[SCSI] libsas, bsg: pass errors through correctly

Currently in BSG, errors returned in req->errors aren't passed back to
the calling programme (either via SG_IO or via read/write).  Fix this,
while preserving the SCSI convention of returning status in
req->errors.

Now update libsas to return errors correctly instead of to ignore
them.

Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/block/bsg.c b/block/bsg.c
index 8e181ab3afb..69b0a9d3330 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -445,6 +445,15 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
         else
                 hdr->dout_resid = rq->data_len;
 
+        /*
+         * If the request generated a negative error number, return it
+         * (providing we aren't already returning an error); if it's
+         * just a protocol response (i.e. non negative), that gets
+         * processed above.
+         */
+        if (!ret && rq->errors < 0)
+                ret = rq->errors;
+
         blk_rq_unmap_user(bio);
         blk_put_request(rq);
 
@@ -837,6 +846,7 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
         struct bsg_device *bd = file->private_data;
         int __user *uarg = (int __user *) arg;
+        int ret;
 
         switch (cmd) {
                 /*
@@ -889,12 +899,12 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                 if (rq->next_rq)
                         bidi_bio = rq->next_rq->bio;
                 blk_execute_rq(bd->queue, NULL, rq, 0);
-                blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
+                ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
 
                 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
                         return -EFAULT;
 
-                return 0;
+                return ret;
         }
         /*
          * block device ioctls