Use PAGE_SHIFT and i_blkbits of bd_inode directly to avoid ugly sizebits
calculation.
Remove ugly sizebits calculation.
Remove unnecessary sizebits parameter of grow_dev_page.
Reduces code size:
Before:
sean@linux-zmni:~/sda5/source/linus_repo/linux> size fs/buffer.o
text data bss dec hex filename
34037 1510 16 35563 8aeb fs/buffer.o
After:
sean@linux-zmni:~/sda5/source/linus_repo/linux> size fs/buffer.o
text data bss dec hex filename
34021 1510 16 35547 8adb fs/buffer.o
Signed-off-by: Sean Fu <fxinr...@gmail.com>
---
fs/buffer.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index 249b83f..143ad78 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -918,7 +918,7 @@ init_page_buffers(struct page *page, struct block_device
*bdev,
*/
static int
grow_dev_page(struct block_device *bdev, sector_t block,
- pgoff_t index, int size, int sizebits, gfp_t gfp)
+ pgoff_t index, int size, gfp_t gfp)
{
struct inode *inode = bdev->bd_inode;
struct page *page;
@@ -945,7 +945,7 @@ grow_dev_page(struct block_device *bdev, sector_t block,
bh = page_buffers(page);
if (bh->b_size == size) {
end_block = init_page_buffers(page, bdev,
- (sector_t)index << sizebits,
+ (sector_t)index << (PAGE_SHIFT
- inode->i_blkbits),
size);
goto done;
}
@@ -965,7 +965,8 @@ grow_dev_page(struct block_device *bdev, sector_t block,
*/
spin_lock(&inode->i_mapping->private_lock);
link_dev_buffers(page, bh);
- end_block = init_page_buffers(page, bdev, (sector_t)index << sizebits,
+ end_block = init_page_buffers(page, bdev,
+ (sector_t)index << (PAGE_SHIFT - inode->i_blkbits),
size);
spin_unlock(&inode->i_mapping->private_lock);
done:
@@ -984,20 +985,13 @@ static int
grow_buffers(struct block_device *bdev, sector_t block, int size, gfp_t gfp)
{
pgoff_t index;
- int sizebits;
-
- sizebits = -1;
- do {
- sizebits++;
- } while ((size << sizebits) < PAGE_SIZE);
-
- index = block >> sizebits;
+ index = block >> (PAGE_SHIFT - bdev->bd_inode->i_blkbits);
/*
* Check for a block which wants to lie outside our maximum possible
* pagecache index. (this comparison is done using sector_t types).
*/
- if (unlikely(index != block >> sizebits)) {
+ if (unlikely(index != block >> (PAGE_SHIFT -
bdev->bd_inode->i_blkbits))) {
printk(KERN_ERR "%s: requested out-of-range block %llu for "
"device %pg\n",
__func__, (unsigned long long)block,
@@ -1006,7 +1000,7 @@ grow_buffers(struct block_device *bdev, sector_t block,
int size, gfp_t gfp)
}
/* Create a page with the proper size buffers.. */
- return grow_dev_page(bdev, block, index, size, sizebits, gfp);
+ return grow_dev_page(bdev, block, index, size, gfp);
}
static struct buffer_head *
--
2.6.2
