md: make reconfig_mutex optional for writes to md sysfs files.

[uclinux-h8/linux.git] / drivers / md / raid5.c

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index d5b8017..aa76865 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5400,21 +5400,25 @@ EXPORT_SYMBOL(raid5_set_cache_size);
 static ssize_t
 raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
 {
-       struct r5conf *conf = mddev->private;
+       struct r5conf *conf;
        unsigned long new;
        int err;
 
        if (len >= PAGE_SIZE)
                return -EINVAL;
-       if (!conf)
-               return -ENODEV;
-
        if (kstrtoul(page, 10, &new))
                return -EINVAL;
-       err = raid5_set_cache_size(mddev, new);
+       err = mddev_lock(mddev);
        if (err)
                return err;
-       return len;
+       conf = mddev->private;
+       if (!conf)
+               err = -ENODEV;
+       else
+               err = raid5_set_cache_size(mddev, new);
+       mddev_unlock(mddev);
+
+       return err ?: len;
 }
 
 static struct md_sysfs_entry
@@ -5438,19 +5442,27 @@ raid5_show_preread_threshold(struct mddev *mddev, char *page)
 static ssize_t
 raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
 {
-       struct r5conf *conf = mddev->private;
+       struct r5conf *conf;
        unsigned long new;
+       int err;
+
        if (len >= PAGE_SIZE)
                return -EINVAL;
-       if (!conf)
-               return -ENODEV;
-
        if (kstrtoul(page, 10, &new))
                return -EINVAL;
-       if (new > conf->max_nr_stripes)
-               return -EINVAL;
-       conf->bypass_threshold = new;
-       return len;
+
+       err = mddev_lock(mddev);
+       if (err)
+               return err;
+       conf = mddev->private;
+       if (!conf)
+               err = -ENODEV;
+       else if (new > conf->max_nr_stripes)
+               err = -EINVAL;
+       else
+               conf->bypass_threshold = new;
+       mddev_unlock(mddev);
+       return err ?: len;
 }
 
 static struct md_sysfs_entry
@@ -5475,29 +5487,35 @@ raid5_show_skip_copy(struct mddev *mddev, char *page)
 static ssize_t
 raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len)
 {
-       struct r5conf *conf = mddev->private;
+       struct r5conf *conf;
        unsigned long new;
+       int err;
+
        if (len >= PAGE_SIZE)
                return -EINVAL;
-       if (!conf)
-               return -ENODEV;
-
        if (kstrtoul(page, 10, &new))
                return -EINVAL;
        new = !!new;
-       if (new == conf->skip_copy)
-               return len;
 
-       mddev_suspend(mddev);
-       conf->skip_copy = new;
-       if (new)
-               mddev->queue->backing_dev_info.capabilities |=
-                                               BDI_CAP_STABLE_WRITES;
-       else
-               mddev->queue->backing_dev_info.capabilities &=
-                                               ~BDI_CAP_STABLE_WRITES;
-       mddev_resume(mddev);
-       return len;
+       err = mddev_lock(mddev);
+       if (err)
+               return err;
+       conf = mddev->private;
+       if (!conf)
+               err = -ENODEV;
+       else if (new != conf->skip_copy) {
+               mddev_suspend(mddev);
+               conf->skip_copy = new;
+               if (new)
+                       mddev->queue->backing_dev_info.capabilities |=
+                               BDI_CAP_STABLE_WRITES;
+               else
+                       mddev->queue->backing_dev_info.capabilities &=
+                               ~BDI_CAP_STABLE_WRITES;
+               mddev_resume(mddev);
+       }
+       mddev_unlock(mddev);
+       return err ?: len;
 }
 
 static struct md_sysfs_entry
@@ -5538,7 +5556,7 @@ static int alloc_thread_groups(struct r5conf *conf, int cnt,
 static ssize_t
 raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
 {
-       struct r5conf *conf = mddev->private;
+       struct r5conf *conf;
        unsigned long new;
        int err;
        struct r5worker_group *new_groups, *old_groups;
@@ -5546,41 +5564,41 @@ raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
 
        if (len >= PAGE_SIZE)
                return -EINVAL;
-       if (!conf)
-               return -ENODEV;
-
        if (kstrtoul(page, 10, &new))
                return -EINVAL;
 
-       if (new == conf->worker_cnt_per_group)
-               return len;
-
-       mddev_suspend(mddev);
+       err = mddev_lock(mddev);
+       if (err)
+               return err;
+       conf = mddev->private;
+       if (!conf)
+               err = -ENODEV;
+       else if (new != conf->worker_cnt_per_group) {
+               mddev_suspend(mddev);
 
-       old_groups = conf->worker_groups;
-       if (old_groups)
-               flush_workqueue(raid5_wq);
+               old_groups = conf->worker_groups;
+               if (old_groups)
+                       flush_workqueue(raid5_wq);
 
-       err = alloc_thread_groups(conf, new,
-                                 &group_cnt, &worker_cnt_per_group,
-                                 &new_groups);
-       if (!err) {
-               spin_lock_irq(&conf->device_lock);
-               conf->group_cnt = group_cnt;
-               conf->worker_cnt_per_group = worker_cnt_per_group;
-               conf->worker_groups = new_groups;
-               spin_unlock_irq(&conf->device_lock);
+               err = alloc_thread_groups(conf, new,
+                                         &group_cnt, &worker_cnt_per_group,
+                                         &new_groups);
+               if (!err) {
+                       spin_lock_irq(&conf->device_lock);
+                       conf->group_cnt = group_cnt;
+                       conf->worker_cnt_per_group = worker_cnt_per_group;
+                       conf->worker_groups = new_groups;
+                       spin_unlock_irq(&conf->device_lock);
 
-               if (old_groups)
-                       kfree(old_groups[0].workers);
-               kfree(old_groups);
+                       if (old_groups)
+                               kfree(old_groups[0].workers);
+                       kfree(old_groups);
+               }
+               mddev_resume(mddev);
        }
+       mddev_unlock(mddev);
 
-       mddev_resume(mddev);
-
-       if (err)
-               return err;
-       return len;
+       return err ?: len;
 }
 
 static struct md_sysfs_entry