}
static struct dma_async_tx_descriptor *
-__2data_recov_4(size_t bytes, int faila, int failb, struct page **blocks,
- struct async_submit_ctl *submit)
+__2data_recov_4(int disks, size_t bytes, int faila, int failb,
+ struct page **blocks, struct async_submit_ctl *submit)
{
struct dma_async_tx_descriptor *tx = NULL;
struct page *p, *q, *a, *b;
void *cb_param = submit->cb_param;
void *scribble = submit->scribble;
- p = blocks[4-2];
- q = blocks[4-1];
+ p = blocks[disks-2];
+ q = blocks[disks-1];
a = blocks[faila];
b = blocks[failb];
}
static struct dma_async_tx_descriptor *
-__2data_recov_5(size_t bytes, int faila, int failb, struct page **blocks,
- struct async_submit_ctl *submit)
+__2data_recov_5(int disks, size_t bytes, int faila, int failb,
+ struct page **blocks, struct async_submit_ctl *submit)
{
struct dma_async_tx_descriptor *tx = NULL;
struct page *p, *q, *g, *dp, *dq;
dma_async_tx_callback cb_fn = submit->cb_fn;
void *cb_param = submit->cb_param;
void *scribble = submit->scribble;
- int uninitialized_var(good);
- int i;
+ int good_srcs, good, i;
- for (i = 0; i < 3; i++) {
+ good_srcs = 0;
+ good = -1;
+ for (i = 0; i < disks-2; i++) {
+ if (blocks[i] == NULL)
+ continue;
if (i == faila || i == failb)
continue;
- else {
- good = i;
- break;
- }
+ good = i;
+ good_srcs++;
}
- BUG_ON(i >= 3);
+ BUG_ON(good_srcs > 1);
- p = blocks[5-2];
- q = blocks[5-1];
+ p = blocks[disks-2];
+ q = blocks[disks-1];
g = blocks[good];
/* Compute syndrome with zero for the missing data pages
* 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);
async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
struct page **blocks, struct async_submit_ctl *submit)
{
+ void *scribble = submit->scribble;
+ int non_zero_srcs, i;
+
BUG_ON(faila == failb);
if (failb < faila)
swap(faila, failb);
pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
- /* we need to preserve the contents of 'blocks' for the async
- * case, so punt to synchronous if a scribble buffer is not available
+ /* if a dma resource is not available or a scribble buffer is not
+ * available punt to the synchronous path. In the 'dma not
+ * available' case be sure to use the scribble buffer to
+ * preserve the content of 'blocks' as the caller intended.
*/
- if (!submit->scribble) {
- void **ptrs = (void **) blocks;
- int i;
+ if (!async_dma_find_channel(DMA_PQ) || !scribble) {
+ void **ptrs = scribble ? scribble : (void **) blocks;
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);
return NULL;
}
- switch (disks) {
- case 4:
+ non_zero_srcs = 0;
+ for (i = 0; i < disks-2 && non_zero_srcs < 4; i++)
+ if (blocks[i])
+ non_zero_srcs++;
+ switch (non_zero_srcs) {
+ case 0:
+ case 1:
+ /* There must be at least 2 sources - the failed devices. */
+ BUG();
+
+ case 2:
/* dma devices do not uniformly understand a zero source pq
* operation (in contrast to the synchronous case), so
- * explicitly handle the 4 disk special case
+ * explicitly handle the special case of a 4 disk array with
+ * both data disks missing.
*/
- return __2data_recov_4(bytes, faila, failb, blocks, submit);
- case 5:
+ return __2data_recov_4(disks, bytes, faila, failb, blocks, submit);
+ case 3:
/* dma devices do not uniformly understand a single
* source pq operation (in contrast to the synchronous
- * case), so explicitly handle the 5 disk special case
+ * case), so explicitly handle the special case of a 5 disk
+ * array with 2 of 3 data disks missing.
*/
- return __2data_recov_5(bytes, faila, failb, blocks, submit);
+ return __2data_recov_5(disks, bytes, faila, failb, blocks, submit);
default:
return __2data_recov_n(disks, bytes, faila, failb, blocks, submit);
}
dma_async_tx_callback cb_fn = submit->cb_fn;
void *cb_param = submit->cb_param;
void *scribble = submit->scribble;
+ int good_srcs, good, i;
struct page *srcs[2];
pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
- /* we need to preserve the contents of 'blocks' for the async
- * case, so punt to synchronous if a scribble buffer is not available
+ /* if a dma resource is not available or a scribble buffer is not
+ * available punt to the synchronous path. In the 'dma not
+ * available' case be sure to use the scribble buffer to
+ * preserve the content of 'blocks' as the caller intended.
*/
- if (!scribble) {
- void **ptrs = (void **) blocks;
- int i;
+ if (!async_dma_find_channel(DMA_PQ) || !scribble) {
+ void **ptrs = scribble ? scribble : (void **) blocks;
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);
return NULL;
}
+ good_srcs = 0;
+ good = -1;
+ for (i = 0; i < disks-2; i++) {
+ if (i == faila)
+ continue;
+ if (blocks[i]) {
+ good = i;
+ good_srcs++;
+ if (good_srcs > 1)
+ break;
+ }
+ }
+ BUG_ON(good_srcs == 0);
+
p = blocks[disks-2];
q = blocks[disks-1];
* 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
- * multiplication
+ /* in the 4-disk case we only need to perform a single source
+ * multiplication with the one good data block.
*/
- if (disks == 4) {
- int good = faila == 0 ? 1 : 0;
+ if (good_srcs == 1) {
struct page *g = blocks[good];
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
git.openpandora.org / pandora-kernel.git / blobdiff