[PATCH v2] f2fs: limit b_size of mapped bh in f2fs_map_bh

From: Chao Yu
Date: Tue Mar 24 2015 - 01:09:03 EST


Map bh over max size which caller defined is not needed, limit it in
f2fs_map_bh.

Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx>
---
v2 change log:
- use min() for cleanup code suggested by Jaegeuk Kim.

fs/f2fs/data.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f0a18a0..279c9c6e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -255,15 +255,13 @@ static void f2fs_map_bh(struct super_block *sb, pgoff_t pgofs,
struct extent_info *ei, struct buffer_head *bh_result)
{
unsigned int blkbits = sb->s_blocksize_bits;
- size_t count;
+ size_t max_size = bh_result->b_size;
+ size_t mapped_size;

clear_buffer_new(bh_result);
map_bh(bh_result, sb, ei->blk + pgofs - ei->fofs);
- count = ei->fofs + ei->len - pgofs;
- if (count < (UINT_MAX >> blkbits))
- bh_result->b_size = (count << blkbits);
- else
- bh_result->b_size = UINT_MAX;
+ mapped_size = (ei->fofs + ei->len - pgofs) << blkbits;
+ bh_result->b_size = min(max_size, mapped_size);
}

static bool lookup_extent_info(struct inode *inode, pgoff_t pgofs,
--
2.3.3


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