[PATCH] md: Remove attempt to use dynamic names in sysfs for component devices on an MD array.

With version-0.90 superblock, component devices on an md device to not have
any stable name related to the array -(version-1 assigns a fixed index when
a device is added to an array, and this remains despit any hot-swap).

The intial code for making these devices appear in sysfs used dynamic
names, which would change whenever a hot-spare was swapped for a failed or
missing device.  This turns out not to be practical in sysfs for a number
of reasons.

This patch changes then naming of component devices to be based on the
result of 'bdevname'.  This is stable and should be unique.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 34 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 199016932de5..8238c1c0ec09 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -762,7 +762,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         struct list_head *tmp;
         mdk_rdev_t *rdev2;
         int next_spare = mddev->raid_disks;
-        char nm[20];
+
 
         /* make rdev->sb match mddev data..
          *
@@ -776,7 +776,6 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
          */
         int i;
         int active=0, working=0,failed=0,spare=0,nr_disks=0;
-        unsigned int fixdesc=0;
 
         rdev->sb_size = MD_SB_BYTES;
 
@@ -830,16 +829,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                         desc_nr = rdev2->raid_disk;
                 else
                         desc_nr = next_spare++;
-                if (desc_nr != rdev2->desc_nr) {
-                        fixdesc |= (1 << desc_nr);
-                        rdev2->desc_nr = desc_nr;
-                        if (rdev2->raid_disk >= 0) {
-                                sprintf(nm, "rd%d", rdev2->raid_disk);
-                                sysfs_remove_link(&mddev->kobj, nm);
-                        }
-                        sysfs_remove_link(&rdev2->kobj, "block");
-                        kobject_del(&rdev2->kobj);
-                }
+                rdev2->desc_nr = desc_nr;
                 d = &sb->disks[rdev2->desc_nr];
                 nr_disks++;
                 d->number = rdev2->desc_nr;
@@ -866,25 +856,6 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                 if (test_bit(WriteMostly, &rdev2->flags))
                         d->state |= (1<<MD_DISK_WRITEMOSTLY);
         }
-        if (fixdesc)
-                ITERATE_RDEV(mddev,rdev2,tmp)
-                        if (fixdesc & (1<<rdev2->desc_nr)) {
-                                snprintf(rdev2->kobj.name, KOBJ_NAME_LEN, "dev%d",
-                                         rdev2->desc_nr);
-                                /* kobject_add gets a ref on the parent, so
-                                 * we have to drop the one we already have
-                                 */
-                                kobject_add(&rdev2->kobj);
-                                kobject_put(rdev->kobj.parent);
-                                sysfs_create_link(&rdev2->kobj,
-                                                  &rdev2->bdev->bd_disk->kobj,
-                                                  "block");
-                                if (rdev2->raid_disk >= 0) {
-                                        sprintf(nm, "rd%d", rdev2->raid_disk);
-                                        sysfs_create_link(&mddev->kobj,
-                                                          &rdev2->kobj, nm);
-                                }
-                        }
         /* now set the "removed" and "faulty" bits on any missing devices */
         for (i=0 ; i < mddev->raid_disks ; i++) {
                 mdp_disk_t *d = &sb->disks[i];
@@ -1237,13 +1208,14 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
                 if (find_rdev_nr(mddev, rdev->desc_nr))
                         return -EBUSY;
         }
+        bdevname(rdev->bdev,b);
+        if (kobject_set_name(&rdev->kobj, "dev-%s", b) < 0)
+                return -ENOMEM;
                         
         list_add(&rdev->same_set, &mddev->disks);
         rdev->mddev = mddev;
-        printk(KERN_INFO "md: bind<%s>\n", bdevname(rdev->bdev,b));
+        printk(KERN_INFO "md: bind<%s>\n", b);
 
-        rdev->kobj.k_name = NULL;
-        snprintf(rdev->kobj.name, KOBJ_NAME_LEN, "dev%d", rdev->desc_nr);
         rdev->kobj.parent = &mddev->kobj;
         kobject_add(&rdev->kobj);