processed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Roman Gushchin <guro@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Fixes: 903d23f0 ("blk-cgroup: allow controllers to output their own stats")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Jens Axboe <axboe@kernel.dk>

With transition to blk-mq, the elevator= kernel argument was removed as
it makes less and less sense with the current variety of devices.  Since
this may surprise some users and there are advices on the Internet that
still suggest to use it, let's at least warn if the parameter is used.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

In scsi_mq_setup_tags(), cmd_size is calculated based on zero size for the
scatter-gather list in case the low level driver uses SG_NONE in its host
template.

cmd_size is passed on to the block layer for calculation of the request
size, and we've seen NULL pointer dereference errors from the block layer
in drivers where SG_NONE is used and a mq IO scheduler is active,
apparently as a consequence of this (see commit 68ab2d76 ("scsi:
cxlflash: Set sg_tablesize to 1 instead of SG_NONE"), and a recent patch by
Finn Thain converting the three m68k NFR5380 drivers to avoid setting
SG_NONE).

Try to avoid these errors by accounting for at least one sg list entry when
calculating cmd_size, regardless of whether the low level driver set a zero
sg_tablesize.

Tested on 030 m68k with the atari_scsi driver - setting sg_tablesize to
SG_NONE no longer results in a crash when loading this driver.

CC: Finn Thain <fthain@telegraphics.com.au>
Link: https://lore.kernel.org/r/1572922150-4358-1-git-send-email-schmitzmic@gmail.comSigned-off-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fix two issues with commit f5187b7d ("scsi: qla2xxx: Optimize NPIV
tear down process"): a missing negation in a wait_event_timeout()
condition, and a missing loop end condition.

Fixes: f5187b7d ("scsi: qla2xxx: Optimize NPIV tear down process")
Link: https://lore.kernel.org/r/20191105145550.10268-1-martin.wilck@suse.comSigned-off-by: Martin Wilck <mwilck@suse.com>
Acked-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The ILLEGAL REQUEST/INVALID FIELD IN CDB error generated by an attempt to
reset a conventional zone does not apply to the reset write pointer command
with the ALL bit set, that is, to REQ_OP_ZONE_RESET_ALL requests. Fix
sd_zbc_complete() to be quiet only in the case of REQ_OP_ZONE_RESET,
excluding REQ_OP_ZONE_RESET_ALL.

Since REQ_OP_ZONE_RESET is the only request handled by sd_zbc_complete(),
also simplify the code using a simple if statement.

[mkp: applied by hand]

Fixes: d81e9d49 ("scsi: implement REQ_OP_ZONE_RESET_ALL")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191027140549.26272-4-damien.lemoal@wdc.comSigned-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull NVMe fixes from Keith:

"We have a few late nvme fixes for a couple device removal kernel
 crashes, and a compat fix for a new ioctl introduced during this merge
 window."

* 'nvme-5.4-rc7' of git://git.infradead.org/nvme:
  nvme: change nvme_passthru_cmd64 to explicitly mark rsvd
  nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths
  nvme-rdma: fix a segmentation fault during module unload

Changing nvme_passthru_cmd64 to add a field: rsvd2. This field is an explicit
marker for the padding space added on certain platforms as a result of the
enlargement of the result field from 32 bit to 64 bits in size, and
fixes differences in struct size when using compat ioctl for 32-bit
binaries on 64-bit architecture.

Fixes: 65e68edc ("nvme: allow 64-bit results in passthru commands")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Charles Machalow <csm10495@gmail.com>
[changelog]
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvme_mpath_clear_ctrl_paths() iterates through
the ctrl->namespaces list while holding ctrl->scan_lock.
This does not seem to be the correct way of protecting
from concurrent list modification.

Specifically, nvme_scan_work() sorts ctrl->namespaces
AFTER unlocking scan_lock.

This may result in the following (rare) crash in ctrl disconnect
during scan_work:

    BUG: kernel NULL pointer dereference, address: 0000000000000050
    Oops: 0000 [#1] SMP PTI
    CPU: 0 PID: 3995 Comm: nvme 5.3.5-050305-generic
    RIP: 0010:nvme_mpath_clear_current_path+0xe/0x90 [nvme_core]
    ...
    Call Trace:
     nvme_mpath_clear_ctrl_paths+0x3c/0x70 [nvme_core]
     nvme_remove_namespaces+0x35/0xe0 [nvme_core]
     nvme_do_delete_ctrl+0x47/0x90 [nvme_core]
     nvme_sysfs_delete+0x49/0x60 [nvme_core]
     dev_attr_store+0x17/0x30
     sysfs_kf_write+0x3e/0x50
     kernfs_fop_write+0x11e/0x1a0
     __vfs_write+0x1b/0x40
     vfs_write+0xb9/0x1a0
     ksys_write+0x67/0xe0
     __x64_sys_write+0x1a/0x20
     do_syscall_64+0x5a/0x130
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
    RIP: 0033:0x7f8d02bfb154

Fix:
After taking scan_lock in nvme_mpath_clear_ctrl_paths()
down_read(&ctrl->namespaces_rwsem) as well to make list traversal safe.
This will not cause deadlocks because taking scan_lock never happens
while holding the namespaces_rwsem.
Moreover, scan work downs namespaces_rwsem in the same order.

Alternative: sort ctrl->namespaces in nvme_scan_work()
while still holding the scan_lock.
This would leave nvme_mpath_clear_ctrl_paths() without correct protection
against ctrl->namespaces modification by anyone other than scan_work.
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

In case there are controllers that are not associated with any RDMA
device (e.g. during unsuccessful reconnection) and the user will unload
the module, these controllers will not be freed and will access already
freed memory. The same logic appears in other fabric drivers as well.

Fixes: 87fd1253 ("nvme-rdma: remove redundant reference between ib_device and tagset")
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>