> On Mar 6, 2019, at 11:46 PM, Dabrowski, Mariusz <mariusz.dabrowski@xxxxxxxxx> wrote:
>
> On 2/18/19 3:04 PM, Mariusz Dabrowski wrote:
>> When the Partial Parity Log is enabled, circular buffer is used to store
>> PPL data. Each write to RAID device causes overwrite of data in this buffer
>> so some write_hint can be set to those request to help drives handle
>> garbage collection. This patch adds new sysfs attribute which can be used
>> to specify which write_hint should be assigned to PPL.
>>
>> Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@xxxxxxxxx>
>> ---
>> v2: moved ppl_write_hint releated stuff from raid5.c to raid5-ppl.c
>>
>> Documentation/admin-guide/md.rst | 3 ++
>> drivers/md/raid5-log.h | 1 +
>> drivers/md/raid5-ppl.c | 63 ++++++++++++++++++++++++++++++++++++++++
>> drivers/md/raid5.c | 1 +
>> 4 files changed, 68 insertions(+)
>>
>> diff --git a/Documentation/admin-guide/md.rst b/Documentation/admin-guide/md.rst
>> index 84de718f24a4..3c51084ffd37 100644
>> --- a/Documentation/admin-guide/md.rst
>> +++ b/Documentation/admin-guide/md.rst
>> @@ -756,3 +756,6 @@ These currently include:
>> The cache mode for raid5. raid5 could include an extra disk for
>> caching. The mode can be "write-throuth" and "write-back". The
>> default is "write-through".
>> +
>> + ppl_write_hint
>> + NVMe stream ID to be set for each PPL write request.
>> diff --git a/drivers/md/raid5-log.h b/drivers/md/raid5-log.h
>> index bfb811407061..43c714a8798c 100644
>> --- a/drivers/md/raid5-log.h
>> +++ b/drivers/md/raid5-log.h
>> @@ -45,6 +45,7 @@ extern void ppl_stripe_write_finished(struct stripe_head *sh);
>> extern int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add);
>> extern void ppl_quiesce(struct r5conf *conf, int quiesce);
>> extern int ppl_handle_flush_request(struct r5l_log *log, struct bio *bio);
>> +extern struct md_sysfs_entry ppl_write_hint;
>>
>> static inline bool raid5_has_log(struct r5conf *conf)
>> {
>> diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
>> index 3a7c36326589..f2b3020c2ac8 100644
>> --- a/drivers/md/raid5-ppl.c
>> +++ b/drivers/md/raid5-ppl.c
>> @@ -21,6 +21,7 @@
>> #include <linux/raid/md_p.h>
>> #include "md.h"
>> #include "raid5.h"
>> +#include "raid5-log.h"
>>
>> /*
>> * PPL consists of a 4KB header (struct ppl_header) and at least 128KB for
>> @@ -116,6 +117,8 @@ struct ppl_conf {
>> /* stripes to retry if failed to allocate io_unit */
>> struct list_head no_mem_stripes;
>> spinlock_t no_mem_stripes_lock;
>> +
>> + unsigned short write_hint;
>> };
>>
>> struct ppl_log {
>> @@ -476,6 +479,7 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
>> bio_set_dev(bio, log->rdev->bdev);
>> bio->bi_iter.bi_sector = log->next_io_sector;
>> bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
>> + bio->bi_write_hint = ppl_conf->write_hint;
>>
>> pr_debug("%s: log->current_io_sector: %llu\n", __func__,
>> (unsigned long long)log->next_io_sector);
>> @@ -505,6 +509,7 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
>> bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES,
>> &ppl_conf->bs);
>> bio->bi_opf = prev->bi_opf;
>> + bio->bi_write_hint = prev->bi_write_hint;
>> bio_copy_dev(bio, prev);
>> bio->bi_iter.bi_sector = bio_end_sector(prev);
>> bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);
>> @@ -1409,6 +1414,7 @@ int ppl_init_log(struct r5conf *conf)
>> atomic64_set(&ppl_conf->seq, 0);
>> INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
>> spin_lock_init(&ppl_conf->no_mem_stripes_lock);
>> + ppl_conf->write_hint = RWF_WRITE_LIFE_NOT_SET;
>>
>> if (!mddev->external) {
>> ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
>> @@ -1503,3 +1509,60 @@ int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
>>
>> return ret;
>> }
>> +
>> +static ssize_t
>> +ppl_write_hint_show(struct mddev *mddev, char *buf)
>> +{
>> + size_t ret = 0;
>> + struct r5conf *conf;
>> + struct ppl_conf *ppl_conf = NULL;
>> +
>> + spin_lock(&mddev->lock);
>> + conf = mddev->private;
>> + if (conf && raid5_has_ppl(conf))
>> + ppl_conf = conf->log_private;
>> + ret = sprintf(buf, "%d\n", ppl_conf ? ppl_conf->write_hint : 0);
>> + spin_unlock(&mddev->lock);
>> +
>> + return ret;
>> +}
>> +
>> +static ssize_t
>> +ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
>> +{
>> + struct r5conf *conf;
>> + struct ppl_conf *ppl_conf;
>> + int err = 0;
>> + unsigned short new;
>> +
>> + if (len >= PAGE_SIZE)
>> + return -EINVAL;
>> + if (kstrtou16(page, 10, &new))
>> + return -EINVAL;
>> +
>> + err = mddev_lock(mddev);
>> + if (err)
>> + return err;
>> +
>> + conf = mddev->private;
>> + if (!conf) {
>> + err = -ENODEV;
>> + } else if (raid5_has_ppl(conf)) {
>> + ppl_conf = conf->log_private;
>> + if (!ppl_conf)
>> + err = -EINVAL;
>> + else
>> + ppl_conf->write_hint = new;
>> + } else {
>> + err = -EINVAL;
>> + }
>> +
>> + mddev_unlock(mddev);
>> +
>> + return err ?: len;
>> +}
>> +
>> +struct md_sysfs_entry
>> +ppl_write_hint = __ATTR(ppl_write_hint, S_IRUGO | S_IWUSR,
>> + ppl_write_hint_show,
>> + ppl_write_hint_store);
>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>> index cecea901ab8c..09562d7cc080 100644
>> --- a/drivers/md/raid5.c
>> +++ b/drivers/md/raid5.c
>> @@ -6660,6 +6660,7 @@ static struct attribute *raid5_attrs[] = {
>> &raid5_skip_copy.attr,
>> &raid5_rmw_level.attr,
>> &r5c_journal_mode.attr,
>> + &ppl_write_hint.attr,
>> NULL,
>> };
>> static struct attribute_group raid5_attrs_group = {
>>
>
> Ping
Sorry for the delay. I somehow missed this one during vacation.
Guoqing, could you please give "Acked-by" or "Reviewed-by" on this?
Thanks,
Song
