kernel/include/scsi/scsi_tcq.h, branch linux-3.17.y

scsi: set REQ_QUEUE for the blk-mq case

2014-11-14T18:10:36Z

commit b1dd2aac4cc0892b82ec60232ed37e3b0af776cc upstream. To generate the right SPI tag messages we need to properly set QUEUE_FLAG_QUEUED in the request_queue and mirror it to the request. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Acked-by: Jens Axboe Reported-by: Meelis Roos Tested-by: Meelis Roos Signed-off-by: Greg Kroah-Hartman

[SCSI] fix regression that accidentally disabled block-based tcq

2014-09-19T12:23:32Z

The scsi blk-mq support accidentally flipped a conditional, which lead to never enabling block based tcq when using the legacy request path. Fixes: d285203cf647d7c9 scsi: add support for a blk-mq based I/O path. Reported-by: Hans de Goede Signed-off-by: Christoph Hellwig Signed-off-by: James Bottomley

scsi: add support for a blk-mq based I/O path.

2014-07-25T21:16:28Z

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 Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Reviewed-by: Webb Scales Acked-by: Jens Axboe Tested-by: Bart Van Assche Tested-by: Robert Elliott

[SCSI] target: Convert TASK_ATTR to scsi_tcq.h definitions

2011-05-24T17:03:56Z

This patch converts target core and follwing scsi-misc upstream fabric modules to use include/scsi/scsi_tcq.h includes for SIMPLE, HEAD_OF_QUEUE and ORDERED SCSI tasks instead of scsi/libsas.h with TASK_ATTR* *) tcm_loop: Convert tcm_loop_allocate_core_cmd() + tcm_loop_device_reset() to scsi_tcq.h *) tcm_fc: Convert ft_send_cmd() from FCP_PTA_* to scsi_tcq.h Reported-by: Christoph Hellwig Signed-off-by: Nicholas A. Bellinger Signed-off-by: James Bottomley

block: remove spurious uses of REQ_HARDBARRIER

2010-09-10T10:35:36Z

REQ_HARDBARRIER is deprecated. Remove spurious uses in the following users. Please note that other than osdblk, all other uses were already spurious before deprecation. * osdblk: osdblk_rq_fn() won't receive any request with REQ_HARDBARRIER set. Remove the test for it. * pktcdvd: use of REQ_HARDBARRIER in pkt_generic_packet() doesn't mean anything. Removed. * aic7xxx_old: Setting MSG_ORDERED_Q_TAG on REQ_HARDBARRIER is spurious. Removed. * sas_scsi_host: Setting TASK_ATTR_ORDERED on REQ_HARDBARRIER is spurious. Removed. * scsi_tcq: The ordered tag path wasn't being used anyway. Removed. Signed-off-by: Tejun Heo Acked-by: Boaz Harrosh Cc: James Bottomley Cc: Peter Osterlund Signed-off-by: Jens Axboe

scsi: make sure that scsi_init_shared_tag_map() doesn't overwrite existing map

2008-10-27T18:25:30Z

Right now callers have to check whether scsi_host->bqt is already set up, it's much cleaner to just have scsi_init_shared_tag_map() does this check on its own. Signed-off-by: Jens Axboe

[PATCH] helper function for retrieving scsi_cmd given host based block layer tag

2006-10-04T17:32:09Z

This was necessitated by the need for a function to get back to a scsi_cmnd, when an hba the posts its (corresponding) completion interrupt with a block layer tag as its reference. Signed-off-by: Mike Christie Signed-off-by: David Somayajulu Signed-off-by: Jens Axboe

[PATCH] BLOCK: Make it possible to disable the block layer [try #6]

2006-09-30T18:52:31Z

Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells Signed-off-by: Jens Axboe

[PATCH] Split struct request ->flags into two parts

2006-09-30T18:23:37Z

Right now ->flags is a bit of a mess: some are request types, and others are just modifiers. Clean this up by splitting it into ->cmd_type and ->cmd_flags. This allows introduction of generic Linux block message types, useful for sending generic Linux commands to block devices. Signed-off-by: Jens Axboe

[SCSI] add failure return to scsi_init_shared_tag_map()

2006-09-02T18:57:28Z

And use it in the stex driver. Signed-off-by: James Bottomley