lwn.git/drivers/md/dm-io.c, branch docs-4.16

block: replace bi_bdev with a gendisk pointer and partitions index

2017-08-23T18:49:55+00:00

This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

Merge branch 'for-4.13/block' of git://git.kernel.dk/linux-block

2017-07-03T17:34:51+00:00

Pull core block/IO updates from Jens Axboe: "This is the main pull request for the block layer for 4.13. Not a huge round in terms of features, but there's a lot of churn related to some core cleanups. Note this depends on the UUID tree pull request, that Christoph already sent out. This pull request contains: - A series from Christoph, unifying the error/stats codes in the block layer. We now use blk_status_t everywhere, instead of using different schemes for different places. - Also from Christoph, some cleanups around request allocation and IO scheduler interactions in blk-mq. - And yet another series from Christoph, cleaning up how we handle and do bounce buffering in the block layer. - A blk-mq debugfs series from Bart, further improving on the support we have for exporting internal information to aid debugging IO hangs or stalls. - Also from Bart, a series that cleans up the request initialization differences across types of devices. - A series from Goldwyn Rodrigues, allowing the block layer to return failure if we will block and the user asked for non-blocking. - Patch from Hannes for supporting setting loop devices block size to that of the underlying device. - Two series of patches from Javier, fixing various issues with lightnvm, particular around pblk. - A series from me, adding support for write hints. This comes with NVMe support as well, so applications can help guide data placement on flash to improve performance, latencies, and write amplification. - A series from Ming, improving and hardening blk-mq support for stopping/starting and quiescing hardware queues. - Two pull requests for NVMe updates. Nothing major on the feature side, but lots of cleanups and bug fixes. From the usual crew. - A series from Neil Brown, greatly improving the bio rescue set support. Most notably, this kills the bio rescue work queues, if we don't really need them. - Lots of other little bug fixes that are all over the place" * 'for-4.13/block' of git://git.kernel.dk/linux-block: (217 commits) lightnvm: pblk: set line bitmap check under debug lightnvm: pblk: verify that cache read is still valid lightnvm: pblk: add initialization check lightnvm: pblk: remove target using async. I/Os lightnvm: pblk: use vmalloc for GC data buffer lightnvm: pblk: use right metadata buffer for recovery lightnvm: pblk: schedule if data is not ready lightnvm: pblk: remove unused return variable lightnvm: pblk: fix double-free on pblk init lightnvm: pblk: fix bad le64 assignations nvme: Makefile: remove dead build rule blk-mq: map all HWQ also in hyperthreaded system nvmet-rdma: register ib_client to not deadlock in device removal nvme_fc: fix error recovery on link down. nvmet_fc: fix crashes on bad opcodes nvme_fc: Fix crash when nvme controller connection fails. nvme_fc: replace ioabort msleep loop with completion nvme_fc: fix double calls to nvme_cleanup_cmd() nvme-fabrics: verify that a controller returns the correct NQN nvme: simplify nvme_dev_attrs_are_visible ...

dm io: fix duplicate bio completion due to missing ref count

2017-06-21T16:04:50+00:00

If only a subset of the devices associated with multiple regions support a given special operation (eg. DISCARD) then the dec_count() that is used to set error for the region must increment the io->count. Otherwise, when the dec_count() is called it can cause the dm-io caller's bio to be completed multiple times. As was reported against the dm-mirror target that had mirror legs with a mix of discard capabilities. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=196077 Reported-by: Zhang Yi Signed-off-by: Mike Snitzer

blk: make the bioset rescue_workqueue optional.

2017-06-18T18:40:59+00:00

This patch converts bioset_create() to not create a workqueue by default, so alloctions will never trigger punt_bios_to_rescuer(). It also introduces a new flag BIOSET_NEED_RESCUER which tells bioset_create() to preserve the old behavior. All callers of bioset_create() that are inside block device drivers, are given the BIOSET_NEED_RESCUER flag. biosets used by filesystems or other top-level users do not need rescuing as the bio can never be queued behind other bios. This includes fs_bio_set, blkdev_dio_pool, btrfs_bioset, xfs_ioend_bioset, and one allocated by target_core_iblock.c. biosets used by md/raid do not need rescuing as their usage was recently audited and revised to never risk deadlock. It is hoped that most, if not all, of the remaining biosets can end up being the non-rescued version. Reviewed-by: Christoph Hellwig Credit-to: Ming Lei (minor fixes) Reviewed-by: Ming Lei Signed-off-by: NeilBrown Signed-off-by: Jens Axboe

blk: replace bioset_create_nobvec() with a flags arg to bioset_create()

2017-06-18T18:40:59+00:00

"flags" arguments are often seen as good API design as they allow easy extensibility. bioset_create_nobvec() is implemented internally as a variation in flags passed to __bioset_create(). To support future extension, make the internal structure part of the API. i.e. add a 'flags' argument to bioset_create() and discard bioset_create_nobvec(). Note that the bio_split allocations in drivers/md/raid* do not need the bvec mempool - they should have used bioset_create_nobvec(). Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: NeilBrown Signed-off-by: Jens Axboe

block: switch bios to blk_status_t

2017-06-09T15:27:32+00:00

Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

dm: support REQ_OP_WRITE_ZEROES

2017-04-08T17:25:38+00:00

Copy & paste from the REQ_OP_WRITE_SAME code. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

dm io: discards don't take a payload

2017-04-08T17:25:38+00:00

Fix up do_region to not allocate a bio_vec for discards. We've got rid of the discard payload allocated by the caller years ago. Obviously this wasn't actually harmful given how long it's been there, but it's still good to avoid the pointless allocation. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

dm io: use bvec iterator helpers to implement .get_page and .next_page

2016-11-21T14:51:57+00:00

Firstly we have mature bvec/bio iterator helper for iterate each page in one bio, not necessary to reinvent a wheel to do that. Secondly the coming multipage bvecs requires this patch. Also add comments about the direct access to bvec table. Signed-off-by: Ming Lei Signed-off-by: Mike Snitzer

block: rename bio bi_rw to bi_opf

2016-08-07T20:41:02+00:00

Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe