Add a source file for the new policy implementation and allow selecting
the policy based on the policy_type parameter in r5l_init_log().
Introduce a new flag for rdev state flags to allow enabling the new
policy from userspace.
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx>
---
drivers/md/Makefile | 2 +-
drivers/md/md.c | 5 +++++
drivers/md/md.h | 3 +++
drivers/md/raid5-cache.c | 17 +++++++++++++++--
drivers/md/raid5-cache.h | 9 ++++++++-
drivers/md/raid5-ppl.c | 20 ++++++++++++++++++++
drivers/md/raid5.c | 42 ++++++++++++++++++++++++++++++++++++------
7 files changed, 88 insertions(+), 10 deletions(-)
create mode 100644 drivers/md/raid5-ppl.c
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 3cbda1a..4d48714 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -18,7 +18,7 @@ dm-cache-cleaner-y += dm-cache-policy-cleaner.o
dm-era-y += dm-era-target.o
dm-verity-y += dm-verity-target.o
md-mod-y += md.o bitmap.o
-raid456-y += raid5.o raid5-cache.o
+raid456-y += raid5.o raid5-cache.o raid5-ppl.o
# Note: link order is important. All raid personalities
# and must come before md.o, as they each initialise
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c7894fb..4876687 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2575,6 +2575,8 @@ state_show(struct md_rdev *rdev, char *page)
len += sprintf(page+len, "journal%s", sep);
if (test_bit(WriteMostly, &flags))
len += sprintf(page+len, "write_mostly%s", sep);
+ if (test_bit(JournalPpl, &flags))
+ len += sprintf(page+len, "journal_ppl%s", sep);
if (test_bit(Blocked, &flags) ||
(rdev->badblocks.unacked_exist
&& !test_bit(Faulty, &flags)))
@@ -2753,6 +2755,9 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
} else if (cmd_match(buf, "-external_bbl") && (rdev->mddev->external)) {
clear_bit(ExternalBbl, &rdev->flags);
err = 0;
+ } else if (cmd_match(buf, "journal_ppl")) {
+ set_bit(JournalPpl, &rdev->flags);
+ err = 0;
}
if (!err)
sysfs_notify_dirent_safe(rdev->sysfs_state);
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 5c08f84..2fc75ac 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -172,6 +172,9 @@ enum flag_bits {
* Usually, this device should be faster
* than other devices in the array
*/
+ JournalPpl, /* This device is used for raid5
+ * Partial Parity Log.
+ */
ClusterRemove,
RemoveSynchronized, /* synchronize_rcu() was called after
* this device was known to be faulty,
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index b10bd4c..9de122a 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -2539,16 +2539,29 @@ struct r5l_policy r5l_journal = {
.handle_flush_request = __r5l_handle_flush_request,
.quiesce = __r5l_quiesce,
};
+extern struct r5l_policy r5l_ppl;
-int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
+int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev, int policy_type)
{
int ret;
struct r5l_log *log = kzalloc(sizeof(*log), GFP_KERNEL);
if (!log)
return -ENOMEM;
+ switch (policy_type) {
+ case RWH_POLICY_JOURNAL:
+ log->policy = &r5l_journal;
+ break;
+ case RWH_POLICY_PPL:
+ log->policy = &r5l_ppl;
+ break;
+ default:
+ kfree(log);
+ return -EINVAL;
+ }
+
log->rdev = rdev;
- log->policy = &r5l_journal;
+ log->rwh_policy = policy_type;
ret = log->policy->init_log(log, conf);
if (ret)
diff --git a/drivers/md/raid5-cache.h b/drivers/md/raid5-cache.h
index c3028a1..2e19453 100644
--- a/drivers/md/raid5-cache.h
+++ b/drivers/md/raid5-cache.h
@@ -81,6 +81,13 @@ struct r5l_log {
struct work_struct deferred_io_work;
struct r5l_policy *policy;
+ enum {
+ RWH_POLICY_OFF,
+ RWH_POLICY_JOURNAL,
+ RWH_POLICY_PPL,
+ } rwh_policy;
+
+ void *private;
};
/*
@@ -142,7 +149,7 @@ struct r5l_policy {
void (*quiesce)(struct r5l_log *log, int state);
};
-extern int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev);
+extern int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev, int policy_type);
extern void r5l_exit_log(struct r5l_log *log);
extern int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh);
extern void r5l_write_stripe_run(struct r5l_log *log);
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
new file mode 100644
index 0000000..263fad7
--- /dev/null
+++ b/drivers/md/raid5-ppl.c
@@ -0,0 +1,20 @@
+/*
+ * Partial Parity Log for closing the RAID5 write hole
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include "raid5.h"
+#include "raid5-cache.h"
+
+struct r5l_policy r5l_ppl;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 58ee1d3..26e4045 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6779,8 +6779,10 @@ static int raid5_run(struct mddev *mddev)
struct r5conf *conf;
int working_disks = 0;
int dirty_parity_disks = 0;
+ int ppl_disks = 0;
struct md_rdev *rdev;
struct md_rdev *journal_dev = NULL;
+ int rwh_policy = RWH_POLICY_OFF;
sector_t reshape_offset = 0;
int i;
long long min_offset_diff = 0;
@@ -6793,6 +6795,10 @@ static int raid5_run(struct mddev *mddev)
rdev_for_each(rdev, mddev) {
long long diff;
+ if (test_bit(JournalPpl, &rdev->flags) &&
+ test_bit(In_sync, &rdev->flags))
+ ppl_disks++;
+
if (test_bit(Journal, &rdev->flags)) {
journal_dev = rdev;
continue;
@@ -6983,6 +6989,22 @@ static int raid5_run(struct mddev *mddev)
goto abort;
}
+ if (ppl_disks) {
+ if (ppl_disks != working_disks) {
+ pr_err("md/raid:%s: distributed PPL must be enabled on all member devices - aborting\n",
+ mdname(mddev));
+ goto abort;
+ }
+ rwh_policy = RWH_POLICY_PPL;
+ }
+
+ if (journal_dev) {
+ if (ppl_disks)
+ pr_warn("md/raid:%s: using journal device and PPL not allowed - ignoring PPL\n",
+ mdname(mddev));
+ rwh_policy = RWH_POLICY_JOURNAL;
+ }
+
/* device size must be a multiple of chunk size */
mddev->dev_sectors &= ~(mddev->chunk_sectors - 1);
mddev->resync_max_sectors = mddev->dev_sectors;
@@ -7108,12 +7130,17 @@ static int raid5_run(struct mddev *mddev)
blk_queue_max_hw_sectors(mddev->queue, UINT_MAX);
}
- if (journal_dev) {
- char b[BDEVNAME_SIZE];
+ if (rwh_policy) {
+ if (journal_dev) {
+ char b[BDEVNAME_SIZE];
- pr_debug("md/raid:%s: using device %s as journal\n",
- mdname(mddev), bdevname(journal_dev->bdev, b));
- if (r5l_init_log(conf, journal_dev))
+ pr_debug("md/raid:%s: using device %s as journal\n",
+ mdname(mddev), bdevname(journal_dev->bdev, b));
+ } else if (rwh_policy == RWH_POLICY_PPL) {
+ pr_debug("md/raid:%s: enabling distributed PPL journal\n",
+ mdname(mddev));
+ }
+ if (r5l_init_log(conf, journal_dev, rwh_policy))
goto abort;
}
@@ -7309,6 +7336,7 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
if (test_bit(Journal, &rdev->flags)) {
char b[BDEVNAME_SIZE];
+ int ret;
if (conf->log)
return -EBUSY;
@@ -7317,7 +7345,9 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
* The array is in readonly mode if journal is missing, so no
* write requests running. We should be safe
*/
- r5l_init_log(conf, rdev);
+ ret = r5l_init_log(conf, rdev, RWH_POLICY_JOURNAL);
+ if (ret)
+ return ret;
pr_debug("md/raid:%s: using device %s as journal\n",
mdname(mddev), bdevname(rdev->bdev, b));
return 0;
--
2.10.1
--
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