linux/block, branch v3.14-rc5

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

2014-02-14T18:45:18Z

Pull block IO fixes from Jens Axboe: "Second round of updates and fixes for 3.14-rc2. Most of this stuff has been queued up for a while. The notable exception is the blk-mq changes, which are naturally a bit more in flux still. The pull request contains: - Two bug fixes for the new immutable vecs, causing crashes with raid or swap. From Kent. - Various blk-mq tweaks and fixes from Christoph. A fix for integrity bio's from Nic. - A few bcache fixes from Kent and Darrick Wong. - xen-blk{front,back} fixes from David Vrabel, Matt Rushton, Nicolas Swenson, and Roger Pau Monne. - Fix for a vec miscount with integrity vectors from Martin. - Minor annotations or fixes from Masanari Iida and Rashika Kheria. - Tweak to null_blk to do more normal FIFO processing of requests from Shlomo Pongratz. - Elevator switching bypass fix from Tejun. - Softlockup in blkdev_issue_discard() fix when !CONFIG_PREEMPT from me" * 'for-linus' of git://git.kernel.dk/linux-block: (31 commits) block: add cond_resched() to potentially long running ioctl discard loop xen-blkback: init persistent_purge_work work_struct blk-mq: pair blk_mq_start_request / blk_mq_requeue_request blk-mq: dont assume rq->errors is set when returning an error from ->queue_rq block: Fix cloning of discard/write same bios block: Fix type mismatch in ssize_t_blk_mq_tag_sysfs_show blk-mq: rework flush sequencing logic null_blk: use blk_complete_request and blk_mq_complete_request virtio_blk: use blk_mq_complete_request blk-mq: rework I/O completions fs: Add prototype declaration to appropriate header file include/linux/bio.h fs: Mark function as static in fs/bio-integrity.c block/null_blk: Fix completion processing from LIFO to FIFO block: Explicitly handle discard/write same segments block: Fix nr_vecs for inline integrity vectors blk-mq: Add bio_integrity setup to blk_mq_make_request blk-mq: initialize sg_reserved_size blk-mq: handle dma_drain_size blk-mq: divert __blk_put_request for MQ ops blk-mq: support at_head inserations for blk_execute_rq ...

block: add cond_resched() to potentially long running ioctl discard loop

2014-02-12T16:36:37Z

When mkfs issues a full device discard and the device only supports discards of a smallish size, we can loop in blkdev_issue_discard() for a long time. If preempt isn't enabled, this can turn into a softlock situation and the kernel will start complaining. Add an explicit cond_resched() at the end of the loop to avoid that. Cc: stable@kernel.org Signed-off-by: Jens Axboe

blk-mq: pair blk_mq_start_request / blk_mq_requeue_request

2014-02-11T16:34:08Z

Make sure we have a proper pairing between starting and requeueing requests. Move the dma drain and REQ_END setup into blk_mq_start_request, and make sure blk_mq_requeue_request properly undoes them, giving us a pair of function to prepare and unprepare a request without leaving side effects. Together this ensures we always clean up properly after BLK_MQ_RQ_QUEUE_BUSY returns from ->queue_rq. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

blk-mq: dont assume rq->errors is set when returning an error from ->queue_rq

2014-02-11T16:34:07Z

rq->errors never has been part of the communication protocol between drivers and the block stack and most drivers will not have initialized it. Return -EIO to upper layers when the driver returns BLK_MQ_RQ_QUEUE_ERROR unconditionally. If a driver want to return a different error it can easily do so by returning success after calling blk_mq_end_io itself. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: Fix type mismatch in ssize_t_blk_mq_tag_sysfs_show

2014-02-10T17:39:53Z

cppcheck detected following format string mismatch. [blk-mq-tag.c:201]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'int'. Change "cpu" from int to unsigned int, because the cpu never become minus value. Signed-off-by: Masanari Iida Signed-off-by: Jens Axboe

blk-mq: rework flush sequencing logic

2014-02-10T16:29:00Z

Witch to using a preallocated flush_rq for blk-mq similar to what's done with the old request path. This allows us to set up the request properly with a tag from the actually allowed range and ->rq_disk as needed by some drivers. To make life easier we also switch to dynamic allocation of ->flush_rq for the old path. This effectively reverts most of "blk-mq: fix for flush deadlock" and "blk-mq: Don't reserve a tag for flush request" Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

blk-mq: rework I/O completions

2014-02-10T16:27:31Z

Rework I/O completions to work more like the old code path. blk_mq_end_io now stays out of the business of deferring completions to others CPUs and calling blk_mark_rq_complete. The latter is very important to allow completing requests that have timed out and thus are already marked completed, the former allows using the IPI callout even for driver specific completions instead of having to reimplement them. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: Explicitly handle discard/write same segments

2014-02-07T20:54:08Z

Immutable biovecs changed the way biovecs are interpreted - drivers no longer use bi_vcnt, they have to go by bi_iter.bi_size (to allow for using part of an existing segment without modifying it). This breaks with discards and write_same bios, since for those bi_size has nothing to do with segments in the biovec. So for now, we need a fairly gross hack - we fortunately know that there will never be more than one segment for the entire request, so we can special case discard/write_same. Signed-off-by: Kent Overstreet Tested-by: Hugh Dickins Signed-off-by: Jens Axboe

blk-mq: Add bio_integrity setup to blk_mq_make_request

2014-02-07T20:45:39Z

This patch adds the missing bio_integrity_enabled() + bio_integrity_prep() setup into blk_mq_make_request() in order to use DIF protection with scsi-mq. Cc: Martin K. Petersen Signed-off-by: Nicholas Bellinger Signed-off-by: Jens Axboe

blk-mq: initialize sg_reserved_size

2014-02-07T18:58:54Z

To behave the same way as the old request path. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe