[PATCH] md: support adding new devices to md arrays via sysfs
Writing major:minor to md/new_dev will bind that device to the array.
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 40ac7fb..825e235 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1987,6 +1987,65 @@
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 @@
&md_chunk_size.attr,
&md_size.attr,
&md_metadata.attr,
+ &md_new_device.attr,
NULL,
};