Make sure to call sd_zbc_init_disk() when the sdkp->zoned field is known,
that is, once sd_read_block_characteristics() is executed in
sd_revalidate_disk(), so that host-aware disks also get initialized.  To do
so, move sd_zbc_init_disk() call in sd_zbc_revalidate_zones() and make sure
to execute it for all zoned disks, including for host-aware disks used as
regular disks as these disk zoned model may be changed back to BLK_ZONED_HA
when partitions are deleted.

Link: https://lore.kernel.org/r/20200915073347.832424-3-damien.lemoal@wdc.com
Fixes: 5795eb443060 ("scsi: sd_zbc: emulate ZONE_APPEND commands")
Cc: <stable@vger.kernel.org> # v5.8+
Reported-by: Borislav Petkov <bp@alien8.de>
Tested-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

When CONFIG_BLK_DEV_ZONED is disabled, allow using host-aware ZBC disks as
regular disks. In this case, ensure that command completion is correctly
executed by changing sd_zbc_complete() to return good_bytes instead of 0
and causing a hang during device probe (endless retries).

When CONFIG_BLK_DEV_ZONED is enabled and a host-aware disk is detected to
have partitions, it will be used as a regular disk. In this case, make sure
to not do anything in sd_zbc_revalidate_zones() as that triggers warnings.

Since all these different cases result in subtle settings of the disk queue
zoned model, introduce the block layer helper function
blk_queue_set_zoned() to generically implement setting up the effective
zoned model according to the disk type, the presence of partitions on the
disk and CONFIG_BLK_DEV_ZONED configuration.

Link: https://lore.kernel.org/r/20200915073347.832424-2-damien.lemoal@wdc.com
Fixes: b72053072c0b ("block: allow partitions on host aware zone devices")
Cc: <stable@vger.kernel.org>
Reported-by: Borislav Petkov <bp@alien8.de>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently, for zoned disks, since blk_revalidate_disk_zones() requires the
disk capacity to be set already to operate correctly, zones revalidation
can only be done on the second revalidate scan once the gendisk capacity is
set at the end of the first scan. As a result, if zone revalidation fails,
there is no second chance to recover from the failure and the disk capacity
is changed to 0, with the disk left unusable.

This can be improved by shuffling around code, specifically, by moving the
call to sd_zbc_revalidate_zones() from sd_zbc_read_zones() to the end of
sd_revalidate_disk(), after set_capacity_revalidate_and_notify() is called
to set the gendisk capacity. With this change, if sd_zbc_revalidate_zones()
fails on the first scan, the second scan will call it again to recover, if
possible.

Using the new struct scsi_disk fields rev_nr_zones and rev_zone_blocks,
sd_zbc_revalidate_zones() does actual work only if it detects a change with
the disk zone configuration. This means that for a successful zones
revalidation on the first scan, the second scan will not cause another
heavy full check.

While at it, remove the unecesary "extern" declaration of
sd_zbc_read_zones().

Link: https://lore.kernel.org/r/20200731054928.668547-1-damien.lemoal@wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fix the kdoc comment of the function sd_ioctl_common() to avoid a compiler
warning when compiling with W=1.

No functional changes.

Link: https://lore.kernel.org/r/20200706123354.452047-1-damien.lemoal@wdc.com
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull SCSI updates from James Bottomley:
 :This series consists of the usual driver updates (qla2xxx, ufs, zfcp,
  target, scsi_debug, lpfc, qedi, qedf, hisi_sas, mpt3sas) plus a host
  of other minor updates.

  There are no major core changes in this series apart from a
  refactoring in scsi_lib.c"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (207 commits)
  scsi: ufs: ti-j721e-ufs: Fix unwinding of pm_runtime changes
  scsi: cxgb3i: Fix some leaks in init_act_open()
  scsi: ibmvscsi: Make some functions static
  scsi: iscsi: Fix deadlock on recovery path during GFP_IO reclaim
  scsi: ufs: Fix WriteBooster flush during runtime suspend
  scsi: ufs: Fix index of attributes query for WriteBooster feature
  scsi: ufs: Allow WriteBooster on UFS 2.2 devices
  scsi: ufs: Remove unnecessary memset for dev_info
  scsi: ufs-qcom: Fix scheduling while atomic issue
  scsi: mpt3sas: Fix reply queue count in non RDPQ mode
  scsi: lpfc: Fix lpfc_nodelist leak when processing unsolicited event
  scsi: target: tcmu: Fix a use after free in tcmu_check_expired_queue_cmd()
  scsi: vhost: Notify TCM about the maximum sg entries supported per command
  scsi: qla2xxx: Remove return value from qla_nvme_ls()
  scsi: qla2xxx: Remove an unused function
  scsi: iscsi: Register sysfs for iscsi workqueue
  scsi: scsi_debug: Parser tables and code interaction
  scsi: core: Refactor scsi_mq_setup_tags function
  scsi: core: Fix incorrect usage of shost_for_each_device
  scsi: qla2xxx: Fix endianness annotations in source files
  ...

Export through sysfs as a scsi_disk attribute the zoned capabilities of a
disk ("zoned_cap" attribute file). This new attribute indicates in human
readable form (i.e. a string) the zoned block capabilities implemented by
the disk as found in the ZONED field of the disk block device
characteristics VPD page. The possible values are:

 - "none": ZONED=00b (not reported), regular disk

 - "host-aware": ZONED=01b, host-aware ZBC disk

 - "drive-managed": ZONED=10b, drive-managed ZBC disk (regular disk
   interface)

For completeness, also add the following value which is detected using the
device type rather than the ZONED field:

 - "host-managed": device type = 0x14 (TYPE_ZBC), host-managed ZBC disk

This new sysfs attribute is purely informational and complementary to the
"zoned" device request queue sysfs attribute as it allows applications and
user daemons (e.g.  udev) to easily differentiate regular disks from
drive-managed SMR disks without the need for direct access tools such as
provided by sg3utils.

Link: https://lore.kernel.org/r/20200515054856.1408575-1-damien.lemoal@wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Print a message indicating that a disk is a drive-managed SMR model when
such drive is found using the ZONED field of the Block Device
Characteristics VPD page (IDENTIFY data on ATA side).

[mkp: typo]

Link: https://lore.kernel.org/r/20200514081953.1252087-1-damien.lemoal@wdc.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Emulate ZONE_APPEND for SCSI disks using a regular WRITE(16) command
with a start LBA set to the target zone write pointer position.

In order to always know the write pointer position of a sequential write
zone, the write pointer of all zones is tracked using an array of 32bits
zone write pointer offset attached to the scsi disk structure. Each
entry of the array indicate a zone write pointer position relative to
the zone start sector. The write pointer offsets are maintained in sync
with the device as follows:
1) the write pointer offset of a zone is reset to 0 when a
   REQ_OP_ZONE_RESET command completes.
2) the write pointer offset of a zone is set to the zone size when a
   REQ_OP_ZONE_FINISH command completes.
3) the write pointer offset of a zone is incremented by the number of
   512B sectors written when a write, write same or a zone append
   command completes.
4) the write pointer offset of all zones is reset to 0 when a
   REQ_OP_ZONE_RESET_ALL command completes.

Since the block layer does not write lock zones for zone append
commands, to ensure a sequential ordering of the regular write commands
used for the emulation, the target zone of a zone append command is
locked when the function sd_zbc_prepare_zone_append() is called from
sd_setup_read_write_cmnd(). If the zone write lock cannot be obtained
(e.g. a zone append is in-flight or a regular write has already locked
the zone), the zone append command dispatching is delayed by returning
BLK_STS_ZONE_RESOURCE.

To avoid the need for write locking all zones for REQ_OP_ZONE_RESET_ALL
requests, use a spinlock to protect accesses and modifications of the
zone write pointer offsets. This spinlock is initialized from sd_probe()
using the new function sd_zbc_init().

Co-developed-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull block updates from Jens Axboe:

 - Online capacity resizing (Balbir)

 - Number of hardware queue change fixes (Bart)

 - null_blk fault injection addition (Bart)

 - Cleanup of queue allocation, unifying the node/no-node API
   (Christoph)

 - Cleanup of genhd, moving code to where it makes sense (Christoph)

 - Cleanup of the partition handling code (Christoph)

 - disk stat fixes/improvements (Konstantin)

 - BFQ improvements (Paolo)

 - Various fixes and improvements

* tag 'for-5.7/block-2020-03-29' of git://git.kernel.dk/linux-block: (72 commits)
  block: return NULL in blk_alloc_queue() on error
  block: move bio_map_* to blk-map.c
  Revert "blkdev: check for valid request queue before issuing flush"
  block: simplify queue allocation
  bcache: pass the make_request methods to blk_queue_make_request
  null_blk: use blk_mq_init_queue_data
  block: add a blk_mq_init_queue_data helper
  block: move the ->devnode callback to struct block_device_operations
  block: move the part_stat* helpers from genhd.h to a new header
  block: move block layer internals out of include/linux/genhd.h
  block: move guard_bio_eod to bio.c
  block: unexport get_gendisk
  block: unexport disk_map_sector_rcu
  block: unexport disk_get_part
  block: mark part_in_flight and part_in_flight_rw static
  block: mark block_depr static
  block: factor out requeue handling from dispatch code
  block/diskstats: replace time_in_queue with sum of request times
  block/diskstats: accumulate all per-cpu counters in one pass
  block/diskstats: more accurate approximation of io_ticks for slow disks
  ...

Some USB bridge devices will return a default set of characteristics during
initialization. And then, once an attached drive has spun up, substitute
the actual parameters reported by the drive. According to the SCSI spec,
the device should return a UNIT ATTENTION in case any reported parameters
change. But in this case the change is made silently after a small window
where default values are reported.

Commit a83da8a4509d ("scsi: sd: Optimal I/O size should be a multiple of
physical block size") validated the reported optimal I/O size against the
physical block size to overcome problems with devices reporting nonsensical
transfer sizes. However, this validation did not account for the fact that
aforementioned devices will return default values during a brief window
during spin-up. The subsequent change in reported characteristics would
invalidate the checking that had previously been performed.

Unset a previously configured optimal I/O size should the sanity checking
fail on subsequent revalidate attempts.

Link: https://lore.kernel.org/r/33fb522e-4f61-1b76-914f-c9e6a3553c9b@gmail.com
Cc: Bryan Gurney <bgurney@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Bernhard Sulzer <micraft.b@gmail.com>
Tested-by: Bernhard Sulzer <micraft.b@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>