raid5-ppl: PPL support for disks with write-back cache enabled

[sfrench/cifs-2.6.git] / drivers / md / raid5-cache.c

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index f1c86d938502e61c93d8951680767f1af5de98e5..3c65f52b68f533397d6c8304d7f2ed9ff9025de9 100644 (file)
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -1111,9 +1111,6 @@ void r5l_write_stripe_run(struct r5l_log *log)
 
 int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
 {
-       if (!log)
-               return -ENODEV;
-
        if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
                /*
                 * in write through (journal only)
@@ -1592,8 +1589,6 @@ void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
 void r5l_quiesce(struct r5l_log *log, int quiesce)
 {
        struct mddev *mddev;
-       if (!log)
-               return;
 
        if (quiesce) {
                /* make sure r5l_write_super_and_discard_space exits */
@@ -2448,7 +2443,6 @@ static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
                raid5_release_stripe(sh);
        }
 
-       md_wakeup_thread(conf->mddev->thread);
        /* reuse conf->wait_for_quiescent in recovery */
        wait_event(conf->wait_for_quiescent,
                   atomic_read(&conf->active_stripes) == 0);
@@ -2491,10 +2485,10 @@ static int r5l_recovery_log(struct r5l_log *log)
        ctx->seq += 10000;
 
        if ((ctx->data_only_stripes == 0) && (ctx->data_parity_stripes == 0))
-               pr_debug("md/raid:%s: starting from clean shutdown\n",
+               pr_info("md/raid:%s: starting from clean shutdown\n",
                         mdname(mddev));
        else
-               pr_debug("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
+               pr_info("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
                         mdname(mddev), ctx->data_only_stripes,
                         ctx->data_parity_stripes);
 
@@ -2577,31 +2571,22 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
 int r5c_journal_mode_set(struct mddev *mddev, int mode)
 {
        struct r5conf *conf;
-       int err;
 
        if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
            mode > R5C_JOURNAL_MODE_WRITE_BACK)
                return -EINVAL;
 
-       err = mddev_lock(mddev);
-       if (err)
-               return err;
        conf = mddev->private;
-       if (!conf || !conf->log) {
-               mddev_unlock(mddev);
+       if (!conf || !conf->log)
                return -ENODEV;
-       }
 
        if (raid5_calc_degraded(conf) > 0 &&
-           mode == R5C_JOURNAL_MODE_WRITE_BACK) {
-               mddev_unlock(mddev);
+           mode == R5C_JOURNAL_MODE_WRITE_BACK)
                return -EINVAL;
-       }
 
        mddev_suspend(mddev);
        conf->log->r5c_journal_mode = mode;
        mddev_resume(mddev);
-       mddev_unlock(mddev);
 
        pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
                 mdname(mddev), mode, r5c_journal_mode_str[mode]);
@@ -2614,6 +2599,7 @@ static ssize_t r5c_journal_mode_store(struct mddev *mddev,
 {
        int mode = ARRAY_SIZE(r5c_journal_mode_str);
        size_t len = length;
+       int ret;
 
        if (len < 2)
                return -EINVAL;
@@ -2625,8 +2611,12 @@ static ssize_t r5c_journal_mode_store(struct mddev *mddev,
                if (strlen(r5c_journal_mode_str[mode]) == len &&
                    !strncmp(page, r5c_journal_mode_str[mode], len))
                        break;
-
-       return r5c_journal_mode_set(mddev, mode) ?: length;
+       ret = mddev_lock(mddev);
+       if (ret)
+               return ret;
+       ret = r5c_journal_mode_set(mddev, mode);
+       mddev_unlock(mddev);
+       return ret ?: length;
 }
 
 struct md_sysfs_entry
@@ -3040,6 +3030,23 @@ ioerr:
        return ret;
 }
 
+int r5l_start(struct r5l_log *log)
+{
+       int ret;
+
+       if (!log)
+               return 0;
+
+       ret = r5l_load_log(log);
+       if (ret) {
+               struct mddev *mddev = log->rdev->mddev;
+               struct r5conf *conf = mddev->private;
+
+               r5l_exit_log(conf);
+       }
+       return ret;
+}
+
 void r5c_update_on_rdev_error(struct mddev *mddev, struct md_rdev *rdev)
 {
        struct r5conf *conf = mddev->private;
@@ -3142,13 +3149,9 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
 
        rcu_assign_pointer(conf->log, log);
 
-       if (r5l_load_log(log))
-               goto error;
-
        set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
        return 0;
 
-error:
        rcu_assign_pointer(conf->log, NULL);
        md_unregister_thread(&log->reclaim_thread);
 reclaim_thread: