Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.15 001/122] SCSI: use the scsi data buffer length to extract transfer size | Date | Mon, 7 Jul 2014 16:56:03 -0700 |
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3.15-stable review patch. If anyone has any objections, please let me know.
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From: "Martin K. Petersen" <martin.petersen@oracle.com>
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>
--- include/scsi/scsi_cmnd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -309,7 +309,7 @@ static inline void set_driver_byte(struc 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;
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