From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 26 Jun 2015 09:44:46 +0000 (+0200)
Subject: block: fix bogus EFAULT error from SG_IO ioctl
X-Git-Tag: submit/tizen/20160607.132125~2208^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2c4cffe85170a001c1d092681c86aa1128295221;p=sdk%2Femulator%2Femulator-kernel.git

block: fix bogus EFAULT error from SG_IO ioctl

Whenever blk_fill_sghdr_rq fails, its errno code is ignored and changed to
EFAULT.  This can cause very confusing errors:

  $ sg_persist -k /dev/sda
  persistent reservation in: pass through os error: Bad address

The fix is trivial, just propagate the return value from
blk_fill_sghdr_rq.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 55b6f15..dda653c 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -326,8 +326,8 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 			goto out_put_request;
 	}
 
-	ret = -EFAULT;
-	if (blk_fill_sghdr_rq(q, rq, hdr, mode))
+	ret = blk_fill_sghdr_rq(q, rq, hdr, mode);
+	if (ret < 0)
 		goto out_free_cdb;
 
 	ret = 0;