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authorMartin K. Petersen <martin.petersen@oracle.com>2014-06-24 16:59:35 +0200
committerJames Bottomley <JBottomley@Parallels.com>2014-07-03 10:50:31 -0700
commit5616b0a46ed82eb9a093f752fc4d7bd3cc688583 (patch)
tree6de33db88c3848749434ea4e8ad09d111378745e
parenta33c070bced8b283e22e8dbae35177a033b810bf (diff)
downloadlinux-5616b0a46ed82eb9a093f752fc4d7bd3cc688583.tar.bz2
[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 <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 Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r--include/scsi/scsi_cmnd.h2
1 files changed, 1 insertions, 1 deletions
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;