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authorNeilBrown <neilb@suse.de>2006-03-27 01:18:14 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-27 08:45:02 -0800
commite464eafdb4400c6d6576ba3840d8bd40340f8a96 (patch)
tree0c3f4003c883264ee08300c02007f06e4d1ebb91 /drivers/md/raid5.c
parent16484bf59634e25d1299761e5ed8bacf22bc6368 (diff)
downloadop-kernel-dev-e464eafdb4400c6d6576ba3840d8bd40340f8a96.zip
op-kernel-dev-e464eafdb4400c6d6576ba3840d8bd40340f8a96.tar.gz
[PATCH] md: Support suspending of IO to regions of an md array
This allows user-space to access data safely. This is needed for raid5 reshape as user-space needs to take a backup of the first few stripes before allowing reshape to commence. It will also be useful in cluster-aware raid1 configurations so that all cluster members can leave a section of the array untouched while a resync/recovery happens. A 'start' and 'end' of the suspended range are written to 2 sysfs attributes. Note that only one range can be suspended at a time. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 355dafb..bb16ac2 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1805,6 +1805,15 @@ static int make_request(request_queue_t *q, struct bio * bi)
goto retry;
}
}
+ /* FIXME what if we get a false positive because these
+ * are being updated.
+ */
+ if (logical_sector >= mddev->suspend_lo &&
+ logical_sector < mddev->suspend_hi) {
+ release_stripe(sh);
+ schedule();
+ goto retry;
+ }
if (test_bit(STRIPE_EXPANDING, &sh->state) ||
!add_stripe_bio(sh, bi, dd_idx, (bi->bi_rw&RW_MASK))) {
@@ -2725,6 +2734,10 @@ static void raid5_quiesce(mddev_t *mddev, int state)
raid5_conf_t *conf = mddev_to_conf(mddev);
switch(state) {
+ case 2: /* resume for a suspend */
+ wake_up(&conf->wait_for_overlap);
+ break;
+
case 1: /* stop all writes */
spin_lock_irq(&conf->device_lock);
conf->quiesce = 1;
@@ -2738,6 +2751,7 @@ static void raid5_quiesce(mddev_t *mddev, int state)
spin_lock_irq(&conf->device_lock);
conf->quiesce = 0;
wake_up(&conf->wait_for_stripe);
+ wake_up(&conf->wait_for_overlap);
spin_unlock_irq(&conf->device_lock);
break;
}
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