From f18573abcc57844a7c3c12699d40eead8728cd8a Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Fri, 11 Apr 2008 12:56:52 +0200 Subject: block: move the padding adjustment to blk_rq_map_sg blk_rq_map_user adjusts bi_size of the last bio. It breaks the rule that req->data_len (the true data length) is equal to sum(bio). It broke the scsi command completion code. commit e97a294ef6938512b655b1abf17656cf2b26f709 was introduced to fix the above issue. However, the partial completion code doesn't work with it. The commit is also a layer violation (scsi mid-layer should not know about the block layer's padding). This patch moves the padding adjustment to blk_rq_map_sg (suggested by James). The padding works like the drain buffer. This patch breaks the rule that req->data_len is equal to sum(sg), however, the drain buffer already broke it. So this patch just restores the rule that req->data_len is equal to sub(bio) without breaking anything new. Now when a low level driver needs padding, blk_rq_map_user and blk_rq_map_user_iov guarantee there's enough room for padding. blk_rq_map_sg can safely extend the last entry of a scatter list. blk_rq_map_sg must extend the last entry of a scatter list only for a request that got through bio_copy_user_iov. This patches introduces new REQ_COPY_USER flag. Signed-off-by: FUJITA Tomonori Cc: Tejun Heo Cc: Mike Christie Cc: James Bottomley Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 6f79d40dd3c0..b3a58adc4352 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -112,6 +112,7 @@ enum rq_flag_bits { __REQ_RW_SYNC, /* request is sync (O_DIRECT) */ __REQ_ALLOCED, /* request came from our alloc pool */ __REQ_RW_META, /* metadata io request */ + __REQ_COPY_USER, /* contains copies of user pages */ __REQ_NR_BITS, /* stops here */ }; @@ -133,6 +134,7 @@ enum rq_flag_bits { #define REQ_RW_SYNC (1 << __REQ_RW_SYNC) #define REQ_ALLOCED (1 << __REQ_ALLOCED) #define REQ_RW_META (1 << __REQ_RW_META) +#define REQ_COPY_USER (1 << __REQ_COPY_USER) #define BLK_MAX_CDB 16 -- cgit v1.2.3 From 2472892a3ce17b177cc0d8099a6391949c75abf2 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 21 Apr 2008 09:51:05 +0200 Subject: block: fix memory hotplug and bouncing in block layer Only noticed this while hacking something else, no test case. blk_max_low_pfn is initialized once at bootup by the block layer from max_low_pfn. But max_low_pfn is not necessarily constant over the runtime of the system when you consider memory hotplug. What could happen if that someone adds memory later the block layer wouldn't get updated and then start bouncing memory unnecessarily. Also on 64bit blk_max_low_pfn actually isn't needed because it just disables bouncing essentially and there is no highmem. And nobody can pass pfns > max_low_pfn to the block layer, because those wouldn't have a struct page and I suspect block layer wouldn't be very happy without that. So set BLK_BOUNCE_HIGH to infinity (-1ULL) on 64bit. That avoids the problem of having to update it on memory hotadd. On 32bit I kept the same behaviour because at least on i386 memory hotadd only adds HIGHMEM, never lowmem. BLK_BOUNCE_ANY is always set to infinity on both 32 and 64bit. Signed-off-by: Andi Kleen Cc: Jens Axboe Acked-by: Yasunori Goto Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b3a58adc4352..c5065e3d2ca9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -535,8 +535,13 @@ extern unsigned long blk_max_low_pfn, blk_max_pfn; * BLK_BOUNCE_ANY : don't bounce anything * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary */ + +#if BITS_PER_LONG == 32 #define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT) -#define BLK_BOUNCE_ANY ((u64)blk_max_pfn << PAGE_SHIFT) +#else +#define BLK_BOUNCE_HIGH -1ULL +#endif +#define BLK_BOUNCE_ANY (-1ULL) #define BLK_BOUNCE_ISA (ISA_DMA_THRESHOLD) /* -- cgit v1.2.3