lkml.org 
[lkml]   [2014]   [Feb]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.13 04/99] mm: fix page leak at nfs_symlink()
    Date
    3.13-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Rafael Aquini <aquini@redhat.com>

    commit a0b54adda3fe4b4cc6d28f2a9217cd35d1aa888c upstream.

    Changes in commit a0b8cab3b9b2 ("mm: remove lru parameter from
    __pagevec_lru_add and remove parts of pagevec API") have introduced a
    call to add_to_page_cache_lru() which causes a leak in nfs_symlink() as
    now the page gets an extra refcount that is not dropped.

    Jan Stancek observed and reported the leak effect while running test8
    from Connectathon Testsuite. After several iterations over the test
    case, which creates several symlinks on a NFS mountpoint, the test
    system was quickly getting into an out-of-memory scenario.

    This patch fixes the page leak by dropping that extra refcount
    add_to_page_cache_lru() is grabbing.

    Signed-off-by: Jan Stancek <jstancek@redhat.com>
    Signed-off-by: Rafael Aquini <aquini@redhat.com>
    Acked-by: Mel Gorman <mgorman@suse.de>
    Acked-by: Rik van Riel <riel@redhat.com>
    Cc: Jeff Layton <jlayton@redhat.com>
    Cc: Trond Myklebust <trond.myklebust@primarydata.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    fs/nfs/dir.c | 5 +++++
    1 file changed, 5 insertions(+)

    --- a/fs/nfs/dir.c
    +++ b/fs/nfs/dir.c
    @@ -1837,6 +1837,11 @@ int nfs_symlink(struct inode *dir, struc
    GFP_KERNEL)) {
    SetPageUptodate(page);
    unlock_page(page);
    + /*
    + * add_to_page_cache_lru() grabs an extra page refcount.
    + * Drop it here to avoid leaking this page later.
    + */
    + page_cache_release(page);
    } else
    __free_page(page);




    \
     
     \ /
      Last update: 2014-02-21 02:02    [W:5.861 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site