diff options
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/scrub.c | 66 | ||||
| -rw-r--r-- | fs/btrfs/sysfs.c | 28 | ||||
| -rw-r--r-- | fs/btrfs/volumes.h | 3 |
3 files changed, 97 insertions, 0 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 485cda3eb8d7..518415d0c122 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -165,6 +165,10 @@ struct scrub_ctx { int readonly; int pages_per_rd_bio; + /* State of IO submission throttling affecting the associated device */ + ktime_t throttle_deadline; + u64 throttle_sent; + int is_dev_replace; u64 write_pointer; @@ -605,6 +609,7 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx( spin_lock_init(&sctx->list_lock); spin_lock_init(&sctx->stat_lock); init_waitqueue_head(&sctx->list_wait); + sctx->throttle_deadline = 0; WARN_ON(sctx->wr_curr_bio != NULL); mutex_init(&sctx->wr_lock); @@ -1988,6 +1993,65 @@ static void scrub_page_put(struct scrub_page *spage) } } +/* + * Throttling of IO submission, bandwidth-limit based, the timeslice is 1 + * second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max. + */ +static void scrub_throttle(struct scrub_ctx *sctx) +{ + const int time_slice = 1000; + struct scrub_bio *sbio; + struct btrfs_device *device; + s64 delta; + ktime_t now; + u32 div; + u64 bwlimit; + + sbio = sctx->bios[sctx->curr]; + device = sbio->dev; + bwlimit = READ_ONCE(device->scrub_speed_max); + if (bwlimit == 0) + return; + + /* + * Slice is divided into intervals when the IO is submitted, adjust by + * bwlimit and maximum of 64 intervals. + */ + div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024))); + div = min_t(u32, 64, div); + + /* Start new epoch, set deadline */ + now = ktime_get(); + if (sctx->throttle_deadline == 0) { + sctx->throttle_deadline = ktime_add_ms(now, time_slice / div); + sctx->throttle_sent = 0; + } + + /* Still in the time to send? */ + if (ktime_before(now, sctx->throttle_deadline)) { + /* If current bio is within the limit, send it */ + sctx->throttle_sent += sbio->bio->bi_iter.bi_size; + if (sctx->throttle_sent <= div_u64(bwlimit, div)) + return; + + /* We're over the limit, sleep until the rest of the slice */ + delta = ktime_ms_delta(sctx->throttle_deadline, now); + } else { + /* New request after deadline, start new epoch */ + delta = 0; + } + + if (delta) { + long timeout; + + timeout = div_u64(delta * HZ, 1000); + schedule_timeout_interruptible(timeout); + } + + /* Next call will start the deadline period */ + sctx->throttle_deadline = 0; +} + static void scrub_submit(struct scrub_ctx *sctx) { struct scrub_bio *sbio; @@ -1995,6 +2059,8 @@ static void scrub_submit(struct scrub_ctx *sctx) if (sctx->curr == -1) return; + scrub_throttle(sctx); + sbio = sctx->bios[sctx->curr]; sctx->curr = -1; scrub_pending_bio_inc(sctx); diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 436ac7b4b334..c45d9b6dfdb5 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -1455,6 +1455,33 @@ static ssize_t btrfs_devinfo_replace_target_show(struct kobject *kobj, } BTRFS_ATTR(devid, replace_target, btrfs_devinfo_replace_target_show); +static ssize_t btrfs_devinfo_scrub_speed_max_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_device *device = container_of(kobj, struct btrfs_device, + devid_kobj); + + return scnprintf(buf, PAGE_SIZE, "%llu\n", + READ_ONCE(device->scrub_speed_max)); +} + +static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_device *device = container_of(kobj, struct btrfs_device, + devid_kobj); + char *endptr; + unsigned long long limit; + + limit = memparse(buf, &endptr); + WRITE_ONCE(device->scrub_speed_max, limit); + return len; +} +BTRFS_ATTR_RW(devid, scrub_speed_max, btrfs_devinfo_scrub_speed_max_show, + btrfs_devinfo_scrub_speed_max_store); + static ssize_t btrfs_devinfo_writeable_show(struct kobject *kobj, struct kobj_attribute *a, char *buf) { @@ -1472,6 +1499,7 @@ static struct attribute *devid_attrs[] = { BTRFS_ATTR_PTR(devid, in_fs_metadata), BTRFS_ATTR_PTR(devid, missing), BTRFS_ATTR_PTR(devid, replace_target), + BTRFS_ATTR_PTR(devid, scrub_speed_max), BTRFS_ATTR_PTR(devid, writeable), NULL }; diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 9c0d84e5ec06..063ce999b9d3 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -143,6 +143,9 @@ struct btrfs_device { struct completion kobj_unregister; /* For sysfs/FSID/devinfo/devid/ */ struct kobject devid_kobj; + + /* Bandwidth limit for scrub, in bytes */ + u64 scrub_speed_max; }; /* |