Re: [PATCH 005 of 006] raid5: Move expansion operations to a workqueue
From: Dan Williams
Date: Thu Jun 29 2006 - 18:50:23 EST
Refresh to apply on top the new version of [PATCH 004 of 006].
-----------
This patch modifies handle_write_operations5() to handle the parity
calculation request made by the reshape code. However this patch does
not move the copy operation associated with an expand to the work queue.
First, it was difficult to find a clean way to pass the parameters of
this operation to the queue. Second, this section of code is a good
candidate for performing the copies with inline calls to the dma
routines.
This patch also cleans up the *_End flags which as of this version of
the patch set are not needed.
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
drivers/md/raid5.c | 51 ++++++++++++++++++++++++++++++++-------------
include/linux/raid/raid5.h | 36 +++++++++++++++----------------
2 files changed, 54 insertions(+), 33 deletions(-)
===================================================================
Index: linux-2.6-raid/drivers/md/raid5.c
===================================================================
--- linux-2.6-raid.orig/drivers/md/raid5.c 2006-06-29 11:43:35.000000000 -0700
+++ linux-2.6-raid/drivers/md/raid5.c 2006-06-29 11:44:30.000000000 -0700
@@ -1250,16 +1250,25 @@
*/
if (locked == 0) {
if (rcw == 0) {
- /* enter stage 1 of reconstruct write operation */
- set_bit(STRIPE_OP_RCW, &sh->state);
- set_bit(STRIPE_OP_RCW_Drain, &sh->ops.state);
- for (i=disks ; i-- ;) {
- struct r5dev *dev = &sh->dev[i];
-
- if (i!=pd_idx && dev->towrite) {
- set_bit(R5_LOCKED, &dev->flags);
+ /* skip the drain operation on an expand */
+ if (test_bit(STRIPE_OP_RCW_Expand, &sh->ops.state)) {
+ set_bit(STRIPE_OP_RCW, &sh->state);
+ set_bit(STRIPE_OP_RCW_Parity, &sh->ops.state);
+ for (i=disks ; i-- ;) {
+ set_bit(R5_LOCKED, &sh->dev[i].flags);
locked++;
}
+ } else { /* enter stage 1 of reconstruct write operation */
+ set_bit(STRIPE_OP_RCW, &sh->state);
+ set_bit(STRIPE_OP_RCW_Drain, &sh->ops.state);
+ for (i=disks ; i-- ;) {
+ struct r5dev *dev = &sh->dev[i];
+
+ if (i!=pd_idx && dev->towrite) {
+ set_bit(R5_LOCKED, &dev->flags);
+ locked++;
+ }
+ }
}
} else {
/* enter stage 1 of read modify write operation */
@@ -2217,16 +2226,24 @@
}
if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) {
+ int work_queued, start_n=1;
/* 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);
- locked++;
- set_bit(R5_Wantwrite, &sh->dev[i].flags);
+ if (!(test_bit(STRIPE_OP_RCW, &sh->state) ||
+ test_bit(STRIPE_OP_RCW_Expand, &sh->ops.state))) {
+ start_n = 0;
+ set_bit(STRIPE_OP_RCW_Expand, &sh->ops.state);
+ }
+ work_queued = handle_write_operations5(sh, 0, start_n);
+ if (work_queued == 0) {
+ for (i= conf->raid_disks; i--;)
+ set_bit(R5_Wantwrite, &sh->dev[i].flags);
+ clear_bit(STRIPE_EXPANDING, &sh->state);
+ clear_bit(STRIPE_OP_RCW_Expand, &sh->ops.state);
+ } else if (work_queued > 0) {
+ locked += work_queued;
}
- clear_bit(STRIPE_EXPANDING, &sh->state);
} else if (expanded) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
@@ -2261,9 +2278,15 @@
release_stripe(sh2);
continue;
}
+ /* to do: perform these operations with a dma engine
+ * inline (rather than pushing to the workqueue)
+ */
+ /*#ifdef CONFIG_DMA_ENGINE*/
+ /*#else*/
memcpy(page_address(sh2->dev[dd_idx].page),
page_address(sh->dev[i].page),
STRIPE_SIZE);
+ /*#endif*/
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++)
Index: linux-2.6-raid/include/linux/raid/raid5.h
===================================================================
--- linux-2.6-raid.orig/include/linux/raid/raid5.h 2006-06-29 11:40:37.000000000 -0700
+++ linux-2.6-raid/include/linux/raid/raid5.h 2006-06-29 11:53:35.000000000 -0700
@@ -214,34 +214,28 @@
/*
* These flags are communication markers between the handle_stripe[5|6]
* routine and the block operations work queue
- * - The *_End definitions are a signal from handle_stripe to the work queue to
- * to ensure the completion of the operation so the results can be committed
- * to disk
* - The *_Done definitions signal completion from work queue to handle_stripe
* - STRIPE_OP_CHECK_IsZero signals parity correctness to handle_stripe
* - All other definitions are service requests for the work queue
*/
#define STRIPE_OP_RCW_Drain 0
#define STRIPE_OP_RCW_Parity 1
-#define STRIPE_OP_RCW_End 2
-#define STRIPE_OP_RCW_Done 3
+#define STRIPE_OP_RCW_Done 2
+#define STRIPE_OP_RCW_Expand 3
#define STRIPE_OP_RMW_ParityPre 4
#define STRIPE_OP_RMW_Drain 5
#define STRIPE_OP_RMW_ParityPost 6
-#define STRIPE_OP_RMW_End 7
-#define STRIPE_OP_RMW_Done 8
-#define STRIPE_OP_CHECK_Gen 9
-#define STRIPE_OP_CHECK_Verify 10
-#define STRIPE_OP_CHECK_End 11
-#define STRIPE_OP_CHECK_Done 12
-#define STRIPE_OP_CHECK_IsZero 13
-#define STRIPE_OP_COMPUTE_Prep 14
-#define STRIPE_OP_COMPUTE_Parity 15
-#define STRIPE_OP_COMPUTE_End 16
-#define STRIPE_OP_COMPUTE_Done 17
-#define STRIPE_OP_COMPUTE_Recover 18
-#define STRIPE_OP_BIOFILL_Copy 19
-#define STRIPE_OP_BIOFILL_Done 20
+#define STRIPE_OP_RMW_Done 7
+#define STRIPE_OP_CHECK_Gen 8
+#define STRIPE_OP_CHECK_Verify 9
+#define STRIPE_OP_CHECK_Done 10
+#define STRIPE_OP_CHECK_IsZero 11
+#define STRIPE_OP_COMPUTE_Prep 12
+#define STRIPE_OP_COMPUTE_Parity 13
+#define STRIPE_OP_COMPUTE_Done 14
+#define STRIPE_OP_COMPUTE_Recover 15
+#define STRIPE_OP_BIOFILL_Copy 16
+#define STRIPE_OP_BIOFILL_Done 17
/*
* Bit mask for status bits not to be cleared by the work queue thread
-
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