[PATCH 11/16] md: use async_tx and raid5_run_ops for raid5 expansion operations

Dan Williams
2007-05-02T06:20:17Z

The parity calculation for an expansion operation is the same as the
calculation performed at the end of a write with the caveat that all blocks
in the stripe are scheduled to be written. An expansion operation is
identified as a stripe with the POSTXOR flag set and the BIODRAIN flag not
set.

The bulk copy operation to the new stripe is handled inline by async_tx.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

drivers/md/raid5.c | 48 ++++++++++++++++++++++++++++++++++++------------
1 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 6bde174..1966713 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2538,18 +2538,32 @@ static void handle_stripe5(struct stripe_head *sh)
}
}

- if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
- /* 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);
+ /* 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_LOCKED, &sh->dev[i].flags);
- locked++;
set_bit(R5_Wantwrite, &sh->dev[i].flags);
+ if (!test_and_set_bit(STRIPE_OP_IO, &sh->ops.pending))
+ sh->ops.count++;
}
- clear_bit(STRIPE_EXPANDING, &sh->state);
- } else if (expanded) {
+ }
+
+ if (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);
+ locked += handle_write_operations5(sh, 0, 1);
+ } else if (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);
@@ -2560,6 +2574,7 @@ static void handle_stripe5(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) {
@@ -2583,9 +2598,12 @@ static void handle_stripe5(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++)
@@ -2597,6 +2615,12 @@ static void handle_stripe5(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);
+ }
}
}