Summary: To save life time of journal device, we can config the device to bypass journal writes for full stripe write. This is configured by: echo "yes" > /sys/block/mdX/md/r5l_bypass_full_stripe and echo "no" > /sys/block/mdX/md/r5l_bypass_full_stripe For file system integrity, full stripe with REQ_FUA will still write to journal first. This patch applies on top of Shaohua's most recent patches: http://marc.info/?l=linux-raid&m=144122700510667 Signed-off-by: Song Liu <songliubraving@xxxxxx> Reviewed-by: Shaohua Li <shli@xxxxxx> --- drivers/md/raid5-cache.c | 20 +++++++++++++++++ drivers/md/raid5.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++ drivers/md/raid5.h | 2 ++ 3 files changed, 78 insertions(+) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 410b85b..0c3ddc5 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -82,6 +82,8 @@ struct r5l_log { struct list_head no_space_stripes; /* pending stripes, log has no space */ spinlock_t no_space_stripes_lock; + + int bypass_full_stripe; }; /* @@ -438,6 +440,7 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) int meta_size; int reserve; int i; + int fua = 0; if (!log) return -EAGAIN; @@ -453,6 +456,8 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) void *addr; if (!test_bit(R5_Wantwrite, &sh->dev[i].flags)) continue; + if (test_bit(R5_WantFUA, &sh->dev[i].flags)) + fua = 1; write_disks++; /* checksum is already calculated in last run */ if (test_bit(STRIPE_LOG_TRAPPED, &sh->state)) @@ -462,6 +467,10 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) addr, PAGE_SIZE); kunmap_atomic(addr); } + + if (log->bypass_full_stripe && (write_disks == sh->disks) && (!fua)) + return -EAGAIN; /* bypass journal device */ + parity_pages = 1 + !!(sh->qd_idx >= 0); data_pages = write_disks - parity_pages; @@ -520,6 +529,16 @@ int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio) return -EAGAIN; } +int r5l_get_bypass_full_stripe(struct r5l_log *log) +{ + return log->bypass_full_stripe; +} + +void r5l_set_bypass_full_stripe(struct r5l_log *log, int val) +{ + log->bypass_full_stripe = val; +} + /* This will run after log space is reclaimed */ static void r5l_run_no_space_stripes(struct r5l_log *log) { @@ -1105,6 +1124,7 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) if (!log->io_kc) goto io_kc; + log->bypass_full_stripe = 0; log->reclaim_thread = md_register_thread(r5l_reclaim_thread, log->rdev->mddev, "reclaim"); if (!log->reclaim_thread) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 394cdf8..5781987 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6223,6 +6223,61 @@ raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR, raid5_show_group_thread_cnt, raid5_store_group_thread_cnt); +static ssize_t +r5l_show_bypass_full_stripe(struct mddev *mddev, char *page) +{ + struct r5conf *conf; + int ret = 0; + + spin_lock(&mddev->lock); + conf = mddev->private; + if (conf) { + if (conf->log) + ret = sprintf(page, "%s\n", + r5l_get_bypass_full_stripe(conf->log) ? "yes" : "no"); + else + ret = sprintf(page, "n/a\n"); + } + spin_unlock(&mddev->lock); + return ret; +} + +static ssize_t +r5l_store_bypass_full_stripe(struct mddev *mddev, const char *page, size_t len) +{ + struct r5conf *conf; + int err = 0; + int val; + + if (strncmp(page, "yes", 3) == 0 && + (page[3] == '\n' || page[3] == '\0')) + val = 1; + else if (strncmp(page, "no", 2) == 0 && + (page[2] == '\n' || page[2] == '\0')) + val = 0; + else + return -EINVAL; + + mddev_suspend(mddev); + spin_lock(&mddev->lock); + conf = mddev->private; + if (conf) { + if (conf->log) { + r5l_set_bypass_full_stripe(conf->log, val); + } else + err = -EINVAL; + } else + err = -ENODEV; + spin_unlock(&mddev->lock); + mddev_resume(mddev); + return err ?: len; +} + +static struct md_sysfs_entry +r5l_bypass_full_stripe = __ATTR(r5l_bypass_full_stripe, S_IRUGO | S_IWUSR, + r5l_show_bypass_full_stripe, + r5l_store_bypass_full_stripe); + static struct attribute *raid5_attrs[] = { &raid5_stripecache_size.attr, &raid5_stripecache_active.attr, @@ -6230,6 +6285,7 @@ static struct attribute *raid5_attrs[] = { &raid5_group_thread_cnt.attr, &raid5_skip_copy.attr, &raid5_rmw_level.attr, + &r5l_bypass_full_stripe.attr, NULL, }; static struct attribute_group raid5_attrs_group = { diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index e6b9a40..c1f6935 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -630,4 +630,6 @@ extern void r5l_write_stripe_run(struct r5l_log *log); extern void r5l_flush_stripe_to_raid(struct r5l_log *log); extern void r5l_stripe_write_finished(struct stripe_head *sh); extern int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio); +extern int r5l_get_bypass_full_stripe(struct r5l_log *log); +extern void r5l_set_bypass_full_stripe(struct r5l_log *log, int val); #endif -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
