From: Johannes Weiner <hannes@cmpxchg.org>
To: Song Liu <songliubraving@fb.com>
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, matthew.wilcox@oracle.com,
kirill.shutemov@linux.intel.com, kernel-team@fb.com,
william.kucharski@oracle.com, akpm@linux-foundation.org,
hdanton@sina.com
Subject: Re: [PATCH v9 1/6] filemap: check compound_head(page)->mapping in filemap_fault()
Date: Wed, 10 Jul 2019 13:51:31 -0400 [thread overview]
Message-ID: <20190710175131.GB11197@cmpxchg.org> (raw)
In-Reply-To: <20190625001246.685563-2-songliubraving@fb.com>
On Mon, Jun 24, 2019 at 05:12:41PM -0700, Song Liu wrote:
> Currently, filemap_fault() avoids trace condition with truncate by
> checking page->mapping == mapping. This does not work for compound
> pages. This patch let it check compound_head(page)->mapping instead.
>
> Acked-by: Rik van Riel <riel@surriel.com>
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
> mm/filemap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/filemap.c b/mm/filemap.c
> index df2006ba0cfa..f5b79a43946d 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -2517,7 +2517,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
> goto out_retry;
>
> /* Did it get truncated? */
> - if (unlikely(page->mapping != mapping)) {
> + if (unlikely(compound_head(page)->mapping != mapping)) {
There is another check like these in pagecache_get_page(), which is
used by find_lock_page() and thus the truncate code (partial page
truncate calls, but this could happen against read-only cache).
next prev parent reply other threads:[~2019-07-10 17:51 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 0:12 [PATCH v9 0/6] Enable THP for text section of non-shmem files Song Liu
2019-06-25 0:12 ` [PATCH v9 1/6] filemap: check compound_head(page)->mapping in filemap_fault() Song Liu
2019-07-10 17:44 ` Johannes Weiner
2019-07-10 17:51 ` Johannes Weiner [this message]
2019-06-25 0:12 ` [PATCH v9 2/6] filemap: update offset check " Song Liu
2019-07-10 17:52 ` Johannes Weiner
2019-06-25 0:12 ` [PATCH v9 3/6] mm,thp: stats for file backed THP Song Liu
2019-07-10 17:59 ` Johannes Weiner
2019-06-25 0:12 ` [PATCH v9 4/6] khugepaged: rename collapse_shmem() and khugepaged_scan_shmem() Song Liu
2019-06-27 13:19 ` Rik van Riel
2019-07-10 18:21 ` Johannes Weiner
2019-06-25 0:12 ` [PATCH v9 5/6] mm,thp: add read-only THP support for (non-shmem) FS Song Liu
2019-07-10 18:48 ` Johannes Weiner
2019-07-22 23:41 ` Song Liu
2019-07-23 23:59 ` Huang, Kai
2019-07-28 6:41 ` Song Liu
2019-06-25 0:12 ` [PATCH v9 6/6] mm,thp: avoid writes to file with THP in pagecache Song Liu
2019-06-27 13:18 ` Rik van Riel
2019-07-10 19:11 ` Johannes Weiner
2019-06-27 12:46 ` [PATCH v9 0/6] Enable THP for text section of non-shmem files Kirill A. Shutemov
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