to #28991349

commit ed76e329d74a4b15ac0f5fd3adbd52ec0178a134 upstream

This is in preparation for allowing multiple sets of maps per
queue, if so desired.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

commit 9393c8de628cf0968d81a17cc11841e42191e041 upstream.

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: NMichael Schmitz <schmitzmic@gmail.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit b7e9e1fb7a9227be34ad4a5e778022c3164494cf ]

Implement .cleanup_rq() callback for freeing driver private part
of the request. Then we can avoid to leak this part if the request isn't
completed by SCSI, and freed by blk-mq or upper layer(such as dm-rq) finally.

Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: <stable@vger.kernel.org>
Fixes: 396eaf21 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 17605afaae825b0291f80c62a7f6565879edaa8a upstream.

Since scsi_device_quiesce() skips SCSI devices that have another state than
RUNNING, OFFLINE or TRANSPORT_OFFLINE, scsi_device_resume() should not
complain about SCSI devices that have been skipped. Hence this patch.  This
patch avoids that the following warning appears during resume:

WARNING: CPU: 3 PID: 1039 at blk_clear_pm_only+0x2a/0x30
CPU: 3 PID: 1039 Comm: kworker/u8:49 Not tainted 5.0.0+ #1
Hardware name: LENOVO 4180F42/4180F42, BIOS 83ET75WW (1.45 ) 05/10/2013
Workqueue: events_unbound async_run_entry_fn
RIP: 0010:blk_clear_pm_only+0x2a/0x30
Call Trace:
 ? scsi_device_resume+0x28/0x50
 ? scsi_dev_type_resume+0x2b/0x80
 ? async_run_entry_fn+0x2c/0xd0
 ? process_one_work+0x1f0/0x3f0
 ? worker_thread+0x28/0x3c0
 ? process_one_work+0x3f0/0x3f0
 ? kthread+0x10c/0x130
 ? __kthread_create_on_node+0x150/0x150
 ? ret_from_fork+0x1f/0x30

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Martin Steigerwald <martin@lichtvoll.de>
Cc: <stable@vger.kernel.org>
Reported-by: NJisheng Zhang <Jisheng.Zhang@synaptics.com>
Tested-by: NJisheng Zhang <Jisheng.Zhang@synaptics.com>
Fixes: 3a0a5299 ("block, scsi: Make SCSI quiesce and resume work reliably") # v4.15
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit cd84a62e0078dce09f4ed349bec84f86c9d54b30 upstream.

The RQF_PREEMPT flag is used for three purposes:
- In the SCSI core, for making sure that power management requests
  are executed even if a device is in the "quiesced" state.
- For domain validation by SCSI drivers that use the parallel port.
- In the IDE driver, for IDE preempt requests.
Rename "preempt-only" into "pm-only" because the primary purpose of
this mode is power management. Since the power management core may
but does not have to resume a runtime suspended device before
performing system-wide suspend and since a later patch will set
"pm-only" mode as long as a block device is runtime suspended, make
it possible to set "pm-only" mode from more than one context. Since
with this change scsi_device_quiesce() is no longer idempotent, make
that function return early if it is called for a quiesced queue.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f9b0530fa02e0c73f31a49ef743e8f44eb8e32cc upstream.

When scsi_init_sense_cache(host) is called concurrently from different
hosts, each code path may find that no cache has been created and
allocate a new one. The lack of locking can lead to potentially
overriding a cache allocated by a different host.

Fix the issue by moving 'mutex_lock(&scsi_sense_cache_mutex)' before
scsi_select_sense_cache().

Fixes: 0a6ac4ee ("scsi: respect unchecked_isa_dma for blk-mq")
Cc: Stable <stable@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit be549d49115422f846b6d96ee8fd7173a5f7ceb0 upstream.

When SCSI blk-mq is enabled, there is a bug in handling errors in
scsi_queue_rq.  Specifically, the bug is not setting result field of
scsi_request correctly when the dispatch of the command has been
failed. Since the upper layer code including the sg_io ioctl expects to
receive any error status from result field of scsi_request, the error is
silently ignored and this could cause data corruptions for some
applications.

Fixes: d285203c ("scsi: add support for a blk-mq based I/O path.")
Cc: <stable@vger.kernel.org>
Signed-off-by: NJaesoo Lee <jalee@purestorage.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 388b4e6a00bb3097278ed1648ac5a1cb48c894e6 ]

scsi_device_quiesce() and scsi_device_resume() are called during
system-wide suspend and resume. scsi_device_quiesce() only succeeds for
SCSI devices that are in one of the RUNNING, OFFLINE or TRANSPORT_OFFLINE
states (see also scsi_set_device_state()).  This patch avoids that the
following warning is triggered when resuming a system for which quiescing a
SCSI device failed:

WARNING: CPU: 2 PID: 11303 at drivers/scsi/scsi_lib.c:2600 scsi_device_resume+0x4f/0x58
CPU: 2 PID: 11303 Comm: kworker/u8:70 Not tainted 5.0.0-rc1+ #50
Hardware name: LENOVO 80E3/Lancer 5B2, BIOS A2CN45WW(V2.13) 08/04/2016
Workqueue: events_unbound async_run_entry_fn
Call Trace:
 scsi_dev_type_resume+0x2e/0x60
 async_run_entry_fn+0x32/0xd8
 process_one_work+0x1f4/0x420
 worker_thread+0x28/0x3c0
 kthread+0x118/0x130
 ret_from_fork+0x22/0x40

Cc: Przemek Socha <soprwa@gmail.com>
Reported-by: NPrzemek Socha <soprwa@gmail.com>
Fixes: 3a0a5299 ("block, scsi: Make SCSI quiesce and resume work reliably") # v4.15
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 4a067cf823d9d8e50d41cfb618011c0d4a969c72 upstream.

Up to 4.12, __scsi_error_from_host_byte() would reset the host byte to
DID_OK for various cases including DID_NEXUS_FAILURE.  Commit
2a842aca ("block: introduce new block status code type") replaced this
function with scsi_result_to_blk_status() and removed the host-byte
resetting code for the DID_NEXUS_FAILURE case.  As the line
set_host_byte(cmd, DID_OK) was preserved for the other cases, I suppose
this was an editing mistake.

The fact that the host byte remains set after 4.13 is causing problems with
the sg_persist tool, which now returns success rather then exit status 24
when a RESERVATION CONFLICT error is encountered.

Fixes: 2a842aca "block: introduce new block status code type"
Signed-off-by: NMartin Wilck <mwilck@suse.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 8dc765d438f1e42b3e8227b3b09fad7d73f4ec9a upstream.

c2856ae2 ("blk-mq: quiesce queue before freeing queue") has
already fixed this race, however the implied synchronize_rcu()
in blk_mq_quiesce_queue() can slow down LUN probe a lot, so caused
performance regression.

Then 1311326c ("blk-mq: avoid to synchronize rcu inside blk_cleanup_queue()")
tried to quiesce queue for avoiding unnecessary synchronize_rcu()
only when queue initialization is done, because it is usual to see
lots of inexistent LUNs which need to be probed.

However, turns out it isn't safe to quiesce queue only when queue
initialization is done. Because when one SCSI command is completed,
the user of sending command can be waken up immediately, then the
scsi device may be removed, meantime the run queue in scsi_end_request()
is still in-progress, so kernel panic can be caused.

In Red Hat QE lab, there are several reports about this kind of kernel
panic triggered during kernel booting.

This patch tries to address the issue by grabing one queue usage
counter during freeing one request and the following run queue.

Fixes: 1311326c ("blk-mq: avoid to synchronize rcu inside blk_cleanup_queue()")
Cc: Andrew Jones <drjones@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: linux-scsi@vger.kernel.org
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Cc: stable <stable@vger.kernel.org>
Cc: jianchao.wang <jianchao.w.wang@oracle.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 32872863.

There is fundamental issue in commit 32872863 (scsi: core: avoid
host-wide host_busy counter for scsi_mq) because SCSI's host busy counter
may not be same with counter of blk-mq's inflight tags, especially in case
of none io scheduler.

We may switch to other approach for addressing this scsi_mq's performance
issue, such as percpu counter or kind of ways, so revert this commit first
for fixing this kind of issue in EH path, as reported by Jens.

Cc: Omar Sandoval <osandov@fb.com>,
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Cc: James Bottomley <james.bottomley@hansenpartnership.com>,
Cc: Christoph Hellwig <hch@lst.de>,
Cc: Don Brace <don.brace@microsemi.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reported-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This reverts commit 265d59aa.

There is fundamental issue in commit 32872863 (scsi: core: avoid
host-wide host_busy counter for scsi_mq) because SCSI's host busy counter
may not be same with counter of blk-mq's inflight tags, especially in case
of none io scheduler.

So revert this commit first.

Cc: Omar Sandoval <osandov@fb.com>,
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Cc: James Bottomley <james.bottomley@hansenpartnership.com>,
Cc: Christoph Hellwig <hch@lst.de>,
Cc: Don Brace <don.brace@microsemi.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jens Axboe <axboe@kernel.dk>
Reported-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

We don't use blk-mq start/stop hw queue any more, so no reason to use
blk_mq_start_hw_queues which does clear_bit, replace it with
blk_mq_run_hw_queues.
Signed-off-by: NJianchao Wang <jianchao.w.wang@oracle.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

To avoid introducing problems like those fixed in commit f7068114
("sr: pass down correctly sized SCSI sense buffer"), this creates a macro
wrapper for scsi_execute() that verifies the size of the sense buffer
similar to what was done for command string sizes in commit 3756f640
("exec: avoid gcc-8 warning for get_task_comm").

Another solution could be to add a length argument to scsi_execute(),
but this function already takes a lot of arguments and Jens was not fond
of that approach.

Additionally, this moves the SCSI_SENSE_BUFFERSIZE definition into
scsi_device.h, and removes a redundant include for scsi_device.h from
scsi_cmnd.h.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

32872863 ("scsi: avoid to hold host-wide counter of host_busy for
scsi_mq") adds one extra check on scsi_host_busy(shost) in
scsi_host_queue_ready(), which is wrong and not necessary, can causes
booting stall on LSI53c895A.

So remove the check.

Cc: Omar Sandoval <osandov@fb.com>,
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Cc: James Bottomley <james.bottomley@hansenpartnership.com>,
Cc: Christoph Hellwig <hch@lst.de>,
Cc: Don Brace <don.brace@microsemi.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Fixes: 32872863 ("scsi: avoid to hold host-wide counter of host_busy for scsi_mq")
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

It isn't necessary to check the host depth in scsi_queue_rq() any more
since it has been respected by blk-mq before calling scsi_queue_rq() via
getting driver tag.

Lots of LUNs may attach to same host and per-host IOPS may reach millions,
so we should avoid expensive atomic operations on the host-wide counter in
the IO path.

This patch implements scsi_host_busy() via blk_mq_tagset_busy_iter() for
reading the count of busy IOs for scsi_mq.

It is observed that IOPS is increased by 15% in IO test on scsi_debug (32
LUNs, 32 submit queues, 1024 can_queue, libaio/dio) in a dual-socket
system.

[mkp: clarified commit message]

Cc: Omar Sandoval <osandov@fb.com>,
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Cc: James Bottomley <james.bottomley@hansenpartnership.com>,
Cc: Christoph Hellwig <hch@lst.de>,
Cc: Don Brace <don.brace@microsemi.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When evaluating a SCSI command's result using the field access macros,
check for equality of the fields and not if a specific bit is set.

This is a preparation patch, for reworking the results field in the
SCSI command.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The scsi_io_completion function contains three BUG() and BUG_ON() calls.
Replace them with WARN variants.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add likely() and unlikely() hints to conditionals on or near the fastpath.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Since the action "reprep" is called from two places, rather than repeat the
code, make a new scsi_io_completion helper with "reprep" as its suffix.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Place scsi_io_completion()'s complex error processing associated with a
local enumeration into a static helper function. That enumeration's values
start with "ACTION_" so use the suffix "_action" in the helper function's
name.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Break out several intertwined paths when cmd->result is non zero and place
them in the scsi_io_completion_nz_result helper function. The logic is not
changed.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Change and add some variable names, adjust some associated comments for
clarity. Correct some misleading comments.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

scsi_end_request() is called multiple times from scsi_io_completion() which
branches on its bool returned value. Add comment before the static
definition of scsi_end_request() about the meaning of that return.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Commit 505aa4b6 ("scsi: sd: Defer spinning up drive while SANITIZE is
in progress") may not be sufficient, especially if the SCSI SANITIZE
command is sent via the bsg or sg pass-throughs, since they don't use the
sd driver.

Add "Sanitize in progress" plus some other recent "... in progress"
additional sense codes into the scsi mid-level so they are treated in a
similar fashion to "Format in progress".

[mkp: checkpatch]
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Same numerical value (for now at least), but a much better documentation
of intent.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Switch everyone to blk_get_request_flags, and then rename
blk_get_request_flags to blk_get_request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We can rely on the dma-mapping code to handle any DMA limits that is
bigger than the ISA DMA mask for us (either using an iommu or swiotlb),
so remove setting the block layer bounce limit for anything but the
unchecked_isa_dma case, or the bouncing for highmem pages.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJens Axboe <axboe@kernel.dk>

Ensure that CONDITION MET and other non-zero status values that indicate
success are translated into BLK_STS_OK.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Lee Duncan <lduncan@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Since the next patch will modify this function such that it checks more than
just the host byte of the SCSI result, rename __scsi_error_from_host_byte()
into scsi_result_to_blk_status().  This patch does not change any
functionality.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Lee Duncan <lduncan@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The description of commit e39a9735 is wrong: it mentions that commit
2a842aca introduced a bug in __scsi_error_from_host_byte() although that
commit did not change the behavior of that function.  Additionally, commit
e39a9735 introduced a bug: it causes commands that fail with
hostbyte=DID_OK and driverbyte=DRIVER_SENSE to be completed with
BLK_STS_OK. Hence revert that commit.

Fixes: e39a9735 ("scsi: core: return BLK_STS_OK for DID_OK in __scsi_error_from_host_byte()")
Reported-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Lee Duncan <lduncan@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The current BSG design tries to shoe-horn the transport-specific
passthrough commands into the overall framework for SCSI passthrough
requests.  This has a couple problems:

 - each passthrough queue has to set the QUEUE_FLAG_SCSI_PASSTHROUGH flag
   despite not dealing with SCSI commands at all.  Because of that these
   queues could also incorrectly accept SCSI commands from in-kernel
   users or through the legacy SCSI_IOCTL_SEND_COMMAND ioctl.
 - the real SCSI bsg queues also incorrectly accept bsg requests of the
   BSG_SUB_PROTOCOL_SCSI_TRANSPORT type
 - the bsg transport code is almost unredable because it tries to reuse
   different SCSI concepts for its own purpose.

This patch instead adds a new bsg_ops structure to handle the two cases
differently, and thus solves all of the above problems.  Another side
effect is that the bsg-lib queues also don't need to embedd a
struct scsi_request anymore.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The SCSI PRE-FETCH (10 or 16) command is present both on hard disks
and some SSDs. It is useful when the address of the next block(s) to
be read is known but it is not following the LBA of the current READ
(so read-ahead won't help). It returns two "good" SCSI Status values.
If the requested blocks have fitted (or will most likely fit (when
the IMMED bit is set)) into the disk's cache, it returns CONDITION
MET. If it didn't (or will not) fit then it returns GOOD status.

The goal of this patch is to stop the SCSI subsystem treating the
CONDITION MET SCSI status as an error. The current state makes the
PRE-FETCH command effectively unusable via pass-throughs.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch has been generated as follows:

for verb in set_unlocked clear_unlocked set clear; do
  replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \
    $(git grep -lw queue_flag_${verb} drivers block/bsg*)
done

Except for protecting all queue flag changes with the queue lock
this patch does not change any functionality.

Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In scsi core, __scsi_queue_insert should just put request back on the
queue and retry using the same command as before. However, for blk-mq,
scsi_mq_requeue_cmd is employed here which will unprepare the
request. To align with the semantics of __scsi_queue_insert, use
blk_mq_requeue_request with kick_requeue_list == true and put the
reference of scsi_device.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NJianchao Wang <jianchao.w.wang@oracle.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When converting __scsi_error_from_host_byte() to BLK_STS error codes the
case DID_OK was forgotten, resulting in it always returning an error.

Fixes: 2a842aca ("block: introduce new block status code type")
Cc: Doug Gilbert <dgilbert@interlog.com>
Signed-off-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Avoid that the recently introduced call_rcu() call in the SCSI core
triggers a double call_rcu() call.
Reported-by: NNatanael Copa <ncopa@alpinelinux.org>
Reported-by: NDamien Le Moal <damien.lemoal@wdc.com>
References: https://bugzilla.kernel.org/show_bug.cgi?id=198861
Fixes: 3bd6f43f ("scsi: core: Ensure that the SCSI error handler gets woken up")
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>
Tested-by: NDamien Le Moal <damien.lemoal@wdc.com>
Cc: Natanael Copa <ncopa@alpinelinux.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Alexandre Oliva <oliva@gnu.org>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch does not change any functionality.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Make scsi_test_unit_ready() send at most as many TURs as specified in
the 'retries' argument instead of retries * (retries + 1) / 2.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This status is returned from driver to block layer if device related
resource is unavailable, but driver can guarantee that IO dispatch
will be triggered in future when the resource is available.

Convert some drivers to return BLK_STS_DEV_RESOURCE.  Also, if driver
returns BLK_STS_RESOURCE and SCHED_RESTART is set, rerun queue after
a delay (BLK_MQ_DELAY_QUEUE) to avoid IO stalls.  BLK_MQ_DELAY_QUEUE is
3 ms because both scsi-mq and nvmefc are using that magic value.

If a driver can make sure there is in-flight IO, it is safe to return
BLK_STS_DEV_RESOURCE because:

1) If all in-flight IOs complete before examining SCHED_RESTART in
blk_mq_dispatch_rq_list(), SCHED_RESTART must be cleared, so queue
is run immediately in this case by blk_mq_dispatch_rq_list();

2) if there is any in-flight IO after/when examining SCHED_RESTART
in blk_mq_dispatch_rq_list():
- if SCHED_RESTART isn't set, queue is run immediately as handled in 1)
- otherwise, this request will be dispatched after any in-flight IO is
  completed via blk_mq_sched_restart()

3) if SCHED_RESTART is set concurently in context because of
BLK_STS_RESOURCE, blk_mq_delay_run_hw_queue() will cover the above two
cases and make sure IO hang can be avoided.

One invariant is that queue will be rerun if SCHED_RESTART is set.
Suggested-by: NJens Axboe <axboe@kernel.dk>
Tested-by: NLaurence Oberman <loberman@redhat.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>