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path: root/drivers/scsi/scsi.c
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2016-04-05scsi: Do not attach VPD to devices that don't support itHannes Reinecke
The patch "scsi: rescan VPD attributes" introduced a regression in which devices that don't support VPD were being scanned for VPD attributes anyway. This could cause issues for some devices and should be avoided so the check for scsi_level has been moved out of scsi_add_lun and into scsi_attach_vpd so that all callers will not scan VPD for devices that don't support it. [mkp: Merge fix] Fixes: 09e2b0b14690 ("scsi: rescan VPD attributes") Cc: <stable@vger.kernel.org> #v4.5+ Suggested-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-11-30scsi: rescan VPD attributesHannes Reinecke
The VPD page information might change, so we need to be able to update it. This patch implements a VPD page rescan whenever the 'rescan' sysfs attribute is triggered. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Shane Seymour <shane.seymour@hpe.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-11-09scsi: use host wide tags by defaultChristoph Hellwig
This patch changes the !blk-mq path to the same defaults as the blk-mq I/O path by always enabling block tagging, and always using host wide tags. We've had blk-mq available for a few releases so bugs with this mode should have been ironed out, and this ensures we get better coverage of over tagging setup over different configs. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-06-01Move code that is used both by initiator and target driversBart Van Assche
Move the functions that are used by both the initiator and target subsystems into scsi_common.c/.h. This change will allow to remove the initiator SCSI header include directives from most SCSI target source files in a later patch. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-03-19scsi: proper state checking and module refcount handling in scsi_device_getChristoph Hellwig
This effectively reverts commits 85b6c7 ("[SCSI] sd: fix cache flushing on module removal (and individual device removal)" and dc4515ea ("scsi: always increment reference count"). We now never call scsi_device_get from the shutdown path, and the fact that we started grabbing reference there in commit 85b6c7 turned out turned out to create more problems than it solves, and required workarounds for workarounds for workarounds. Move back to properly checking the device state and carefully handle module refcounting. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2015-02-11Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull first round of SCSI updates from James Bottomley: "This is the usual grab bag of driver updates (hpsa, storvsc, mp2sas, megaraid_sas, ses) plus an assortment of minor updates. There's also an update to ufs which adds new phy drivers and finally a new logging infrastructure for SCSI" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (114 commits) scsi_logging: return void for dev_printk() functions scsi: print single-character strings with seq_putc scsi: merge consecutive seq_puts calls scsi: replace seq_printf with seq_puts aha152x: replace seq_printf with seq_puts advansys: replace seq_printf with seq_puts scsi: remove SPRINTF macro sg: remove an unused variable hpsa: Use local workqueues instead of system workqueues hpsa: add in P840ar controller model name hpsa: add in gen9 controller model names hpsa: detect and report failures changing controller transport modes hpsa: shorten the wait for the CISS doorbell mode change ack hpsa: refactor duplicated scan completion code into a new routine hpsa: move SG descriptor set-up out of hpsa_scatter_gather() hpsa: do not use function pointers in fast path command submission hpsa: print CDBs instead of kernel virtual addresses for uncommon errors hpsa: do not use a void pointer for scsi_cmd field of struct CommandList hpsa: return failed from device reset/abort handlers hpsa: check for ctlr lockup after command allocation in main io path ...
2015-01-23scsi: always increment reference countRusty Russell
James reported: > After e513cc1 module: Remove stop_machine from module unloading, > module_refcount() is returning (unsigned long)-1 when called from within > a routine that runs in module_exit. This is confusing the scsi device > put code which is coded to detect a module_refcount() of zero for > running within a module exit routine and not try to do another > module_put. The fix is to restore the original behaviour of > module_refcount() and return zero if we're running inside an exit > routine. The correct fix is to turn try_module_get() into __module_get(), and always do the module_put(). Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-09scsi: Do not display buffer pointers in scsi_log_send()Hannes Reinecke
scsi_log_send() would display buffer pointer for higher logging levels. This is not only of questionable value but also exposes kernel pointer to userspace, which is discouraged in some setups. So drop this message altogether. Tested-by: Robert Elliott <elliott@hp.com> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-01-09scsi: use per-cpu buffer for formatting scsi_print_result()Hannes Reinecke
Convert scsi_print_result() to use the per-cpu buffer for decoding the command result and disposition. Tested-by: Robert Elliott <elliott@hp.com> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-12-18Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley
2014-12-08Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley
Conflicts: drivers/scsi/scsi_debug.c Agreed and tested resolution to a merge problem between a fix in scsi_debug and a driver update Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-12-04scsi: never drop to untagged mode during queue ramp downChristoph Hellwig
Dropping to untagged mode when ramping down a queue due to QUEUE FULL events has two problems: - nothing in the midlayer or drivers ever moves back to tagged mode during queue ramp up. - cmd_per_lun isn't the untagged queue depth for many modern drivers that can handle multiple untagged commands, and this is the only place in the midlayer assuming that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-12-04scsi: remove ->change_queue_type methodChristoph Hellwig
Since we got rid of ordered tag support in 2010 the prime use case of switching on and off ordered tags has been obsolete. The other function of enabling/disabling tagging entirely has only been correctly implemented by the 53c700 driver and isn't generally useful. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24scsi: move scsi_dispatch_cmd to scsi_lib.cChristoph Hellwig
scsi_lib.c is where the rest of the I/O submission path lives, so move scsi_dispatch_cmd there and mark it static. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-24scsi: drop reason argument from ->change_queue_depthChristoph Hellwig
Drop the now unused reason argument from the ->change_queue_depth method. Also add a return value to scsi_adjust_queue_depth, and rename it to scsi_change_queue_depth now that it can be used as the default ->change_queue_depth implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12scsi: don't set tagging state from scsi_adjust_queue_depthChristoph Hellwig
Remove the tagged argument from scsi_adjust_queue_depth, and just let it handle the queue depth. For most drivers those two are fairly separate, given that most modern drivers don't care about the SCSI "tagged" status of a command at all, and many old drivers allow queuing of multiple untagged commands in the driver. Instead we start out with the ->simple_tags flag set before calling ->slave_configure, which is how all drivers actually looking at ->simple_tags except for one worke anyway. The one other case looks broken, but I've kept the behavior as-is for now. Except for that we only change ->simple_tags from the ->change_queue_type, and when rejecting a tag message in a single driver, so keeping this churn out of scsi_adjust_queue_depth is a clear win. Now that the usage of scsi_adjust_queue_depth is more obvious we can also remove all the trivial instances in ->slave_alloc or ->slave_configure that just set it to the cmd_per_lun default. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-11-12scsi: always assign block layer tags if enabledChristoph Hellwig
Allow a driver to ask for block layer tags by setting .use_blk_tags in the host template, in which case it will always see a valid value in request->tag, similar to the behavior when using blk-mq. This means even SCSI "untagged" commands will now have a tag, which is especially useful when using a host-wide tag map. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12scsi: remove ordered_tags scsi_device fieldChristoph Hellwig
Remove the ordered_tags field, we haven't been issuing ordered tags based on it since the big barrier rework in 2010. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-11-12scsi: provide a generic change_queue_type methodChristoph Hellwig
Most drivers use exactly the same implementation, so provide it as a library function. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12scsi: simplify scsi_log_(send|completion)Hannes Reinecke
Simplify scsi_log_(send|completion) by externalizing scsi_mlreturn_string() and always print the command address. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12scsi: use sdev as argument for sense code printingHannes Reinecke
We should be using the standard dev_printk() variants for sense code printing. [hch: remove __scsi_print_sense call in xen-scsiback, Acked by Juergen] [hch: folded bracing fix from Dan Carpenter] Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-10-01scsi: add a CONFIG_SCSI_MQ_DEFAULT optionChristoph Hellwig
Add a Kconfig option to enable the blk-mq path for SCSI by default to ease testing and deployment in setups that know they benefit from blk-mq. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Robert Elliott <elliott@hp.com> Tested-by: Robert Elliott <elliott@hp.com>
2014-09-15scsi: don't store LUN bits in CDB[1] for USB mass-storage devicesAlan Stern
The SCSI specification requires that the second Command Data Byte should contain the LUN value in its high-order bits if the recipient device reports SCSI level 2 or below. Nevertheless, some USB mass-storage devices use those bits for other purposes in vendor-specific commands. Currently Linux has no way to send such commands, because the SCSI stack always overwrites the LUN bits. Testing shows that Windows 7 and XP do not store the LUN bits in the CDB when sending commands to a USB device. This doesn't matter if the device uses the Bulk-Only or UAS transports (which virtually all modern USB mass-storage devices do), as these have a separate mechanism for sending the LUN value. Therefore this patch introduces a flag in the Scsi_Host structure to inform the SCSI midlayer that a transport does not require the LUN bits to be stored in the CDB, and it makes usb-storage set this flag for all devices using the Bulk-Only transport. (UAS is handled by a separate driver, but it doesn't really matter because no SCSI-2 or lower device is at all likely to use UAS.) The patch also cleans up the code responsible for storing the LUN value by adding a bitflag to the scsi_device structure. The test for whether to stick the LUN value in the CDB can be made when the device is probed, and stored for future use rather than being made over and over in the fast path. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Tiziano Bacocco <tiziano.bacocco@gmail.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-08-15[SCSI] save command pool address of Scsi_HostJuergen Gross
If a scsi host driver specifies .cmd_len in it's scsi_host_template, a driver's private command pool is needed. scsi_find_host_cmd_pool() will locate it, but scsi_alloc_host_cmd_pool() isn't saving the pool address in the host template. This will result in an access error when the host is removed. Avoid the problem by saving the address of a new allocated command pool where it is expected. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Fixes: 89d9a567952baec13e26ada3e438f1b642d66b6e Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-07-29scsi: use short driver name for per-driver cmd slab cachesJames Bottomley
hostt->name might contain space, so use the ->proc_name short name instead when creating per-driver command slabs. Signed-off-by: James Bottomley <JBottomley@Parallels.com> Reported-by: poma <pomidorabelisima@gmail.com> Tested-by: poma <pomidorabelisima@gmail.com> Reviewed-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-25scsi: update scsi_device_typesChristoph Hellwig
Add two new device types, most importantly the zoned block device one. Split from an earlier patch by Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
2014-07-25scsi: add support for a blk-mq based I/O path.Christoph Hellwig
This patch adds support for an alternate I/O path in the scsi midlayer which uses the blk-mq infrastructure instead of the legacy request code. Use of blk-mq is fully transparent to drivers, although for now a host template field is provided to opt out of blk-mq usage in case any unforseen incompatibilities arise. In general replacing the legacy request code with blk-mq is a simple and mostly mechanical transformation. The biggest exception is the new code that deals with the fact the I/O submissions in blk-mq must happen from process context, which slightly complicates the I/O completion handler. The second biggest differences is that blk-mq is build around the concept of preallocated requests that also include driver specific data, which in SCSI context means the scsi_cmnd structure. This completely avoids dynamic memory allocations for the fast path through I/O submission. Due the preallocated requests the MQ code path exclusively uses the host-wide shared tag allocator instead of a per-LUN one. This only affects drivers actually using the block layer provided tag allocator instead of their own. Unlike the old path blk-mq always provides a tag, although drivers don't have to use it. For now the blk-mq path is disable by defauly and must be enabled using the "use_blk_mq" module parameter. Once the remaining work in the block layer to make blk-mq more suitable for slow devices is complete I hope to make it the default and eventually even remove the old code path. Based on the earlier scsi-mq prototype by Nicholas Bellinger. Thanks to Bart Van Assche and Robert Elliot for testing, benchmarking and various sugestions and code contributions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25scsi: fix the {host,target,device}_blocked counter messChristoph Hellwig
Seems like these counters are missing any sort of synchronization for updates, as a over 10 year old comment from me noted. Fix this by using atomic counters, and while we're at it also make sure they are in the same cacheline as the _busy counters and not needlessly stored to in every I/O completion. With the new model the _busy counters can temporarily go negative, so all the readers are updated to check for > 0 values. Longer term every successful I/O completion will reset the counters to zero, so the temporarily negative values will not cause any harm. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25scsi: convert host_busy to atomic_tChristoph Hellwig
Avoid taking the host-wide host_lock to check the per-host queue limit. Instead we do an atomic_inc_return early on to grab our slot in the queue, and if necessary decrement it after finishing all checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25scsi: set ->scsi_done before calling scsi_dispatch_cmdChristoph Hellwig
The blk-mq code path will set this to a different function, so make the code simpler by setting it up in a legacy-request specific place. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-25scsi: centralize command re-queueing in scsi_dispatch_fnChristoph Hellwig
Make sure we only have the logic for requeing commands in one place. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Webb Scales <webbnh@hp.com> Acked-by: Jens Axboe <axboe@kernel.dk> Tested-by: Bart Van Assche <bvanassche@acm.org> Tested-by: Robert Elliott <elliott@hp.com>
2014-07-17scsi: cleanup switch in scsi_adjust_queue_depthDouglas Gilbert
While checking what scsi_adjust_queue_depth() did I thought its switch statement could be clearer: - remove redundant assignment (to sdev->queue_depth) - re-order cases (thus removing the fall-through) Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Robert Elliott <elliott@hp.com> Tested-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-17scsi: remove various exports that were only used by scsi_tgtChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-07-17scsi: use dev_printk variants where possibleHannes Reinecke
Using dev_printk variants prefixes the logging message with the originating device, which makes debugging easier. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-17scsi: use 64-bit LUNsHannes Reinecke
The SCSI standard defines 64-bit values for LUNs, and large arrays employing large or hierarchical LUN numbers become more and more common. So update the linux SCSI stack to use 64-bit LUN numbers. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Ewan Milne <emilne@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-17scsi: remove two cancel_delayed_work() calls from the mid-layerBart Van Assche
scsi_put_command() is either invoked before blk_start_request() or after block layer processing has completed. scsi_cmnd.abort_work is scheduled from inside the SCSI timeout handler. The block layer guarantees that either the regular completion handler (softirq_done_fn()) or the timeout handler (rq_timed_out_fn()) is invoked but not both. This means that scsi_put_command() is never invoked while abort_work is scheduled. Hence remove the cancel_delayed_work() call from scsi_put_command(). Similarly, scsi_abort_command() is only invoked from the SCSI timeout handler. If scsi_abort_command() is invoked for a SCSI command with the SCSI_EH_ABORT_SCHEDULED flag set this means that scmd_eh_abort_handler() has already invoked scsi_queue_insert() and hence that scsi_cmnd.abort_work is no longer pending. Hence also remove the cancel_delayed_work() call from scsi_abort_command(). Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-04-11Merge branch 'async-scsi-resume' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci Pull async SCSI resume support from Dan Williams: "Allow disks and other devices to resume in parallel. This provides a tangible speed up for a non-esoteric use case (laptop resume): https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach" * 'async-scsi-resume' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci: scsi: async sd resume
2014-04-10scsi: async sd resumeDan Williams
async_schedule() sd resume work to allow disks and other devices to resume in parallel. This moves the entirety of scsi_device resume to an async context to ensure that scsi_device_resume() remains ordered with respect to the completion of the start/stop command. For the duration of the resume, new command submissions (that do not originate from the scsi-core) will be deferred (BLKPREP_DEFER). It adds a new ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain) as a container of these operations. Like scsi_sd_probe_domain it is flushed at sd_remove() time to ensure async ops do not continue past the end-of-life of the sdev. The implementation explicitly refrains from reusing scsi_sd_probe_domain directly for this purpose as it is flushed at the end of dpm_resume(), potentially defeating some of the benefit. Given sdevs are quiesced it is permissible for these resume operations to bleed past the async_synchronize_full() calls made by the driver core. We defer the resolution of which pm callback to call until scsi_dev_type_{suspend|resume} time and guarantee that the callback parameter is never NULL. With this in place the type of resume operation is encoded in the async function identifier. There is a concern that async resume could trigger PSU overload. In the enterprise, storage enclosures enforce staggered spin-up regardless of what the kernel does making async scanning safe by default. Outside of that context a user can disable asynchronous scanning via a kernel command line or CONFIG_SCSI_SCAN_ASYNC. Honor that setting when deciding whether to do resume asynchronously. Inspired by Todd's analysis and initial proposal [2]: https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach Cc: Len Brown <len.brown@intel.com> Cc: Phillip Susi <psusi@ubuntu.com> [alan: bug fix and clean up suggestion] Acked-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Todd Brandt <todd.e.brandt@linux.intel.com> [djbw: kick all resume work to the async queue] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-03-27[SCSI] add support for per-host cmd poolsChristoph Hellwig
This allows drivers to specify the size of their per-command private data in the host template and then get extra memory allocated for each command instead of needing another allocation in ->queuecommand. With the current SCSI code that already does multiple allocations for each command this probably doesn't make a big performance impact, but it allows to clean up the drivers, and prepare them for using the blk-mq infrastructure where the common allocation will make a difference. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27[SCSI] simplify command allocation and freeing a bitChristoph Hellwig
Just have one level of alloc/free functions that take a host instead of two levels for the allocation and different calling conventions for the free. [fengguang.wu@intel.com: docbook problems spotted, now fixed] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27[SCSI] megaraid: simplify internal command handlingChristoph Hellwig
We don't use the passed in scsi command for anything, so just add a adapter- wide internal status to go along with the internal scb that is used unter int_mtx to pass back the return value and get rid of all the complexities and abuse of the scsi_cmnd structure. This gets rid of the only user of scsi_allocate_command/scsi_free_command, which can now be removed. [jejb: checkpatch fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Adam Radford <aradford@gmail.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27[SCSI] Add EVPD page 0x83 and 0x80 to sysfsHannes Reinecke
EVPD page 0x83 is used to uniquely identify the device. So instead of having each and every program issue a separate SG_IO call to retrieve this information it does make far more sense to display it in sysfs. Some older devices (most notably tapes) will only report reliable information in page 0x80 (Unit Serial Number). So export this in the sysfs attribute 'vpd_pg80'. [jejb: checkpatch fix] [hare: attach after transport configure] [fengguang.wu@intel.com: spotted problems with the original now fixed] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-27[SCSI] Return VPD page length in scsi_vpd_inquiry()Hannes Reinecke
We should be returning the number of bytes of the requested VPD page in scsi_vpd_inquiry. This makes it easier for the caller to verify the required space. [jejb: fix up mm warning spotted by Sergey] Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15[SCSI] do not manipulate device reference counts in scsi_get/put_commandChristoph Hellwig
Many callers won't need this and we can optimize them away. In addition the handling in the __-prefixed variants was inconsistant to start with. Based on an earlier patch from Bart Van Assche. [jejb: fix kerneldoc probelm picked up by Fengguang Wu] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2014-03-15[SCSI] avoid useless free_list lock roundtripsChristoph Hellwig
Avoid hitting the host-wide free_list lock unless we need to put a command back onto the freelist. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19[SCSI] Update documentationHannes Reinecke
The documentation has gone out-of-sync, so update it to the current status. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-12-19[SCSI] improved eh timeout handlerHannes Reinecke
When a command runs into a timeout we need to send an 'ABORT TASK' TMF. This is typically done by the 'eh_abort_handler' LLDD callback. Conceptually, however, this function is a normal SCSI command, so there is no need to enter the error handler. This patch implements a new scsi_abort_command() function which invokes an asynchronous function scsi_eh_abort_handler() to abort the commands via the usual 'eh_abort_handler'. If abort succeeds the command is either retried or terminated, depending on the number of allowed retries. However, 'eh_eflags' records the abort, so if the retry would fail again the command is pushed onto the error handler without trying to abort it (again); it'll be cleared up from SCSI EH. [hare: smatch detected stray switch fixed] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-10-25[SCSI] remove check for 'resetting'Hannes Reinecke
Field is now unused, so this is dead code. [jejb: remove resetting and last_reset from Scsi_Host] Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-02[SCSI] Don't attempt to send extended INQUIRY command if skip_vpd_pages is setMartin K. Petersen
If a device has the skip_vpd_pages flag set we should simply fail the scsi_get_vpd_page() call. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Stuart Foster <smf.linux@ntlworld.com> Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-06-26[SCSI] sd: Update WRITE SAME heuristicsMartin K. Petersen
SATA drives located behind a SAS controller would incorrectly receive WRITE SAME commands. Tweak the heuristics so that: - If REPORT SUPPORTED OPERATION CODES is provided we will use that to choose between WRITE SAME(16), WRITE SAME(10) and disabled. This also fixes an issue with the old code which would issue WRITE SAME(10) despite the command not being whitelisted in REPORT SUPPORTED OPERATION CODES. - If REPORT SUPPORTED OPERATION CODES is not provided we will fall back to WRITE SAME(10) unless the device has an ATA Information VPD page. The assumption is that a SATL which is smart enough to implement WRITE SAME would also provide REPORT SUPPORTED OPERATION CODES. To facilitate the new heuristics scsi_report_opcode() has been modified to so we can distinguish between "operation not supported" and "RSOC not supported". Reported-by: H. Peter Anvin <hpa@zytor.com> Tested-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>