The patch titled Subject: loopdev: ignore negative offset when calculate loop device size has been removed from the -mm tree. Its filename was loopdev-ignore-negative-offset-when-calculate-loop-device-size.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Guo Chao <yan@xxxxxxxxxxxxxxxxxx> Subject: loopdev: ignore negative offset when calculate loop device size Negative offset may cause loop device size larger than backing file size. $ fallocate -l 1M a $ losetup --offset 0xffffffffffff0000 /dev/loop0 a $ blockdev --getsize64 /dev/loop0 1114112 $ ls -l a -rw-r--r-- 1 root root 1048576 Jan 23 12:46 a $ cat /dev/loop0 cat: /dev/loop0: Input/output error It makes no sense to do that. Only apply offset when it's positive. Fix a typo in the comment by the way. Signed-off-by: Guo Chao <yan@xxxxxxxxxxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Guo Chao <yan@xxxxxxxxxxxxxxxxxx> Cc: M. Hindess <hindessm@xxxxxxxxxx> Cc: Nikanth Karthikesan <knikanth@xxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/block/loop.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff -puN drivers/block/loop.c~loopdev-ignore-negative-offset-when-calculate-loop-device-size drivers/block/loop.c --- a/drivers/block/loop.c~loopdev-ignore-negative-offset-when-calculate-loop-device-size +++ a/drivers/block/loop.c @@ -162,12 +162,13 @@ static struct loop_func_table *xfer_func static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file) { - loff_t size, loopsize; + loff_t loopsize; /* Compute loopsize in bytes */ - size = i_size_read(file->f_mapping->host); - loopsize = size - offset; - /* offset is beyond i_size, wierd but possible */ + loopsize = i_size_read(file->f_mapping->host); + if (offset > 0) + loopsize -= offset; + /* offset is beyond i_size, weird but possible */ if (loopsize < 0) return 0; _ Patches currently in -mm which might be from yan@xxxxxxxxxxxxxxxxxx are linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html