[PATCH 1/3 linux-next] udf: fix ioctl errors

[Fabian Frederick]

Currently, lsattr for instance in udf directory gives
"udf: Invalid argument While reading flags on ..."

This patch returns -ENOIOCTLCMD
when command is unknown to have more accurate message like this:
"Inappropriate ioctl for device While reading flags on ..."

As suggested by Jan Kara, if arg is NULL with a correct ioctl,
we return -VM_FAULT_SIGBUS to report error.

Signed-off-by: Fabian Frederick <fabf@xxxxxxxxx>
---
 fs/udf/file.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/udf/file.c b/fs/udf/file.c
index dbcb3a4a..d44b3cb 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -184,9 +184,10 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		goto out;
 	}
 
-	if (!arg) {
+	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
+		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
 		udf_debug("invalid argument to udf_ioctl\n");
-		result = -EINVAL;
+		result = -VM_FAULT_SIGBUS;
 		goto out;
 	}
 
@@ -220,6 +221,8 @@ long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 				      UDF_I(inode)->i_ext.i_data,
 				      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 		goto out;
+	default:
+		return -ENOIOCTLCMD;
 	}
 
 out:
-- 
2.9.3