lkml.org 
[lkml]   [2016]   [Jul]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/4] fs: befs: Remove redundant validation from befs_find_brun_direct
On 02/07/16 09:05, Salah Triki wrote:
> The only caller of befs_find_brun_direct is befs_fblock2brun, which
> already validates that the block is within the range of direct blocks.
> So remove the duplicate validation.
>
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> ---
> fs/befs/datastream.c | 8 --------
> 1 file changed, 8 deletions(-)
>
> diff --git a/fs/befs/datastream.c b/fs/befs/datastream.c
> index 26cc417..e224b9a 100644
> --- a/fs/befs/datastream.c
> +++ b/fs/befs/datastream.c
> @@ -249,17 +249,9 @@ befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
> int i;
> const befs_block_run *array = data->direct;
> befs_blocknr_t sum;
> - befs_blocknr_t max_block =
> - data->max_direct_range >> BEFS_SB(sb)->block_shift;
>
> befs_debug(sb, "---> %s, find %lu", __func__, (unsigned long)blockno);
>
> - if (blockno > max_block) {
> - befs_error(sb, "%s passed block outside of direct region",
> - __func__);
> - return BEFS_ERR;
> - }
> -
> for (i = 0, sum = 0; i < BEFS_NUM_DIRECT_BLOCKS;
> sum += array[i].len, i++) {
> if (blockno >= sum && blockno < sum + (array[i].len)) {
>

Hi Salah,

These aren't the same check though. If we ignore the BEFS_SB(sb)->block_shift just to
comparing them, we can consider the checks to be the following.

In befs_fblock2brun():
if (fblock < data->max_direct_range)

In befs_find_brun_direct():
if (fblock > data->max_direct_range)

Notice how one checks if the block is past the range, and the other checks if it isn't
before it.

They also looked similar to me the first time I saw them and I had to double-check :)

Thanks,
Luis


\
 
 \ /
  Last update: 2016-07-02 14:21    [W:0.105 / U:2.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site