Commit Graph
1756 Commits
Author SHA1 Message Date
Linus Torvalds a84c804215 Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley"
 "No core changes. The largest driver fix is the reversion of threaded
  interrupt handlers in UFS and the next is the resume deadlock fix in
  hisi_sas which extends into libsas"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ufs: core: Initialize hba->rpmbs list in ufshcd
  scsi: mpi3mr: Fix potential deadlock in mpi3mr_fault_uevent_emit
  scsi: target: Clear cmd_cnt when initial counter enrollment fails
  scsi: zfcp: Fix memory leak during adapter release by destroying gid_pn_req
  scsi: ufs: core: Revert "Delegate the interrupt service routine to a threaded IRQ handler"
  scsi: ufs: core: Cancel RTC work in active-active suspend
  scsi: scsi_debug: Fix REPORT ZONES alloc_len underflow OOB write
  scsi: target: iblock: Fix wrong PR ops NULL check for PREEMPT/RELEASE
  scsi: ufs: dt-bindings: Add missing mcq reg for qcom,sa8255p-ufshc
  scsi: libsas: Fix HA resume deadlock and hisi_sas disk-wake race
  scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer
  scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer
2026-08-02 09:32:07 -07:00
Linus Torvalds f30ca2ce7d Merge tag 'ata-7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux
Pull ata fixes from Damien Le Moal:

 - Fix PCI resource initialization in the sata_mv driver to keep legacy
   Marvell boards functional (Rosen)

 - Fix ahci_ceva driver initialization error path (Radhey)

 - Fix libata header file to remove a kernel doc compilation warning
   (Randy)

 - Increase the timeout for the STANDBY IMMEDIATE command to avoid
   suspend failures with drives that are slow to respond to this command
   (Matt)

 - Fixes for the handling of timed out commands in the presence of
   deferred non-NCQ commands, to avoid excessive delays in executing the
   error handler (me)

 - Disable link power management for a couple of WD drives that have
   been identified as not functioning properly when power management is
   used (Niklas)

 - Fix the device iteration loop when checking for link power management
   support to correctly handle port multiplier setups (Niklas)

* tag 'ata-7.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
  ata: libata-sata: fix ata_scsi_lpm_supported() iteration
  ata: libata-core: Disable LPM on WD Green 2.5 480GB
  ata: libata-core: Disable LPM on some WD drives
  scsi: libsas: terminate deferred commands on time out
  ata: libata-scsi: schedule deferred atapi command
  ata: libata-scsi: terminate deferred commands on time out
  ata: libata-eh: Increase STANDBY IMMEDIATE timeout
  ata: libata: avoid kernel-doc warnings
  ata: ahci_ceva: fix error paths in ceva_ahci_platform_enable_resources()
  ata: sata_mv: accept 1 or 2 resources in platform probe
2026-07-31 17:05:13 -07:00
Damien Le Moal de202d2251 scsi: libsas: terminate deferred commands on time out
If a command times out while we have deferred non-NCQ commands waiting to
be issued, the SCSI EH task is not immediately woken up as the waiting
deferred commands are never issued nor completed, thus leaving the SCSI
host in a busy state (shost->host_failed != scsi_host_busy(shost)) which
prevents the SCSI EH task from being woken up. Eventually, when the
deferred commands also time out, the SCSI EH task is woken up and the
timeout processing occurs.

Avoid this unnecessary additional SCSI EH wake up time with the same
method as implemented in libata-scsi, using the eh_timed_out SCSI host
template operation. The function sas_eh_timed_out() implements this
operation and executes the function ata_scsi_retry_deferred_qc()
for SATA devices.

Co-developed-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Fixes: 0ea84089db ("ata: libata-scsi: avoid Non-NCQ command starvation")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Tested-by: Igor Pylypiv <ipylypiv@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-07-29 10:52:04 +09:00
Xingui YangandMartin K. Petersen 3dbbbf656b scsi: libsas: Fix HA resume deadlock and hisi_sas disk-wake race
Commit fbefe22811 ("scsi: libsas: Don't always drain event workqueue
for HA resume") introduced sas_resume_ha_no_sync() to avoid a deadlock:
the PHYE_RESUME_TIMEOUT handler, running on the HA event workqueue,
calls sas_deform_port() -> sas_destruct_devices(), which removes SCSI
devices and waits for the host to become runtime-active. But the host
cannot resume until sas_resume_ha() -> sas_drain_work() returns, and the
drain is blocked on that very handler.

However skipping the drain reintroduces a race: hisi_sas returns from
resume before all PHY UP work and libsas discovery work finish. The
controller may then autosuspend while disks are still waking up. The
disks issue IO to a suspended controller, the IO fails, and the disks
get disabled.

Fix the deadlock at its source by moving the PHYE_RESUME_TIMEOUT
notification to after sas_drain_work(). By then the host resume is about
to complete, so device removal through device_link no longer blocks on
the resume and the cycle is broken.

With the deadlock gone, restore sas_resume_ha() (the draining variant)
in hisi_sas and remove sas_resume_ha_no_sync().

The reorder is safe for the other libsas consumers (isci, pm8001,
aic94xx, mvsas). During suspend, sas_suspend_devices() calls
sas_notify_lldd_dev_gone() for each device, which sets dev->lldd_dev to
NULL. When scsi_unblock_requests re-enables I/O in resume, any I/O to a
timed-out phy's disk is immediately rejected by the LLDD before reaching
hardware: isci returns SAS_DEVICE_UNKNOWN (mapped to DID_BAD_TARGET),
and pm8001 returns SAS_PHY_DOWN (mapped to DID_NO_CONNECT). Both
complete directly via scsi_done() without entering SCSI EH. This is
identical in both the old and new ordering since lldd_dev_gone runs
during suspend, before resume. The reorder only affects when the
PHYE_RESUME_TIMEOUT handler runs (synchronized by sas_drain_work()
vs. asynchronous after resume returns), not whether I/O can reach the
device. aic94xx and mvsas do not register any PM ops and never reach
this code path.

Fixes: fbefe22811 ("scsi: libsas: Don't always drain event workqueue for HA resume")
Signed-off-by: Xingui Yang <yangxingui@huawei.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://patch.msgid.link/20260716081145.3950172-1-yangxingui@huawei.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-07-26 15:34:03 -04:00
David JefferyandMartin K. Petersen dccf3b1798 scsi: core: wake eh reliably when using scsi_schedule_eh
Drivers which use the scsi_schedule_eh function to run the error handler
currently risk the error handler thread never waking once all commands are
timed out or inactive. There is no enforced memory order between setting
the host into error recovery state and counting busy commands. This can
result in a race with scsi_dec_host_busy where neither CPU sees both
conditions of all commands inactive and the host error state to request
waking the error handler.

To fix this, run the scsi_schedule_eh's scsi_eh_wakeup from a new work item
which will use rcu to ensure scsi_schedule_eh's call to scsi_host_busy will
occur after the error state is globally visible and will be seen by any
current scsi_dec_host_busy callers.

Fixes: 6eb045e092 ("scsi: core: avoid host-wide host_busy counter for scsi_mq")
Signed-off-by: David Jeffery <djeffery@redhat.com>
Link: https://patch.msgid.link/20260615174630.11492-1-djeffery@redhat.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-07-12 22:21:22 -04:00
Catalin IacobandMartin K. Petersen e81f1079f9 scsi: core: Remove export for scsi_device_from_queue()
Commit 1cea5180f2 ("block: remove pktcdvd driver") left behind an export
that is now dead code. Remove it and move the declaration of
scsi_device_from_queue() to drivers/scsi/scsi_priv.h.

Signed-off-by: Catalin Iacob <iacobcatalin@gmail.com>
Link: https://patch.msgid.link/20260608-remove-pktcdvd-references-v4-1-72f88b04cc87@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-06-15 21:48:31 -04:00
Bart Van AsscheandMartin K. Petersen 20fd1648f3 scsi: core: Convert INQUIRY information
Currently the vendor, model, and revision members of struct scsi_device
are pointers to fixed-length strings that are not NUL-terminated.
Fixed-precision format specifiers (e.g., "%.8s") are required whenever
they are printed and strncmp() must be used to compare these fields.
This is error-prone.

Convert these fields to fixed-size character arrays within struct
scsi_device. Remove an !sdev->model check because sdev->model is now
guaranteed not to be NULL.

This patch fixes a bug in the qla2xxx driver. It makes the following
code safe:

		if (state_flags & BIT_4)
			scmd_printk(KERN_WARNING, cp,
			    "Unsupported device '%s' found.\n",
			    cp->device->vendor);

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Brian Bunker <brian@purestorage.com>
Link: https://patch.msgid.link/20260515205222.1754621-4-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-05-22 21:49:05 -04:00
Bart Van AsscheandMartin K. Petersen b1968f4650 scsi: core: target: Add INQUIRY-related constants to scsi_common.h
Move three constants from target/target_core_base.h into
scsi/scsi_common.h. Add three new constants in the scsi_common.h header
file. This patch prepares for using these constants in the SCSI core.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Brian Bunker <brian@purestorage.com>
Link: https://patch.msgid.link/20260515205222.1754621-2-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-05-22 21:49:04 -04:00
Thomas WeißschuhandMartin K. Petersen 1a2f61970a scsi: libsas: Delete unused to_dom_device() and to_dev_attr()
These macros are unused and to_dev_attr() will conflict with an upcoming
centralization of general attribute macros.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://patch.msgid.link/20260408-libsas-cleanup-v1-1-826325bbc0ba@weissschuh.net
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-04-08 21:55:51 -04:00
Chaohai ChenandMartin K. Petersen 7a3aff163c scsi: core: Drop using the host_lock to protect async_scan race condition
Previously, host_lock was used to prevent bit-set conflicts in async_scan,
but this approach introduced naked reads in some code paths.

Convert async_scan from a bitfield to a bool type to eliminate bit-level
conflicts entirely. Use __guarded_by(&scan_mutex) to indicate that the
async_scan variable is protected by scan_mutex.

Signed-off-by: Chaohai Chen <wdhh6@aliyun.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://patch.msgid.link/20260305025125.3649517-1-wdhh6@aliyun.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-03-07 10:58:33 -05:00
Igor PylypivandMartin K. Petersen 94c125bafa scsi: core: Add 'serial' sysfs attribute for SCSI/SATA
Add a 'serial' sysfs attribute for SCSI and SATA devices. This attribute
exposes the Unit Serial Number, which is derived from the Device
Identification Vital Product Data (VPD) page 0x80.

Whitespace is stripped from the retrieved serial number to handle the
different alignment (right-aligned for SCSI, potentially left-aligned for
SATA). As noted in SAT-5 10.5.3, "Although SPC-5 defines the PRODUCT SERIAL
NUMBER field as right-aligned, ACS-5 does not require its SERIAL NUMBER
field to be right-aligned. Therefore, right-alignment of the PRODUCT SERIAL
NUMBER field for the translation is not assured."

This attribute is used by tools such as lsblk to display the serial number
of block devices.

[mkp: length adjustment]

Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20260209212151.342151-1-ipylypiv@google.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-02-28 20:03:00 -05:00
Linus Torvalds d4a379a52c Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI updates from James Bottomley:
 "Usual driver updates (qla2xxx, mpi3mr, mpt3sas, ufs) plus assorted
  cleanups and fixes.

  The biggest core change is the massive code motion in the sd driver to
  remove forward declarations and the most significant change is to
  enumify the queuecommand return"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (78 commits)
  scsi: csiostor: Fix dereference of null pointer rn
  scsi: buslogic: Reduce stack usage
  scsi: ufs: host: mediatek: Require CONFIG_PM
  scsi: ufs: mediatek: Fix page faults in ufs_mtk_clk_scale() trace event
  scsi: smartpqi: Fix memory leak in pqi_report_phys_luns()
  scsi: mpi3mr: Make driver probing asynchronous
  scsi: ufs: core: Flush exception handling work when RPM level is zero
  scsi: efct: Use IRQF_ONESHOT and default primary handler
  scsi: ufs: core: Use a host-wide tagset in SDB mode
  scsi: qla2xxx: target: Add WQ_PERCPU to alloc_workqueue() users
  scsi: qla2xxx: Add WQ_PERCPU to alloc_workqueue() users
  scsi: qla4xxx: Add WQ_PERCPU to alloc_workqueue() users
  scsi: mpi3mr: Driver version update to 8.17.0.3.50
  scsi: mpi3mr: Fixed the W=1 compilation warning
  scsi: mpi3mr: Record and report controller firmware faults
  scsi: mpi3mr: Update MPI Headers to revision 39
  scsi: mpi3mr: Use negotiated link rate from DevicePage0
  scsi: mpi3mr: Avoid redundant diag-fault resets
  scsi: mpi3mr: Rename log data save helper to reflect threaded/BH context
  scsi: mpi3mr: Add module parameter to control threaded IRQ polling
  ...
2026-02-12 15:43:02 -08:00
Bart Van AsscheandMartin K. Petersen 0db3f51839 scsi: Change the return type of the .queuecommand() callback
In clang version 21.1 and later the -Wimplicit-enum-enum-cast warning
option has been introduced. This warning is enabled by default and can
be used to catch .queuecommand() implementations that return another
value than 0 or one of the SCSI_MLQUEUE_* constants. Hence this patch
that changes the return type of the .queuecommand() implementations from
'int' into 'enum scsi_qc_status'. No functionality has been changed.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260115210357.2501991-6-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-01-23 21:32:34 -05:00
Martin K. Petersen 3a8a4ee99c Merge patch series "scsi: Make use of bus callbacks"
Uwe Kleine-König <u.kleine-koenig@baylibre.com> says:

Hello,

this is v2 of the series to make the scsi subsystem stop using the
callbacks .probe(), .remove() and .shutdown() of struct device_driver.
Instead use their designated alternatives in struct bus_type.

The eventual goal is to drop the callbacks from struct device_driver.

The 2nd patch introduces some legacy handling for drivers still using
the device_driver callbacks. This results in a runtime warning (in
driver_register()). The following patches convert all in-tree drivers
(and thus fix the warnings one after another).
Conceptually this legacy handling could be dropped at the end of the
series, but I think this is a bad idea because this silently breaks
out-of-tree drivers (which also covers drivers that are currently
prepared for mainline submission) and in-tree drivers I might have
missed (though I'm convinced I catched them all). That convinces me that
keeping the legacy handling for at least one development cycle is the
right choice. I'll care for that at the latest when I remove the
callbacks from struct device_driver.

Link: https://patch.msgid.link/cover.1766133330.git.u.kleine-koenig@baylibre.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-01-11 21:33:19 -05:00
Uwe Kleine-KönigandMartin K. Petersen f7d4f1bf57 scsi: core: sysfs: Make use of bus callbacks
Introduce a bus-specific probe, remove and shutdown function. For now
this only allows to get rid of a cast of the generic device to a SCSI
device in the drivers and changes the remove prototype to return
void---a non-zero return value is ignored anyhow.

The objective is to get rid of users of struct device_driver callbacks
.probe(), .remove() and .shutdown() to eventually remove these. Until
all SCSI drivers are converted, this results in a runtime warning about
the drivers needing an update because there is a bus probe function and
a driver probe function. The in-tree drivers are fixed by the following
commits.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/a54e363a3fd2054fb924afd7df44bca7f444b5f1.1766133330.git.u.kleine-koenig@baylibre.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-01-11 21:31:58 -05:00
Uwe Kleine-KönigandMartin K. Petersen 7d42bcea57 scsi: core: Pass a struct scsi_driver to scsi_{,un}register_driver()
This aligns with what other subsystems do, reduces boilerplate a bit for
device drivers and is less error prone.

Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/ac17fdea58e384cb514c639306d48ce0005820b0.1766133330.git.u.kleine-koenig@baylibre.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-01-11 21:31:57 -05:00
Brian KaoandMartin K. Petersen 9a49157dee scsi: core: Fix error handler encryption support
Some low-level drivers (LLD) access block layer crypto fields, such as
rq->crypt_keyslot and rq->crypt_ctx within `struct request`, to
configure hardware for inline encryption.  However, SCSI Error Handling
(EH) commands (e.g., TEST UNIT READY, START STOP UNIT) should not
involve any encryption setup.

To prevent drivers from erroneously applying crypto settings during EH,
this patch saves the original values of rq->crypt_keyslot and
rq->crypt_ctx before an EH command is prepared via scsi_eh_prep_cmnd().
These fields in the 'struct request' are then set to NULL.  The original
values are restored in scsi_eh_restore_cmnd() after the EH command
completes.

This ensures that the block layer crypto context does not leak into EH
command execution.

Signed-off-by: Brian Kao <powenkao@google.com>
Link: https://patch.msgid.link/20251218031726.2642834-1-powenkao@google.com
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2026-01-04 15:16:20 -05:00
Bart Van AsscheandMartin K. Petersen 0f9c4be787 scsi: core: Introduce an enumeration type for the SCSI_MLQUEUE constants
Multiple functions in the SCSI core accept an 'int reason' argument.
The 'int' type of these arguments doesn't make it clear what values are
acceptable for these arguments. Document which values are supported for
these arguments by introducing the enumeration type scsi_qc_status. 'qc'
in the type name stands for 'queuecommand' since the values passed as
the 'reason' argument are the .queuecommand() return values.

Cc: John Garry <john.g.garry@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251113181730.1109331-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-12-16 22:20:26 -05:00
Sarah CataniaandMartin K. Petersen bd2bc52869 scsi: scsi_transport_fc: Introduce encryption group in fc_rport attribute
Introduce a new structure for reporting an encrypted session over an
fc_rport.  The encryption group is added as an attribute in struct
fc_rport and reports information in fc_encryption_info.  This structure
contains a status member variable, which stores a bit value indicating
an encrypted session.

Signed-off-by: Sarah Catania <sarah.catania@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://patch.msgid.link/20251211001659.138635-2-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-12-16 21:56:48 -05:00
Martin K. Petersen e54f7b4b81 Merge branch 6.18/scsi-fixes into 6.19/scsi-staging
Pull in fixes branch to resolve UFS merge conflict.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-11-19 22:59:25 -05:00
Martin K. Petersen ab57a18665 Merge patch series "Optimize the hot path in the UFS driver"
Bart Van Assche <bvanassche@acm.org> says:

Hi Martin,

This patch series optimizes the hot path of the UFS driver by making
struct scsi_cmnd and struct ufshcd_lrb adjacent. Making these two data
structures adjacent is realized as follows:

@@ -9040,6 +9046,7 @@ static const struct scsi_host_template ufshcd_driver_template = {
     .name           = UFSHCD,
     .proc_name      = UFSHCD,
     .map_queues     = ufshcd_map_queues,
+    .cmd_size       = sizeof(struct ufshcd_lrb),
     .init_cmd_priv  = ufshcd_init_cmd_priv,
     .queuecommand   = ufshcd_queuecommand,
     .mq_poll        = ufshcd_poll,

The following changes had to be made prior to making these two data
structures adjacent:
* Add support for driver-internal and reserved commands in the SCSI core.
* Instead of making the reserved command slot (hba->reserved_slot)
  invisible to the SCSI core, let the SCSI core allocate a reserved command.
* Remove all UFS data structure members that are no longer needed
  because struct scsi_cmnd and struct ufshcd_lrb are now adjacent
* Call ufshcd_init_lrb() from inside the code for queueing a command instead of
  calling this function before I/O starts. This is necessary because
  ufshcd_memory_alloc() allocates fewer instances than the block layer
  allocates requests. See also the following code in the block layer
  core:

    if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx,
                hctx->numa_node))

  Although the UFS driver could be modified such that ufshcd_init_lrb()
  is called from ufshcd_init_cmd_priv(), realizing this would require
  moving the memory allocations that happen from inside
  ufshcd_memory_alloc() into ufshcd_init_cmd_priv(). That would make
  this patch series even larger. Although ufshcd_init_lrb() is called for each
  command, the benefits of reduced indirection and better cache efficiency
  outweigh the small overhead of per-command lrb initialization.
* ufshcd_add_scsi_host() happens now before any device management
  commands are submitted. This change is necessary because this patch
  makes device management command allocation happen when the SCSI host
  is allocated.
* Allocate as many command slots as the host controller supports. Decrease
  host->cmds_per_lun if necessary once it is clear whether or not the UFS
  device supports less command slots than the host controller.

Please consider this patch series for the next merge window.

Thanks,

Bart.

Link: https://patch.msgid.link/20251031204029.2883185-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-11-12 18:16:05 -05:00
Hannes ReineckeandMartin K. Petersen a2ab4e3328 scsi: core: Add scsi_{get,put}_internal_cmd() helpers
Add helper functions to allow LLDDs to allocate and free internal commands.

[ bvanassche: changed the 'nowait' argument into a 'flags' argument. See also
  https://lore.kernel.org/linux-scsi/20211125151048.103910-3-hare@suse.de/ ]

Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251031204029.2883185-7-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-11-12 17:02:31 -05:00
John GarryandMartin K. Petersen 11ea1de3fc scsi: core: Introduce .queue_reserved_command()
Reserved commands will be used by SCSI LLDs for submitting internal
commands. Since the SCSI host, target and device limits do not apply to
the reserved command use cases, bypass the SCSI host limit checks for
reserved commands. Introduce the .queue_reserved_command() callback for
reserved commands. Additionally, do not activate the SCSI error handler
if a reserved command fails such that reserved commands can be submitted
from inside the SCSI error handler.

[ bvanassche: modified patch title and patch description. Renamed
  .reserved_queuecommand() into .queue_reserved_command(). Changed
  the second argument of __blk_mq_end_request() from 0 into error
  code in the completion path if cmd->result != 0. Rewrote the
  scsi_queue_rq() changes. See also
  https://lore.kernel.org/linux-scsi/1666693096-180008-5-git-send-email-john.garry@huawei.com/ ]

Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://patch.msgid.link/20251031204029.2883185-6-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-11-12 17:02:31 -05:00
Hannes ReineckeandMartin K. Petersen d630fbf6fc scsi: core: Support allocating a pseudo SCSI device
Allocate a pseudo SCSI device if 'nr_reserved_cmds' has been set. Pseudo
SCSI devices have the SCSI ID <max_id>:U64_MAX so they won't clash with
any devices the LLD might create. Pseudo SCSI devices are excluded from
scanning and will not show up in sysfs. Additionally, pseudo SCSI
devices are skipped by shost_for_each_device(). This prevents that the
SCSI error handler tries to submit a reset to a non-existent logical
unit.

Do not allocate a budget map for pseudo SCSI devices since the
cmd_per_lun limit does not apply to pseudo SCSI devices.

Do not perform queue depth ramp up / ramp down for pseudo SCSI devices.

Pseudo SCSI devices will be used to send internal commands to a storage
device.

[ bvanassche: edited patch description / renamed host_sdev into
  pseudo_sdev / unexported scsi_get_host_dev() / modified error path in
  scsi_get_pseudo_dev() / skip pseudo devices in __scsi_iterate_devices()
  and also when calling sdev_init(), sdev_configure() and sdev_destroy().
  See also
  https://lore.kernel.org/linux-scsi/20211125151048.103910-2-hare@suse.de/ ]

Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251031204029.2883185-5-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-11-12 17:02:31 -05:00
Hannes ReineckeandMartin K. Petersen d604e1ec24 scsi: core: Support allocating reserved commands
Quite some drivers are using management commands internally. These
commands typically use the same tag pool as regular SCSI commands. Tags
for these management commands are set aside before allocating the
block-mq tag bitmap for regular SCSI commands. The block layer already
supports this via the reserved tag mechanism. Add a new field
'nr_reserved_cmds' to the SCSI host template to instruct the block layer
to set aside a tag space for these management commands by using reserved
tags. Exclude reserved commands from .can_queue because .can_queue is
visible in sysfs.

[ bvanassche: modified patch title and patch description. Left out the
  following statements: "if (sht->nr_reserved_cmds)" and also
  "if (sdev->host->nr_reserved_cmds) flags |= BLK_MQ_REQ_RESERVED;". Moved
  nr_reserved_cmds declarations and statements close to the
  corresponding can_queue declarations and statements. See also
  https://lore.kernel.org/linux-scsi/20210503150333.130310-11-hare@suse.de/ ]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251031204029.2883185-2-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-11-12 17:02:30 -05:00