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authorDan Williams <dan.j.williams@intel.com>2009-07-14 12:20:37 -0700
committerDan Williams <dan.j.williams@intel.com>2009-08-29 19:09:27 -0700
commit0a82a6239beecc95db6e05fe43ee62d16b381d38 (patch)
tree524f6417ae8128f5b1da322872e860bd4af5840d /include/linux/async_tx.h
parentb2f46fd8ef3dff2ab30f31126833f78b7480283a (diff)
async_tx: add support for asynchronous RAID6 recovery operations
async_raid6_2data_recov() recovers two data disk failures async_raid6_datap_recov() recovers a data disk and the P disk These routines are a port of the synchronous versions found in drivers/md/raid6recov.c. The primary difference is breaking out the xor operations into separate calls to async_xor. Two helper routines are introduced to perform scalar multiplication where needed. async_sum_product() multiplies two sources by scalar coefficients and then sums (xor) the result. async_mult() simply multiplies a single source by a scalar. This implemention also includes, in contrast to the original synchronous-only code, special case handling for the 4-disk and 5-disk array cases. In these situations the default N-disk algorithm will present 0-source or 1-source operations to dma devices. To cover for dma devices where the minimum source count is 2 we implement 4-disk and 5-disk handling in the recovery code. [ Impact: asynchronous raid6 recovery routines for 2data and datap cases ] Cc: Yuri Tikhonov <yur@emcraft.com> Cc: Ilya Yanok <yanok@emcraft.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include/linux/async_tx.h')
-rw-r--r--include/linux/async_tx.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h
index e6ce5f004f98..866e61c4e2e0 100644
--- a/include/linux/async_tx.h
+++ b/include/linux/async_tx.h
@@ -194,5 +194,13 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int src_cnt,
size_t len, enum sum_check_flags *pqres, struct page *spare,
struct async_submit_ctl *submit);
+struct dma_async_tx_descriptor *
+async_raid6_2data_recov(int src_num, size_t bytes, int faila, int failb,
+ struct page **ptrs, struct async_submit_ctl *submit);
+
+struct dma_async_tx_descriptor *
+async_raid6_datap_recov(int src_num, size_t bytes, int faila,
+ struct page **ptrs, struct async_submit_ctl *submit);
+
void async_tx_quiesce(struct dma_async_tx_descriptor **tx);
#endif /* _ASYNC_TX_H_ */