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md: handle_stripe5 - add request/completion logic for async expand ops 

When a stripe is being expanded bulk copying takes place to move the data
from the old stripe to the new.  Since raid5_run_ops only operates on one
stripe at a time these bulk copies are handled in-line under the stripe
lock.  In the dma offload case we poll for the completion of the operation.

After the data has been copied into the new stripe the parity needs to be
recalculated across the new disks.  We reuse the existing postxor
functionality to carry out this calculation.  By setting STRIPE_OP_POSTXOR
without setting STRIPE_OP_BIODRAIN the completion path in handle stripe
can differentiate expand operations from normal write operations.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-By: NeilBrown <neilb@suse.de>
This commit is contained in:
Dan Williams 2007-01-02 13:52:31 -07:00
parent b5e98d65d3
commit f0a50d3754
1 changed files with 39 additions and 13 deletions
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52
drivers/md/raid5.c
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@ -2653,6 +2653,7 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
/* We have read all the blocks in this stripe and now we need to
* copy some of them into a target stripe for expand.
*/
struct dma_async_tx_descriptor *tx = NULL;
clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
for (i = 0; i < sh->disks; i++)
if (i != sh->pd_idx && (r6s && i != r6s->qd_idx)) {
@ -2678,9 +2679,12 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
release_stripe(sh2);
continue;
}
memcpy(page_address(sh2->dev[dd_idx].page),
page_address(sh->dev[i].page),
STRIPE_SIZE);
/* place all the copies on one channel */
tx = async_memcpy(sh2->dev[dd_idx].page,
sh->dev[i].page, 0, 0, STRIPE_SIZE,
ASYNC_TX_DEP_ACK, tx, NULL, NULL);
set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
for (j = 0; j < conf->raid_disks; j++)
@ -2693,6 +2697,12 @@ static void handle_stripe_expansion(raid5_conf_t *conf, struct stripe_head *sh,
set_bit(STRIPE_HANDLE, &sh2->state);
}
release_stripe(sh2);
/* done submitting copies, wait for them to complete */
if (i + 1 >= sh->disks) {
async_tx_ack(tx);
dma_wait_for_async_tx(tx);
}
}
}
@ -2931,18 +2941,34 @@ static void handle_stripe5(struct stripe_head *sh)
}
}
if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
/* Finish postxor operations initiated by the expansion
* process
*/
if (test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete) &&
!test_bit(STRIPE_OP_BIODRAIN, &sh->ops.pending)) {
clear_bit(STRIPE_EXPANDING, &sh->state);
clear_bit(STRIPE_OP_POSTXOR, &sh->ops.pending);
clear_bit(STRIPE_OP_POSTXOR, &sh->ops.ack);
clear_bit(STRIPE_OP_POSTXOR, &sh->ops.complete);
for (i = conf->raid_disks; i--; ) {
set_bit(R5_Wantwrite, &sh->dev[i].flags);
if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
sh->ops.count++;
}
}
if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
!test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
/* Need to write out all blocks after computing parity */
sh->disks = conf->raid_disks;
sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks);
compute_parity5(sh, RECONSTRUCT_WRITE);
for (i = conf->raid_disks; i--; ) {
set_bit(R5_LOCKED, &sh->dev[i].flags);
s.locked++;
set_bit(R5_Wantwrite, &sh->dev[i].flags);
}
clear_bit(STRIPE_EXPANDING, &sh->state);
} else if (s.expanded) {
sh->pd_idx = stripe_to_pdidx(sh->sector, conf,
conf->raid_disks);
s.locked += handle_write_operations5(sh, 0, 1);
} else if (s.expanded &&
!test_bit(STRIPE_OP_POSTXOR, &sh->ops.pending)) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
wake_up(&conf->wait_for_overlap);