[PATCH 1/5] mm/readahead: Check return value of read_pages

[raghu.prabhu13@gmail.com]

From: Raghavendra D Prabhu <rprabhu@wnohang.net>

Return value of a_ops->readpage will be propagated to return value of read_pages
and __do_page_cache_readahead.

Signed-off-by: Raghavendra D Prabhu <rprabhu@wnohang.net>
---
 mm/readahead.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/mm/readahead.c b/mm/readahead.c
index ea8f8fa..461fcc0 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -113,7 +113,7 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 {
 	struct blk_plug plug;
 	unsigned page_idx;
-	int ret;
+	int ret = 0;
 
 	blk_start_plug(&plug);
 
@@ -129,11 +129,12 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 		list_del(&page->lru);
 		if (!add_to_page_cache_lru(page, mapping,
 					page->index, GFP_KERNEL)) {
-			mapping->a_ops->readpage(filp, page);
+			ret = mapping->a_ops->readpage(filp, page);
+			if (ret < 0)
+				break;
 		}
 		page_cache_release(page);
 	}
-	ret = 0;
 
 out:
 	blk_finish_plug(&plug);
@@ -160,6 +161,7 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
 	LIST_HEAD(page_pool);
 	int page_idx;
 	int ret = 0;
+	int ret_read = 0;
 	loff_t isize = i_size_read(inode);
 
 	if (isize == 0)
@@ -198,10 +200,10 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
 	 * will then handle the error.
 	 */
 	if (ret)
-		read_pages(mapping, filp, &page_pool, ret);
+		ret_read = read_pages(mapping, filp, &page_pool, ret);
 	BUG_ON(!list_empty(&page_pool));
 out:
-	return ret;
+	return (ret_read < 0 ? ret_read : ret);
 }
 
 /*
-- 
1.7.12.1

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