+__ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
+
+static ssize_t
+resync_start_show(mddev_t *mddev, char *page)
+{
+ return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
+}
+
+static ssize_t
+resync_start_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 long n = simple_strtoull(buf, &e, 10);
+
+ if (mddev->pers)
+ return -EBUSY;
+ if (!*buf || (*e && *e != '\n'))
+ return -EINVAL;
+
+ mddev->recovery_cp = n;
+ return len;
+}
+static struct md_sysfs_entry md_resync_start =
+__ATTR(resync_start, S_IRUGO|S_IWUSR, resync_start_show, resync_start_store);
+
+/*
+ * The array state can be:
+ *
+ * clear
+ * No devices, no size, no level
+ * Equivalent to STOP_ARRAY ioctl
+ * inactive
+ * May have some settings, but array is not active
+ * all IO results in error
+ * When written, doesn't tear down array, but just stops it
+ * suspended (not supported yet)
+ * All IO requests will block. The array can be reconfigured.
+ * Writing this, if accepted, will block until array is quiessent
+ * readonly
+ * no resync can happen. no superblocks get written.
+ * write requests fail
+ * read-auto
+ * like readonly, but behaves like 'clean' on a write request.
+ *
+ * clean - no pending writes, but otherwise active.
+ * When written to inactive array, starts without resync
+ * If a write request arrives then
+ * if metadata is known, mark 'dirty' and switch to 'active'.
+ * if not known, block and switch to write-pending
+ * If written to an active array that has pending writes, then fails.
+ * active
+ * fully active: IO and resync can be happening.
+ * When written to inactive array, starts with resync
+ *
+ * write-pending
+ * clean, but writes are blocked waiting for 'active' to be written.
+ *
+ * active-idle
+ * like active, but no writes have been seen for a while (100msec).
+ *
+ */
+enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
+ write_pending, active_idle, bad_word};
+static char *array_states[] = {
+ "clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
+ "write-pending", "active-idle", NULL };
+
+static int match_word(const char *word, char **list)
+{
+ int n;
+ for (n=0; list[n]; n++)
+ if (cmd_match(word, list[n]))
+ break;
+ return n;
+}
+
+static ssize_t
+array_state_show(mddev_t *mddev, char *page)
+{
+ enum array_state st = inactive;
+
+ if (mddev->pers)
+ switch(mddev->ro) {
+ case 1:
+ st = readonly;
+ break;
+ case 2:
+ st = read_auto;
+ break;
+ case 0:
+ if (mddev->in_sync)
+ st = clean;
+ else if (mddev->safemode)
+ st = active_idle;
+ else
+ st = active;
+ }
+ else {
+ if (list_empty(&mddev->disks) &&
+ mddev->raid_disks == 0 &&
+ mddev->size == 0)
+ st = clear;
+ else
+ st = inactive;
+ }
+ return sprintf(page, "%s\n", array_states[st]);
+}
+
+static int do_md_stop(mddev_t * mddev, int ro);
+static int do_md_run(mddev_t * mddev);
+static int restart_array(mddev_t *mddev);
+
+static ssize_t
+array_state_store(mddev_t *mddev, const char *buf, size_t len)
+{
+ int err = -EINVAL;
+ enum array_state st = match_word(buf, array_states);
+ switch(st) {
+ case bad_word:
+ break;
+ case clear:
+ /* stopping an active array */
+ if (mddev->pers) {
+ if (atomic_read(&mddev->active) > 1)
+ return -EBUSY;
+ err = do_md_stop(mddev, 0);
+ }
+ break;
+ case inactive:
+ /* stopping an active array */
+ if (mddev->pers) {
+ if (atomic_read(&mddev->active) > 1)
+ return -EBUSY;
+ err = do_md_stop(mddev, 2);
+ }
+ break;
+ case suspended:
+ break; /* not supported yet */
+ case readonly:
+ if (mddev->pers)
+ err = do_md_stop(mddev, 1);
+ else {
+ mddev->ro = 1;
+ err = do_md_run(mddev);
+ }
+ break;
+ case read_auto:
+ /* stopping an active array */
+ if (mddev->pers) {
+ err = do_md_stop(mddev, 1);
+ if (err == 0)
+ mddev->ro = 2; /* FIXME mark devices writable */
+ } else {
+ mddev->ro = 2;
+ err = do_md_run(mddev);
+ }
+ break;
+ case clean:
+ if (mddev->pers) {
+ restart_array(mddev);
+ spin_lock_irq(&mddev->write_lock);
+ if (atomic_read(&mddev->writes_pending) == 0) {
+ mddev->in_sync = 1;
+ set_bit(MD_CHANGE_CLEAN, &mddev->flags);
+ }
+ spin_unlock_irq(&mddev->write_lock);
+ } else {
+ mddev->ro = 0;
+ mddev->recovery_cp = MaxSector;
+ err = do_md_run(mddev);
+ }
+ break;
+ case active:
+ if (mddev->pers) {
+ restart_array(mddev);
+ clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
+ wake_up(&mddev->sb_wait);
+ err = 0;
+ } else {
+ mddev->ro = 0;
+ err = do_md_run(mddev);
+ }
+ break;
+ case write_pending:
+ case active_idle:
+ /* these cannot be set */
+ break;
+ }
+ if (err)
+ return err;
+ else
+ return len;
+}
+static struct md_sysfs_entry md_array_state =
+__ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);