ramdisk: use kmap_atomic() in rd_blkdev_pagecache_IO()
We don't actualy need to kmap the blockdev inode's pages at all, because
they're ~__GFP_HIGHMEM. But it's future-safe, and cheap.
---
25-akpm/drivers/block/rd.c | 19 +++++++++----------
1 files changed, 9 insertions(+), 10 deletions(-)
diff -puN drivers/block/rd.c~ramdisk-use-kmap_atomic drivers/block/rd.c
--- 25/drivers/block/rd.c~ramdisk-use-kmap_atomic 2004-05-18 02:22:01.112108008 -0700
+++ 25-akpm/drivers/block/rd.c 2004-05-18 02:22:49.291783584 -0700
@@ -168,7 +168,7 @@ static struct address_space_operations r
static int rd_blkdev_pagecache_IO(int rw, struct bio_vec *vec, sector_t sector,
struct address_space *mapping)
{
- unsigned long index = sector >> (PAGE_CACHE_SHIFT - 9);
+ pgoff_t index = sector >> (PAGE_CACHE_SHIFT - 9);
unsigned int vec_offset = vec->bv_offset;
int offset = (sector << 9) & ~PAGE_CACHE_MASK;
int size = vec->bv_len;
@@ -199,25 +199,24 @@ static int rd_blkdev_pagecache_IO(int rw
index++;
if (rw == READ) {
- src = kmap(page) + offset;
- dst = kmap(vec->bv_page) + vec_offset;
+ src = kmap_atomic(page, KM_USER0) + offset;
+ dst = kmap_atomic(vec->bv_page, KM_USER1) + vec_offset;
} else {
- dst = kmap(page) + offset;
- src = kmap(vec->bv_page) + vec_offset;
+ src = kmap_atomic(vec->bv_page, KM_USER0) + vec_offset;
+ dst = kmap_atomic(page, KM_USER1) + offset;
}
offset = 0;
vec_offset += count;
memcpy(dst, src, count);
- kunmap(page);
- kunmap(vec->bv_page);
+ kunmap_atomic(src, KM_USER0);
+ kunmap_atomic(dst, KM_USER1);
- if (rw == READ) {
+ if (rw == READ)
flush_dcache_page(vec->bv_page);
- } else {
+ else
set_page_dirty(page);
- }
unlock_page(page);
put_page(page);
} while (size);
_