[PATCH] md: allow array level to be set textually via sysfs

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 48 insertions, 13 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index ecc0166ba779..594d8c312e6a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -303,12 +303,15 @@ static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
         return NULL;
 }
 
-static struct mdk_personality *find_pers(int level)
+static struct mdk_personality *find_pers(int level, char *clevel)
 {
         struct mdk_personality *pers;
-        list_for_each_entry(pers, &pers_list, list)
-                if (pers->level == level)
+        list_for_each_entry(pers, &pers_list, list) {
+                if (level != LEVEL_NONE && pers->level == level)
                         return pers;
+                if (strcmp(pers->name, clevel)==0)
+                        return pers;
+        }
         return NULL;
 }
 
@@ -715,6 +718,7 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                 mddev->ctime = sb->ctime;
                 mddev->utime = sb->utime;
                 mddev->level = sb->level;
+                mddev->clevel[0] = 0;
                 mddev->layout = sb->layout;
                 mddev->raid_disks = sb->raid_disks;
                 mddev->size = sb->size;
@@ -1051,6 +1055,7 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                 mddev->ctime = le64_to_cpu(sb->ctime) & ((1ULL << 32)-1);
                 mddev->utime = le64_to_cpu(sb->utime) & ((1ULL << 32)-1);
                 mddev->level = le32_to_cpu(sb->level);
+                mddev->clevel[0] = 0;
                 mddev->layout = le32_to_cpu(sb->layout);
                 mddev->raid_disks = le32_to_cpu(sb->raid_disks);
                 mddev->size = le64_to_cpu(sb->size)/2;
@@ -1774,15 +1779,36 @@ static ssize_t
 level_show(mddev_t *mddev, char *page)
 {
         struct mdk_personality *p = mddev->pers;
-        if (p == NULL && mddev->raid_disks == 0)
-                return 0;
-        if (mddev->level >= 0)
-                return sprintf(page, "raid%d\n", mddev->level);
-        else
+        if (p)
                 return sprintf(page, "%s\n", p->name);
+        else if (mddev->clevel[0])
+                return sprintf(page, "%s\n", mddev->clevel);
+        else if (mddev->level != LEVEL_NONE)
+                return sprintf(page, "%d\n", mddev->level);
+        else
+                return 0;
+}
+
+static ssize_t
+level_store(mddev_t *mddev, const char *buf, size_t len)
+{
+        int rv = len;
+        if (mddev->pers)
+                return -EBUSY;
+        if (len == 0)
+                return 0;
+        if (len >= sizeof(mddev->clevel))
+                return -ENOSPC;
+        strncpy(mddev->clevel, buf, len);
+        if (mddev->clevel[len-1] == '\n')
+                len--;
+        mddev->clevel[len] = 0;
+        mddev->level = LEVEL_NONE;
+        return rv;
 }
 
-static struct md_sysfs_entry md_level = __ATTR_RO(level);
+static struct md_sysfs_entry md_level =
+__ATTR(level, 0644, level_show, level_store);
 
 static ssize_t
 raid_disks_show(mddev_t *mddev, char *page)
@@ -2158,7 +2184,10 @@ static int do_md_run(mddev_t * mddev)
         }
 
 #ifdef CONFIG_KMOD
-        request_module("md-level-%d", mddev->level);
+        if (mddev->level != LEVEL_NONE)
+                request_module("md-level-%d", mddev->level);
+        else if (mddev->clevel[0])
+                request_module("md-%s", mddev->clevel);
 #endif
 
         /*
@@ -2180,15 +2209,21 @@ static int do_md_run(mddev_t * mddev)
                 return -ENOMEM;
 
         spin_lock(&pers_lock);
-        pers = find_pers(mddev->level);
+        pers = find_pers(mddev->level, mddev->clevel);
         if (!pers || !try_module_get(pers->owner)) {
                 spin_unlock(&pers_lock);
-                printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
-                       mddev->level);
+                if (mddev->level != LEVEL_NONE)
+                        printk(KERN_WARNING "md: personality for level %d is not loaded!\n",
+                               mddev->level);
+                else
+                        printk(KERN_WARNING "md: personality for level %s is not loaded!\n",
+                               mddev->clevel);
                 return -EINVAL;
         }
         mddev->pers = pers;
         spin_unlock(&pers_lock);
+        mddev->level = pers->level;
+        strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
 
         mddev->recovery = 0;
         mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */