summaryrefslogtreecommitdiffstats
path: root/block
Commit message (Collapse)AuthorAgeFilesLines
* block: Inline blk_integrity in struct gendiskMartin K. Petersen2015-10-213-102/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up until now the_integrity profile has been dynamically allocated and attached to struct gendisk after the disk has been made active. This causes problems because NVMe devices need to register the profile prior to the partition table being read due to a mandatory metadata buffer requirement. In addition, DM goes through hoops to deal with preallocating, but not initializing integrity profiles. Since the integrity profile is small (4 bytes + a pointer), Christoph suggested moving it to struct gendisk proper. This requires several changes: - Moving the blk_integrity definition to genhd.h. - Inlining blk_integrity in struct gendisk. - Removing the dynamic allocation code. - Adding helper functions which allow gendisk to set up and tear down the integrity sysfs dir when a disk is added/deleted. - Adding a blk_integrity_revalidate() callback for updating the stable pages bdi setting. - The calls that depend on whether a device has an integrity profile or not now key off of the bi->profile pointer. - Simplifying the integrity support routines in DM (Mike Snitzer). Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Export integrity data interval size in sysfsMartin K. Petersen2015-10-211-0/+14
| | | | | | | | | | | The size of the data interval was not exported in the sysfs integrity directory. Export it so that userland apps can tell whether the interval is different from the device's logical block size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Reduce the size of struct blk_integrityMartin K. Petersen2015-10-212-5/+5
| | | | | | | | | | | | | | | The per-device properties in the blk_integrity structure were previously unsigned short. However, most of the values fit inside a char. The only exception is the data interval size and we can work around that by storing it as a power of two. This cuts the size of the dynamic portion of blk_integrity in half. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Consolidate static integrity profile propertiesMartin K. Petersen2015-10-213-25/+16
| | | | | | | | | | | | | | | | We previously made a complete copy of a device's data integrity profile even though several of the fields inside the blk_integrity struct are pointers to fixed template entries in t10-pi.c. Split the static and per-device portions so that we can reference the template directly. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Move integrity kobject to struct gendiskMartin K. Petersen2015-10-211-11/+11
| | | | | | | | | | | | | The integrity kobject purely exists to support the integrity subdirectory in sysfs and doesn't really have anything to do with the blk_integrity data structure. Move the kobject to struct gendisk where it belongs. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge tag 'v4.3-rc4' into for-4.4/coreJens Axboe2015-10-096-65/+128
|\ | | | | | | | | | | | | Linux 4.3-rc4 Pulling in v4.3-rc4 to avoid conflicts with NVMe fixes that have gone in since for-4.4/core was based.
| * blk-mq: factor out a helper to iterate all tags for a request_queueChristoph Hellwig2015-10-013-18/+25
| | | | | | | | | | | | | | | | | | And replace the blk_mq_tag_busy_iter with it - the driver use has been replaced with a new helper a while ago, and internal to the block we only need the new version. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: fix racy updates of rq->errorsChristoph Hellwig2015-10-011-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_mq_complete_request may be a no-op if the request has already been completed by others means (e.g. a timeout or cancellation), but currently drivers have to set rq->errors before calling blk_mq_complete_request, which might leave us with the wrong error value. Add an error parameter to blk_mq_complete_request so that we can defer setting rq->errors until we known we won the race to complete the request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: fix deadlock when reading cpu_listAkinobu Mita2015-09-292-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPU hotplug handling for blk-mq (blk_mq_queue_reinit) acquires all_q_mutex in blk_mq_queue_reinit_notify() and then removes sysfs entries by blk_mq_sysfs_unregister(). Removing sysfs entry needs to be blocked until the active reference of the kernfs_node to be zero. On the other hand, reading blk_mq_hw_sysfs_cpu sysfs entry (e.g. /sys/block/nullb0/mq/0/cpu_list) acquires all_q_mutex in blk_mq_hw_sysfs_cpus_show(). If these happen at the same time, a deadlock can happen. Because one can wait for the active reference to be zero with holding all_q_mutex, and the other tries to acquire all_q_mutex with holding the active reference. The reason that all_q_mutex is acquired in blk_mq_hw_sysfs_cpus_show() is to avoid reading an imcomplete hctx->cpumask. Since reading sysfs entry for blk-mq needs to acquire q->sysfs_lock, we can avoid deadlock and reading an imcomplete hctx->cpumask by protecting q->sysfs_lock while hctx->cpumask is being updated. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: avoid inserting requests before establishing new mappingAkinobu Mita2015-09-293-19/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Notifier callbacks for CPU_ONLINE action can be run on the other CPU than the CPU which was just onlined. So it is possible for the process running on the just onlined CPU to insert request and run hw queue before establishing new mapping which is done by blk_mq_queue_reinit_notify(). This can cause a problem when the CPU has just been onlined first time since the request queue was initialized. At this time ctx->index_hw for the CPU, which is the index in hctx->ctxs[] for this ctx, is still zero before blk_mq_queue_reinit_notify() is called by notifier callbacks for CPU_ONLINE action. For example, there is a single hw queue (hctx) and two CPU queues (ctx0 for CPU0, and ctx1 for CPU1). Now CPU1 is just onlined and a request is inserted into ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is still zero. And then while running hw queue, flush_busy_ctxs() finds bit0 is set in pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list is ignored. Fix it by ensuring that new mapping is established before onlined cpu starts running. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: fix q->mq_usage_counter access raceAkinobu Mita2015-09-291-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPU hotplug handling for blk-mq (blk_mq_queue_reinit) accesses q->mq_usage_counter while freezing all request queues in all_q_list. On the other hand, q->mq_usage_counter is deinitialized in blk_mq_free_queue() before deleting the queue from all_q_list. So if CPU hotplug event occurs in the window, percpu_ref_kill() is called with q->mq_usage_counter which has already been marked dead, and it triggers warning. Fix it by deleting the queue from all_q_list earlier than destroying q->mq_usage_counter. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: Fix use after of free q->mq_mapAkinobu Mita2015-09-291-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CPU hotplug handling for blk-mq (blk_mq_queue_reinit) updates q->mq_map by blk_mq_update_queue_map() for all request queues in all_q_list. On the other hand, q->mq_map is released before deleting the queue from all_q_list. So if CPU hotplug event occurs in the window, invalid memory access can happen. Fix it by releasing q->mq_map in blk_mq_release() to make it happen latter than removal from all_q_list. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Suggested-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: fix sysfs registration/unregistration raceAkinobu Mita2015-09-292-11/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race between cpu hotplug handling and adding/deleting gendisk for blk-mq, where both are trying to register and unregister the same sysfs entries. null_add_dev --> blk_mq_init_queue --> blk_mq_init_allocated_queue --> add to 'all_q_list' (*) --> add_disk --> blk_register_queue --> blk_mq_register_disk (++) null_del_dev --> del_gendisk --> blk_unregister_queue --> blk_mq_unregister_disk (--) --> blk_cleanup_queue --> blk_mq_free_queue --> del from 'all_q_list' (*) blk_mq_queue_reinit --> blk_mq_sysfs_unregister (-) --> blk_mq_sysfs_register (+) While the request queue is added to 'all_q_list' (*), blk_mq_queue_reinit() can be called for the queue anytime by CPU hotplug callback. But blk_mq_sysfs_unregister (-) and blk_mq_sysfs_register (+) in blk_mq_queue_reinit must not be called before blk_mq_register_disk (++) and after blk_mq_unregister_disk (--) is finished. Because '/sys/block/*/mq/' is not exists. There has already been BLK_MQ_F_SYSFS_UP flag in hctx->flags which can be used to track these sysfs stuff, but it is only fixing this issue partially. In order to fix it completely, we just need per-queue flag instead of per-hctx flag with appropriate locking. So this introduces q->mq_sysfs_init_done which is properly protected with all_q_mutex. Also, we need to ensure that blk_mq_map_swqueue() is called with all_q_mutex is held. Since hctx->nr_ctx is reset temporarily and updated in blk_mq_map_swqueue(), so we should avoid blk_mq_register_hctx() seeing the temporary hctx->nr_ctx value in CPU hotplug handling or adding/deleting gendisk . Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
| * blk-mq: avoid setting hctx->tags->cpumask before allocationAkinobu Mita2015-09-291-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | When unmapped hw queue is remapped after CPU topology is changed, hctx->tags->cpumask has to be set after hctx->tags is setup in blk_mq_map_swqueue(), otherwise it causes null pointer dereference. Fixes: f26cdc8536 ("blk-mq: Shared tag enhancements") Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Keith Busch <keith.busch@intel.com> Cc: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* | block: kmemleak: Track the page allocations for struct requestCatalin Marinas2015-09-231-0/+11
|/ | | | | | | | | | | | | | | The pages allocated for struct request contain pointers to other slab allocations (via ops->init_request). Since kmemleak does not track/scan page allocations, the slab objects will be reported as leaks (false positives). This patch adds kmemleak callbacks to allow tracking of such pages. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche<bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2015-09-196-39/+61
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block updates from Jens Axboe: "This is a bit bigger than it should be, but I could (did) not want to send it off last week due to both wanting extra testing, and expecting a fix for the bounce regression as well. In any case, this contains: - Fix for the blk-merge.c compilation warning on gcc 5.x from me. - A set of back/front SG gap merge fixes, from me and from Sagi. This ensures that we honor SG gapping for integrity payloads as well. - Two small fixes for null_blk from Matias, fixing a leak and a capacity propagation issue. - A blkcg fix from Tejun, fixing a NULL dereference. - A fast clone optimization from Ming, fixing a performance regression since the arbitrarily sized bio's were introduced. - Also from Ming, a regression fix for bouncing IOs" * 'for-linus' of git://git.kernel.dk/linux-block: block: fix bounce_end_io block: blk-merge: fast-clone bio when splitting rw bios block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg block: Copy a user iovec if it includes gaps block: Refuse adding appending a gapped integrity page to a bio block: Refuse request/bio merges with gaps in the integrity payload block: Check for gaps on front and back merges null_blk: fix wrong capacity when bs is not 512 bytes null_blk: fix memory leak on cleanup block: fix bogus compiler warnings in blk-merge.c
| * block: fix bounce_end_ioMing Lei2015-09-171-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When bio bounce is involved, one new bio and its biovecs are cloned from the comming bio, which can be one fast-cloned bio from upper layer(such as dm). So it is obviously wrong to assume the start index of the coming( original) bio's io vector is zero, which can be any value between 0 and (bi_max_vecs - 1), especially in case of bio split. This patch fixes Fedora's booting oops on i386, often with the following kernel log together: > [ 9.026738] systemd[1]: Switching root. > [ 9.036467] systemd-journald[149]: Received SIGTERM from PID 1 > (systemd). > [ 9.082262] BUG: Bad page state in process kworker/u5:1 pfn:372ac > [ 9.083989] page:f3d32ae0 count:0 mapcount:0 mapping:f2252178 > index:0x16a > [ 9.085755] flags: 0x40020021(locked|lru|mappedtodisk) > [ 9.087284] page dumped because: page still charged to cgroup > [ 9.088772] bad because of flags: > [ 9.089731] flags: 0x21(locked|lru) > [ 9.090818] page->mem_cgroup:f2c3e400 Reported-by: Josh Boyer <jwboyer@fedoraproject.org> Tested-by: Adam Williamson <awilliam@redhat.com> Cc: Ming Lin <mlin@kernel.org> Cc: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: blk-merge: fast-clone bio when splitting rw biosMing Lei2015-09-171-15/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | biovecs has become immutable since v3.13, so it isn't necessary to allocate biovecs for the new cloned bios, then we can save one extra biovecs allocation/copy, and the allocation is often not fixed-length and a bit more expensive. For example, if the 'max_sectors_kb' of null blk's queue is set as 16(32 sectors) via sysfs just for making more splits, this patch can increase throught about ~70% in the sequential read test over null_blk(direct io, bs: 1M). Cc: Christoph Hellwig <hch@infradead.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Ming Lin <ming.l@ssi.samsung.com> Cc: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lei <ming.lei@canonical.com> This fixes a performance regression introduced by commit 54efd50bfd, and allows us to take full advantage of the fact that we have immutable bio_vecs. Hand applied, as it rejected violently with commit 5014c311baa2. Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkgTejun Heo2015-09-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While making the root blkg unconditional, ec13b1d6f0a0 ("blkcg: always create the blkcg_gq for the root blkcg") removed the part which clears q->root_blkg and ->root_rl.blkg during q exit. This leaves the two pointers dangling after blkg_destroy_all(). blk-throttle exit path performs blkg traversals and dereferences ->root_blkg and can lead to the following oops. BUG: unable to handle kernel NULL pointer dereference at 0000000000000558 IP: [<ffffffff81389746>] __blkg_lookup+0x26/0x70 ... task: ffff88001b4e2580 ti: ffff88001ac0c000 task.ti: ffff88001ac0c000 RIP: 0010:[<ffffffff81389746>] [<ffffffff81389746>] __blkg_lookup+0x26/0x70 ... Call Trace: [<ffffffff8138d14a>] blk_throtl_drain+0x5a/0x110 [<ffffffff8138a108>] blkcg_drain_queue+0x18/0x20 [<ffffffff81369a70>] __blk_drain_queue+0xc0/0x170 [<ffffffff8136a101>] blk_queue_bypass_start+0x61/0x80 [<ffffffff81388c59>] blkcg_deactivate_policy+0x39/0x100 [<ffffffff8138d328>] blk_throtl_exit+0x38/0x50 [<ffffffff8138a14e>] blkcg_exit_queue+0x3e/0x50 [<ffffffff8137016e>] blk_release_queue+0x1e/0xc0 ... While the bug is a straigh-forward use-after-free bug, it is tricky to reproduce because blkg release is RCU protected and the rest of exit path usually finishes before RCU grace period. This patch fixes the bug by updating blkg_destro_all() to clear q->root_blkg and ->root_rl.blkg. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: "Richard W.M. Jones" <rjones@redhat.com> Reported-by: Josh Boyer <jwboyer@fedoraproject.org> Link: http://lkml.kernel.org/g/CA+5PVA5rzQ0s4723n5rHBcxQa9t0cW8BPPBekr_9aMRoWt2aYg@mail.gmail.com Fixes: ec13b1d6f0a0 ("blkcg: always create the blkcg_gq for the root blkcg") Cc: stable@vger.kernel.org # v4.2+ Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: Copy a user iovec if it includes gapsSagi Grimberg2015-09-111-2/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | For drivers that don't support gaps in the SG lists handed to them we must bounce (copy the user buffers) and pass a bio that does not include gaps. This doesn't matter for any current user, but will help to allow iser which can't handle gaps to use the block virtual boundary instead of using driver-local bounce buffering when handling SG_IO commands. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: Refuse adding appending a gapped integrity page to a bioSagi Grimberg2015-09-111-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | This is only theoretical at the moment given that the only subsystems that generate integrity payloads are the block layer itself and the scsi target (which generate well aligned integrity payloads). But when we will expose integrity meta-data to user-space, we'll need to refuse appending a page with a gap (if the queue virtual boundary is set). Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: Refuse request/bio merges with gaps in the integrity payloadSagi Grimberg2015-09-112-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If a driver sets the block queue virtual boundary mask, it means that it cannot handle gaps so we must not allow those in the integrity payload as well. Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Fixed up by me to have duplicate integrity merge functions, depending on whether block integrity is enabled or not. Fixes a compilations issue with CONFIG_BLK_DEV_INTEGRITY unset. Signed-off-by: Jens Axboe <axboe@fb.com>
| * block: Check for gaps on front and back mergesJens Axboe2015-09-031-13/+6
| | | | | | | | | | | | | | | | | | | | | | | | We are checking for gaps to previous bio_vec, which can only detect back merges gaps. Moreover, at the point where we check for a gap, we don't know if we will attempt a back or a front merge. Thus, check for gap to prev in a back merge attempt and check for a gap to next in a front merge attempt. Signed-off-by: Jens Axboe <axboe@fb.com> [sagig: Minor rename change] Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
| * block: fix bogus compiler warnings in blk-merge.cJens Axboe2015-09-021-8/+7
| | | | | | | | | | | | | | | | | | The compiler can't figure out that bvprv is initialized whenever 'prev' is set to 1 as well. Use a pointer to bvprv instead, setting it to NULL initially, and get rid of the 'prev' tracking. This dumbs it down enough that gcc is happy. Signed-off-by: Jens Axboe <axboe@fb.com>
* | Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-blockLinus Torvalds2015-09-106-800/+891
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull blk-cg updates from Jens Axboe: "A bit later in the cycle, but this has been in the block tree for a a while. This is basically four patchsets from Tejun, that improve our buffered cgroup writeback. It was dependent on the other cgroup changes, but they went in earlier in this cycle. Series 1 is set of 5 patches that has cgroup writeback updates: - bdi_writeback iteration fix which could lead to some wb's being skipped or repeated during e.g. sync under memory pressure. - Simplification of wb work wait mechanism. - Writeback tracepoints updated to report cgroup. Series 2 is is a set of updates for the CFQ cgroup writeback handling: cfq has always charged all async IOs to the root cgroup. It didn't have much choice as writeback didn't know about cgroups and there was no way to tell who to blame for a given writeback IO. writeback finally grew support for cgroups and now tags each writeback IO with the appropriate cgroup to charge it against. This patchset updates cfq so that it follows the blkcg each bio is tagged with. Async cfq_queues are now shared across cfq_group, which is per-cgroup, instead of per-request_queue cfq_data. This makes all IOs follow the weight based IO resource distribution implemented by cfq. - Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff. - Other misc review points addressed, acks added and rebased. Series 3 is the blkcg policy cleanup patches: This patchset contains assorted cleanups for blkcg_policy methods and blk[c]g_policy_data handling. - alloc/free added for blkg_policy_data. exit dropped. - alloc/free added for blkcg_policy_data. - blk-throttle's async percpu allocation is replaced with direct allocation. - all methods now take blk[c]g_policy_data instead of blkcg_gq or blkcg. And finally, series 4 is a set of patches cleaning up the blkcg stats handling: blkcg's stats have always been somwhat of a mess. This patchset tries to improve the situation a bit. - The following patches added to consolidate blkcg entry point and blkg creation. This is in itself is an improvement and helps colllecting common stats on bio issue. - per-blkg stats now accounted on bio issue rather than request completion so that bio based and request based drivers can behave the same way. The issue was spotted by Vivek. - cfq-iosched implements custom recursive stats and blk-throttle implements custom per-cpu stats. This patchset make blkcg core support both by default. - cfq-iosched and blk-throttle keep track of the same stats multiple times. Unify them" * 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits) blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/ blkcg: implement interface for the unified hierarchy blkcg: misc preparations for unified hierarchy interface blkcg: separate out tg_conf_updated() from tg_set_conf() blkcg: move body parsing from blkg_conf_prep() to its callers blkcg: mark existing cftypes as legacy blkcg: rename subsystem name from blkio to io blkcg: refine error codes returned during blkcg configuration blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device() blkcg: reduce stack usage of blkg_rwstat_recursive_sum() blkcg: remove cfqg_stats->sectors blkcg: move io_service_bytes and io_serviced stats into blkcg_gq blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq blkcg: make blkcg_[rw]stat per-cpu blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it blkcg: consolidate blkg creation in blkcg_bio_issue_check() blk-throttle: improve queue bypass handling blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup() blkcg: inline [__]blkg_lookup() ...
| * | blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchyTejun Heo2015-08-182-15/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup is trying to make interface consistent across different controllers. For weight based resource control, the knob should have the range [1, 10000] and default to 100. This patch updates cfq-iosched so that the weight range conforms. The internal calculations have enough range and the widening of the weight range shouldn't cause any problem. * blkcg_policy->cpd_bind_fn() is added. If present, this is invoked when blkcg is attached to a hierarchy. * cfq_cpd_init() is updated to use the new default value on the unified hierarchy. * cfq_cpd_bind() callback is implemented to clear per-blkg configs and apply the default config matching the hierarchy type. * cfqd->root_group->[leaf_]weight initialization in cfq_init_queue() is moved into !CONFIG_CFQ_GROUP_IOSCHED block. cfq_cpd_bind() is now responsible for initializing the initial weights when blkcg is enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/Tejun Heo2015-08-181-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkcg is gonna switch to cgroup common weight range as defined by CGROUP_WEIGHT_* on the unified hierarchy. In preparation, rename CFQ_WEIGHT_* constants to CFQ_WEIGHT_LEGACY_*. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: implement interface for the unified hierarchyTejun Heo2015-08-183-5/+221
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkcg interface grew to be the biggest of all controllers and unfortunately most inconsistent too. The interface files are inconsistent with a number of cloes duplicates. Some files have recursive variants while others don't. There's distinction between normal and leaf weights which isn't intuitive and there are a lot of stat knobs which don't make much sense outside of debugging and expose too much implementation details to userland. In the unified hierarchy, everything is always hierarchical and internal nodes can't have tasks rendering the two structural issues twisting the current interface. The interface has to be updated in a significant anyway and this is a good chance to revamp it as a whole. This patch implements blkcg interface for the unified hierarchy. * (from a previous patch) blkcg is identified by "io" instead of "blkio" on the unified hierarchy. Given that the whole interface is updated anyway, the rename shouldn't carry noticeable conversion overhead. * The original interface consisted of 27 files is replaced with the following three files. blkio.stat : per-blkcg stats blkio.weight : per-cgroup and per-cgroup-queue weight settings blkio.max : per-cgroup-queue bps and iops max limits Documentation/cgroups/unified-hierarchy.txt updated accordingly. v2: blkcg_policy->dfl_cftypes wasn't removed on blkcg_policy_unregister() corrupting the cftypes list. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: misc preparations for unified hierarchy interfaceTejun Heo2015-08-182-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | * Export blkg_dev_name() * Drop unnecessary @cft from __cfq_set_weight(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: separate out tg_conf_updated() from tg_set_conf()Tejun Heo2015-08-181-28/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tg_set_conf() is largely consisted of parsing and setting the new config and the follow-up application and propagation. This patch separates out the latter part into tg_conf_updated(). This will be used to implement interface for the unified hierarchy. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: move body parsing from blkg_conf_prep() to its callersTejun Heo2015-08-183-20/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, blkg_conf_prep() expects input to be of the following form MAJ:MIN NUM and reads the NUM part into blkg_conf_ctx->v. This is quite restrictive and gets in the way in implementing blkcg interface for the unified hierarchy. This patch updates blkg_conf_prep() so that it expects MAJ:MIN BODY_STR where BODY_STR is an arbitrary string. blkg_conf_ctx->v is replaced with ->body which is a char pointer pointing to the start of BODY_STR. Parsing of the body is moved to blkg_conf_prep()'s callers. To allow using, for example, strsep() on blkg_conf_ctx->val, it is a non-const pointer and to accommodate that const is dropped from @input too. This doesn't cause any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: mark existing cftypes as legacyTejun Heo2015-08-183-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkcg is about to grow interface for the unified hierarchy. Add legacy to existing cftypes. * blkcg_policy->cftypes -> blkcg_policy->legacy_cftypes * blk-cgroup.c:blkcg_files -> blkcg_legacy_files * cfq-iosched.c:cfq_blkcg_files -> cfq_blkcg_legacy_files * blk-throttle.c:throtl_files -> throtl_legacy_files Pure renames. No functional change. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: rename subsystem name from blkio to ioTejun Heo2015-08-182-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkio interface has become messy over time and is currently the largest. In addition to the inconsistent naming scheme, it has multiple stat files which report more or less the same thing, a number of debug stat files which expose internal details which shouldn't have been part of the public interface in the first place, recursive and non-recursive stats and leaf and non-leaf knobs. Both recursive vs. non-recursive and leaf vs. non-leaf distinctions don't make any sense on the unified hierarchy as only leaf cgroups can contain processes. cgroups is going through a major interface revision with the unified hierarchy involving significant fundamental usage changes and given that a significant portion of the interface doesn't make sense anymore, it's a good time to reorganize the interface. As the first step, this patch renames the external visible subsystem name from "blkio" to "io". This is more concise, matches the other two major subsystem names, "cpu" and "memory", and better suited as blkcg will be involved in anything writeback related too whether an actual block device is involved or not. As the subsystem legacy_name is set to "blkio", the only userland visible change outside the unified hierarchy is that blkcg is reported as "io" instead of "blkio" in the subsystem initialized message during boot. On the unified hierarchy, blkcg now appears as "io". Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: cgroups@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: refine error codes returned during blkcg configurationTejun Heo2015-08-182-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkcg currently returns -EINVAL for most errors which can be pretty confusing given that the failure modes are quite varied. Update the error returns so that * -EINVAL only for syntactic errors. * -ERANGE if the value is out of range. * -ENODEV if the target device can't be found. * -EOPNOTSUPP if the policy is not enabled on the target device. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device()Tejun Heo2015-08-181-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkg_to_cfqg() and blkcg_to_cfqgd() on a valid blkg with the policy enabled are guaranteed to return non-NULL and the counterpart in blk-throttle doesn't have these checks either. Remove the spurious NULL checks. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: reduce stack usage of blkg_rwstat_recursive_sum()Tejun Heo2015-08-181-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent percpu conversion of blkg_rwstat triggered the following warning in certain configurations. block/blk-cgroup.c:654:1: warning: the frame size of 1360 bytes is larger than 1024 bytes This is because blkg_rwstat now contains four percpu_counter which can be pretty big depending on debug options although it shouldn't be a problem in production configs. This patch removes one of the two local blkg_rwstat variables used by blkg_rwstat_recursive_sum() to reduce stack usage. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Link: http://article.gmane.org/gmane.linux.kernel.cgroups/13835 Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: remove cfqg_stats->sectorsTejun Heo2015-08-181-19/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cfq_stats->sectors is a blkg_stat which keeps track of the total number of sectors serviced; however, this can be trivially calculated from blkcg_gq->stat_bytes. The only thing necessary is adding up READs and WRITEs and then dividing by sector size. Remove cfqg_stats->sectors and make cfq print "sectors" and "sectors_recursive" from stat_bytes. While this is a bit more code, it removes duplicate stat allocations and updates and ensures that the reported stats stay in tune with each other. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: move io_service_bytes and io_serviced stats into blkcg_gqTejun Heo2015-08-183-90/+113
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, both cfq-iosched and blk-throttle keep track of io_service_bytes and io_serviced stats. While keeping track of them separately may be useful during development, it doesn't make much sense otherwise. Also, blk-throttle was counting bio's as IOs while cfq-iosched request's, which is more confusing than informative. This patch adds ->stat_bytes and ->stat_ios to blkg (blkcg_gq), removes the counterparts from cfq-iosched and blk-throttle and let them print from the common blkg counters. The common counters are incremented during bio issue in blkcg_bio_issue_check(). The outputs are still filtered by whether the policy has blkg_policy_data on a given blkg, so cfq's output won't show up if it has never been used for a given blkg. The only times when the outputs would differ significantly are when policies are attached on the fly or elevators are switched back and forth. Those are quite exceptional operations and I don't think they warrant keeping separate counters. v3: Update blkio-controller.txt accordingly. v2: Account IOs during bio issues instead of request completions so that bio-based drivers can be handled the same way. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gqTejun Heo2015-08-182-31/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, blkg_[rw]stat_recursive_sum() assume that the target counter is located in pd (blkg_policy_data); however, some counters are planned to be moved to blkg (blkcg_gq). This patch updates blkg_[rw]stat_recursive_sum() to take blkg and blkg_policy pointers instead of pd. If policy is NULL, it indexes into blkg. If non-NULL, into the blkg's pd of the policy. The existing usages are updated to maintain the current behaviors. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: make blkcg_[rw]stat per-cpuTejun Heo2015-08-183-83/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkcg_[rw]stat are used as stat counters for blkcg policies. It isn't per-cpu by itself and blk-throttle makes it per-cpu by wrapping around it. This patch makes blkcg_[rw]stat per-cpu and drop the ad-hoc per-cpu wrapping in blk-throttle. * blkg_[rw]stat->cnt is replaced with cpu_cnt which is struct percpu_counter. This makes syncp unnecessary as remote accesses are handled by percpu_counter itself. * blkg_[rw]stat_init() can now fail due to percpu allocation failure and thus are updated to return int. * percpu_counters need explicit freeing. blkg_[rw]stat_exit() added. * As blkg_rwstat->cpu_cnt[] can't be read directly anymore, reading and summing results are stored in ->aux_cnt[] instead. * Custom per-cpu stat implementation in blk-throttle is removed. This makes all blkcg stat counters per-cpu without complicating policy implmentations. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with itTejun Heo2015-08-182-53/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup stats are local to each cgroup and doesn't propagate to ancestors by default. When recursive stats are necessary, the sum is calculated over all the descendants. This initially was for backward compatibility to support both group-local and recursive stats but this mode of operation makes general sense as stat update is much hotter thafn reporting those stats. This however ends up losing recursive stats when a child is removed. To work around this, cfq-iosched adds its stats to its parent cfq_group->dead_stats which is summed up together when calculating recursive stats. It's planned that the core stats will be moved to blkcg_gq, so we want to move the mechanism for keeping track of the stats of dead children from cfq to blkcg core. This patch adds blkg_[rw]stat->aux_cnt which are atomic64_t's keeping track of auxiliary counts which are excluded when reading local counts but included for recursive. blkg_[rw]stat_merge() which were used by cfq to implement dead_stats are replaced by blkg_[rw]stat_add_aux(), and cfq now forwards stats of a dead cgroup to the aux counts of parent->stats instead of separate ->dead_stats. This will also help making blkg_[rw]stats per-cpu. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: consolidate blkg creation in blkcg_bio_issue_check()Tejun Heo2015-08-185-97/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkg (blkcg_gq) currently is created by blkcg policies invoking blkg_lookup_create() which ends up repeating about the same code in different policies. Theoretically, this can avoid the overhead of looking and/or creating blkg's if blkcg is enabled but no policy is in use; however, the cost of blkg lookup / creation is very low especially if only the root blkcg is in use which is highly likely if no blkcg policy is in active use - it boils down to a single very predictable conditional and surrounding RCU protection. This patch consolidates blkg creation to a new function blkcg_bio_issue_check() which is called during bio issue from generic_make_request_checks(). blkcg_bio_issue_check() is now the only function which tries to create missing blkg's. The subsequent policy and request_list operations just perform blkg_lookup() and if missing falls back to the root. * blk_get_rl() no longer tries to create blkg. It uses blkg_lookup() instead of blkg_lookup_create(). * blk_throtl_bio() is now called from blkcg_bio_issue_check() with rcu read locked and blkg already looked up. Both throtl_lookup_tg() and throtl_lookup_create_tg() are dropped. * cfq is similarly updated. cfq_lookup_create_cfqg() is replaced with cfq_lookup_cfqg()which uses blkg_lookup(). This consolidates blkg handling and avoids unnecessary blkg creation retries under memory pressure. In addition, this provides a common bio entry point into blkcg where things like common accounting can be performed. v2: Build fixes for !CONFIG_CFQ_GROUP_IOSCHED and !CONFIG_BLK_DEV_THROTTLING. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-throttle: improve queue bypass handlingTejun Heo2015-08-181-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a queue is bypassing, all blkcg policies should become noops but blk-throttle wasn't. It only became noop if the queue was dying. While this wouldn't lead to an oops as falling back to the root blkg is safe in this case, this can be a bit surprising - a bypassing queue could still be applying throttle limits. Fix it by removing blk_queue_dying() test in throtl_lookup_create_tg() and testing blk_queue_bypass() in blk_throtl_bio() and bypassing before doing anything else. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: move root blkg lookup optimization from throtl_lookup_tg() to ↵Tejun Heo2015-08-181-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __blkg_lookup() Currently, both throttle and cfq policies implement their own root blkg (blkcg_gq) lookup fast path. This patch moves root blkg optimization from throtl_lookup_tg() to __blkg_lookup(). cfq-iosched currently doesn't use blkg_lookup() but will be converted and drop the optimization too. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: inline [__]blkg_lookup()Tejun Heo2015-08-181-36/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blkg_lookup() checks whether the target queue is bypassing and, if not, calls __blkg_lookup() which first checks the lookup hint and then performs radix tree walk. The operations upto hint checking are trivial and there are many users of this function. This patch inlines blkg_lookup() and the fast path part of __blkg_lookup(). The radix tree lookup and hint update are now in blkg_lookup_slowpath(). This will help consolidating blkg handling by easing moving root blkcg short-circuit to inlined lookup fast path. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: replace blkcg_policy->cpd_size with ->cpd_alloc/free_fn() methodsTejun Heo2015-08-182-16/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Each active policy has a cpd (blkcg_policy_data) on each blkcg. The cpd's were allocated by blkcg core and each policy could request to allocate extra space at the end by setting blkcg_policy->cpd_size larger than the size of cpd. This is a bit unusual but blkg (blkcg_gq) policy data used to be handled this way too so it made sense to be consistent; however, blkg policy data switched to alloc/free callbacks. This patch makes similar changes to cpd handling. blkcg_policy->cpd_alloc/free_fn() are added to replace ->cpd_size. As cpd allocation is now done from policy side, it can simply allocate a larger area which embeds cpd at the beginning. As ->cpd_alloc_fn() may be able to perform all necessary initializations, this patch makes ->cpd_init_fn() optional. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: minor updates around blkcg_policy_dataTejun Heo2015-08-182-17/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Rename blkcg->pd[] to blkcg->cpd[] so that cpd is consistently used for blkcg_policy_data. * Make blkcg_policy->cpd_init_fn() take blkcg_policy_data instead of blkcg. This makes it consistent with blkg_policy_data methods and to-be-added cpd alloc/free methods. * blkcg_policy_data->blkcg and cpd_to_blkcg() added so that cpd_init_fn() can determine the associated blkcg from blkcg_policy_data. v2: blkcg_policy_data->blkcg initializations were missing. Added. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blkcg: make blkcg_policy methods take a pointer to blkcg_policy_dataTejun Heo2015-08-183-23/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly added ->pd_alloc_fn() and ->pd_free_fn() deal with pd (blkg_policy_data) while the older ones use blkg (blkcg_gq). As using blkg doesn't make sense for ->pd_alloc_fn() and after allocation pd can always be mapped to blkg and given that these are policy-specific methods, it makes sense to converge on pd. This patch makes all methods deal with pd instead of blkg. Most conversions are trivial. In blk-cgroup.c, a couple method invocation sites now test whether pd exists instead of policy state for consistency. This shouldn't cause any behavioral differences. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-throttle: clean up blkg_policy_data alloc/init/exit/free methodsTejun Heo2015-08-183-52/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the recent addition of alloc and free methods, things became messier. This patch reorganizes them according to the followings. * ->pd_alloc_fn() Responsible for allocation and static initializations - the ones which can be done independent of where the pd might be attached. * ->pd_init_fn() Initializations which require the knowledge of where the pd is attached. * ->pd_free_fn() The counter part of pd_alloc_fn(). Static de-init and freeing. This leaves ->pd_exit_fn() without any users. Removed. While at it, collapse an one liner function throtl_pd_exit(), which has only one user, into its user. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
| * | blk-throttle: remove asynchrnous percpu stats allocation mechanismTejun Heo2015-08-181-87/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because percpu allocator couldn't do non-blocking allocations, blk-throttle was forced to implement an ad-hoc asynchronous allocation mechanism for its percpu stats for cases where blkg's (blkcg_gq's) are allocated from an IO path without sleepable context. Now that percpu allocator can handle gfp_mask and blkg_policy_data alloc / free are handled by policy methods, the ad-hoc asynchronous allocation mechanism can be replaced with direct allocation from tg_stats_alloc_fn(). Rit it out. This ensures that an active throtl_grp always has valid non-NULL ->stats_cpu. Remove checks on it. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-30 10:11:35 +0000