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authorDarrick J. Wong <djwong@us.ibm.com>2011-05-27 12:23:34 -0700
committerAl Viro <viro@zeniv.linux.org.uk>2011-05-28 01:03:21 -0400
commit3d08bcc887a1c8d12be8d81f747ffa2e8a44b67b (patch)
tree258f4e3d384e451c921c5e0c503fd368f236a20a
parent98702467f829177b3993f17da9fe5c202d160e5e (diff)
mm: Wait for writeback when grabbing pages to begin a write
When grabbing a page for a buffered IO write, the mm should wait for writeback on the page to complete so that the page does not become writable during the IO operation. This change is needed to provide page stability during writes for all filesystems. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--mm/filemap.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index bcdc393b658..dac95a24dea 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2327,7 +2327,7 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping,
repeat:
page = find_lock_page(mapping, index);
if (page)
- return page;
+ goto found;
page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~gfp_notmask);
if (!page)
@@ -2340,6 +2340,8 @@ repeat:
goto repeat;
return NULL;
}
+found:
+ wait_on_page_writeback(page);
return page;
}
EXPORT_SYMBOL(grab_cache_page_write_begin);