RAID6 is only allowed to choose 'reconstruct-write' while RAID5 is
also allow 'read-modify-write'
Apart from this difference, handle_stripe_dirtying[56] are nearly
identical. So resolve these differences and create just one function.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
drivers/md/raid5.c | 77 ++++++++++++++--------------------------------------
1 files changed, 21 insertions(+), 56 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ea796a9..b1eba98 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2468,11 +2468,19 @@ static void handle_stripe_clean_event(raid5_conf_t *conf,
md_wakeup_thread(conf->mddev->thread);
}
-static void handle_stripe_dirtying5(raid5_conf_t *conf,
- struct stripe_head *sh, struct stripe_head_state *s, int disks)
+static void handle_stripe_dirtying(raid5_conf_t *conf,
+ struct stripe_head *sh,
+ struct stripe_head_state *s,
+ int disks)
{
int rmw = 0, rcw = 0, i;
- for (i = disks; i--; ) {
+ if (conf->max_degraded == 2) {
+ /* RAID6 requires 'rcw' in current implementation
+ * Calculate the real rcw later - for now fake it
+ * look like rcw is cheaper
+ */
+ rcw = 1; rmw = 2;
+ } else for (i = disks; i--; ) {
/* would I have to read this buffer for read_modify_write */
struct r5dev *dev = &sh->dev[i];
if ((dev->towrite || i == sh->pd_idx) &&
@@ -2519,16 +2527,19 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf,
}
}
}
- if (rcw <= rmw && rcw > 0)
+ if (rcw <= rmw && rcw > 0) {
/* want reconstruct write, but need to get some data */
+ rcw = 0;
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (!test_bit(R5_OVERWRITE, &dev->flags) &&
- i != sh->pd_idx &&
+ i != sh->pd_idx && i != sh->qd_idx &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(test_bit(R5_UPTODATE, &dev->flags) ||
- test_bit(R5_Wantcompute, &dev->flags)) &&
- test_bit(R5_Insync, &dev->flags)) {
+ test_bit(R5_Wantcompute, &dev->flags))) {
+ rcw++;
+ if (!test_bit(R5_Insync, &dev->flags))
+ continue; /* it's a failed drive */
if (
test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
pr_debug("Read_old block "
@@ -2542,6 +2553,7 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf,
}
}
}
+ }
/* now if nothing is locked, and if we have enough data,
* we can start a write request
*/
@@ -2558,53 +2570,6 @@ static void handle_stripe_dirtying5(raid5_conf_t *conf,
schedule_reconstruction(sh, s, rcw == 0, 0);
}
-static void handle_stripe_dirtying6(raid5_conf_t *conf,
- struct stripe_head *sh, struct stripe_head_state *s,
- int disks)
-{
- int rcw = 0, pd_idx = sh->pd_idx, i;
- int qd_idx = sh->qd_idx;
-
- set_bit(STRIPE_HANDLE, &sh->state);
- for (i = disks; i--; ) {
- struct r5dev *dev = &sh->dev[i];
- /* check if we haven't enough data */
- if (!test_bit(R5_OVERWRITE, &dev->flags) &&
- i != pd_idx && i != qd_idx &&
- !test_bit(R5_LOCKED, &dev->flags) &&
- !(test_bit(R5_UPTODATE, &dev->flags) ||
- test_bit(R5_Wantcompute, &dev->flags))) {
- rcw++;
- if (!test_bit(R5_Insync, &dev->flags))
- continue; /* it's a failed drive */
-
- if (
- test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
- pr_debug("Read_old stripe %llu "
- "block %d for Reconstruct\n",
- (unsigned long long)sh->sector, i);
- set_bit(R5_LOCKED, &dev->flags);
- set_bit(R5_Wantread, &dev->flags);
- s->locked++;
- } else {
- pr_debug("Request delayed stripe %llu "
- "block %d for Reconstruct\n",
- (unsigned long long)sh->sector, i);
- set_bit(STRIPE_DELAYED, &sh->state);
- set_bit(STRIPE_HANDLE, &sh->state);
- }
- }
- }
- /* now if nothing is locked, and if we have enough data, we can start a
- * write request
- */
- if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
- s->locked == 0 && rcw == 0 &&
- !test_bit(STRIPE_BIT_DELAY, &sh->state)) {
- schedule_reconstruction(sh, s, 1, 0);
- }
-}
-
static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
struct stripe_head_state *s, int disks)
{
@@ -3100,7 +3065,7 @@ static int handle_stripe5(struct stripe_head *sh, struct stripe_head_state *s)
* block.
*/
if (s->to_write && !sh->reconstruct_state && !sh->check_state)
- handle_stripe_dirtying5(conf, sh, s, disks);
+ handle_stripe_dirtying(conf, sh, s, disks);
/* maybe we need to check and possibly fix the parity for this stripe
* Any reads will already have been scheduled, so we just see if enough
@@ -3289,7 +3254,7 @@ static int handle_stripe6(struct stripe_head *sh, struct stripe_head_state *s)
* block.
*/
if (s->to_write && !sh->reconstruct_state && !sh->check_state)
- handle_stripe_dirtying6(conf, sh, s, disks);
+ handle_stripe_dirtying(conf, sh, s, disks);
/* maybe we need to check and possibly fix the parity for this stripe
* Any reads will already have been scheduled, so we just see if enough
--
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