BMC/Intel-BMC/linux.git/block/blk-cgroup.c, branch dev-5.7

bdi: use bdi_dev_name() to get device name

2020-05-09T22:07:39+00:00

Use the common interface bdi_dev_name() to get device name. Signed-off-by: Yufen Yu Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jan Kara Reviewed-by: Bart Van Assche Add missing include BFQ Signed-off-by: Jens Axboe

blkcg: don't offline parent blkcg first

2020-04-01T20:56:44+00:00

blkcg->cgwb_refcnt is used to delay blkcg offlining so that blkgs don't get offlined while there are active cgwbs on them. However, it ends up making offlining unordered sometimes causing parents to be offlined before children. Let's fix this by making child blkcgs pin the parents' online states. Note that pin/unpin names are chosen over get/put intentionally because css uses get/put online for something different. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

blkcg: rename blkcg->cgwb_refcnt to ->online_pin and always use it

2020-04-01T20:56:42+00:00

blkcg->cgwb_refcnt is used to delay blkcg offlining so that blkgs don't get offlined while there are active cgwbs on them. However, it ends up making offlining unordered sometimes causing parents to be offlined before children. To fix it, we want child blkcgs to pin the parents' online states turning the refcnt into a more generic online pinning mechanism. In prepartion, * blkcg->cgwb_refcnt -> blkcg->online_pin * blkcg_cgwb_get/put() -> blkcg_pin/unpin_online() * Take them out of CONFIG_CGROUP_WRITEBACK Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

block: simplify queue allocation

2020-03-27T16:23:43+00:00

Current make_request based drivers use either blk_alloc_queue_node or blk_alloc_queue to allocate a queue, and then set up the make_request_fn function pointer and a few parameters using the blk_queue_make_request helper. Simplify this by passing the make_request pointer to blk_alloc_queue, and while at it merge the _node variant into the main helper by always passing a node_id, and remove the superfluous gfp_mask parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

blk-cgroup: remove blkcg_drain_queue

2019-12-12T16:26:55+00:00

Since blk_drain_queue had already been removed, so this function is not needed anymore. Signed-off-by: Guoqing Jiang Signed-off-by: Jens Axboe

blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT

2019-11-07T19:28:13+00:00

blkg_rwstat is now only used by bfq-iosched and blk-throtl when on cgroup1. Let's move it into its own files and gate it behind a config option. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

blk-cgroup: reimplement basic IO stats using cgroup rstat

2019-11-07T19:28:13+00:00

blk-cgroup has been using blkg_rwstat to track basic IO stats. Unfortunately, reading recursive stats scales badly as itinvolves walking all descendants. On systems with a huge number of cgroups (dead or alive), this can lead to substantial CPU cost when reading IO stats. This patch reimplements basic IO stats using cgroup rstat which uses more memory but makes recursive stat reading O(# descendants which have been active since last reading) instead of O(# descendants). * blk-cgroup core no longer uses sync/async stats. Introduce new stat enums - BLKG_IOSTAT_{READ|WRITE|DISCARD}. * Add blkg_iostat[_set] which encapsulates byte and io stats, last values for propagation delta calculation and u64_stats_sync for correctness on 32bit archs. * Update the new percpu stat counters directly and implement blkcg_rstat_flush() to implement propagation. * blkg_print_stat() can now bring the stats up to date by calling cgroup_rstat_flush() and print them instead of directly summing up all descendants. * It now allocates 96 bytes per cpu. It used to be 40 bytes. Signed-off-by: Tejun Heo Cc: Dan Schatzberg Cc: Daniel Xu Signed-off-by: Jens Axboe

blk-cgroup: remove now unused blkg_print_stat_{bytes|ios}_recursive()

2019-11-07T19:28:13+00:00

These don't have users anymore. Remove them. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

blkcg: make blkcg_print_stat() print stats only for online blkgs

2019-11-07T00:08:38+00:00

blkcg_print_stat() iterates blkgs under RCU and doesn't test whether the blkg is online. This can call into pd_stat_fn() on a pd which is still being initialized leading to an oops. The heaviest operation - recursively summing up rwstat counters - is already done while holding the queue_lock. Expand queue_lock to cover the other operations and skip the blkg if it isn't online yet. The online state is protected by both blkcg and queue locks, so this guarantees that only online blkgs are processed. Signed-off-by: Tejun Heo Reported-by: Roman Gushchin Cc: Josef Bacik Fixes: 903d23f0a354 ("blk-cgroup: allow controllers to output their own stats") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Jens Axboe

blkcg: Fix multiple bugs in blkcg_activate_policy()

2019-10-15T16:13:00+00:00

blkcg_activate_policy() has the following bugs. * cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") added @blkcg to ->pd_alloc_fn(); however, blkcg_activate_policy() ends up using pd's allocated for the root blkcg for all preallocations, so ->pd_init_fn() for non-root blkcgs can be passed in pd's which are allocated for the root blkcg. For blk-iocost, this means that ->pd_init_fn() can write beyond the end of the allocated object as it determines the length of the flex array at the end based on the blkcg's nesting level. * Each pd is initialized as they get allocated. If alloc fails, the policy will get freed with pd's initialized on it. * After the above partial failure, the partial pds are not freed. This patch fixes all the above issues by * Restructuring blkcg_activate_policy() so that alloc and init passes are separate. Init takes place only after all allocs succeeded and on failure all allocated pds are freed. * Unifying and fixing the cleanup of the remaining pd_prealloc. Signed-off-by: Tejun Heo Fixes: cf09a8ee19ad ("blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()") Signed-off-by: Jens Axboe