From b098636cf04c89db4036fedc778da0acc666ad1a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 11 May 2011 15:52:21 +1000 Subject: md: allow resync_start to be set while an array is active. The sysfs attribute 'resync_start' (known internally as recovery_cp), records where a resync is up to. A value of 0 means the array is not known to be in-sync at all. A value of MaxSector means the array is believed to be fully in-sync. When the size of member devices of an array (RAID1,RAID4/5/6) is increased, the array can be increased to match. This process sets resync_start to the old end-of-device offset so that the new part of the array gets resynced. However with RAID1 (and RAID6) a resync is not technically necessary and may be undesirable. So it would be good if the implied resync after the array is resized could be avoided. So: change 'resync_start' so the value can be changed while the array is active, and as a precaution only allow it to be changed while resync/recovery is 'frozen'. Changing it once resync has started is not going to be useful anyway. This allows the array to be resized without a resync by: write 'frozen' to 'sync_action' write new size to 'component_size' (this will set resync_start) write 'none' to 'resync_start' write 'idle' to 'sync_action'. Also slightly improve some tests on recovery_cp when resizing raid1/raid5. Now that an arbitrary value could be set we should be more careful in our tests. Signed-off-by: NeilBrown --- drivers/md/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/md.c') diff --git a/drivers/md/md.c b/drivers/md/md.c index 5469ae35ee15..aa640a85bb21 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3324,7 +3324,7 @@ resync_start_store(mddev_t *mddev, const char *buf, size_t len) char *e; unsigned long long n = simple_strtoull(buf, &e, 10); - if (mddev->pers) + if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) return -EBUSY; if (cmd_match(buf, "none")) n = MaxSector; -- cgit v1.2.3-58-ga151