kernel/block/blk-throttle.c, branch linux-5.1.y

blk-throttle: fix zero wait time for iops throttled group

2019-07-26T07:13:07Z

commit 3a10f999ffd464d01c5a05592a15470a3c4bbc36 upstream. After commit 991f61fe7e1d ("Blk-throttle: reduce tail io latency when iops limit is enforced") wait time could be zero even if group is throttled and cannot issue requests right now. As a result throtl_select_dispatch() turns into busy-loop under irq-safe queue spinlock. Fix is simple: always round up target time to the next throttle slice. Fixes: 991f61fe7e1d ("Blk-throttle: reduce tail io latency when iops limit is enforced") Signed-off-by: Konstantin Khlebnikov Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

blkcg: consolidate bio_issue_init() to be a part of core

2018-12-08T05:26:37Z

bio_issue_init among other things initializes the timestamp for an IO. Rather than have this logic handled by policies, this consolidates it to be on the init paths (normal, clone, bounce clone). Signed-off-by: Dennis Zhou Acked-by: Tejun Heo Reviewed-by: Liu Bo Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe

blkcg: associate blkg when associating a device

2018-12-08T05:26:37Z

Previously, blkg association was handled by controller specific code in blk-throttle and blk-iolatency. However, because a blkg represents a relationship between a blkcg and a request_queue, it makes sense to keep the blkg->q and bio->bi_disk->queue consistent. This patch moves association into the bio_set_dev macro(). This should cover the majority of cases where the device is set/changed keeping the two pointers consistent. Fallback code is added to blkcg_bio_issue_check() to catch any missing paths. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe

blkcg: introduce common blkg association logic

2018-12-08T05:26:36Z

There are 3 ways blkg association can happen: association with the current css, with the page css (swap), or from the wbc css (writeback). This patch handles how association is done for the first case where we are associating bsaed on the current css. If there is already a blkg associated, the css will be reused and association will be redone as the request_queue may have changed. Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Acked-by: Tejun Heo Signed-off-by: Jens Axboe

blkcg: convert blkg_lookup_create() to find closest blkg

2018-12-08T05:26:36Z

There are several scenarios where blkg_lookup_create() can fail such as the blkcg dying, request_queue is dying, or simply being OOM. Most handle this by simply falling back to the q->root_blkg and calling it a day. This patch implements the notion of closest blkg. During blkg_lookup_create(), if it fails to create, return the closest blkg found or the q->root_blkg. blkg_try_get_closest() is introduced and used during association so a bio is always attached to a blkg. Signed-off-by: Dennis Zhou Acked-by: Tejun Heo Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe

block: add queue_is_mq() helper

2018-11-16T15:34:06Z

Various spots check for q->mq_ops being non-NULL, but provide a helper to do this instead. Where the ->mq_ops != NULL check is redundant, remove it. Since mq == rq-based now that legacy is gone, get rid of the queue_is_rq_based() and just use queue_is_mq() everywhere. Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: remove the queue_lock indirection

2018-11-15T19:17:28Z

With the legacy request path gone there is no good reason to keep queue_lock as a pointer, we can always use the embedded lock now. Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Fixed floppy and blk-cgroup missing conversions and half done edits. Signed-off-by: Jens Axboe

block: remove queue_lockdep_assert_held

2018-11-15T19:13:21Z

The only remaining user unconditionally drops and reacquires the lock, which means we really don't need any additional (conditional) annotation. Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: remove QUEUE_FLAG_BYPASS and ->bypass

2018-11-15T19:13:15Z

Unused since the removal of the legacy request code. Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

blkcg: revert blkcg cleanups series

2018-11-02T01:59:53Z

This reverts a series committed earlier due to null pointer exception bug report in [1]. It seems there are edge case interactions that I did not consider and will need some time to understand what causes the adverse interactions. The original series can be found in [2] with a follow up series in [3]. [1] https://www.spinics.net/lists/cgroups/msg20719.html [2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/ [3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/ This reverts the following commits: d459d853c2ed, b2c3fa546705, 101246ec02b5, b3b9f24f5fcc, e2b0989954ae, f0fcb3ec89f3, c839e7a03f92, bdc2491708c4, 74b7c02a9bc1, 5bf9a1f3b4ef, a7b39b4e961c, 07b05bcc3213, 49f4c2dc2b50, 27e6fa996c53 Signed-off-by: Dennis Zhou Signed-off-by: Jens Axboe