4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jason Yan <[email protected]> commit 621f6401fdeefe96dfe9eab4b167c7c39f552bb0 upstream. The return value of smp_execute_task_sg() is the untransferred residual, but bsg_job_done() requires the length of payload received. This makes SMP passthrough commands from userland by sg ioctl to libsas get a wrong response. The userland tools such as smp_utils failed because of these wrong responses: ~#smp_discover /dev/bsg/expander-2\:13 response too short, len=0 ~#smp_discover /dev/bsg/expander-2\:134 response too short, len=0 Fix this by passing the actual received length to bsg_job_done(). And if smp_execute_task_sg() returns 0, this means received length is exactly the buffer length. [mkp: typo] Fixes: 651a01364994 ("scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough") Signed-off-by: Jason Yan <[email protected]> Reported-by: chenqilin <[email protected]> Tested-by: chenqilin <[email protected]> CC: Christoph Hellwig <[email protected]> Signed-off-by: Martin K. Petersen <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/scsi/libsas/sas_expander.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/drivers/scsi/libsas/sas_expander.c +++ b/drivers/scsi/libsas/sas_expander.c @@ -2145,7 +2145,7 @@ void sas_smp_handler(struct bsg_job *job struct sas_rphy *rphy) { struct domain_device *dev; - unsigned int reslen = 0; + unsigned int rcvlen = 0; int ret = -EINVAL; /* no rphy means no smp target support (ie aic94xx host) */ @@ -2179,12 +2179,12 @@ void sas_smp_handler(struct bsg_job *job ret = smp_execute_task_sg(dev, job->request_payload.sg_list, job->reply_payload.sg_list); - if (ret > 0) { - /* positive number is the untransferred residual */ - reslen = ret; + if (ret >= 0) { + /* bsg_job_done() requires the length received */ + rcvlen = job->reply_payload.payload_len - ret; ret = 0; } out: - bsg_job_done(job, ret, reslen); + bsg_job_done(job, ret, rcvlen); }
