[PATCH 3.4 106/214] zram: allow request end to coincide with disksize

Greg Kroah-Hartman
2014-06-05T04:52:36Z

From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

commit 75c7caf5a052ffd8db3312fa7864ee2d142890c4 upstream.

Pass valid_io_request() checks if request end coincides with disksize
(end equals bound), only fail if we attempt to read beyond the bound.

mkfs.ext2 produces numerous errors:
[ 2164.632747] quiet_error: 1 callbacks suppressed
[ 2164.633260] Buffer I/O error on device zram0, logical block 153599
[ 2164.633265] lost page write due to I/O error on zram0

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/staging/zram/zram_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -547,7 +547,7 @@ static inline int valid_io_request(struc
end = start + (bio->bi_size >> SECTOR_SHIFT);
bound = zram->disksize >> SECTOR_SHIFT;
/* out of range range */
- if (unlikely(start >= bound || end >= bound || start > end))
+ if (unlikely(start >= bound || end > bound || start > end))
return 0;

/* I/O request is valid */