diff options
| -rw-r--r-- | Documentation/md.txt | 8 | ||||
| -rw-r--r-- | drivers/md/md.c | 26 |
2 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index 1dd0fb6021cf..9710138d101a 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -166,6 +166,14 @@ All md devices contain: will be empty. If an array is being resized (not currently possible) this will contain the larger of the old and new sizes. + chunk_size + This is the size if bytes for 'chunks' and is only relevant to + raid levels that involve striping (1,4,5,6,10). The address space + of the array is conceptually divided into chunks and consecutive + chunks are striped onto neighbouring devices. + The size should be atleast PAGE_SIZE (4k) and should be a power + of 2. This can only be set while assembling an array + 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 0b3081aa4d63..9e57e97bd530 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1795,6 +1795,31 @@ raid_disks_show(mddev_t *mddev, char *page) static struct md_sysfs_entry md_raid_disks = __ATTR_RO(raid_disks); static ssize_t +chunk_size_show(mddev_t *mddev, char *page) +{ + return sprintf(page, "%d\n", mddev->chunk_size); +} + +static ssize_t +chunk_size_store(mddev_t *mddev, const char *buf, size_t len) +{ + /* can only set chunk_size if array is not yet active */ + char *e; + unsigned long n = simple_strtoul(buf, &e, 10); + + if (mddev->pers) + return -EBUSY; + if (!*buf || (*e && *e != '\n')) + return -EINVAL; + + mddev->chunk_size = n; + return len; +} +static struct md_sysfs_entry md_chunk_size = +__ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store); + + +static ssize_t action_show(mddev_t *mddev, char *page) { char *type = "idle"; @@ -1861,6 +1886,7 @@ md_mismatches = __ATTR_RO(mismatch_cnt); static struct attribute *md_default_attrs[] = { &md_level.attr, &md_raid_disks.attr, + &md_chunk_size.attr, NULL, }; |