diff options
| author | Martin K. Petersen <martin.petersen@oracle.com> | 2014-06-24 16:59:35 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-09 11:21:23 -0700 |
| commit | 65e98a83a95c5c3e5b6e686173054a557626909c (patch) | |
| tree | 7ce3af1ea9f3540a27c2e86dea00f77be09c01fc | |
| parent | 89b2a066a5c4a14e9bee3e16054c06a8400415e6 (diff) | |
SCSI: use the scsi data buffer length to extract transfer size
commit 5616b0a46ed82eb9a093f752fc4d7bd3cc688583 upstream.
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 <hch@infradead.org>
Debugged-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Fixes: d77e65350f2d82dfa0557707d505711f5a43c8fd
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/scsi/scsi_cmnd.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index a100c6e266c..c95c0774a86 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -309,7 +309,7 @@ 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; |