diff options
| -rw-r--r-- | Documentation/md.txt | 9 | ||||
| -rw-r--r-- | drivers/md/md.c | 131 |
2 files changed, 98 insertions, 42 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index 9710138d101..0a2e10a4040 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -174,6 +174,15 @@ All md devices contain: The size should be atleast PAGE_SIZE (4k) and should be a power of 2. This can only be set while assembling an array + component_size + For arrays with data redundancy (i.e. not raid0, linear, faulty, + multipath), all components must be the same size - or at least + there must a size that they all provide space for. This is a key + part or the geometry of the array. It is measured in sectors + and can be read from here. Writing to this value may resize + the array if the personality supports it (raid1, raid5, raid6), + and if the component drives are large enough. + As component devices are added to an md array, they appear in the 'md' directory as new directories named dev-XXX diff --git a/drivers/md/md.c b/drivers/md/md.c index 9e57e97bd53..d568ab4a487 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1820,6 +1820,44 @@ __ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store); static ssize_t +size_show(mddev_t *mddev, char *page) +{ + return sprintf(page, "%llu\n", (unsigned long long)mddev->size); +} + +static int update_size(mddev_t *mddev, unsigned long size); + +static ssize_t +size_store(mddev_t *mddev, const char *buf, size_t len) +{ + /* If array is inactive, we can reduce the component size, but + * not increase it (except from 0). + * If array is active, we can try an on-line resize + */ + char *e; + int err = 0; + unsigned long long size = simple_strtoull(buf, &e, 10); + if (!*buf || *buf == '\n' || + (*e && *e != '\n')) + return -EINVAL; + + if (mddev->pers) { + err = update_size(mddev, size); + md_update_sb(mddev); + } else { + if (mddev->size == 0 || + mddev->size > size) + mddev->size = size; + else + err = -ENOSPC; + } + return err ? err : len; +} + +static struct md_sysfs_entry md_size = +__ATTR(component_size, 0644, size_show, size_store); + +static ssize_t action_show(mddev_t *mddev, char *page) { char *type = "idle"; @@ -1887,6 +1925,7 @@ static struct attribute *md_default_attrs[] = { &md_level.attr, &md_raid_disks.attr, &md_chunk_size.attr, + &md_size.attr, NULL, }; @@ -3005,6 +3044,54 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info) return 0; } +static int update_size(mddev_t *mddev, unsigned long size) +{ + mdk_rdev_t * rdev; + int rv; + struct list_head *tmp; + + if (mddev->pers->resize == NULL) + return -EINVAL; + /* The "size" is the amount of each device that is used. + * This can only make sense for arrays with redundancy. + * linear and raid0 always use whatever space is available + * We can only consider changing the size if no resync + * or reconstruction is happening, and if the new size + * is acceptable. It must fit before the sb_offset or, + * if that is <data_offset, it must fit before the + * size of each device. + * If size is zero, we find the largest size that fits. + */ + if (mddev->sync_thread) + return -EBUSY; + ITERATE_RDEV(mddev,rdev,tmp) { + sector_t avail; + int fit = (size == 0); + if (rdev->sb_offset > rdev->data_offset) + avail = (rdev->sb_offset*2) - rdev->data_offset; + else + avail = get_capacity(rdev->bdev->bd_disk) + - rdev->data_offset; + if (fit && (size == 0 || size > avail/2)) + size = avail/2; + if (avail < ((sector_t)size << 1)) + return -ENOSPC; + } + rv = mddev->pers->resize(mddev, (sector_t)size *2); + if (!rv) { + struct block_device *bdev; + + bdev = bdget_disk(mddev->gendisk, 0); + if (bdev) { + down(&bdev->bd_inode->i_sem); + i_size_write(bdev->bd_inode, mddev->array_size << 10); + up(&bdev->bd_inode->i_sem); + bdput(bdev); + } + } + return rv; +} + /* * update_array_info is used to change the configuration of an * on-line array. @@ -3053,49 +3140,9 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info) else return mddev->pers->reconfig(mddev, info->layout, -1); } - if (mddev->size != info->size) { - mdk_rdev_t * rdev; - struct list_head *tmp; - if (mddev->pers->resize == NULL) - return -EINVAL; - /* The "size" is the amount of each device that is used. - * This can only make sense for arrays with redundancy. - * linear and raid0 always use whatever space is available - * We can only consider changing the size if no resync - * or reconstruction is happening, and if the new size - * is acceptable. It must fit before the sb_offset or, - * if that is <data_offset, it must fit before the - * size of each device. - * If size is zero, we find the largest size that fits. - */ - if (mddev->sync_thread) - return -EBUSY; - ITERATE_RDEV(mddev,rdev,tmp) { - sector_t avail; - int fit = (info->size == 0); - if (rdev->sb_offset > rdev->data_offset) - avail = (rdev->sb_offset*2) - rdev->data_offset; - else - avail = get_capacity(rdev->bdev->bd_disk) - - rdev->data_offset; - if (fit && (info->size == 0 || info->size > avail/2)) - info->size = avail/2; - if (avail < ((sector_t)info->size << 1)) - return -ENOSPC; - } - rv = mddev->pers->resize(mddev, (sector_t)info->size *2); - if (!rv) { - struct block_device *bdev; + if (mddev->size != info->size) + rv = update_size(mddev, info->size); - bdev = bdget_disk(mddev->gendisk, 0); - if (bdev) { - down(&bdev->bd_inode->i_sem); - i_size_write(bdev->bd_inode, mddev->array_size << 10); - up(&bdev->bd_inode->i_sem); - bdput(bdev); - } - } - } if (mddev->raid_disks != info->raid_disks) { /* change the number of raid disks */ if (mddev->pers->reshape == NULL) |