From 5dd33c9a4c29015f6d87568d33521c98931a387e Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 16 Oct 2009 16:40:25 +1100 Subject: md/async: don't pass a memory pointer as a page pointer. 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 --- drivers/md/raid5.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c4366c9373c..dcd9e659ed9 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 { -- cgit v1.2.3