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Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c35
1 files changed, 29 insertions, 6 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 16f5c21963db..1c829a0b234b 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -64,6 +64,10 @@
#define cpu_to_group(cpu) cpu_to_node(cpu)
#define ANY_GROUP NUMA_NO_NODE
+static bool devices_handle_discard_safely = false;
+module_param(devices_handle_discard_safely, bool, 0644);
+MODULE_PARM_DESC(devices_handle_discard_safely,
+ "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
static struct workqueue_struct *raid5_wq;
/*
* Stripe cache
@@ -1910,7 +1914,8 @@ static int resize_stripes(struct r5conf *conf, int newsize)
conf->slab_cache = sc;
conf->active_name = 1-conf->active_name;
- conf->pool_size = newsize;
+ if (!err)
+ conf->pool_size = newsize;
return err;
}
@@ -2892,7 +2897,8 @@ static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
(s->failed >= 2 && fdev[1]->toread) ||
(sh->raid_conf->level <= 5 && s->failed && fdev[0]->towrite &&
!test_bit(R5_OVERWRITE, &fdev[0]->flags)) ||
- (sh->raid_conf->level == 6 && s->failed && s->to_write))) {
+ ((sh->raid_conf->level == 6 || sh->sector >= sh->raid_conf->mddev->recovery_cp)
+ && s->failed && s->to_write))) {
/* we would like to get this block, possibly by computing it,
* otherwise read it if the backing disk is insync
*/
@@ -3023,6 +3029,8 @@ static void handle_stripe_clean_event(struct r5conf *conf,
}
if (!discard_pending &&
test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
+ int hash = sh->hash_lock_index;
+
clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
if (sh->qd_idx >= 0) {
@@ -3036,9 +3044,9 @@ static void handle_stripe_clean_event(struct r5conf *conf,
* no updated data, so remove it from hash list and the stripe
* will be reinitialized
*/
- spin_lock_irq(&conf->device_lock);
+ spin_lock_irq(conf->hash_locks + hash);
remove_hash(sh);
- spin_unlock_irq(&conf->device_lock);
+ spin_unlock_irq(conf->hash_locks + hash);
if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
set_bit(STRIPE_HANDLE, &sh->state);
@@ -3066,7 +3074,8 @@ static void handle_stripe_dirtying(struct r5conf *conf,
* generate correct data from the parity.
*/
if (conf->max_degraded == 2 ||
- (recovery_cp < MaxSector && sh->sector >= recovery_cp)) {
+ (recovery_cp < MaxSector && sh->sector >= recovery_cp &&
+ s->failed == 0)) {
/* Calculate the real rcw later - for now make it
* look like rcw is cheaper
*/
@@ -3779,6 +3788,8 @@ static void handle_stripe(struct stripe_head *sh)
set_bit(R5_Wantwrite, &dev->flags);
if (prexor)
continue;
+ if (s.failed > 1)
+ continue;
if (!test_bit(R5_Insync, &dev->flags) ||
((i == sh->pd_idx || i == sh->qd_idx) &&
s.failed == 0))
@@ -6115,7 +6126,7 @@ static int run(struct mddev *mddev)
mddev->queue->limits.discard_granularity = stripe;
/*
* unaligned part of discard request will be ignored, so can't
- * guarantee discard_zerors_data
+ * guarantee discard_zeroes_data
*/
mddev->queue->limits.discard_zeroes_data = 0;
@@ -6140,6 +6151,18 @@ static int run(struct mddev *mddev)
!bdev_get_queue(rdev->bdev)->
limits.discard_zeroes_data)
discard_supported = false;
+ /* Unfortunately, discard_zeroes_data is not currently
+ * a guarantee - just a hint. So we only allow DISCARD
+ * if the sysadmin has confirmed that only safe devices
+ * are in use by setting a module parameter.
+ */
+ if (!devices_handle_discard_safely) {
+ if (discard_supported) {
+ pr_info("md/raid456: discard support disabled due to uncertainty.\n");
+ pr_info("Set raid456.devices_handle_discard_safely=Y to override.\n");
+ }
+ discard_supported = false;
+ }
}
if (discard_supported &&