[PATCH 005 of 5] md: Improve partition detection in md array.

NeilBrown
2007-05-08T04:30:32Z

md currently uses ->media_changed to make sure rescan_partitions
is call on md array after they are assembled.

However that doesn't happen until the array is opened, which is later
than some people would like.

So use blkdev_ioctl to do the rescan immediately that the
array has been assembled.

This means we can remove all the ->change infrastructure as it was only used
to trigger a partition rescan.

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./drivers/md/md.c | 26 ++++++++------------------
./drivers/md/raid1.c | 1 -
./drivers/md/raid5.c | 2 --
./include/linux/raid/md_k.h | 1 -
4 files changed, 8 insertions(+), 22 deletions(-)

diff .prev/drivers/md/md.c ./drivers/md/md.c
--- .prev/drivers/md/md.c 2007-05-08 14:24:00.000000000 +1000
+++ ./drivers/md/md.c 2007-05-07 17:47:15.000000000 +1000
@@ -3104,6 +3104,7 @@ static int do_md_run(mddev_t * mddev)
struct gendisk *disk;
struct mdk_personality *pers;
char b[BDEVNAME_SIZE];
+ struct block_device *bdev;

if (list_empty(&mddev->disks))
/* cannot run an array with no devices.. */
@@ -3331,7 +3332,13 @@ static int do_md_run(mddev_t * mddev)
md_wakeup_thread(mddev->thread);
md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */

- mddev->changed = 1;
+ bdev = bdget_disk(mddev->gendisk, 0);
+ if (bdev) {
+ bd_set_size(bdev, mddev->array_size << 1);
+ blkdev_ioctl(bdev->bd_inode, NULL, BLKRRPART, 0);
+ bdput(bdev);
+ }
+
md_new_event(mddev);
kobject_uevent(&mddev->gendisk->kobj, KOBJ_CHANGE);
return 0;
@@ -3453,7 +3460,6 @@ static int do_md_stop(mddev_t * mddev, i
mddev->pers = NULL;

set_capacity(disk, 0);
- mddev->changed = 1;

if (mddev->ro)
mddev->ro = 0;
@@ -4593,20 +4599,6 @@ static int md_release(struct inode *inod
return 0;
}

-static int md_media_changed(struct gendisk *disk)
-{
- mddev_t *mddev = disk->private_data;
-
- return mddev->changed;
-}
-
-static int md_revalidate(struct gendisk *disk)
-{
- mddev_t *mddev = disk->private_data;
-
- mddev->changed = 0;
- return 0;
-}
static struct block_device_operations md_fops =
{
.owner = THIS_MODULE,
@@ -4614,8 +4606,6 @@ static struct block_device_operations md
.release = md_release,
.ioctl = md_ioctl,
.getgeo = md_getgeo,
- .media_changed = md_media_changed,
- .revalidate_disk= md_revalidate,
};

static int md_thread(void * arg)

diff .prev/drivers/md/raid1.c ./drivers/md/raid1.c
--- .prev/drivers/md/raid1.c 2007-05-08 14:24:00.000000000 +1000
+++ ./drivers/md/raid1.c 2007-05-07 17:02:27.000000000 +1000
@@ -2063,7 +2063,6 @@ static int raid1_resize(mddev_t *mddev,
*/
mddev->array_size = sectors>>1;
set_capacity(mddev->gendisk, mddev->array_size << 1);
- mddev->changed = 1;
if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) {
mddev->recovery_cp = mddev->size << 1;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);

diff .prev/drivers/md/raid5.c ./drivers/md/raid5.c
--- .prev/drivers/md/raid5.c 2007-05-08 14:24:00.000000000 +1000
+++ ./drivers/md/raid5.c 2007-05-07 17:03:05.000000000 +1000
@@ -4514,7 +4514,6 @@ static int raid5_resize(mddev_t *mddev,
sectors &= ~((sector_t)mddev->chunk_size/512 - 1);
mddev->array_size = (sectors * (mddev->raid_disks-conf->max_degraded))>>1;
set_capacity(mddev->gendisk, mddev->array_size << 1);
- mddev->changed = 1;
if (sectors/2 > mddev->size && mddev->recovery_cp == MaxSector) {
mddev->recovery_cp = mddev->size << 1;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -4649,7 +4648,6 @@ static void end_reshape(raid5_conf_t *co
conf->mddev->array_size = conf->mddev->size *
(conf->raid_disks - conf->max_degraded);
set_capacity(conf->mddev->gendisk, conf->mddev->array_size << 1);
- conf->mddev->changed = 1;

bdev = bdget_disk(conf->mddev->gendisk, 0);
if (bdev) {

diff .prev/include/linux/raid/md_k.h ./include/linux/raid/md_k.h
--- .prev/include/linux/raid/md_k.h 2007-05-08 14:24:00.000000000 +1000
+++ ./include/linux/raid/md_k.h 2007-05-08 14:24:36.000000000 +1000
@@ -201,7 +201,6 @@ struct mddev_s
struct mutex reconfig_mutex;
atomic_t active;

- int changed; /* true if we might need to reread partition info */
int degraded; /* whether md should consider
* adding a spare
*/