Takuya Yoshikawa
2010-Jun-04 08:14 UTC
[PATCH] btrfs: use zero_user family instead of writing down the same sequence repeatedly
As other filesystems do, btrfs can use zero_user family.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
---
fs/btrfs/compression.c | 12 +++---------
fs/btrfs/extent_io.c | 44 ++++++++------------------------------------
2 files changed, 11 insertions(+), 45 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 396039b..12aded9 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -512,17 +512,11 @@ static noinline int add_ra_bio_pages(struct inode *inode,
free_extent_map(em);
if (page->index == end_index) {
- char *userpage;
size_t zero_offset = isize & (PAGE_CACHE_SIZE - 1);
- if (zero_offset) {
- int zeros;
- zeros = PAGE_CACHE_SIZE - zero_offset;
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + zero_offset, 0, zeros);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
- }
+ if (zero_offset)
+ zero_user_segment(page, zero_offset,
+ PAGE_CACHE_SIZE);
}
ret = bio_add_page(cb->orig_bio, page,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index a4080c2..15dce48 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2039,25 +2039,15 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
}
if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
- char *userpage;
size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
- if (zero_offset) {
- iosize = PAGE_CACHE_SIZE - zero_offset;
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + zero_offset, 0, iosize);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
- }
+ if (zero_offset)
+ zero_user_segment(page, zero_offset, PAGE_CACHE_SIZE);
}
while (cur <= end) {
if (cur >= last_byte) {
- char *userpage;
iosize = PAGE_CACHE_SIZE - page_offset;
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + page_offset, 0, iosize);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
+ zero_user(page, page_offset, iosize);
set_extent_uptodate(tree, cur, cur + iosize - 1,
GFP_NOFS);
unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
@@ -2096,11 +2086,7 @@ static int __extent_read_full_page(struct extent_io_tree
*tree,
/* we''ve found a hole, just zero and go on */
if (block_start == EXTENT_MAP_HOLE) {
- char *userpage;
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + page_offset, 0, iosize);
- flush_dcache_page(page);
- kunmap_atomic(userpage, KM_USER0);
+ zero_user(page, page_offset, iosize);
set_extent_uptodate(tree, cur, cur + iosize - 1,
GFP_NOFS);
@@ -2236,15 +2222,9 @@ static int __extent_writepage(struct page *page, struct
writeback_control *wbc,
return 0;
}
- if (page->index == end_index) {
- char *userpage;
+ if (page->index == end_index)
+ zero_user_segment(page, pg_offset, PAGE_CACHE_SIZE);
- userpage = kmap_atomic(page, KM_USER0);
- memset(userpage + pg_offset, 0,
- PAGE_CACHE_SIZE - pg_offset);
- kunmap_atomic(userpage, KM_USER0);
- flush_dcache_page(page);
- }
pg_offset = 0;
set_page_extent_mapped(page);
@@ -2789,16 +2769,8 @@ int extent_prepare_write(struct extent_io_tree *tree,
if (!PageUptodate(page) && isnew &&
(block_off_end > to || block_off_start < from)) {
- void *kaddr;
-
- kaddr = kmap_atomic(page, KM_USER0);
- if (block_off_end > to)
- memset(kaddr + to, 0, block_off_end - to);
- if (block_off_start < from)
- memset(kaddr + block_off_start, 0,
- from - block_off_start);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
+ zero_user_segments(page, to, block_off_end,
+ block_off_start, from);
}
if ((em->block_start != EXTENT_MAP_HOLE &&
em->block_start != EXTENT_MAP_INLINE) &&
--
1.6.3.3