kernel/include/scsi/scsi_device.h, branch linux-5.11.y

scsi: core: Only re-run queue in scsi_end_request() if device queue is busy

2020-09-16T02:20:11Z

The request queue is currently run unconditionally in scsi_end_request() if both target queue and host queue are ready. Recently Long Li reported that cost of a queue run can be very heavy in case of high queue depth. Improve this situation by only running the request queue when this LUN is busy. Link: https://lore.kernel.org/r/20200910075056.36509-1-ming.lei@redhat.com Reported-by: Long Li Tested-by: Long Li Tested-by: Kashyap Desai Reviewed-by: Bart Van Assche Reviewed-by: Hannes Reinecke Reviewed-by: Ewan D. Milne Reviewed-by: John Garry Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen

block: move dma drain handling to scsi

2020-04-22T16:47:35Z

Don't burden the common block code with with specifics of the libata DMA draining mechanism. Instead move most of the code to the scsi midlayer. That also means the nr_phys_segments adjustments in the blk-mq fast path can go away entirely, given that SCSI never looks at nr_phys_segments after mapping the request to a scatterlist. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

scsi: core: avoid repetitive logging of device offline messages

2020-03-12T03:09:27Z

Large queues of I/O to offline devices that are eventually submitted when devices are unblocked result in a many repeated "rejecting I/O to offline device" messages. These messages can fill up the dmesg buffer in crash dumps so no useful prior messages remain. In addition, if a serial console is used, the flood of messages can cause a hard lockup in the console code. Introduce a flag indicating the message has already been logged for the device, and reset the flag when scsi_device_set_state() changes the device state. Link: https://lore.kernel.org/r/20200311143930.20674-1-emilne@redhat.com Reviewed-by: Bart van Assche Signed-off-by: Ewan D. Milne Signed-off-by: Martin K. Petersen

scsi: Replace zero-length array with flexible-array member

2020-03-12T03:07:56Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Link: https://lore.kernel.org/r/20200224161406.GA21454@embeddedor Reviewed-by: Lee Duncan Reviewed-by: Satish Kharat Signed-off-by: Gustavo A. R. Silva Signed-off-by: Martin K. Petersen

scsi: core: Remove cmd_list functionality

2020-02-29T01:54:55Z

Remove cmd_list functionality; no users left. With that the scsi_put_command() becomes empty, so remove that one, too. Link: https://lore.kernel.org/r/20200228075318.91255-14-hare@suse.de Reviewed-by: Christoph Hellwig Reviewed-by: Bart van Assche Signed-off-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

scsi: core: Adjust DBD setting in MODE SENSE for caching mode page per LLD

2019-12-20T03:08:52Z

UFS JEDEC standards require DBD field to be set to 1 in mode sense command. This patch allows LLD to define the setting of DBD, if required. Link: https://lore.kernel.org/r/0101016ed3d643f9-ffd45d6c-c593-4a13-a18f-a32da3d3bb97-000000@us-west-2.amazonses.com Reviewed-by: Avri Altman Signed-off-by: Can Guo Signed-off-by: Martin K. Petersen

scsi: core: Add sysfs attributes for VPD pages 0h and 89h

2019-10-01T03:24:36Z

Add sysfs attributes for the ATA information page and Supported VPD Pages page. Link: https://lore.kernel.org/r/20190926162216.56591-1-ryanattard@ryanattard.info Signed-off-by: Ryan Attard Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: core: allow auto suspend override by low-level driver

2019-10-01T03:01:17Z

Rework from previous work by: Sujit Reddy Thumma Until now the scsi mid-layer forbids runtime suspend till userspace enables it. This is mainly to quarantine some disks with broken runtime power management or have high latencies executing suspend resume callbacks. If the userspace doesn't enable the runtime suspend the underlying hardware will be always on even when it is not doing any useful work and thus wasting power. Some low-level drivers for the controllers can efficiently use runtime power management to reduce power consumption and improve battery life. Allow runtime suspend parameters override within the LLD itself instead of waiting for userspace to control the power management. Link: https://lore.kernel.org/r/1568649411-5127-2-git-send-email-stanley.chu@mediatek.com Reviewed-by: Avri Altman Reviewed-by: Bart Van Assche Signed-off-by: Stanley Chu Signed-off-by: Martin K. Petersen

scsi: Check sense buffer size at build time

2018-08-02T21:23:51Z

To avoid introducing problems like those fixed in commit f7068114d45e ("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 3756f6401c30 ("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: Christoph Hellwig Signed-off-by: Kees Cook Signed-off-by: Jens Axboe

scsi: devinfo: change blist_flag_t to 64bit

2018-04-20T23:14:35Z

Space for SCSI blist flags is gradually running out. Change the type to __u64 and fix a checkpatch complaint about symbolic mode flags in scsi_devinfo.c. Make checkpatch happy by replacing simple_strtoul() with kstrtoull(). Signed-off-by: Martin Wilck Signed-off-by: Martin K. Petersen