[PATCH 7/8] mm/swap: check swapfile blocksize greater than PAGE_SIZE

[Weijie Yang]

If S_ISREG swapfile's blocksize > PAGE_SIZE, it is not suitable to be
a swapfile, because swap slot is fixed to PAGE_SIZE.

This patch check this situation and return -EINVAL if it happens.

Signed-off-by: Weijie Yang <weijie.yang@xxxxxxxxxxx>
---
 mm/page_io.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/page_io.c b/mm/page_io.c
index 7247be6..3d9bd12 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -150,6 +150,8 @@ int generic_swapfile_activate(struct swap_info_struct *sis,
 	int ret;
 
 	blkbits = inode->i_blkbits;
+	if(blkbits > PAGE_SHIFT)
+		return -EINVAL;
 	blocks_per_page = PAGE_SIZE >> blkbits;
 
 	/*
-- 
1.7.10.4


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