[PATCH] md: Remove the 'disks' array from md which holds the gendisk structures.

From: NeilBrown <neilb@cse.unsw.edu.au>

Move the pointers into mddev.  The reduces dependance on MAX_MD_DEVS.

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9e3677475da0d12fb9906d8d02da74a9ffab455a..c363ce0e77e785948a2061b716a61cbba2c6bc70 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -124,8 +124,6 @@ static ctl_table raid_root_table[] = {
 
 static struct block_device_operations md_fops;
 
-static struct gendisk *disks[MAX_MD_DEVS];
-
 /*
  * Enables to iterate over all existing md arrays
  * all_mddevs_lock protects this list as well as mddev_map.
@@ -1463,7 +1461,7 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
                return NULL;
 
        down(&disks_sem);
-       if (disks[unit]) {
+       if (mddev->gendisk) {
                up(&disks_sem);
                mddev_put(mddev);
                return NULL;
@@ -1481,7 +1479,7 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
        disk->private_data = mddev;
        disk->queue = mddev->queue;
        add_disk(disk);
-       disks[mdidx(mddev)] = disk;
+       mddev->gendisk = disk;
        up(&disks_sem);
        return NULL;
 }
@@ -1599,7 +1597,7 @@ static int do_md_run(mddev_t * mddev)
 
        unit = mdidx(mddev);
        md_probe(0, &unit, NULL);
-       disk = disks[unit];
+       disk = mddev->gendisk;
        if (!disk)
                return -ENOMEM;
 
@@ -1650,7 +1648,7 @@ static int do_md_run(mddev_t * mddev)
 
 static int restart_array(mddev_t *mddev)
 {
-       struct gendisk *disk = disks[mdidx(mddev)];
+       struct gendisk *disk = mddev->gendisk;
        int err;
 
        /*
@@ -1690,7 +1688,7 @@ out:
 static int do_md_stop(mddev_t * mddev, int ro)
 {
        int err = 0;
-       struct gendisk *disk = disks[mdidx(mddev)];
+       struct gendisk *disk = mddev->gendisk;
 
        if (mddev->pers) {
                if (atomic_read(&mddev->active)>2) {
@@ -1741,7 +1739,7 @@ static int do_md_stop(mddev_t * mddev, int ro)
                export_array(mddev);
 
                mddev->array_size = 0;
-               disk = disks[mdidx(mddev)];
+               disk = mddev->gendisk;
                if (disk)
                        set_capacity(disk, 0);
        } else
@@ -2532,7 +2530,7 @@ static int md_ioctl(struct inode *inode, struct file *file,
                        err = put_user (4, (char *) &loc->sectors);
                        if (err)
                                goto abort_unlock;
-                       err = put_user(get_capacity(disks[mdidx(mddev)])/8,
+                       err = put_user(get_capacity(mddev->gendisk)/8,
                                                (short *) &loc->cylinders);
                        if (err)
                                goto abort_unlock;
@@ -3574,6 +3572,8 @@ static void autostart_arrays(void)
 
 static __exit void md_exit(void)
 {
+       mddev_t *mddev;
+       struct list_head *tmp;
        int i;
        blk_unregister_region(MKDEV(MAJOR_NR,0), MAX_MD_DEVS);
        for (i=0; i < MAX_MD_DEVS; i++)
@@ -3586,15 +3586,14 @@ static __exit void md_exit(void)
 #ifdef CONFIG_PROC_FS
        remove_proc_entry("mdstat", NULL);
 #endif
-       for (i = 0; i < MAX_MD_DEVS; i++) {
-               struct gendisk *disk = disks[i];
-               mddev_t *mddev;
-               if (!disks[i])
+       ITERATE_MDDEV(mddev,tmp) {
+               struct gendisk *disk = mddev->gendisk;
+               if (!disk)
                        continue;
-               mddev = disk->private_data;
                export_array(mddev);
                del_gendisk(disk);
                put_disk(disk);
+               mddev->gendisk = NULL;
                mddev_put(mddev);
        }
 }

diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 411ca178ea059cc49edca5fb74e3906ee0a52f75..7b6e12c45dc9dcb45aa98db34fae82dba1348caa 100644 (file)
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -191,6 +191,8 @@ struct mddev_s
        int                             sb_dirty;
        int                             ro;
 
+       struct gendisk                  *gendisk;
+
        /* Superblock information */
        int                             major_version,
                                        minor_version,