scsi: scsi_debug: Fix do_device_access() handling of unexpected SG copy length

If the sg_copy_buffer() call returns less than sdebug_sector_size, then
we drop out of the copy loop. However, we still report that we copied
the full expected amount, which is not proper.

Fix by keeping a running total and return that value.

Fixes: 84f3a3c01d ("scsi: scsi_debug: Atomic write support")
Reported-by: Colin Ian King <colin.i.king@gmail.com>
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241018101655.4207-1-john.g.garry@oracle.com
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
John Garry 2024-10-18 10:16:55 +00:00 committed by Martin K. Petersen
parent fca6caeb4a
commit d28d17a845

View file

@ -3651,7 +3651,7 @@ static int do_device_access(struct sdeb_store_info *sip, struct scsi_cmnd *scp,
enum dma_data_direction dir;
struct scsi_data_buffer *sdb = &scp->sdb;
u8 *fsp;
int i;
int i, total = 0;
/*
* Even though reads are inherently atomic (in this driver), we expect
@ -3688,18 +3688,16 @@ static int do_device_access(struct sdeb_store_info *sip, struct scsi_cmnd *scp,
fsp + (block * sdebug_sector_size),
sdebug_sector_size, sg_skip, do_write);
sdeb_data_sector_unlock(sip, do_write);
if (ret != sdebug_sector_size) {
ret += (i * sdebug_sector_size);
total += ret;
if (ret != sdebug_sector_size)
break;
}
sg_skip += sdebug_sector_size;
if (++block >= sdebug_store_sectors)
block = 0;
}
ret = num * sdebug_sector_size;
sdeb_data_unlock(sip, atomic);
return ret;
return total;
}
/* Returns number of bytes copied or -1 if error. */