[PATCH] md: delay starting md threads until array is completely setup
When an array is started we start one or two threads (two if there is a
reshape or recovery that needs to be completed).
We currently start these *before* the array is completely set up and in
particular before queue->queuedata is set. If the thread actually starts
very quickly on another CPU, we can end up dereferencing queue->queuedata
and oops.
This patch also makes sure we don't try to start a recovery if a reshape is
being restarted.
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 9f76e0c..fb50e56 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3095,7 +3095,6 @@
}
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
- md_wakeup_thread(mddev->thread);
if (mddev->sb_dirty)
md_update_sb(mddev);
@@ -3116,7 +3115,7 @@
* start recovery here. If we leave it to md_check_recovery,
* it will remove the drives and not do the right thing
*/
- if (mddev->degraded) {
+ if (mddev->degraded && !mddev->sync_thread) {
struct list_head *rtmp;
int spares = 0;
ITERATE_RDEV(mddev,rdev,rtmp)
@@ -3137,10 +3136,11 @@
mdname(mddev));
/* leave the spares where they are, it shouldn't hurt */
mddev->recovery = 0;
- } else
- md_wakeup_thread(mddev->sync_thread);
+ }
}
}
+ md_wakeup_thread(mddev->thread);
+ md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
mddev->changed = 1;
md_new_event(mddev);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 5764387..a02f35f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3246,9 +3246,6 @@
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
mddev->sync_thread = md_register_thread(md_do_sync, mddev,
"%s_reshape");
- /* FIXME if md_register_thread fails?? */
- md_wakeup_thread(mddev->sync_thread);
-
}
/* read-ahead size must cover two whole stripes, which is