md/raid6 passes a list of 'struct page *' to the async_tx routines,
which then either DMA map them for offload, or take the page_address
for CPU based calculations.
For RAID6 we sometime leave 'blanks' in the list of pages.
For CPU based calcs, we want to treat theses as a page of zeros.
For offloaded calculations, we simply don't pass a page to the
hardware.
Currently the 'blanks' are encoded as a pointer to
raid6_empty_zero_page. This is a 4096 byte memory region, not a
'struct page'. This is mostly handled correctly but is rather ugly.
So change the code to pass and expect a NULL pointer for the blanks.
When taking page_address of a page, we need to check for a NULL and
in that case use raid6_empty_zero_page.
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
crypto/async_tx/async_pq.c | 15 ++++-----------
crypto/async_tx/async_raid6_recov.c | 16 +++++++++++-----
drivers/md/raid5.c | 4 ++--
3 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
index b88db6d..9ab1ce4 100644
--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -30,11 +30,6 @@
*/
static struct page *scribble;
-static bool is_raid6_zero_block(struct page *p)
-{
- return p == (void *) raid6_empty_zero_page;
-}
-
/* the struct page *blocks[] parameter passed to async_gen_syndrome()
* and async_syndrome_val() contains the 'P' destination address at
* blocks[disks-2] and the 'Q' destination address at blocks[disks-1]
@@ -83,7 +78,7 @@ do_async_gen_syndrome(struct dma_chan *chan, struct page **blocks,
* sources and update the coefficients accordingly
*/
for (i = 0, idx = 0; i < src_cnt; i++) {
- if (is_raid6_zero_block(blocks[i]))
+ if (blocks[i] == NULL)
continue;
dma_src[idx] = dma_map_page(dma->dev, blocks[i], offset, len,
DMA_TO_DEVICE);
@@ -160,9 +155,9 @@ do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
srcs = (void **) blocks;
for (i = 0; i < disks; i++) {
- if (is_raid6_zero_block(blocks[i])) {
+ if (blocks[i] == NULL) {
BUG_ON(i > disks - 3); /* P or Q can't be zero */
- srcs[i] = blocks[i];
+ srcs[i] = (void*)raid6_empty_zero_page;
} else
srcs[i] = page_address(blocks[i]) + offset;
}
@@ -290,12 +285,10 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
if (submit->flags & ASYNC_TX_FENCE)
dma_flags |= DMA_PREP_FENCE;
for (i = 0; i < disks; i++)
- if (likely(blocks[i])) {
- BUG_ON(is_raid6_zero_block(blocks[i]));
+ if (likely(blocks[i]))
dma_src[i] = dma_map_page(dev, blocks[i],
offset, len,
DMA_TO_DEVICE);
- }
for (;;) {
tx = device->device_prep_dma_pq_val(chan, pq, dma_src,
diff --git a/crypto/async_tx/async_raid6_recov.c b/crypto/async_tx/async_raid6_recov.c
index 6d73dde..8e30b6e 100644
--- a/crypto/async_tx/async_raid6_recov.c
+++ b/crypto/async_tx/async_raid6_recov.c
@@ -263,10 +263,10 @@ __2data_recov_n(int disks, size_t bytes, int faila, int failb,
* delta p and delta q
*/
dp = blocks[faila];
- blocks[faila] = (void *)raid6_empty_zero_page;
+ blocks[faila] = NULL;
blocks[disks-2] = dp;
dq = blocks[failb];
- blocks[failb] = (void *)raid6_empty_zero_page;
+ blocks[failb] = NULL;
blocks[disks-1] = dq;
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
@@ -338,7 +338,10 @@ async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
async_tx_quiesce(&submit->depend_tx);
for (i = 0; i < disks; i++)
- ptrs[i] = page_address(blocks[i]);
+ if (blocks[i] == NULL)
+ ptrs[i] = (void*)raid6_empty_zero_page;
+ else
+ ptrs[i] = page_address(blocks[i]);
raid6_2data_recov(disks, bytes, faila, failb, ptrs);
@@ -398,7 +401,10 @@ async_raid6_datap_recov(int disks, size_t bytes, int faila,
async_tx_quiesce(&submit->depend_tx);
for (i = 0; i < disks; i++)
- ptrs[i] = page_address(blocks[i]);
+ if (blocks[i] == NULL)
+ ptrs[i] = (void*)raid6_empty_zero_page;
+ else
+ ptrs[i] = page_address(blocks[i]);
raid6_datap_recov(disks, bytes, faila, ptrs);
@@ -414,7 +420,7 @@ async_raid6_datap_recov(int disks, size_t bytes, int faila,
* Use the dead data page as temporary storage for delta q
*/
dq = blocks[faila];
- blocks[faila] = (void *)raid6_empty_zero_page;
+ blocks[faila] = NULL;
blocks[disks-1] = dq;
/* in the 4 disk case we only need to perform a single source
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c4366c9..dcd9e65 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -720,7 +720,7 @@ static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh)
int i;
for (i = 0; i < disks; i++)
- srcs[i] = (void *)raid6_empty_zero_page;
+ srcs[i] = NULL;
count = 0;
i = d0_idx;
@@ -816,7 +816,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
* slot number conversion for 'faila' and 'failb'
*/
for (i = 0; i < disks ; i++)
- blocks[i] = (void *)raid6_empty_zero_page;
+ blocks[i] = NULL;
count = 0;
i = d0_idx;
do {
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
