From 5616b0a46ed82eb9a093f752fc4d7bd3cc688583 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 24 Jun 2014 16:59:35 +0200 Subject: [PATCH] [SCSI] use the scsi data buffer length to extract transfer size Commit 8846bab180fa introduced a helper that can be used to query the wire transfer size for a SCSI command taking protection information into account. However, some commands do not have a 1:1 mapping between the block range they work on and the payload size (discard, write same). After the scatterlist has been set up these requests use __data_len to store the number of bytes to report completion on. This means that callers of scsi_transfer_length() would get the wrong byte count for these types of requests. To overcome this we make scsi_transfer_length() use the scatterlist length in the scsi_data_buffer as basis for the wire transfer calculation instead of __data_len. Reported-by: Christoph Hellwig Debugged-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Fixes: d77e65350f2d82dfa0557707d505711f5a43c8fd Cc: stable@vger.kernel.org Signed-off-by: James Bottomley --- include/scsi/scsi_cmnd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index 42ed789ebafc..e0ae71098144 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -318,7 +318,7 @@ static inline void set_driver_byte(struct scsi_cmnd *cmd, char status) static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd) { - unsigned int xfer_len = blk_rq_bytes(scmd->request); + unsigned int xfer_len = scsi_out(scmd)->length; unsigned int prot_op = scsi_get_prot_op(scmd); unsigned int sector_size = scmd->device->sector_size; -- 2.20.1