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block-comment-for-block-and-drivers-for-linux-5.3.patch
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From c2ddb6621deaea914d312cbddefa201ca7cb385a Mon Sep 17 00:00:00 2001
From: Dongli Zhang <dongli.zhang0129@gmail.com>
Date: Sun, 1 Dec 2019 23:44:29 -0800
Subject: [PATCH 1/1] block comment for block and drivers for linux-5.3
Signed-off-by: Dongli Zhang <dongli.zhang0129@gmail.com>
---
block/badblocks.c | 26 ++
block/bio-integrity.c | 8 +
block/bio.c | 43 +++
block/blk-cgroup.c | 34 ++
block/blk-core.c | 9 +
block/blk-flush.c | 97 +++++
block/blk-integrity.c | 13 +
block/blk-iolatency.c | 243 +++++++++++++
block/blk-map.c | 62 ++++
block/blk-merge.c | 55 +++
block/blk-mq-cpumap.c | 41 +++
block/blk-mq-pci.c | 32 ++
block/blk-mq-rdma.c | 18 +
block/blk-mq-sched.c | 15 +
block/blk-mq-tag.c | 113 ++++++
block/blk-mq-tag.h | 38 ++
block/blk-mq-virtio.c | 31 ++
block/blk-mq.c | 655 ++++++++++++++++++++++++++++++++++
block/blk-mq.h | 44 +++
block/blk-rq-qos.c | 31 ++
block/blk-rq-qos.h | 28 ++
block/blk-settings.c | 17 +
block/blk-softirq.c | 46 +++
block/blk-stat.c | 14 +
block/blk-throttle.c | 4 +
block/blk-timeout.c | 42 +++
block/blk-wbt.c | 10 +
block/blk.h | 16 +
block/bounce.c | 12 +
block/partitions/check.c | 4 +
drivers/block/virtio_blk.c | 86 +++++
drivers/nvme/host/core.c | 16 +
drivers/nvme/host/fabrics.c | 11 +
drivers/nvme/host/fabrics.h | 9 +
drivers/nvme/host/fault_inject.c | 4 +
drivers/nvme/host/nvme.h | 27 ++
drivers/nvme/host/pci.c | 6 +
drivers/nvme/host/rdma.c | 687 ++++++++++++++++++++++++++++++++++++
drivers/nvme/target/core.c | 67 ++++
drivers/nvme/target/io-cmd-file.c | 35 ++
drivers/nvme/target/loop.c | 56 +++
drivers/nvme/target/nvmet.h | 11 +
drivers/scsi/fcoe/fcoe.c | 10 +
drivers/scsi/fcoe/fcoe_transport.c | 5 +
drivers/scsi/scsi_transport_fc.c | 22 ++
drivers/scsi/scsi_transport_iscsi.c | 10 +
fs/block_dev.c | 14 +
fs/direct-io.c | 21 ++
fs/iomap/direct-io.c | 7 +
include/linux/bio.h | 179 ++++++++++
include/linux/blk-cgroup.h | 10 +
include/linux/blk-mq.h | 321 +++++++++++++++++
include/linux/blk_types.h | 114 ++++++
include/linux/blkdev.h | 218 ++++++++++++
include/linux/bvec.h | 136 +++++++
include/linux/fs.h | 12 +
include/linux/percpu-refcount.h | 63 ++++
include/linux/uio.h | 26 ++
include/rdma/rdma_cm.h | 12 +
lib/iov_iter.c | 27 ++
lib/sbitmap.c | 25 ++
61 files changed, 4048 insertions(+)
diff --git a/block/badblocks.c b/block/badblocks.c
index 2e5f569..e1c1eac 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -50,6 +50,13 @@
* -1: there are bad blocks which have not yet been acknowledged in metadata.
* plus the start/length of the first bad section we overlap.
*/
+/*
+ * called by:
+ * - drivers/block/null_blk_main.c|1176| <<null_handle_cmd>> if (!is_flush && badblocks_check(&nullb->dev->badblocks, sector,
+ * - drivers/md/md.h|214| <<is_badblock>> int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s,
+ * - drivers/nvdimm/nd.h|425| <<is_bad_pmem>> return !!badblocks_check(bb, sector, len / 512, &first_bad,
+ * - drivers/nvdimm/pfn_devs.c|383| <<nd_pfn_clear_memmap_errors>> bb_present = badblocks_check(&nd_region->bb, meta_start,
+ */
int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
sector_t *first_bad, int *bad_sectors)
{
@@ -160,6 +167,14 @@ static void badblocks_update_acked(struct badblocks *bb)
* 0: success
* 1: failed to set badblocks (out of space)
*/
+/*
+ * called by:
+ * - block/badblocks.c|537| <<badblocks_store>> if (badblocks_set(bb, sector, length, !unack))
+ * - drivers/block/null_blk_main.c|384| <<nullb_device_badblocks_store>> ret = badblocks_set(&t_dev->badblocks, start,
+ * - drivers/md/md.c|1637| <<super_1_load>> if (badblocks_set(&rdev->badblocks, sector, count, 1))
+ * - drivers/md/md.c|9137| <<rdev_set_badblocks>> rv = badblocks_set(&rdev->badblocks, s, sectors, 0);
+ * - drivers/nvdimm/badrange.c|170| <<set_badblock>> if (badblocks_set(bb, s, num, 1))
+ */
int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
int acknowledged)
{
@@ -514,6 +529,12 @@ EXPORT_SYMBOL_GPL(badblocks_show);
* Return:
* Length of the buffer processed or -ve error.
*/
+/*
+ * called by:
+ * - block/genhd.c|851| <<disk_badblocks_store>> return badblocks_store(disk->bb, page, len, 0);
+ * - drivers/md/md.c|3322| <<bb_store>> int rv = badblocks_store(&rdev->badblocks, page, len, 0);
+ * - drivers/md/md.c|3337| <<ubb_store>> return badblocks_store(&rdev->badblocks, page, len, 1);
+ */
ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
int unack)
{
@@ -572,6 +593,11 @@ static int __badblocks_init(struct device *dev, struct badblocks *bb,
* 0: success
* -ve errno: on error
*/
+/*
+ * called by:
+ * - drivers/block/null_blk_main.c|514| <<null_alloc_dev>> if (badblocks_init(&dev->badblocks, 0)) {
+ * - drivers/md/md.c|3503| <<md_rdev_init>> return badblocks_init(&rdev->badblocks, 0);
+ */
int badblocks_init(struct badblocks *bb, int enable)
{
return __badblocks_init(NULL, bb, enable);
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index fb95dbb..6bb2874 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -34,6 +34,14 @@ void blk_flush_integrity(void)
* metadata. nr_vecs specifies the maximum number of pages containing
* integrity metadata that can be attached.
*/
+/*
+ * called by:
+ * - block/bio-integrity.c|249| <<bio_integrity_prep>> bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
+ * - block/bio-integrity.c|414| <<bio_integrity_clone>> bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
+ * - drivers/md/dm-crypt.c|1003| <<dm_crypt_integrity_io_alloc>> bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
+ * - drivers/nvme/host/core.c|838| <<nvme_add_user_metadata>> bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
+ * - drivers/target/target_core_iblock.c|641| <<iblock_alloc_bip>> bip = bio_integrity_alloc(bio, GFP_NOIO,
+ */
struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
gfp_t gfp_mask,
unsigned int nr_vecs)
diff --git a/block/bio.c b/block/bio.c
index 299a0e7..9d766b1 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -298,6 +298,11 @@ void bio_reset(struct bio *bio)
}
EXPORT_SYMBOL(bio_reset);
+/*
+ * called by:
+ * - block/bio.c|313| <<bio_chain_endio>> bio_endio(__bio_chain_endio(bio));
+ * - block/bio.c|1816| <<bio_endio>> bio = __bio_chain_endio(bio);
+ */
static struct bio *__bio_chain_endio(struct bio *bio)
{
struct bio *parent = bio->bi_private;
@@ -570,6 +575,9 @@ EXPORT_SYMBOL(bio_put);
*
* Caller must ensure that @bio_src is not freed before @bio.
*/
+/*
+ * cloned bio must not modify vec list
+ */
void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
{
BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
@@ -586,7 +594,13 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
bio->bi_opf = bio_src->bi_opf;
bio->bi_ioprio = bio_src->bi_ioprio;
bio->bi_write_hint = bio_src->bi_write_hint;
+ /*
+ * 类型是struct bvec_iter bi_iter;
+ */
bio->bi_iter = bio_src->bi_iter;
+ /*
+ * 类型是struct bio_vec *bi_io_vec;
+ */
bio->bi_io_vec = bio_src->bi_io_vec;
bio_clone_blkg_association(bio, bio_src);
@@ -602,10 +616,17 @@ EXPORT_SYMBOL(__bio_clone_fast);
*
* Like __bio_clone_fast, only also allocates the returned bio
*/
+/*
+ * cloned bio must not modify vec list
+ */
struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
{
struct bio *b;
+ /*
+ * If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is
+ * backed by the @bs's mempool
+ */
b = bio_alloc_bioset(gfp_mask, 0, bs);
if (!b)
return NULL;
@@ -1348,6 +1369,10 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
* Map the user space address into a bio suitable for io to a block
* device. Returns an error pointer in case of error.
*/
+/*
+ * called by:
+ * - block/blk-map.c|75| <<__blk_rq_map_user_iov>> bio = bio_map_user_iov(q, iter, gfp_mask);
+ */
struct bio *bio_map_user_iov(struct request_queue *q,
struct iov_iter *iter,
gfp_t gfp_mask)
@@ -1356,6 +1381,9 @@ struct bio *bio_map_user_iov(struct request_queue *q,
struct bio *bio;
int ret;
+ /*
+ * 返回iov_iter->count
+ */
if (!iov_iter_count(iter))
return ERR_PTR(-EINVAL);
@@ -1363,6 +1391,9 @@ struct bio *bio_map_user_iov(struct request_queue *q,
if (!bio)
return ERR_PTR(-ENOMEM);
+ /*
+ * 只要iov_iter->count不为0
+ */
while (iov_iter_count(iter)) {
struct page **pages;
ssize_t bytes;
@@ -1409,6 +1440,12 @@ struct bio *bio_map_user_iov(struct request_queue *q,
break;
}
+ /*
+ * 在以下使用BIO_USER_MAPPED:
+ * - block/bio.c|1424| <<bio_map_user_iov>> bio_set_flag(bio, BIO_USER_MAPPED);
+ * - block/blk-map.c|64| <<__blk_rq_unmap_user>> if (bio_flagged(bio, BIO_USER_MAPPED))
+ * - block/blk-map.c|168| <<blk_rq_map_user_iov>> if (!bio_flagged(bio, BIO_USER_MAPPED))
+ */
bio_set_flag(bio, BIO_USER_MAPPED);
/*
@@ -1845,6 +1882,12 @@ EXPORT_SYMBOL(bio_endio);
* to @bio's bi_io_vec; it is the caller's responsibility to ensure that
* @bio is not freed before the split.
*/
+/*
+ * 制作一个新的bio (split)
+ * split是从start到参数的sectors
+ * bio则变成从参数的sectors到最后
+ * 返回split
+ */
struct bio *bio_split(struct bio *bio, int sectors,
gfp_t gfp, struct bio_set *bs)
{
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 55a7dc2..4a68a57 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1165,6 +1165,10 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
* RETURNS:
* 0 on success, -errno on failure.
*/
+/*
+ * called by:
+ * - block/blk-core.c|535| <<blk_alloc_queue_node>> if (blkcg_init_queue(q))
+ */
int blkcg_init_queue(struct request_queue *q)
{
struct blkcg_gq *new_blkg, *blkg;
@@ -1295,6 +1299,21 @@ static void blkcg_exit(struct task_struct *tsk)
tsk->throttle_queue = NULL;
}
+/*
+ * 在以下使用io_cgrp_subsys:
+ * - block/blk-cgroup.c|1321| <<global>> EXPORT_SYMBOL_GPL(io_cgrp_subsys);
+ * - block/bfq-cgroup.c|495| <<bfq_cpd_init>> d->weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ?
+ * - block/bio.c|2137| <<bio_associate_blkg_from_page>> css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys);
+ * - block/blk-cgroup.c|1497| <<blkcg_policy_register>> WARN_ON(cgroup_add_dfl_cftypes(&io_cgrp_subsys,
+ * - block/blk-cgroup.c|1500| <<blkcg_policy_register>> WARN_ON(cgroup_add_legacy_cftypes(&io_cgrp_subsys,
+ * - block/blk-throttle.c|298| <<tg_bps_limit>> if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent)
+ * - block/blk-throttle.c|328| <<tg_iops_limit>> if (cgroup_subsys_on_dfl(io_cgrp_subsys) && !blkg->parent)
+ * - block/blk-throttle.c|537| <<throtl_pd_init>> if (cgroup_subsys_on_dfl(io_cgrp_subsys) && blkg->parent)
+ * - block/blk-throttle.c|1389| <<tg_conf_updated>> if (!cgroup_subsys_on_dfl(io_cgrp_subsys) || !blkg->parent ||
+ * - include/linux/backing-dev.h|253| <<inode_cgwb_enabled>> cgroup_subsys_on_dfl(io_cgrp_subsys) &&
+ * - mm/backing-dev.c|535| <<cgwb_create>> blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
+ * - mm/backing-dev.c|660| <<wb_get_create>> &io_cgrp_subsys);
+ */
struct cgroup_subsys io_cgrp_subsys = {
.css_alloc = blkcg_css_alloc,
.css_offline = blkcg_css_offline,
@@ -1436,6 +1455,12 @@ EXPORT_SYMBOL_GPL(blkcg_deactivate_policy);
* Register @pol with blkcg core. Might sleep and @pol may be modified on
* successful registration. Returns 0 on success and -errno on failure.
*/
+/*
+ * called by:
+ * - block/bfq-iosched.c|6762| <<bfq_init>> ret = blkcg_policy_register(&blkcg_policy_bfq);
+ * - block/blk-iolatency.c|1045| <<iolatency_init>> return blkcg_policy_register(&blkcg_policy_iolatency);
+ * - block/blk-throttle.c|2482| <<throtl_init>> return blkcg_policy_register(&blkcg_policy_throtl);
+ */
int blkcg_policy_register(struct blkcg_policy *pol)
{
struct blkcg *blkcg;
@@ -1548,6 +1573,10 @@ void blkcg_policy_unregister(struct blkcg_policy *pol)
}
EXPORT_SYMBOL_GPL(blkcg_policy_unregister);
+/*
+ * called by:
+ * - include/linux/blk-cgroup.h|714| <<blkcg_punt_bio_submit>> return __blkcg_punt_bio_submit(bio);
+ */
bool __blkcg_punt_bio_submit(struct bio *bio)
{
struct blkcg_gq *blkg = bio->bi_blkg;
@@ -1737,6 +1766,11 @@ void blkcg_maybe_throttle_current(void)
* throttle once. If the task needs to be throttled again it'll need to be
* re-set at the next time we see the task.
*/
+/*
+ * called by:
+ * - block/blk-iolatency.c|289| <<__blkcg_iolatency_throttle>> blkcg_schedule_throttle(rqos->q, use_memdelay);
+ * - mm/swapfile.c|3753| <<mem_cgroup_throttle_swaprate>> blkcg_schedule_throttle(bdev_get_queue(si->bdev),
+ */
void blkcg_schedule_throttle(struct request_queue *q, bool use_memdelay)
{
if (unlikely(current->flags & PF_KTHREAD))
diff --git a/block/blk-core.c b/block/blk-core.c
index d0cc6e1..bb92ff5 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -305,6 +305,15 @@ void blk_put_queue(struct request_queue *q)
}
EXPORT_SYMBOL(blk_put_queue);
+/*
+ * called by:
+ * - block/blk-core.c|338| <<blk_cleanup_queue>> blk_set_queue_dying(q);
+ * - drivers/block/mtip32xx/mtip32xx.c|4216| <<mtip_pci_remove>> blk_set_queue_dying(dd->queue);
+ * - drivers/block/rbd.c|7237| <<do_rbd_remove>> blk_set_queue_dying(rbd_dev->disk->queue);
+ * - drivers/md/dm.c|2377| <<__dm_destroy>> blk_set_queue_dying(md->queue);
+ * - drivers/nvme/host/core.c|107| <<nvme_set_queue_dying>> blk_set_queue_dying(ns->queue);
+ * - drivers/nvme/host/multipath.c|673| <<nvme_mpath_remove_disk>> blk_set_queue_dying(head->disk->queue);
+ */
void blk_set_queue_dying(struct request_queue *q)
{
blk_queue_flag_set(QUEUE_FLAG_DYING, q);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index aedd932..513f347 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -75,6 +75,37 @@
#include "blk-mq-tag.h"
#include "blk-mq-sched.h"
+/*
+ * 硬盘在控制器上的一块内存芯片,其类型一般以SDRAM为主,具有极快的存取速度,
+ * 它是硬盘内部存储和外界接口之间的缓冲器.由于硬盘的内部数据传输速度和外界
+ * 介面传输速度不同,缓存在其中起到一个缓冲的作用.缓存的大小与速度是直接关
+ * 系到硬盘的传输速度的重要因素,能够大幅度地提高硬盘整体性能.
+ *
+ * 如果硬盘的cache启用了,那么很有可能写入的数据是写到了硬盘的cache中,而没
+ * 有真正写到磁盘介质上.
+ *
+ * 在linux下,查看磁盘cache是否开启可通过hdparm命令:
+ *
+ * #hdparm -W /dev/sdx //是否开启cache，1为enable
+ * #hdparm -W 0 /dev/sdx //关闭cache
+ * #hdparm -W 1 /dev/sdx //enable cache
+ *
+ * REQ_FUA : forced unit access,绕过磁盘cache,直接把数据写到磁盘介质中.
+ * REQ_PREFLUSH: request for cache flush, 表示把磁盘cache中的data刷新到磁盘介质中,防止掉电丢失
+ *
+ * blk_insert_flush()是非常重要的入口!
+ */
+
+/*
+ * 冲刷的过程中request_queue为什么要使用双缓冲队列来存放fs_request?
+ *
+ * 双缓冲队列可以做到只执行一次冲刷请求就可以完成多个fs_request的冲刷要求.队列自
+ * 带的冲刷request在执行的过程中,blk_insert_flush()可以被调用多次,来自上层的
+ * fs_request被添加到pending1队列,等待冲刷request的下一次执行,当冲刷requst可以再
+ * 次被执行时,pending1队列不再接收新的fs_request(fs_request被加入到pending2队列),
+ * 冲刷request执行完毕后,pending1队列所有的fs_request的PREFLUSH/POSTFLUSH执行完毕.
+ */
+
/* PREFLUSH/FUA sequences */
enum {
REQ_FSEQ_PREFLUSH = (1 << 0), /* pre-flushing in progress */
@@ -95,13 +126,37 @@ enum {
static void blk_kick_flush(struct request_queue *q,
struct blk_flush_queue *fq, unsigned int flags);
+/*
+ * called by:
+ * - block/blk-flush.c|358| <<blk_insert_flush>> unsigned int policy = blk_flush_policy(fflags, rq);
+ */
static unsigned int blk_flush_policy(unsigned long fflags, struct request *rq)
{
+ /*
+ * If a request doesn't have data, only REQ_PREFLUSH makes sense, which
+ * indicates a simple flush request. If there is data, REQ_PREFLUSH indicates
+ * that the device cache should be flushed before the data is executed, and
+ * REQ_FUA means that the data must be on non-volatile media on request
+ * completion.
+ *
+ * If the device doesn't have writeback cache, PREFLUSH and FUA don't make any
+ * difference. The requests are either completed immediately if there's no data
+ * or executed as normal requests otherwise.
+ *
+ * If the device has writeback cache and supports FUA, REQ_PREFLUSH is
+ * translated to PREFLUSH but REQ_FUA is passed down directly with DATA.
+ *
+ * If the device has writeback cache and doesn't support FUA, REQ_PREFLUSH
+ * is translated to PREFLUSH and REQ_FUA to POSTFLUSH.
+ */
unsigned int policy = 0;
if (blk_rq_sectors(rq))
policy |= REQ_FSEQ_DATA;
+ /*
+ * QUEUE_FLAG_WC: Write back caching
+ */
if (fflags & (1UL << QUEUE_FLAG_WC)) {
if (rq->cmd_flags & REQ_PREFLUSH)
policy |= REQ_FSEQ_PREFLUSH;
@@ -313,6 +368,10 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
blk_flush_queue_rq(flush_rq, false);
}
+/*
+ * 在以下使用:
+ * - block/blk-flush.c|409| <<blk_insert_flush>> rq->end_io = mq_flush_data_end_io;
+ */
static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
{
struct request_queue *q = rq->q;
@@ -346,6 +405,11 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
* @rq is being submitted. Analyze what needs to be done and put it on the
* right queue.
*/
+/*
+ * called by:
+ * - block/blk-mq-sched.c|388| <<blk_mq_sched_insert_request>> blk_insert_flush(rq);
+ * - block/blk-mq.c|2001| <<blk_mq_make_request>> blk_insert_flush(rq);
+ */
void blk_insert_flush(struct request *rq)
{
struct request_queue *q = rq->q;
@@ -419,6 +483,31 @@ void blk_insert_flush(struct request *rq)
* room for storing the error offset in case of a flush error, if they
* wish to.
*/
+/*
+ * called by:
+ * - drivers/md/dm-integrity.c|2536| <<bitmap_flush_work>> blkdev_issue_flush(ic->dev->bdev, GFP_NOIO, NULL);
+ * - drivers/md/dm-zoned-metadata.c|660| <<dmz_write_sb>> ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL);
+ * - drivers/md/dm-zoned-metadata.c|701| <<dmz_write_dirty_mblocks>> ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL);
+ * - drivers/md/dm-zoned-metadata.c|770| <<dmz_flush_metadata>> ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL);
+ * - drivers/md/raid5-ppl.c|1040| <<ppl_recover>> ret = blkdev_issue_flush(rdev->bdev, GFP_KERNEL, NULL);
+ * - drivers/nvme/target/io-cmd-bdev.c|221| <<nvmet_bdev_flush>> if (blkdev_issue_flush(req->ns->bdev, GFP_KERNEL, NULL))
+ * - fs/block_dev.c|689| <<blkdev_fsync>> error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL);
+ * - fs/ext4/fsync.c|157| <<ext4_sync_file>> err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/ext4/ialloc.c|1427| <<ext4_init_inode_table>> blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL);
+ * - fs/ext4/super.c|5142| <<ext4_sync_fs>> err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/fat/file.c|207| <<fat_file_fsync>> return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/hfsplus/inode.c|343| <<hfsplus_file_fsync>> blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/hfsplus/super.c|242| <<hfsplus_sync_fs>> blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/jbd2/checkpoint.c|417| <<jbd2_cleanup_journal_tail>> blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
+ * - fs/jbd2/commit.c|781| <<jbd2_journal_commit_transaction>> blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
+ * - fs/jbd2/commit.c|885| <<jbd2_journal_commit_transaction>> blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
+ * - fs/jbd2/recovery.c|289| <<jbd2_journal_recover>> err2 = blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
+ * - fs/libfs.c|1040| <<generic_file_fsync>> return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/nilfs2/the_nilfs.h|378| <<nilfs_flush_device>> err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL);
+ * - fs/ocfs2/file.c|197| <<ocfs2_sync_file>> ret = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/reiserfs/file.c|168| <<reiserfs_sync_file>> blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
+ * - fs/xfs/xfs_super.c|658| <<xfs_blkdev_issue_flush>> blkdev_issue_flush(buftarg->bt_bdev, GFP_NOFS, NULL);
+ */
int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
sector_t *error_sector)
{
@@ -461,6 +550,10 @@ int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
}
EXPORT_SYMBOL(blkdev_issue_flush);
+/*
+ * called by:
+ * - block/blk-mq.c|2563| <<blk_mq_alloc_hctx>> hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size,
+ */
struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
int node, int cmd_size, gfp_t flags)
{
@@ -490,6 +583,10 @@ struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
return NULL;
}
+/*
+ * called by:
+ * - block/blk-mq-sysfs.c|43| <<blk_mq_hw_sysfs_release>> blk_free_flush_queue(hctx->fq);
+ */
void blk_free_flush_queue(struct blk_flush_queue *fq)
{
/* bio based request queue hasn't flush queue */
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index ca39b46..5dbeee2 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -385,6 +385,15 @@ static const struct blk_integrity_profile nop_profile = {
* struct with values appropriate for the underlying hardware. See
* Documentation/block/data-integrity.rst.
*/
+/*
+ * called by:
+ * - drivers/md/dm-integrity.c|3140| <<dm_integrity_set>> blk_integrity_register(disk, &bi);
+ * - drivers/md/dm-table.c|1265| <<dm_table_register_integrity>> blk_integrity_register(dm_disk(md),
+ * - drivers/md/md.c|2185| <<md_integrity_register>> blk_integrity_register(mddev->gendisk,
+ * - drivers/nvdimm/core.c|412| <<nd_integrity_init>> blk_integrity_register(disk, &bi);
+ * - drivers/nvme/host/core.c|1537| <<nvme_init_integrity>> blk_integrity_register(disk, &integrity);
+ * - drivers/scsi/sd_dif.c|81| <<sd_dif_config_host>> blk_integrity_register(disk, &bi);
+ */
void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
{
struct blk_integrity *bi = &disk->queue->integrity;
@@ -415,6 +424,10 @@ void blk_integrity_unregister(struct gendisk *disk)
}
EXPORT_SYMBOL(blk_integrity_unregister);
+/*
+ * called by:
+ * - block/genhd.c|747| <<__device_add_disk>> blk_integrity_add(disk);
+ */
void blk_integrity_add(struct gendisk *disk)
{
if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 0fff7b5..67791d3 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -78,6 +78,19 @@
#include "blk-stat.h"
#include "blk.h"
+/*
+ * 在以下使用DEFAULT_SCALE_COOKIE:
+ * - block/blk-iolatency.c|442| <<scale_cookie_change>> if (old < DEFAULT_SCALE_COOKIE)
+ * - block/blk-iolatency.c|443| <<scale_cookie_change>> diff = DEFAULT_SCALE_COOKIE - old;
+ * - block/blk-iolatency.c|446| <<scale_cookie_change>> if (scale + old > DEFAULT_SCALE_COOKIE)
+ * - block/blk-iolatency.c|448| <<scale_cookie_change>> DEFAULT_SCALE_COOKIE);
+ * - block/blk-iolatency.c|567| <<check_scale_change>> if (cur_cookie == DEFAULT_SCALE_COOKIE) {
+ * - block/blk-iolatency.c|670| <<iolatency_check_latencies>> atomic_read(&lat_info->scale_cookie) == DEFAULT_SCALE_COOKIE)
+ * - block/blk-iolatency.c|806| <<blkiolatency_timer_fn>> if (cookie >= DEFAULT_SCALE_COOKIE)
+ * - block/blk-iolatency.c|904| <<iolatency_clear_scaling>> atomic_set(&lat_info->scale_cookie, DEFAULT_SCALE_COOKIE);
+ * - block/blk-iolatency.c|1142| <<iolatency_pd_init>> atomic_set(&iolat->scale_cookie, DEFAULT_SCALE_COOKIE);
+ * - block/blk-iolatency.c|1145| <<iolatency_pd_init>> atomic_set(&iolat->child_lat.scale_cookie, DEFAULT_SCALE_COOKIE);
+ */
#define DEFAULT_SCALE_COOKIE 1000000U
static struct blkcg_policy blkcg_policy_iolatency;
@@ -89,11 +102,22 @@ struct blk_iolatency {
atomic_t enabled;
};
+/*
+ * called by:
+ * - block/blk-iolatency.c|462| <<blkcg_iolatency_throttle>> struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
+ * - block/blk-iolatency.c|647| <<blkcg_iolatency_exit>> struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
+ * - block/blk-iolatency.c|991| <<iolatency_pd_init>> struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
+ */
static inline struct blk_iolatency *BLKIOLATENCY(struct rq_qos *rqos)
{
return container_of(rqos, struct blk_iolatency, rqos);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|466| <<blkcg_iolatency_throttle>> if (!blk_iolatency_enabled(blkiolat))
+ * - block/blk-iolatency.c|611| <<blkcg_iolatency_done_bio>> enabled = blk_iolatency_enabled(iolat->blkiolat);
+ */
static inline bool blk_iolatency_enabled(struct blk_iolatency *blkiolat)
{
return atomic_read(&blkiolat->enabled) > 0;
@@ -152,7 +176,16 @@ struct iolatency_grp {
struct child_latency_info child_lat;
};
+/*
+ * 在以下使用BLKIOLATENCY_MIN_WIN_SIZE:
+ * - block/blk-iolatency.c|881| <<iolatency_set_min_lat_nsec>> iolat->cur_win_nsec = max_t(u64, val << 4, BLKIOLATENCY_MIN_WIN_SIZE);
+ */
#define BLKIOLATENCY_MIN_WIN_SIZE (100 * NSEC_PER_MSEC)
+/*
+ * 在以下使用BLKIOLATENCY_MAX_WIN_SIZE:
+ * - block/blk-iolatency.c|178| <<BLKIOLATENCY_EXP_BUCKET_SIZE>> #define BLKIOLATENCY_EXP_BUCKET_SIZE (BLKIOLATENCY_MAX_WIN_SIZE / \
+ * - block/blk-iolatency.c|883| <<iolatency_set_min_lat_nsec>> BLKIOLATENCY_MAX_WIN_SIZE);
+ */
#define BLKIOLATENCY_MAX_WIN_SIZE NSEC_PER_SEC
/*
* These are the constants used to fake the fixed-point moving average
@@ -163,9 +196,23 @@ struct iolatency_grp {
* elapse immediately. Note, windows only elapse with IO activity. Idle
* periods extend the most recent window.
*/
+/*
+ * 在以下使用BLKIOLATENCY_NR_EXP_FACTORS:
+ * - block/blk-iolatency.c|184| <<global>> static const u64 iolatency_exp_factors[BLKIOLATENCY_NR_EXP_FACTORS] = {
+ * - block/blk-iolatency.c|179| <<BLKIOLATENCY_EXP_BUCKET_SIZE>> (BLKIOLATENCY_NR_EXP_FACTORS - 1))
+ * - block/blk-iolatency.c|346| <<iolat_update_total_lat_avg>> exp_idx = min_t(int , BLKIOLATENCY_NR_EXP_FACTORS - 1,
+ */
#define BLKIOLATENCY_NR_EXP_FACTORS 5
+/*
+ * 在以下使用BLKIOLATENCY_EXP_BUCKET_SIZE:
+ * - block/blk-iolatency.c|348| <<iolat_update_total_lat_avg>> BLKIOLATENCY_EXP_BUCKET_SIZE));
+ */
#define BLKIOLATENCY_EXP_BUCKET_SIZE (BLKIOLATENCY_MAX_WIN_SIZE / \
(BLKIOLATENCY_NR_EXP_FACTORS - 1))
+/*
+ * used by:
+ * - block/blk-iolatency.c|264| <<iolat_update_total_lat_avg>> iolatency_exp_factors[exp_idx],
+ */
static const u64 iolatency_exp_factors[BLKIOLATENCY_NR_EXP_FACTORS] = {
2045, // exp(1/600) - 600 samples
2039, // exp(1/240) - 240 samples
@@ -174,21 +221,66 @@ static const u64 iolatency_exp_factors[BLKIOLATENCY_NR_EXP_FACTORS] = {
2014, // exp(1/60) - 60 samples
};
+/*
+ * called by:
+ * - block/blk-iolatency.c|184| <<blkg_to_lat>> return pd_to_lat(blkg_to_pd(blkg, &blkcg_policy_iolatency));
+ * - block/blk-iolatency.c|878| <<iolatency_prfill_limit>> struct iolatency_grp *iolat = pd_to_lat(pd);
+ * - block/blk-iolatency.c|934| <<iolatency_pd_stat>> struct iolatency_grp *iolat = pd_to_lat(pd);
+ * - block/blk-iolatency.c|988| <<iolatency_pd_init>> struct iolatency_grp *iolat = pd_to_lat(pd);
+ * - block/blk-iolatency.c|1040| <<iolatency_pd_offline>> struct iolatency_grp *iolat = pd_to_lat(pd);
+ * - block/blk-iolatency.c|1063| <<iolatency_pd_free>> struct iolatency_grp *iolat = pd_to_lat(pd);
+ */
static inline struct iolatency_grp *pd_to_lat(struct blkg_policy_data *pd)
{
return pd ? container_of(pd, struct iolatency_grp, pd) : NULL;
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|404| <<check_scale_change>> parent = blkg_to_lat(lat_to_blkg(iolat)->parent);
+ * - block/blk-iolatency.c|470| <<blkcg_iolatency_throttle>> struct iolatency_grp *iolat = blkg_to_lat(blkg);
+ * - block/blk-iolatency.c|543| <<iolatency_check_latencies>> parent = blkg_to_lat(blkg->parent);
+ * - block/blk-iolatency.c|607| <<blkcg_iolatency_done_bio>> iolat = blkg_to_lat(bio->bi_blkg);
+ * - block/blk-iolatency.c|616| <<blkcg_iolatency_done_bio>> iolat = blkg_to_lat(blkg);
+ * - block/blk-iolatency.c|682| <<blkiolatency_timer_fn>> iolat = blkg_to_lat(blkg);
+ * - block/blk-iolatency.c|760| <<iolatency_set_min_lat_nsec>> struct iolatency_grp *iolat = blkg_to_lat(blkg);
+ * - block/blk-iolatency.c|780| <<iolatency_clear_scaling>> struct iolatency_grp *iolat = blkg_to_lat(blkg->parent);
+ * - block/blk-iolatency.c|812| <<iolatency_set_limit>> iolat = blkg_to_lat(ctx.blkg);
+ * - block/blk-iolatency.c|855| <<iolatency_set_limit>> struct iolatency_grp *tmp = blkg_to_lat(blkg);
+ * - block/blk-iolatency.c|1021| <<iolatency_pd_init>> struct iolatency_grp *parent = blkg_to_lat(blkg->parent);
+ */
static inline struct iolatency_grp *blkg_to_lat(struct blkcg_gq *blkg)
{
return pd_to_lat(blkg_to_pd(blkg, &blkcg_policy_iolatency));
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|324| <<__blkcg_iolatency_throttle>> unsigned use_delay = atomic_read(&lat_to_blkg(iolat)->use_delay);
+ * - block/blk-iolatency.c|413| <<scale_change>> if (old == 1 && blkcg_unuse_delay(lat_to_blkg(iolat)))
+ * - block/blk-iolatency.c|439| <<check_scale_change>> if (lat_to_blkg(iolat)->parent == NULL)
+ * - block/blk-iolatency.c|442| <<check_scale_change>> parent = blkg_to_lat(lat_to_blkg(iolat)->parent);
+ * - block/blk-iolatency.c|483| <<check_scale_change>> blkcg_use_delay(lat_to_blkg(iolat));
+ * - block/blk-iolatency.c|489| <<check_scale_change>> blkcg_clear_delay(lat_to_blkg(iolat));
+ * - block/blk-iolatency.c|548| <<iolatency_record_time>> blkcg_add_delay(lat_to_blkg(iolat), now, sub - req_time);
+ * - block/blk-iolatency.c|564| <<iolatency_check_latencies>> struct blkcg_gq *blkg = lat_to_blkg(iolat);
+ * - block/blk-iolatency.c|1027| <<iolatency_pd_init>> struct blkcg_gq *blkg = lat_to_blkg(iolat);
+ * - block/blk-iolatency.c|1079| <<iolatency_pd_offline>> struct blkcg_gq *blkg = lat_to_blkg(iolat);
+ */
static inline struct blkcg_gq *lat_to_blkg(struct iolatency_grp *iolat)
{
return pd_to_blkg(&iolat->pd);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|571| <<iolatency_check_latencies>> latency_stat_init(iolat, &stat);
+ * - block/blk-iolatency.c|577| <<iolatency_check_latencies>> latency_stat_init(iolat, s);
+ * - block/blk-iolatency.c|625| <<iolatency_check_latencies>> latency_stat_init(iolat, &iolat->cur_stat);
+ * - block/blk-iolatency.c|944| <<iolatency_ssd_stat>> latency_stat_init(iolat, &stat);
+ * - block/blk-iolatency.c|1041| <<iolatency_pd_init>> latency_stat_init(iolat, stat);
+ * - block/blk-iolatency.c|1044| <<iolatency_pd_init>> latency_stat_init(iolat, &iolat->cur_stat);
+ */
static inline void latency_stat_init(struct iolatency_grp *iolat,
struct latency_stat *stat)
{
@@ -199,6 +291,12 @@ static inline void latency_stat_init(struct iolatency_grp *iolat,
blk_rq_stat_init(&stat->rqs);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|576| <<iolatency_check_latencies>> latency_stat_sum(iolat, &stat, s);
+ * - block/blk-iolatency.c|597| <<iolatency_check_latencies>> latency_stat_sum(iolat, &iolat->cur_stat, &stat);
+ * - block/blk-iolatency.c|949| <<iolatency_ssd_stat>> latency_stat_sum(iolat, &stat, s);
+ */
static inline void latency_stat_sum(struct iolatency_grp *iolat,
struct latency_stat *sum,
struct latency_stat *stat)
@@ -210,6 +308,10 @@ static inline void latency_stat_sum(struct iolatency_grp *iolat,
blk_rq_stat_sum(&sum->rqs, &stat->rqs);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|580| <<iolatency_record_time>> latency_stat_record_time(iolat, req_time);
+ */
static inline void latency_stat_record_time(struct iolatency_grp *iolat,
u64 req_time)
{
@@ -223,6 +325,12 @@ static inline void latency_stat_record_time(struct iolatency_grp *iolat,
put_cpu_ptr(stat);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|618| <<iolatency_check_latencies>> if (latency_sum_ok(iolat, &stat) &&
+ * - block/blk-iolatency.c|634| <<iolatency_check_latencies>> if (latency_sum_ok(iolat, &iolat->cur_stat) &&
+ * - block/blk-iolatency.c|635| <<iolatency_check_latencies>> latency_sum_ok(iolat, &stat)) {
+ */
static inline bool latency_sum_ok(struct iolatency_grp *iolat,
struct latency_stat *stat)
{
@@ -234,6 +342,12 @@ static inline bool latency_sum_ok(struct iolatency_grp *iolat,
return stat->rqs.mean <= iolat->min_lat_nsec;
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|627| <<iolatency_check_latencies>> lat_info->nr_samples += latency_stat_samples(iolat, &iolat->cur_stat);
+ * - block/blk-iolatency.c|628| <<iolatency_check_latencies>> iolat->nr_samples = latency_stat_samples(iolat, &iolat->cur_stat);
+ * - block/blk-iolatency.c|636| <<iolatency_check_latencies>> if (latency_stat_samples(iolat, &iolat->cur_stat) <
+ */
static inline u64 latency_stat_samples(struct iolatency_grp *iolat,
struct latency_stat *stat)
{
@@ -242,6 +356,10 @@ static inline u64 latency_stat_samples(struct iolatency_grp *iolat,
return stat->rqs.nr_samples;
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|615| <<iolatency_check_latencies>> iolat_update_total_lat_avg(iolat, &stat);
+ */
static inline void iolat_update_total_lat_avg(struct iolatency_grp *iolat,
struct latency_stat *stat)
{
@@ -265,18 +383,30 @@ static inline void iolat_update_total_lat_avg(struct iolatency_grp *iolat,
stat->rqs.mean);
}
+/*
+ * used by:
+ * - block/blk-iolatency.c|369| <<__blkcg_iolatency_throttle>> rq_qos_wait(rqw, iolat, iolat_acquire_inflight, iolat_cleanup_cb);
+ */
static void iolat_cleanup_cb(struct rq_wait *rqw, void *private_data)
{
atomic_dec(&rqw->inflight);
wake_up(&rqw->wait);
}
+/*
+ * used by:
+ * - block/blk-iolatency.c|369| <<__blkcg_iolatency_throttle>> rq_qos_wait(rqw, iolat, iolat_acquire_inflight, iolat_cleanup_cb);
+ */
static bool iolat_acquire_inflight(struct rq_wait *rqw, void *private_data)
{
struct iolatency_grp *iolat = private_data;
return rq_wait_inc_below(rqw, iolat->rq_depth.max_depth);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|543| <<blkcg_iolatency_throttle>> __blkcg_iolatency_throttle(rqos, iolat, issue_as_root,
+ */
static void __blkcg_iolatency_throttle(struct rq_qos *rqos,
struct iolatency_grp *iolat,
bool issue_as_root,
@@ -306,6 +436,11 @@ static void __blkcg_iolatency_throttle(struct rq_qos *rqos,
#define SCALE_DOWN_FACTOR 2
#define SCALE_UP_FACTOR 4
+/*
+ * called by:
+ * - block/blk-iolatency.c|426| <<scale_cookie_change>> unsigned long scale = scale_amount(qd, up);
+ * - block/blk-iolatency.c|466| <<scale_change>> unsigned long scale = scale_amount(qd, up);
+ */
static inline unsigned long scale_amount(unsigned long qd, bool up)
{
return max(up ? qd >> SCALE_UP_FACTOR : qd >> SCALE_DOWN_FACTOR, 1UL);
@@ -320,6 +455,12 @@ static inline unsigned long scale_amount(unsigned long qd, bool up)
* the global scale cookie goes up or down they know which way they need to go
* based on their last knowledge of it.
*/
+/*
+ * called by:
+ * - block/blk-iolatency.c|673| <<iolatency_check_latencies>> scale_cookie_change(iolat->blkiolat, lat_info, true);
+ * - block/blk-iolatency.c|683| <<iolatency_check_latencies>> scale_cookie_change(iolat->blkiolat, lat_info, false);
+ * - block/blk-iolatency.c|799| <<blkiolatency_timer_fn>> scale_cookie_change(iolat->blkiolat, lat_info, true);
+ */
static void scale_cookie_change(struct blk_iolatency *blkiolat,
struct child_latency_info *lat_info,
bool up)
@@ -362,6 +503,10 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
* queue depth at a time so we don't get wild swings and hopefully dial in to
* fairer distribution of the overall queue depth.
*/
+/*
+ * called by:
+ * - block/blk-iolatency.c|555| <<check_scale_change>> scale_change(iolat, direction > 0);
+ */
static void scale_change(struct iolatency_grp *iolat, bool up)
{
unsigned long qd = iolat->blkiolat->rqos.q->nr_requests;
@@ -388,6 +533,10 @@ static void scale_change(struct iolatency_grp *iolat, bool up)
}
/* Check our parent and see if the scale cookie has changed. */
+/*
+ * called by:
+ * - block/blk-iolatency.c|574| <<blkcg_iolatency_throttle>> check_scale_change(iolat);
+ */
static void check_scale_change(struct iolatency_grp *iolat)
{
struct iolatency_grp *parent;
@@ -457,6 +606,12 @@ static void check_scale_change(struct iolatency_grp *iolat)
scale_change(iolat, direction > 0);
}
+/*
+ * called by:
+ * - block/blk-rq-qos.c|76| <<__rq_qos_throttle>> rqos->ops->throttle(rqos, bio);
+ *
+ * struct rq_qos_ops blkcg_iolatency_ops.throttle = blkcg_iolatency_throttle()
+ */
static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio)
{
struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
@@ -482,6 +637,10 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio)
mod_timer(&blkiolat->timer, jiffies + HZ);
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|779| <<blkcg_iolatency_done_bio>> iolatency_record_time(iolat, &bio->bi_issue, now,
+ */
static void iolatency_record_time(struct iolatency_grp *iolat,
struct bio_issue *issue, u64 now,
bool issue_as_root)
@@ -517,6 +676,10 @@ static void iolatency_record_time(struct iolatency_grp *iolat,
#define BLKIOLATENCY_MIN_ADJUST_TIME (500 * NSEC_PER_MSEC)
#define BLKIOLATENCY_MIN_GOOD_SAMPLES 5
+/*
+ * called by:
+ * - block/blk-iolatency.c|633| <<blkcg_iolatency_done_bio>> iolatency_check_latencies(iolat, now);
+ */
static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now)
{
struct blkcg_gq *blkg = lat_to_blkg(iolat);
@@ -585,6 +748,12 @@ static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now)
spin_unlock_irqrestore(&lat_info->lock, flags);
}
+/*
+ * called by:
+ * - block/blk-rq-qos.c|94| <<__rq_qos_done_bio>> rqos->ops->done_bio(rqos, bio);
+ *
+ * struct rq_qos_ops blkcg_iolatency_ops.done_bio = blkcg_iolatency_done_bio()
+ */
static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
{
struct blkcg_gq *blkg;
@@ -638,6 +807,9 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
}
}
+/*
+ * struct rq_qos_ops blkcg_iolatency_ops.exit = blkcg_iolatency_exit()
+ */
static void blkcg_iolatency_exit(struct rq_qos *rqos)
{
struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
@@ -647,12 +819,20 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
kfree(blkiolat);
}
+/*
+ * 在以下使用blkcg_iolatency_ops:
+ * - block/blk-iolatency.c|886| <<blk_iolatency_init>> rqos->ops = &blkcg_iolatency_ops;
+ */
static struct rq_qos_ops blkcg_iolatency_ops = {
.throttle = blkcg_iolatency_throttle,
.done_bio = blkcg_iolatency_done_bio,
.exit = blkcg_iolatency_exit,
};
+/*
+ * used by:
+ * - block/blk-iolatency.c|898| <<blk_iolatency_init>> timer_setup(&blkiolat->timer, blkiolatency_timer_fn, 0);
+ */
static void blkiolatency_timer_fn(struct timer_list *t)
{
struct blk_iolatency *blkiolat = from_timer(blkiolat, t, timer);
@@ -714,6 +894,10 @@ static void blkiolatency_timer_fn(struct timer_list *t)
rcu_read_unlock();
}
+/*
+ * called by only:
+ * - block/blk-cgroup.c|1193| <<blkcg_init_queue>> ret = blk_iolatency_init(q);
+ */
int blk_iolatency_init(struct request_queue *q)
{
struct blk_iolatency *blkiolat;
@@ -747,6 +931,11 @@ int blk_iolatency_init(struct request_queue *q)
* return 1 for enabling iolatency, return -1 for disabling iolatency, otherwise
* return 0.
*/
+/*
+ * called by:
+ * - block/blk-iolatency.c|990| <<iolatency_set_limit>> enable = iolatency_set_min_lat_nsec(blkg, lat_val);
+ * - block/blk-iolatency.c|1194| <<iolatency_pd_offline>> ret = iolatency_set_min_lat_nsec(blkg, 0);
+ */
static int iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
{
struct iolatency_grp *iolat = blkg_to_lat(blkg);
@@ -766,6 +955,11 @@ static int iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
return 0;
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|997| <<iolatency_set_limit>> iolatency_clear_scaling(blkg);
+ * - block/blk-iolatency.c|1199| <<iolatency_pd_offline>> iolatency_clear_scaling(blkg);
+ */
static void iolatency_clear_scaling(struct blkcg_gq *blkg)
{
if (blkg->parent) {
@@ -885,6 +1079,10 @@ static int iolatency_print_limit(struct seq_file *sf, void *v)
return 0;
}
+/*
+ * called by:
+ * - block/blk-iolatency.c|932| <<iolatency_pd_stat>> return iolatency_ssd_stat(iolat, buf, size);
+ */
static size_t iolatency_ssd_stat(struct iolatency_grp *iolat, char *buf,
size_t size)
{
@@ -910,6 +1108,12 @@ static size_t iolatency_ssd_stat(struct iolatency_grp *iolat, char *buf,
iolat->rq_depth.max_depth);
}
+/*
+ * called by:
+ * - block/blk-cgroup.c|962| <<blkcg_print_stat>> written = pol->pd_stat_fn(blkg->pd[i], buf+off, size-off);
+ *
+ * struct blkcg_policy blkcg_policy_iolatency.pd_stat_fn = iolatency_pd_stat()
+ */
static size_t iolatency_pd_stat(struct blkg_policy_data *pd, char *buf,
size_t size)
{
@@ -934,6 +1138,14 @@ static size_t iolatency_pd_stat(struct blkg_policy_data *pd, char *buf,
}
+/*
+ * called by:
+ * - block/blk-cgroup.c|178| <<blkg_alloc>> pd = pol->pd_alloc_fn(gfp_mask, q->node);
+ * - block/blk-cgroup.c|1368| <<blkcg_activate_policy>> pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q->node);
+ * - block/blk-cgroup.c|1384| <<blkcg_activate_policy>> pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q->node);
+ *
+ * struct blkcg_policy blkcg_policy_iolatency.pd_alloc_fn = iolatency_pd_alloc()
+ */
static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp, int node)
{
struct iolatency_grp *iolat;
@@ -950,6 +1162,13 @@ static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp, int node)
return &iolat->pd;
}
+/*
+ * called by:
+ * - block/blk-cgroup.c|279| <<blkg_create>> pol->pd_init_fn(blkg->pd[i]);
+ * - block/blk-cgroup.c|1396| <<blkcg_activate_policy>> pol->pd_init_fn(pd);
+ *
+ * struct blkcg_policy blkcg_policy_iolatency.pd_init_fn = iolatency_pd_init()