[PATCH] block: fix bogus EFAULT error from SG_IO ioctl

From: Paolo Bonzini
Date: Fri Jun 26 2015 - 05:45:05 EST


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@xxxxxxxxxx>
---
block/scsi_ioctl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 55b6f15dac90..dda653ce7b24 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;
--
2.4.3

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