Provide an ability to rate limit based on mbps in addition to the iops delay calculated from number of discardable extents.
Signed-off-by: Dennis Zhou <[email protected]> --- fs/btrfs/ctree.h | 2 ++ fs/btrfs/discard.c | 11 +++++++++++ fs/btrfs/sysfs.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 43 insertions(+) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index b0823961d049..e81f699347e0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -447,10 +447,12 @@ struct btrfs_discard_ctl { spinlock_t lock; struct btrfs_block_group_cache *cache; struct list_head discard_list[BTRFS_NR_DISCARD_LISTS]; + u64 prev_discard; atomic_t discard_extents; atomic64_t discardable_bytes; atomic_t delay; atomic_t iops_limit; + atomic64_t bps_limit; }; /* delayed seq elem */ diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c index c7afb5f8240d..072c73f48297 100644 --- a/fs/btrfs/discard.c +++ b/fs/btrfs/discard.c @@ -176,6 +176,13 @@ void btrfs_discard_schedule_work(struct btrfs_discard_ctl *discard_ctl, cache = find_next_cache(discard_ctl, now); if (cache) { u64 delay = atomic_read(&discard_ctl->delay); + s64 bps_limit = atomic64_read(&discard_ctl->bps_limit); + + if (bps_limit) + delay = max_t(u64, delay, + msecs_to_jiffies(MSEC_PER_SEC * + discard_ctl->prev_discard / + bps_limit)); if (now < cache->discard_delay) delay = max_t(u64, delay, @@ -213,6 +220,8 @@ static void btrfs_discard_workfn(struct work_struct *work) btrfs_trim_block_group(cache, &trimmed, cache->discard_cursor, btrfs_block_group_end(cache), 0, true); + discard_ctl->prev_discard = trimmed; + if (cache->discard_cursor >= btrfs_block_group_end(cache)) { if (btrfs_discard_bitmaps(cache)) { remove_from_discard_list(discard_ctl, cache); @@ -324,10 +333,12 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info) for (i = 0; i < BTRFS_NR_DISCARD_LISTS; i++) INIT_LIST_HEAD(&discard_ctl->discard_list[i]); + discard_ctl->prev_discard = 0; atomic_set(&discard_ctl->discard_extents, 0); atomic64_set(&discard_ctl->discardable_bytes, 0); atomic_set(&discard_ctl->delay, BTRFS_DISCARD_MAX_DELAY); atomic_set(&discard_ctl->iops_limit, BTRFS_DISCARD_MAX_IOPS); + atomic64_set(&discard_ctl->bps_limit, 0); } void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index b9a62e470316..6fc4d644401b 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -522,10 +522,40 @@ static ssize_t btrfs_discard_iops_limit_store(struct kobject *kobj, BTRFS_ATTR_RW(discard, iops_limit, btrfs_discard_iops_limit_show, btrfs_discard_iops_limit_store); +static ssize_t btrfs_discard_bps_limit_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); + + return snprintf(buf, PAGE_SIZE, "%lld\n", + atomic64_read(&fs_info->discard_ctl.bps_limit)); +} + +static ssize_t btrfs_discard_bps_limit_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj->parent); + s64 bps_limit; + int ret; + + ret = kstrtos64(buf, 10, &bps_limit); + if (ret || bps_limit < 0) + return -EINVAL; + + atomic64_set(&fs_info->discard_ctl.bps_limit, bps_limit); + + return len; +} +BTRFS_ATTR_RW(discard, bps_limit, btrfs_discard_bps_limit_show, + btrfs_discard_bps_limit_store); + static const struct attribute *discard_attrs[] = { BTRFS_ATTR_PTR(discard, discard_extents), BTRFS_ATTR_PTR(discard, discardable_bytes), BTRFS_ATTR_PTR(discard, iops_limit), + BTRFS_ATTR_PTR(discard, bps_limit), NULL, }; -- 2.17.1
