lkml.org 
[lkml]   [2010]   [Sep]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] vfs: calculate block-size correctly
I sent this patch half mount ago, but no response at all. If anything is
wrong, please tell me. Thanks a lots. This is my first time to send patch
to linux kernel.

The invocation of __getblk(bdev, block, size) will cause kernel stall if
the @size parameter is not equal to the blockr-size of @bdev, which is saved
in bdev->bd_inode->i_blkbits.

submit_bh() has the similar problem.

This patch calculates the block-size using i_blkbits.
So that, for example, __getblk() can get a 4K buffer head while the
block-size of @bdev is 1K.

Signed-off-by: Cong Meng <mcpacino@gmail.com>
---
fs/buffer.c | 7 ++-----
1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 3e7dca2..f7f9d33 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1051,10 +1051,7 @@ grow_buffers(struct block_device *bdev, sector_t block, int size)
pgoff_t index;
int sizebits;

- sizebits = -1;
- do {
- sizebits++;
- } while ((size << sizebits) < PAGE_SIZE);
+ sizebits = PAGE_CACHE_SHIFT - bdev->bd_inode->i_blkbits;

index = block >> sizebits;

@@ -2924,7 +2921,7 @@ int submit_bh(int rw, struct buffer_head * bh)
*/
bio = bio_alloc(GFP_NOIO, 1);

- bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
+ bio->bi_sector = bh->b_blocknr << (bh->b_bdev->bd_inode->i_blkbits - 9);
bio->bi_bdev = bh->b_bdev;
bio->bi_io_vec[0].bv_page = bh->b_page;
bio->bi_io_vec[0].bv_len = bh->b_size;

\
 
 \ /
  Last update: 2010-09-08 12:11    [W:0.064 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site