Patchwork cifs: fix page refcount leak

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Submitter Jeff Layton
Date May 25, 2010, 4:28 p.m.
Message ID <1274804917-23814-1-git-send-email-jlayton@redhat.com>
Download mbox | patch
Permalink /patch/53555/
State New
Headers show

Comments

Jeff Layton - May 25, 2010, 4:28 p.m.
Commit 315e995c63a15cb4d4efdbfd70fe2db191917f7a is causing OOM kills
when stress-testing a CIFS filesystem. The VFS readpages operation takes
a page reference. The older code just handed this reference off to the
page cache, but the new code takes an extra one. The simplest fix is to
put the new reference after add_to_page_cache_lru.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
---
 fs/cifs/file.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
Nick Piggin - May 25, 2010, 4:54 p.m.
On Tue, May 25, 2010 at 12:28:37PM -0400, Jeff Layton wrote:
> Commit 315e995c63a15cb4d4efdbfd70fe2db191917f7a is causing OOM kills
> when stress-testing a CIFS filesystem. The VFS readpages operation takes
> a page reference. The older code just handed this reference off to the
> page cache, but the new code takes an extra one. The simplest fix is to
> put the new reference after add_to_page_cache_lru.
> 
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> Cc: Nick Piggin <npiggin@suse.de>

Acked-by: Nick Piggin <npiggin@suse.de>

> ---
>  fs/cifs/file.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 310533d..29ca398 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -1919,6 +1919,7 @@ static void cifs_copy_cache_pages(struct address_space *mapping,
>  			bytes_read -= PAGE_CACHE_SIZE;
>  			continue;
>  		}
> +		page_cache_release(page);
>  
>  		target = kmap_atomic(page, KM_USER0);
>  
> -- 
> 1.6.6.1

Patch

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 310533d..29ca398 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1919,6 +1919,7 @@  static void cifs_copy_cache_pages(struct address_space *mapping,
 			bytes_read -= PAGE_CACHE_SIZE;
 			continue;
 		}
+		page_cache_release(page);
 
 		target = kmap_atomic(page, KM_USER0);