diff options
| -rw-r--r-- | Documentation/md.txt | 8 | ||||
| -rw-r--r-- | drivers/md/md.c | 60 |
2 files changed, 68 insertions, 0 deletions
diff --git a/Documentation/md.txt b/Documentation/md.txt index 7b3d471bb9f..b8d172b254f 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -200,6 +200,14 @@ All md devices contain: This can be written only while the array is being assembled, not after it is started. + new_dev + This file can be written but not read. The value written should + be a block device number as major:minor. e.g. 8:0 + This will cause that device to be attached to the array, if it is + available. It will then appear at md/dev-XXX (depending on the + name of the device) and further configuration is then possible. + + 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 40ac7fbab61..825e235b791 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1987,6 +1987,65 @@ chunk_size_store(mddev_t *mddev, const char *buf, size_t len) static struct md_sysfs_entry md_chunk_size = __ATTR(chunk_size, 0644, chunk_size_show, chunk_size_store); +static ssize_t +null_show(mddev_t *mddev, char *page) +{ + return -EINVAL; +} + +static ssize_t +new_dev_store(mddev_t *mddev, const char *buf, size_t len) +{ + /* buf must be %d:%d\n? giving major and minor numbers */ + /* The new device is added to the array. + * If the array has a persistent superblock, we read the + * superblock to initialise info and check validity. + * Otherwise, only checking done is that in bind_rdev_to_array, + * which mainly checks size. + */ + char *e; + int major = simple_strtoul(buf, &e, 10); + int minor; + dev_t dev; + mdk_rdev_t *rdev; + int err; + + if (!*buf || *e != ':' || !e[1] || e[1] == '\n') + return -EINVAL; + minor = simple_strtoul(e+1, &e, 10); + if (*e && *e != '\n') + return -EINVAL; + dev = MKDEV(major, minor); + if (major != MAJOR(dev) || + minor != MINOR(dev)) + return -EOVERFLOW; + + + if (mddev->persistent) { + rdev = md_import_device(dev, mddev->major_version, + mddev->minor_version); + if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) { + mdk_rdev_t *rdev0 = list_entry(mddev->disks.next, + mdk_rdev_t, same_set); + err = super_types[mddev->major_version] + .load_super(rdev, rdev0, mddev->minor_version); + if (err < 0) + goto out; + } + } else + rdev = md_import_device(dev, -1, -1); + + if (IS_ERR(rdev)) + return PTR_ERR(rdev); + err = bind_rdev_to_array(rdev, mddev); + out: + if (err) + export_rdev(rdev); + return err ? err : len; +} + +static struct md_sysfs_entry md_new_device = +__ATTR(new_dev, 0200, null_show, new_dev_store); static ssize_t size_show(mddev_t *mddev, char *page) @@ -2144,6 +2203,7 @@ static struct attribute *md_default_attrs[] = { &md_chunk_size.attr, &md_size.attr, &md_metadata.attr, + &md_new_device.attr, NULL, }; |