2006-09-28 19:10:05

by Adam Litke

Subject: [TRIVIAL PATCH] mm: Make filemap_nopage use NOPAGE_SIGBUS

Hi Andrew. This is just a "nice to have" cleanup patch. Any chance on
getting it merged (lest I forget about it again)? Thanks.

While reading trough filemap_nopage() I found the 'return NULL'
statements a bit confusing since we already have two constants defined
for ->nopage error conditions. Since a NULL return value really means
NOPAGE_SIGBUS, just return that to make the code more readable.

Signed-off-by: Adam Litke <[email protected]>

filemap.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff -upN reference/mm/filemap.c current/mm/filemap.c
--- reference/mm/filemap.c
+++ current/mm/filemap.c
@@ -1454,7 +1454,7 @@ outside_data_content:
* accessible..
*/
if (area->vm_mm == current->mm)
- return NULL;
+ return NOPAGE_SIGBUS;
/* Fall through to the non-read-ahead case */
no_cached_page:
/*
@@ -1479,7 +1479,7 @@ no_cached_page:
*/
if (error == -ENOMEM)
return NOPAGE_OOM;
- return NULL;
+ return NOPAGE_SIGBUS;

page_not_uptodate:
if (!did_readaround) {
@@ -1548,7 +1548,7 @@ page_not_uptodate:
*/
shrink_readahead_size_eio(file, ra);
page_cache_release(page);
- return NULL;
+ return NOPAGE_SIGBUS;
}
EXPORT_SYMBOL(filemap_nopage);

--
Adam Litke - (agl at us.ibm.com)
IBM Linux Technology Center

2006-09-28 19:15:20

by Hugh Dickins

Subject: Re: [TRIVIAL PATCH] mm: Make filemap_nopage use NOPAGE_SIGBUS

On Thu, 28 Sep 2006, Adam Litke wrote:
> Hi Andrew. This is just a "nice to have" cleanup patch. Any chance on
> getting it merged (lest I forget about it again)? Thanks.
>
> While reading trough filemap_nopage() I found the 'return NULL'
> statements a bit confusing since we already have two constants defined
> for ->nopage error conditions. Since a NULL return value really means
> NOPAGE_SIGBUS, just return that to make the code more readable.
>
> Signed-off-by: Adam Litke <[email protected]>

That's long confused and irritated me, gladly
Acked-by: Hugh Dickins <[email protected]>

>
> filemap.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
> diff -upN reference/mm/filemap.c current/mm/filemap.c
> --- reference/mm/filemap.c
> +++ current/mm/filemap.c
> @@ -1454,7 +1454,7 @@ outside_data_content:
> * accessible..
> */
> if (area->vm_mm == current->mm)
> - return NULL;
> + return NOPAGE_SIGBUS;
> /* Fall through to the non-read-ahead case */
> no_cached_page:
> /*
> @@ -1479,7 +1479,7 @@ no_cached_page:
> */
> if (error == -ENOMEM)
> return NOPAGE_OOM;
> - return NULL;
> + return NOPAGE_SIGBUS;
>
> page_not_uptodate:
> if (!did_readaround) {
> @@ -1548,7 +1548,7 @@ page_not_uptodate:
> */
> shrink_readahead_size_eio(file, ra);
> page_cache_release(page);
> - return NULL;
> + return NOPAGE_SIGBUS;
> }
> EXPORT_SYMBOL(filemap_nopage);
>
> --
> Adam Litke - (agl at us.ibm.com)
> IBM Linux Technology Center
>