autofs4: improve parameter usage

The parameter usage in the device node ioctl code uses arg1 and arg2 as
parameter names.  This patch redefines the parameter names to reflect what
they actually are in an effort to make the code more readable.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 63b7c7a..054d6d9 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -180,7 +180,7 @@
 				     struct autofs_sb_info *sbi,
 				     struct autofs_dev_ioctl *param)
 {
-	param->arg1 = sbi->version;
+	param->protover.version = sbi->version;
 	return 0;
 }
 
@@ -189,7 +189,7 @@
 					struct autofs_sb_info *sbi,
 					struct autofs_dev_ioctl *param)
 {
-	param->arg1 = sbi->sub_version;
+	param->protosubver.sub_version = sbi->sub_version;
 	return 0;
 }
 
@@ -335,13 +335,13 @@
 	int err, fd;
 
 	/* param->path has already been checked */
-	if (!param->arg1)
+	if (!param->openmount.devid)
 		return -EINVAL;
 
 	param->ioctlfd = -1;
 
 	path = param->path;
-	devid = param->arg1;
+	devid = param->openmount.devid;
 
 	err = 0;
 	fd = autofs_dev_ioctl_open_mountpoint(path, devid);
@@ -373,7 +373,7 @@
 {
 	autofs_wqt_t token;
 
-	token = (autofs_wqt_t) param->arg1;
+	token = (autofs_wqt_t) param->ready.token;
 	return autofs4_wait_release(sbi, token, 0);
 }
 
@@ -388,8 +388,8 @@
 	autofs_wqt_t token;
 	int status;
 
-	token = (autofs_wqt_t) param->arg1;
-	status = param->arg2 ? param->arg2 : -ENOENT;
+	token = (autofs_wqt_t) param->fail.token;
+	status = param->fail.status ? param->fail.status : -ENOENT;
 	return autofs4_wait_release(sbi, token, status);
 }
 
@@ -412,10 +412,10 @@
 	int pipefd;
 	int err = 0;
 
-	if (param->arg1 == -1)
+	if (param->setpipefd.pipefd == -1)
 		return -EINVAL;
 
-	pipefd = param->arg1;
+	pipefd = param->setpipefd.pipefd;
 
 	mutex_lock(&sbi->wq_mutex);
 	if (!sbi->catatonic) {
@@ -457,8 +457,8 @@
 {
 	unsigned long timeout;
 
-	timeout = param->arg1;
-	param->arg1 = sbi->exp_timeout / HZ;
+	timeout = param->timeout.timeout;
+	param->timeout.timeout = sbi->exp_timeout / HZ;
 	sbi->exp_timeout = timeout * HZ;
 	return 0;
 }
@@ -489,7 +489,7 @@
 	path = param->path;
 	devid = sbi->sb->s_dev;
 
-	param->arg1 = param->arg2 = -1;
+	param->requester.uid = param->requester.gid = -1;
 
 	/* Get nameidata of the parent directory */
 	err = path_lookup(path, LOOKUP_PARENT, &nd);
@@ -505,8 +505,8 @@
 		err = 0;
 		autofs4_expire_wait(nd.path.dentry);
 		spin_lock(&sbi->fs_lock);
-		param->arg1 = ino->uid;
-		param->arg2 = ino->gid;
+		param->requester.uid = ino->uid;
+		param->requester.gid = ino->gid;
 		spin_unlock(&sbi->fs_lock);
 	}
 
@@ -529,7 +529,7 @@
 	int err = -EAGAIN;
 	int how;
 
-	how = param->arg1;
+	how = param->expire.how;
 	mnt = fp->f_path.mnt;
 
 	if (sbi->type & AUTOFS_TYPE_TRIGGER)
@@ -565,9 +565,9 @@
 				      struct autofs_sb_info *sbi,
 				      struct autofs_dev_ioctl *param)
 {
-	param->arg1 = 0;
+	param->askumount.may_umount = 0;
 	if (may_umount(fp->f_path.mnt))
-		param->arg1 = 1;
+		param->askumount.may_umount = 1;
 	return 0;
 }
 
@@ -600,6 +600,7 @@
 	struct nameidata nd;
 	const char *path;
 	unsigned int type;
+	unsigned int devid, magic;
 	int err = -ENOENT;
 
 	if (param->size <= sizeof(*param)) {
@@ -608,10 +609,10 @@
 	}
 
 	path = param->path;
-	type = param->arg1;
+	type = param->ismountpoint.in.type;
 
-	param->arg1 = 0;
-	param->arg2 = 0;
+	param->ismountpoint.out.devid = devid = 0;
+	param->ismountpoint.out.magic = magic = 0;
 
 	if (!fp || param->ioctlfd == -1) {
 		if (type == AUTOFS_TYPE_ANY) {
@@ -622,7 +623,7 @@
 				goto out;
 
 			sb = nd.path.dentry->d_sb;
-			param->arg1 = new_encode_dev(sb->s_dev);
+			devid = new_encode_dev(sb->s_dev);
 		} else {
 			struct autofs_info *ino;
 
@@ -635,14 +636,14 @@
 				goto out_release;
 
 			ino = autofs4_dentry_ino(nd.path.dentry);
-			param->arg1 = autofs4_get_dev(ino->sbi);
+			devid = autofs4_get_dev(ino->sbi);
 		}
 
 		err = 0;
 		if (nd.path.dentry->d_inode &&
 		    nd.path.mnt->mnt_root == nd.path.dentry) {
 			err = 1;
-			param->arg2 = nd.path.dentry->d_inode->i_sb->s_magic;
+			magic = nd.path.dentry->d_inode->i_sb->s_magic;
 		}
 	} else {
 		dev_t devid = new_encode_dev(sbi->sb->s_dev);
@@ -655,18 +656,21 @@
 		if (err)
 			goto out_release;
 
-		param->arg1 = autofs4_get_dev(sbi);
+		devid = autofs4_get_dev(sbi);
 
 		err = have_submounts(nd.path.dentry);
 
 		if (nd.path.mnt->mnt_mountpoint != nd.path.mnt->mnt_root) {
 			if (follow_down(&nd.path.mnt, &nd.path.dentry)) {
 				struct inode *inode = nd.path.dentry->d_inode;
-				param->arg2 = inode->i_sb->s_magic;
+				magic = inode->i_sb->s_magic;
 			}
 		}
 	}
 
+	param->ismountpoint.out.devid = devid;
+	param->ismountpoint.out.magic = magic;
+
 out_release:
 	path_put(&nd.path);
 out: