[ 50/60] zram: allow request end to coincide with disksize

From: Greg Kroah-Hartman
Date: Tue Aug 13 2013 - 02:44:21 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>

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@xxxxxxxxx>
Cc: Thomas Backlund <tmb@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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
@@ -432,7 +432,7 @@ 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 */


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