Hi,
Am Freitag, 27. Juni 2008 08:51 schrieb NeilBrown:
> From: Chris Webb <chris@xxxxxxxxxxxx>
> Allow /sys/block/mdX/md/rdY/size to change on running arrays, moving the
> superblock if necessary for this metadata version. We prevent the available
> space from shrinking to less than the used size, and allow it to be set to
> zero to fill all the available space on the underlying device.
I'm very happy of this new feature. But I'm a little confused how to use it
correctly.
Can md now recognize the change by itself and I only have to run mdadm --grow?
Or have I manually update /sys/block/mdX/md/rdY/size and afterwards run
mdadm --grow?
To be on the safe side I'd first lvresize one disk of the raid1, then do
mdadm --grow to let md update/move the superblock of this disk. And after
this is successful, lvresize the other disk and do mdadm --grow. So in case
of a failure i wouldn't loose the whole raid1!?
Am I correct or am I missing something?
> Signed-off-by: Chris Webb <chris@xxxxxxxxxxxx>
> Signed-off-by: Neil Brown <neilb@xxxxxxx>
>
> ### Diffstat output
> ./drivers/md/md.c | 100
> ++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 87
> insertions(+), 13 deletions(-)
>
> diff .prev/drivers/md/md.c ./drivers/md/md.c
> --- .prev/drivers/md/md.c 2008-06-27 16:22:03.000000000 +1000
> +++ ./drivers/md/md.c 2008-06-27 16:22:03.000000000 +1000
> @@ -658,11 +658,14 @@ static unsigned int calc_sb_csum(mdp_sup
> */
>
> struct super_type {
> - char *name;
> - struct module *owner;
> - int (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int
> minor_version); - int (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
> - void (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
> + char *name;
> + struct module *owner;
> + int (*load_super)(mdk_rdev_t *rdev, mdk_rdev_t *refdev,
> + int minor_version);
> + int (*validate_super)(mddev_t *mddev, mdk_rdev_t *rdev);
> + void (*sync_super)(mddev_t *mddev, mdk_rdev_t *rdev);
> + unsigned long long (*rdev_size_change)(mdk_rdev_t *rdev,
> + unsigned long long size);
> };
>
> /*
> @@ -1004,6 +1007,27 @@ static void super_90_sync(mddev_t *mddev
> }
>
> /*
> + * rdev_size_change for 0.90.0
> + */
> +static unsigned long long
> +super_90_rdev_size_change(mdk_rdev_t *rdev, unsigned long long size)
> +{
> + if (size && size < rdev->mddev->size)
> + return 0; /* component must fit device */
> + size *= 2; /* convert to sectors */
> + if (rdev->mddev->bitmap_offset)
> + return 0; /* can't move bitmap */
> + rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
> + if (!size || size > rdev->sb_offset*2)
> + size = rdev->sb_offset*2;
> + md_super_write(rdev->mddev, rdev, rdev->sb_offset << 1, rdev->sb_size,
> + rdev->sb_page);
> + md_super_wait(rdev->mddev);
> + return size/2; /* kB for sysfs */
> +}
> +
> +
> +/*
> * version 1 superblock
> */
>
> @@ -1328,21 +1352,59 @@ static void super_1_sync(mddev_t *mddev,
> sb->sb_csum = calc_sb_1_csum(sb);
> }
>
> +static unsigned long long
> +super_1_rdev_size_change(mdk_rdev_t *rdev, unsigned long long size)
> +{
> + struct mdp_superblock_1 *sb;
> + unsigned long long max_size;
> + if (size && size < rdev->mddev->size)
> + return 0; /* component must fit device */
> + size *= 2; /* convert to sectors */
> + if (rdev->sb_offset < rdev->data_offset/2) {
> + /* minor versions 1 and 2; superblock before data */
> + max_size = (rdev->bdev->bd_inode->i_size >> 9);
> + max_size -= rdev->data_offset;
> + if (!size || size > max_size)
> + size = max_size;
> + } else if (rdev->mddev->bitmap_offset) {
> + /* minor version 0 with bitmap we can't move */
> + return 0;
> + } else {
> + /* minor version 0; superblock after data */
> + sector_t sb_offset;
> + sb_offset = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
> + sb_offset &= ~(sector_t)(4*2 - 1);
> + max_size = rdev->size*2 + sb_offset - rdev->sb_offset*2;
> + if (!size || size > max_size)
> + size = max_size;
> + rdev->sb_offset = sb_offset/2;
> + }
> + sb = (struct mdp_superblock_1 *) page_address(rdev->sb_page);
> + sb->data_size = cpu_to_le64(size);
> + sb->super_offset = rdev->sb_offset*2;
> + sb->sb_csum = calc_sb_1_csum(sb);
> + md_super_write(rdev->mddev, rdev, rdev->sb_offset << 1, rdev->sb_size,
> + rdev->sb_page);
> + md_super_wait(rdev->mddev);
> + return size/2; /* kB for sysfs */
> +}
>
> static struct super_type super_types[] = {
> [0] = {
> .name = "0.90.0",
> .owner = THIS_MODULE,
> - .load_super = super_90_load,
> - .validate_super = super_90_validate,
> - .sync_super = super_90_sync,
> + .load_super = super_90_load,
> + .validate_super = super_90_validate,
> + .sync_super = super_90_sync,
> + .rdev_size_change = super_90_rdev_size_change,
> },
> [1] = {
> .name = "md-1",
> .owner = THIS_MODULE,
> - .load_super = super_1_load,
> - .validate_super = super_1_validate,
> - .sync_super = super_1_sync,
> + .load_super = super_1_load,
> + .validate_super = super_1_validate,
> + .sync_super = super_1_sync,
> + .rdev_size_change = super_1_rdev_size_change,
> },
> };
>
> @@ -2060,8 +2122,20 @@ rdev_size_store(mdk_rdev_t *rdev, const
>
> if (e==buf || (*e && *e != '\n'))
> return -EINVAL;
> - if (my_mddev->pers && rdev->raid_disk >= 0)
> - return -EBUSY;
> + if (my_mddev->pers && rdev->raid_disk >= 0) {
> + if (rdev->mddev->persistent) {
> + size = super_types[rdev->mddev->major_version].
> + rdev_size_change(rdev, size);
> + if (!size)
> + return -EBUSY;
> + } else if (!size) {
> + size = (rdev->bdev->bd_inode->i_size >> 10);
> + size -= rdev->data_offset/2;
> + }
> + if (size < rdev->mddev->size)
> + return -EINVAL; /* component must fit device */
> + }
> +
> rdev->size = size;
> if (size > oldsize && rdev->mddev->external) {
> /* need to check that all other rdevs with the same ->bdev
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
greetings
eMHa
Attachment:
pgp50jVVdjA9P.pgp
Description: PGP signature
