Three more md fixes for 4.1

The main issue fixed here is a rare race which can result in two reshape
 threads running at once, which doesn't end well.
 Also a minor issue with a write to a sysfs file returning the wrong value.
 Backports to 4.0-stable are indicated.
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Merge tag 'md/4.1-rc7-fixes' of git://neil.brown.name/md

Pull three more md fixes from Neil Brown:
 "Hasn't been a good cycle for md has it :-(

  The main issue fixed here is a rare race which can result in two
  reshape threads running at once, which doesn't end well.

  Also a minor issue with a write to a sysfs file returning the wrong
  value.  Backports to 4.0-stable are indicated"

* tag 'md/4.1-rc7-fixes' of git://neil.brown.name/md:
  md: make sure MD_RECOVERY_DONE is clear before starting recovery/resync
  md: Close race when setting 'action' to 'idle'.
  md: don't return 0 from array_state_store
This commit is contained in:
Linus Torvalds 2015-06-12 11:33:03 -07:00
commit 7b565d9d1f
3 changed files with 10 additions and 6 deletions

View File

@ -3834,7 +3834,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
err = -EBUSY;
}
spin_unlock(&mddev->lock);
return err;
return err ?: len;
}
err = mddev_lock(mddev);
if (err)
@ -4217,13 +4217,14 @@ action_store(struct mddev *mddev, const char *page, size_t len)
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
else
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
flush_workqueue(md_misc_wq);
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
if (mddev_lock(mddev) == 0) {
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
mddev_lock(mddev) == 0) {
flush_workqueue(md_misc_wq);
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_reap_sync_thread(mddev);
mddev_unlock(mddev);
}
mddev_unlock(mddev);
}
} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
@ -8261,6 +8262,7 @@ void md_reap_sync_thread(struct mddev *mddev)
if (mddev_is_clustered(mddev))
md_cluster_ops->metadata_update_finish(mddev);
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);

View File

@ -4156,6 +4156,7 @@ static int raid10_start_reshape(struct mddev *mddev)
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);

View File

@ -7354,6 +7354,7 @@ static int raid5_start_reshape(struct mddev *mddev)
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
mddev->sync_thread = md_register_thread(md_do_sync, mddev,