Re: [PATCH] mtd: blktrans: change blktrans_getgeo rerurn value
From: Wenlin Kang
Date: Thu May 21 2015 - 04:23:33 EST
On 2015å05æ21æ 16:05, Brian Norris wrote:
On Thu, May 21, 2015 at 09:56:21AM +0200, Richard Weinberger wrote:
On Wed, May 20, 2015 at 9:33 PM, Brian Norris
<computersforpeace@xxxxxxxxx> wrote:
On Wed, May 13, 2015 at 02:29:16PM +0800, Wenlin Kang wrote:
Modify function blktrans_getgeo()'s return value to -ENXIO when
dev->tr->getgeo == NULL.
We shouldn't make the return value to 0 when dev->tr->getgeo == NULL,
because the function blktrans_getgeo() has an output value "hd_geometry"
which is usually used by some application, if return 0, it will make some
application get the wrong information.
Signed-off-by: Wenlin Kang <wenlin.kang@xxxxxxxxxxxxx>
---
drivers/mtd/mtd_blkdevs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 2b0c5287..f8bb16e 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -273,7 +273,7 @@ static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
if (!dev->mtd)
goto unlock;
- ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : 0;
+ ret = dev->tr->getgeo ? dev->tr->getgeo(dev, geo) : -ENXIO;
Good catch. I don't think ENXIO is correct in this case, though. Maybe
-EOPNOTSUPP or -ENOSYS? The latter might make more sense I guess.
I'd vote for -ENOTTY as this is what HDIO_GETGEIO returns
if the function is not implemented and blktrans_getgeo()
is only a wrapper around that.
I suppose that makes more sense.
See https://www.kernel.org/doc/Documentation/ioctl/hdio.txt
But this only mentions EINVAL...
and block/ioctl.c.
Anyway, I pushed EOPNOTSUPP, but I can fix that up if we agree.
Brian
Hi Brian
I just read block/compat_ioctl.c, in that I found the follow,
51 static int compat_hdio_getgeo(struct gendisk *disk, struct
block_device *bdev,
52 struct compat_hd_geometry __user *ugeo)
53 {
54 struct hd_geometry geo;
55 int ret;
56
57 if (!ugeo)
58 return -EINVAL;
59 if (!disk->fops->getgeo)
60 return -ENOTTY;
So, as Richard said, -ENOTTY should also be OK, and before last
commit(048d87199566663e4edc4880df3703c04bcf41d9), it's -ENOTTY, so I
think you can modify it,
or let know whether I need to resent it again.
--
Thanks,
Wenlin Kang
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