user/sven/linux.git/Documentation/block, branch v4.4.151

null_blk: register as a LightNVM device

2015-11-16T22:22:28Z

Add support for registering as a LightNVM device. This allows us to evaluate the performance of the LightNVM subsystem. In /drivers/Makefile, LightNVM is moved above block device drivers to make sure that the LightNVM media managers have been initialized before drivers under /drivers/block are initialized. Signed-off-by: Matias Bjørling Fix by Jens Axboe to remove unneeded slab cache and the following memory leak. Signed-off-by: Jens Axboe

block: add an API for Persistent Reservations

2015-10-21T20:46:56Z

This commits adds a driver API and ioctls for controlling Persistent Reservations s/genericly/generically/ at the block layer. Persistent Reservations are supported by SCSI and NVMe and allow controlling who gets access to a device in a shared storage setup. Note that we add a pr_ops structure to struct block_device_operations instead of adding the members directly to avoid bloating all instances of devices that will never support Persistent Reservations. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

Documentation: update notes in biovecs about arbitrarily sized bios

2015-08-13T18:32:07Z

Update block/biovecs.txt so that it includes a note on what kind of effects arbitrarily sized bios would bring to the block layer. Also fix a trivial typo, bio_iter_iovec. Cc: Christoph Hellwig Cc: Kent Overstreet Cc: Jonathan Corbet Cc: linux-doc@vger.kernel.org Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe

block: add a bi_error field to struct bio

2015-07-29T14:55:15Z

Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe

block: make /sys/block//queue/discard_max_bytes writeable

2015-07-17T14:41:53Z

Lots of devices support huge discard sizes these days. Depending on how the device handles them internally, huge discards can introduce massive latencies (hundreds of msec) on the device side. We have a sysfs file, discard_max_bytes, that advertises the max hardware supported discard size. Make this writeable, and split the settings into a soft and hard limit. This can be set from 'discard_granularity' and up to the hardware limit. Add a new sysfs file, 'discard_max_hw_bytes', that shows the hw set limit. Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe

Documentation: Remove mentioning of block barriers

2015-03-20T13:41:56Z

Remove mentioning of block barriers since they were removed. Reviewed-by: Christoph Hellwig Signed-off-by: Leonid V. Fedorenchik Signed-off-by: Jonathan Corbet

Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block

2014-12-13T22:14:23Z

Pull block driver core update from Jens Axboe: "This is the pull request for the core block IO changes for 3.19. Not a huge round this time, mostly lots of little good fixes: - Fix a bug in sysfs blktrace interface causing a NULL pointer dereference, when enabled/disabled through that API. From Arianna Avanzini. - Various updates/fixes/improvements for blk-mq: - A set of updates from Bart, mostly fixing buts in the tag handling. - Cleanup/code consolidation from Christoph. - Extend queue_rq API to be able to handle batching issues of IO requests. NVMe will utilize this shortly. From me. - A few tag and request handling updates from me. - Cleanup of the preempt handling for running queues from Paolo. - Prevent running of unmapped hardware queues from Ming Lei. - Move the kdump memory limiting check to be in the correct location, from Shaohua. - Initialize all software queues at init time from Takashi. This prevents a kobject warning when CPUs are brought online that weren't online when a queue was registered. - Single writeback fix for I_DIRTY clearing from Tejun. Queued with the core IO changes, since it's just a single fix. - Version X of the __bio_add_page() segment addition retry from Maurizio. Hope the Xth time is the charm. - Documentation fixup for IO scheduler merging from Jan. - Introduce (and use) generic IO stat accounting helpers for non-rq drivers, from Gu Zheng. - Kill off artificial limiting of max sectors in a request from Christoph" * 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits) bio: modify __bio_add_page() to accept pages that don't start a new segment blk-mq: Fix uninitialized kobject at CPU hotplugging blktrace: don't let the sysfs interface remove trace from running list blk-mq: Use all available hardware queues blk-mq: Micro-optimize bt_get() blk-mq: Fix a race between bt_clear_tag() and bt_get() blk-mq: Avoid that __bt_get_word() wraps multiple times blk-mq: Fix a use-after-free blk-mq: prevent unmapped hw queue from being scheduled blk-mq: re-check for available tags after running the hardware queue blk-mq: fix hang in bt_get() blk-mq: move the kdump check to blk_mq_alloc_tag_set blk-mq: cleanup tag free handling blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map blk: introduce generic io stat accounting help function blk-mq: handle the single queue case in blk_mq_hctx_next_cpu genhd: check for int overflow in disk_expand_part_tbl() blk-mq: add blk_mq_free_hctx_request() blk-mq: export blk_mq_free_request() blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable ...

scsi: add new scsi-command flag for tagged commands

2014-11-12T10:19:40Z

Currently scsi piggy backs on the block layer to define the concept of a tagged command. But we want to be able to have block-level host-wide tags assigned even for untagged commands like the initial INQUIRY, so add a new SCSI-level flag for commands that are tagged at the scsi level, so that even commands without that set can have tags assigned to them. Note that this alredy is the case for the blk-mq code path, and this just lets the old path catch up with it. We also set this flag based upon sdev->simple_tags instead of the block queue flag, so that it is entirely independent of the block layer tagging, and thus always correct even if a driver doesn't use block level tagging yet. Also remove the old blk_rq_tagged; it was only used by SCSI drivers, and removing it forces them to look for the proper replacement. Signed-off-by: Christoph Hellwig Reviewed-by: Mike Christie Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke

block: Expand a bit documentation about elevator_allow_merge_fn

2014-11-04T15:28:15Z

Explain that two requests can be merged without elevator_allow_merge_fn() being called. Signed-off-by: Jan Kara Signed-off-by: Jens Axboe

Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block

2014-10-18T18:53:51Z

Pull core block layer changes from Jens Axboe: "This is the core block IO pull request for 3.18. Apart from the new and improved flush machinery for blk-mq, this is all mostly bug fixes and cleanups. - blk-mq timeout updates and fixes from Christoph. - Removal of REQ_END, also from Christoph. We pass it through the ->queue_rq() hook for blk-mq instead, freeing up one of the request bits. The space was overly tight on 32-bit, so Martin also killed REQ_KERNEL since it's no longer used. - blk integrity updates and fixes from Martin and Gu Zheng. - Update to the flush machinery for blk-mq from Ming Lei. Now we have a per hardware context flush request, which both cleans up the code should scale better for flush intensive workloads on blk-mq. - Improve the error printing, from Rob Elliott. - Backing device improvements and cleanups from Tejun. - Fixup of a misplaced rq_complete() tracepoint from Hannes. - Make blk_get_request() return error pointers, fixing up issues where we NULL deref when a device goes bad or missing. From Joe Lawrence. - Prep work for drastically reducing the memory consumption of dm devices from Junichi Nomura. This allows creating clone bio sets without preallocating a lot of memory. - Fix a blk-mq hang on certain combinations of queue depths and hardware queues from me. - Limit memory consumption for blk-mq devices for crash dump scenarios and drivers that use crazy high depths (certain SCSI shared tag setups). We now just use a single queue and limited depth for that" * 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits) block: Remove REQ_KERNEL blk-mq: allocate cpumask on the home node bio-integrity: remove the needless fail handle of bip_slab creating block: include func name in __get_request prints block: make blk_update_request print prefix match ratelimited prefix blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio block: fix alignment_offset math that assumes io_min is a power-of-2 blk-mq: Make bt_clear_tag() easier to read blk-mq: fix potential hang if rolling wakeup depth is too high block: add bioset_create_nobvec() block: use bio_clone_fast() in blk_rq_prep_clone() block: misplaced rq_complete tracepoint sd: Honor block layer integrity handling flags block: Replace strnicmp with strncasecmp block: Add T10 Protection Information functions block: Don't merge requests if integrity flags differ block: Integrity checksum flag block: Relocate bio integrity flags block: Add a disk flag to block integrity profile block: Add prefix to block integrity profile flags ...