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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 /mm
parent98702467f829177b3993f17da9fe5c202d160e5e (diff)
downloadlwn-3d08bcc887a1c8d12be8d81f747ffa2e8a44b67b.tar.gz
lwn-3d08bcc887a1c8d12be8d81f747ffa2e8a44b67b.zip
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index bcdc393b6580..dac95a24deac 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);