[PATCH v4 59/59] switch init_mkdir() to use of do_mkdirat(), etc.

[Al Viro <viro@zeniv.linux.org.uk>]

Completely straightforward, the only obstacle is do_mknodat() being
static.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/init.c     | 88 ++++-----------------------------------------------
 fs/internal.h |  1 +
 fs/namei.c    |  2 +-
 3 files changed, 8 insertions(+), 83 deletions(-)

diff --git a/fs/init.c b/fs/init.c
index e0f5429c0a49..da6500d2ee98 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -140,78 +140,19 @@ int __init init_stat(const char *filename, struct kstat *stat, int flags)
 
 int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
 {
-	struct dentry *dentry;
-	struct path path;
-	int error;
-
-	if (S_ISFIFO(mode) || S_ISSOCK(mode))
-		dev = 0;
-	else if (!(S_ISBLK(mode) || S_ISCHR(mode)))
-		return -EINVAL;
-
-	dentry = start_creating_path(AT_FDCWD, filename, &path, 0);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
-
-	mode = mode_strip_umask(d_inode(path.dentry), mode);
-	error = security_path_mknod(&path, dentry, mode, dev);
-	if (!error)
-		error = vfs_mknod(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode, new_decode_dev(dev), NULL);
-	end_creating_path(&path, dentry);
-	return error;
+	return do_mknodat(AT_FDCWD, getname_kernel(filename), mode, dev);
 }
 
 int __init init_link(const char *oldname, const char *newname)
 {
-	struct dentry *new_dentry;
-	struct path old_path, new_path;
-	struct mnt_idmap *idmap;
-	int error;
-
-	error = kern_path(oldname, 0, &old_path);
-	if (error)
-		return error;
-
-	new_dentry = start_creating_path(AT_FDCWD, newname, &new_path, 0);
-	error = PTR_ERR(new_dentry);
-	if (IS_ERR(new_dentry))
-		goto out;
-
-	error = -EXDEV;
-	if (old_path.mnt != new_path.mnt)
-		goto out_dput;
-	idmap = mnt_idmap(new_path.mnt);
-	error = may_linkat(idmap, &old_path);
-	if (unlikely(error))
-		goto out_dput;
-	error = security_path_link(old_path.dentry, &new_path, new_dentry);
-	if (error)
-		goto out_dput;
-	error = vfs_link(old_path.dentry, idmap, new_path.dentry->d_inode,
-			 new_dentry, NULL);
-out_dput:
-	end_creating_path(&new_path, new_dentry);
-out:
-	path_put(&old_path);
-	return error;
+	return do_linkat(AT_FDCWD, getname_kernel(oldname),
+			 AT_FDCWD, getname_kernel(newname), 0);
 }
 
 int __init init_symlink(const char *oldname, const char *newname)
 {
-	struct dentry *dentry;
-	struct path path;
-	int error;
-
-	dentry = start_creating_path(AT_FDCWD, newname, &path, 0);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
-	error = security_path_symlink(&path, dentry, oldname);
-	if (!error)
-		error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
-				    dentry, oldname, NULL);
-	end_creating_path(&path, dentry);
-	return error;
+	return do_symlinkat(getname_kernel(oldname), AT_FDCWD,
+			    getname_kernel(newname));
 }
 
 int __init init_unlink(const char *pathname)
@@ -221,24 +162,7 @@ int __init init_unlink(const char *pathname)
 
 int __init init_mkdir(const char *pathname, umode_t mode)
 {
-	struct dentry *dentry;
-	struct path path;
-	int error;
-
-	dentry = start_creating_path(AT_FDCWD, pathname, &path,
-				     LOOKUP_DIRECTORY);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
-	mode = mode_strip_umask(d_inode(path.dentry), mode);
-	error = security_path_mkdir(&path, dentry, mode);
-	if (!error) {
-		dentry = vfs_mkdir(mnt_idmap(path.mnt), path.dentry->d_inode,
-				  dentry, mode, NULL);
-		if (IS_ERR(dentry))
-			error = PTR_ERR(dentry);
-	}
-	end_creating_path(&path, dentry);
-	return error;
+	return do_mkdirat(AT_FDCWD, getname_kernel(pathname), mode);
 }
 
 int __init init_rmdir(const char *pathname)
diff --git a/fs/internal.h b/fs/internal.h
index 5c3e4eac34f2..4c4d2733c47a 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -60,6 +60,7 @@ int may_linkat(struct mnt_idmap *idmap, const struct path *link);
 int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
 		 struct filename *newname, unsigned int flags);
 int do_mkdirat(int dfd, struct filename *name, umode_t mode);
+int do_mknodat(int dfd, struct filename *name, umode_t mode, unsigned int dev);
 int do_symlinkat(struct filename *from, int newdfd, struct filename *to);
 int do_linkat(int olddfd, struct filename *old, int newdfd,
 			struct filename *new, int flags);
diff --git a/fs/namei.c b/fs/namei.c
index cbddd5d44a12..7418a4e725da 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -5038,7 +5038,7 @@ static int may_mknod(umode_t mode)
 	}
 }
 
-static int do_mknodat(int dfd, struct filename *__name, umode_t mode,
+int do_mknodat(int dfd, struct filename *__name, umode_t mode,
 		unsigned int dev)
 {
 	CLASS(filename_consume, name)(__name);
-- 
2.47.3