[PATCH] Check for compound pages in set_page_dirty()

Jens Axboe
2007-07-18T14:16:15Z

Hi,

We have these checks scattered, makes sense to put them in
set_page_dirty() instead. This also fixes a bug where __bio_unmap_user()
does set_page_dirty_lock() without checking for a compound page, instead
of adding one more check we move it to set_page_dirty().

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/fs/bio.c b/fs/bio.c
index cd888f9..ff96cd9 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -902,7 +902,7 @@ void bio_set_pages_dirty(struct bio *bio)
for (i = 0; i < bio->bi_vcnt; i++) {
struct page *page = bvec[i].bv_page;

- if (page && !PageCompound(page))
+ if (page)
set_page_dirty_lock(page);
}
}
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 52bb263..72195bc 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -426,7 +426,7 @@ static int dio_bio_complete(struct dio *dio, struct bio *bio)
for (page_no = 0; page_no < bio->bi_vcnt; page_no++) {
struct page *page = bvec[page_no].bv_page;

- if (dio->rw == READ && !PageCompound(page))
+ if (dio->rw == READ)
set_page_dirty_lock(page);
page_cache_release(page);
}
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 886ea0d..3c590b9 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -861,8 +861,12 @@ EXPORT_SYMBOL(redirty_page_for_writepage);
*/
int fastcall set_page_dirty(struct page *page)
{
- struct address_space *mapping = page_mapping(page);
+ struct address_space *mapping;
+
+ if (unlikely(PageCompound(page)))
+ return 0;

+ mapping = page_mapping(page);
if (likely(mapping)) {
int (*spd)(struct page *) = mapping->a_ops->set_page_dirty;
#ifdef CONFIG_BLOCK

--
Jens Axboe