---
drivers/md/md.c | 79 ++++++++++++++++++++++++++++++++++++---------
include/linux/raid/md_k.h | 2 +
2 files changed, 66 insertions(+), 15 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index cbe0f20..0e0e1ff 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -202,12 +202,68 @@ static DEFINE_SPINLOCK(all_mddevs_lock);
)
-static int md_fail_request(struct request_queue *q, struct bio *bio)
+/* Rather than calling directly into the personality make_request function,
+ * IO requests come here first so that we can check if the device is
+ * being suspended pending a reconfiguration.
+ * We hold a refcount over the call to ->make_request. By the time that
+ * call has finished, the bio has been linked into some internal structure
+ * and so is visible to ->quiesce(), so we don't need the refcount any more.
+ */
+static int md_make_request(struct request_queue *q, struct bio *bio)
{
- bio_io_error(bio);
- return 0;
+ mddev_t *mddev = q->queuedata;
+ int rv;
+ if (mddev == NULL || mddev->pers == NULL) {
+ bio_io_error(bio);
+ return 0;
+ }
+ rcu_read_lock();
+ if (mddev->suspended) {
+ DEFINE_WAIT(__wait);
+ for(;;) {
+ prepare_to_wait(&mddev->sb_wait, &__wait,
+ TASK_UNINTERRUPTIBLE);
+ if (!mddev->suspended)
+ break;
+ rcu_read_unlock();
+ schedule();
+ rcu_read_lock();
+ }
+ finish_wait(&mddev->sb_wait, &__wait);
+ }
+ atomic_inc(&mddev->active_io);
+ rcu_read_unlock();
+ rv = mddev->pers->make_request(q, bio);
+ if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
+ wake_up(&mddev->sb_wait);
+
+ return rv;
}
+static void mddev_suspend(mddev_t *mddev)
+{
+ BUG_ON(mddev->suspended);
+ mddev->suspended = 1;
+ synchronize_rcu();
+ wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
+ mddev->pers->quiesce(mddev, 1);
+ md_unregister_thread(mddev->thread);
+ mddev->thread = NULL;
+ /* we now know that no code is executing in the personality module,
+ * except possibly the tail end of a ->bi_end_io function, but that
+ * is certain to complete before the module has a chance to get
+ * unloaded
+ */
+}
+
+static void mddev_resume(mddev_t *mddev)
+{
+ mddev->suspended = 0;
+ wake_up(&mddev->sb_wait);
+ mddev->pers->quiesce(mddev, 0);
+}
+
+
static inline mddev_t *mddev_get(mddev_t *mddev)
{
atomic_inc(&mddev->active);
@@ -315,6 +371,7 @@ static mddev_t * mddev_find(dev_t unit)
init_timer(&new->safemode_timer);
atomic_set(&new->active, 1);
atomic_set(&new->openers, 0);
+ atomic_set(&new->active_io, 0);
spin_lock_init(&new->write_lock);
init_waitqueue_head(&new->sb_wait);
init_waitqueue_head(&new->recovery_wait);
@@ -3597,10 +3654,12 @@ static int md_alloc(dev_t dev, char *name)
mddev_put(mddev);
return -ENOMEM;
}
+ mddev->queue->queuedata = mddev;
+
/* Can be unlocked because the queue is new: no concurrency */
queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
- blk_queue_make_request(mddev->queue, md_fail_request);
+ blk_queue_make_request(mddev->queue, md_make_request);
disk = alloc_disk(1 << shift);
if (!disk) {
@@ -3896,16 +3955,6 @@ static int do_md_run(mddev_t * mddev)
set_capacity(disk, mddev->array_sectors);
- /* If we call blk_queue_make_request here, it will
- * re-initialise max_sectors etc which may have been
- * refined inside -> run. So just set the bits we need to set.
- * Most initialisation happended when we called
- * blk_queue_make_request(..., md_fail_request)
- * earlier.
- */
- mddev->queue->queuedata = mddev;
- mddev->queue->make_request_fn = mddev->pers->make_request;
-
/* If there is a partially-recovered drive we need to
* start recovery here. If we leave it to md_check_recovery,
* it will remove the drives and not do the right thing
@@ -4035,7 +4084,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
md_super_wait(mddev);
if (mddev->ro)
set_disk_ro(disk, 0);
- blk_queue_make_request(mddev->queue, md_fail_request);
+
mddev->pers->stop(mddev);
mddev->queue->merge_bvec_fn = NULL;
mddev->queue->unplug_fn = NULL;
diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h
index 9598155..a815bab 100644
--- a/include/linux/raid/md_k.h
+++ b/include/linux/raid/md_k.h
@@ -132,6 +132,8 @@ struct mddev_s
#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
#define MD_CHANGE_PENDING 2 /* superblock update in progress */
+ int suspended;
+ atomic_t active_io;
int ro;
struct gendisk *gendisk;
--
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