kernel/linux.git/drivers/scsi/scsi.c, branch linux-7.1.y

scsi: core: Support allocating a pseudo SCSI device

2025-11-12T22:02:31+00:00

Allocate a pseudo SCSI device if 'nr_reserved_cmds' has been set. Pseudo SCSI devices have the SCSI 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 Signed-off-by: Hannes Reinecke Signed-off-by: Bart Van Assche Link: https://patch.msgid.link/20251031204029.2883185-5-bvanassche@acm.org Signed-off-by: Martin K. Petersen

scsi: core: Make the budget map optional

2025-11-12T22:02:31+00:00

Prepare for not allocating a budget map for pseudo SCSI devices by checking whether a budget map has been allocated before using it. Reviewed-by: Hannes Reinecke Cc: John Garry Cc: Ming Lei Signed-off-by: Bart Van Assche Link: https://patch.msgid.link/20251031204029.2883185-4-bvanassche@acm.org Signed-off-by: Martin K. Petersen

scsi: core: Fix kernel doc for scsi_track_queue_full()

2025-07-15T00:56:55+00:00

Sphinx reports indentation warning on scsi_track_queue_full() return values: Documentation/driver-api/scsi:101: ./drivers/scsi/scsi.c:247: ERROR: Unexpected indentation. [docutils] Fix the warning by making the return values listing a bullet list. Fixes: eb44820c28bc ("[SCSI] Add Documentation and integrate into docbook build") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20250702035822.18072-2-bagasdotme@gmail.com Signed-off-by: Martin K. Petersen

scsi: core: Remember if a device is an ATA device

2025-06-16T18:29:59+00:00

scsi_add_lun() tests the device vendor string of SCSI devices to detect if a SCSI device is in fact an ATA device, in order to correctly handle SATL power management. The function scsi_cdl_enable() also requires knowing if a SCSI device is an ATA device to control the state of the device CDL feature but this function does that by testing for the presence of the VPD page 89h (ATA INFORMATION page). sd_read_write_same() also has a similar test. Simplify these different methods by adding the is_ata field to struct scsi_device to remember that a SCSI device is in fact an ATA one based on the device vendor name test. This field can also allow low level SCSI host adapter drivers to take special actions for ATA devices (e.g. to better handle ATA NCQ errors). With this, simplify scsi_cdl_enable() and sd_read_write_same(). Signed-off-by: Damien Le Moal Link: https://lore.kernel.org/r/20250611093421.2901633-1-dlemoal@kernel.org Reviewed-by: Igor Pylypiv Signed-off-by: Martin K. Petersen

scsi: Improve CDL control

2025-04-22T07:06:08+00:00

With ATA devices supporting the CDL feature, using CDL requires that the feature be enabled with a SET FEATURES command. This command is issued as the translated command for the MODE SELECT command issued by scsi_cdl_enable() when the user enables CDL through the device cdl_enable sysfs attribute. However, the implementation of scsi_cdl_enable() always issues a MODE SELECT command for ATA devices when the enable argument is true, even if CDL is already enabled on the device. While this does not cause any issue with using CDL descriptors with read/write commands (the CDL feature will be enabled on the drive), issuing the MODE SELECT command even when the device CDL feature is already enabled will cause a reset of the ATA device CDL statistics log page (as defined in ACS, any CDL enable action must reset the device statistics). Avoid this needless actions (and the implied statistics log page reset) by modifying scsi_cdl_enable() to issue the MODE SELECT command to enable CDL if and only if CDL is not reported as already enabled on the device. And while at it, simplify the initialization of the is_ata boolean variable and move the declaration of the scsi mode data and sense header variables to within the scope of ATA device handling. Fixes: 1b22cfb14142 ("scsi: core: Allow enabling and disabling command duration limits") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Niklas Cassel Reviewed-by: Igor Pylypiv Reviewed-by: Martin K. Petersen

scsi: core: Use a switch statement when attaching VPD pages

2025-03-11T01:57:37+00:00

The original code used if statements to update discovered VPD pages when found. This had the side-effect of not breaking the loop when a page was found. Use an idiomatic switch statement instead. Signed-off-by: Chaohai Chen Link: https://lore.kernel.org/r/20250226065802.234144-1-wdhh6@aliyun.com Signed-off-by: Martin K. Petersen

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

scsi: core: Disable CDL by default

2024-06-12T01:14:54+00:00

For SCSI devices supporting the Command Duration Limits feature set, the user can enable/disable this feature use through the sysfs device attribute "cdl_enable". This attribute modification triggers a call to scsi_cdl_enable() to enable and disable the feature for ATA devices and set the scsi device cdl_enable field to the user provided bool value. For SCSI devices supporting CDL, the feature set is always enabled and scsi_cdl_enable() is reduced to setting the cdl_enable field. However, for ATA devices, a drive may spin-up with the CDL feature enabled by default. But the SCSI device cdl_enable field is always initialized to false (CDL disabled), regardless of the actual device CDL feature state. For ATA devices managed by libata (or libsas), libata-core always disables the CDL feature set when the device is attached, thus syncing the state of the CDL feature on the device and of the SCSI device cdl_enable field. However, for ATA devices connected to a SAS HBA, the CDL feature is not disabled on scan for ATA devices that have this feature enabled by default, leading to an inconsistent state of the feature on the device with the SCSI device cdl_enable field. Avoid this inconsistency by adding a call to scsi_cdl_enable() in scsi_cdl_check() to make sure that the device-side state of the CDL feature set always matches the scsi device cdl_enable field state. This implies that CDL will always be disabled for ATA devices connected to SAS HBAs, which is consistent with libata/libsas initialization of the device. Reported-by: Scott McCoy Fixes: 1b22cfb14142 ("scsi: core: Allow enabling and disabling command duration limits") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Link: https://lore.kernel.org/r/20240607012507.111488-1-dlemoal@kernel.org Reviewed-by: Niklas Cassel Reviewed-by: Igor Pylypiv Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen

scsi: core: Handle devices which return an unusually large VPD page count

2024-05-24T00:35:32+00:00

Peter Schneider reported that a system would no longer boot after updating to 6.8.4. Peter bisected the issue and identified commit b5fc07a5fb56 ("scsi: core: Consult supported VPD page list prior to fetching page") as being the culprit. Turns out the enclosure device in Peter's system reports a byteswapped page length for VPD page 0. It reports "02 00" as page length instead of "00 02". This causes us to attempt to access 516 bytes (page length + header) of information despite only 2 pages being present. Limit the page search scope to the size of our VPD buffer to guard against devices returning a larger page count than requested. Link: https://lore.kernel.org/r/20240521023040.2703884-1-martin.petersen@oracle.com Fixes: b5fc07a5fb56 ("scsi: core: Consult supported VPD page list prior to fetching page") Cc: stable@vger.kernel.org Reported-by: Peter Schneider Closes: https://lore.kernel.org/all/eec6ebbf-061b-4a7b-96dc-ea748aa4d035@googlemail.com/ Tested-by: Peter Schneider Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2024-03-22T20:31:07+00:00

Pull more SCSI updates from James Bottomley: "The vfs has long had a write lifetime hint mechanism that gives the expected longevity on storage of the data being written. f2fs was the original consumer of this and used the hint for flash data placement (mostly to avoid write amplification by placing objects with similar lifetimes in the same erase block). More recently the SCSI based UFS (Universal Flash Storage) drivers have wanted to take advantage of this as well, for the same reasons as f2fs, necessitating plumbing the write hints through the block layer and then adding it to the SCSI core. The vfs write_hints already taken plumbs this as far as block and this completes the SCSI core enabling based on a recently agreed reuse of the old write command group number. The additions to the scsi_debug driver are for emulating this property so we can run tests on it in the absence of an actual UFS device" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: scsi_debug: Maintain write statistics per group number scsi: scsi_debug: Implement GET STREAM STATUS scsi: scsi_debug: Implement the IO Advice Hints Grouping mode page scsi: scsi_debug: Allocate the MODE SENSE response from the heap scsi: scsi_debug: Rework subpage code error handling scsi: scsi_debug: Rework page code error handling scsi: scsi_debug: Support the block limits extension VPD page scsi: scsi_debug: Reduce code duplication scsi: sd: Translate data lifetime information scsi: scsi_proto: Add structures and constants related to I/O groups and streams scsi: core: Query the Block Limits Extension VPD page