From: Song Liu <songliubraving@fb.com>
To: <linux-mm@kvack.org>, <linux-fsdevel@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <matthew.wilcox@oracle.com>, <kirill.shutemov@linux.intel.com>,
<kernel-team@fb.com>, <william.kucharski@oracle.com>,
<akpm@linux-foundation.org>, <hdanton@sina.com>,
Song Liu <songliubraving@fb.com>
Subject: [PATCH v10 2/7] filemap: check compound_head(page)->mapping in pagecache_get_page()
Date: Thu, 1 Aug 2019 11:42:39 -0700 [thread overview]
Message-ID: <20190801184244.3169074-3-songliubraving@fb.com> (raw)
In-Reply-To: <20190801184244.3169074-1-songliubraving@fb.com>
Similar to previous patch, pagecache_get_page() avoids race 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.
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
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 d0bd9e585c2f..aaee1ef96f6d 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1644,7 +1644,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
}
/* Has the page been truncated? */
- if (unlikely(page->mapping != mapping)) {
+ if (unlikely(compound_head(page)->mapping != mapping)) {
unlock_page(page);
put_page(page);
goto repeat;
--
2.17.1
next prev parent reply other threads:[~2019-08-01 18:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-01 18:42 [PATCH v10 0/7] Enable THP for text section of non-shmem files Song Liu
2019-08-01 18:42 ` [PATCH v10 1/7] filemap: check compound_head(page)->mapping in filemap_fault() Song Liu
2019-08-01 18:42 ` Song Liu [this message]
2019-08-12 20:33 ` [PATCH v10 2/7] filemap: check compound_head(page)->mapping in pagecache_get_page() Johannes Weiner
2019-08-01 18:42 ` [PATCH v10 3/7] filemap: update offset check in filemap_fault() Song Liu
2019-08-01 18:42 ` [PATCH v10 4/7] mm,thp: stats for file backed THP Song Liu
2019-08-01 18:42 ` [PATCH v10 5/7] khugepaged: rename collapse_shmem() and khugepaged_scan_shmem() Song Liu
2019-08-01 18:42 ` [PATCH v10 6/7] mm,thp: add read-only THP support for (non-shmem) FS Song Liu
2019-08-12 20:36 ` Johannes Weiner
2019-08-01 18:42 ` [PATCH v10 7/7] mm,thp: avoid writes to file with THP in pagecache Song Liu
2019-08-12 20:38 ` Johannes Weiner
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