fs: rename {vfs,kernel}_tmpfile_open()

Overlayfs and cachefiles use vfs_open_tmpfile() to open a tmpfile
without accounting for nr_files.

Rename this helper to kernel_tmpfile_open() to better reflect this
helper is used for kernel internal users.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230615112229.2143178-2-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/cachefiles/namei.c

@@ -451,9 +451,9 @@ struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
 
 	ret = cachefiles_inject_write_error();
 	if (ret == 0) {
-		file = vfs_tmpfile_open(&nop_mnt_idmap, &parentpath, S_IFREG,
-					O_RDWR | O_LARGEFILE | O_DIRECT,
-					cache->cache_cred);
+		file = kernel_tmpfile_open(&nop_mnt_idmap, &parentpath, S_IFREG,
+					   O_RDWR | O_LARGEFILE | O_DIRECT,
+					   cache->cache_cred);
 		ret = PTR_ERR_OR_ZERO(file);
 	}
 	if (ret) {

fs/namei.c

@@ -3703,7 +3703,7 @@ static int vfs_tmpfile(struct mnt_idmap *idmap,
 }
 
 /**
- * vfs_tmpfile_open - open a tmpfile for kernel internal use
+ * kernel_tmpfile_open - open a tmpfile for kernel internal use
  * @idmap:	idmap of the mount the inode was found from
  * @parentpath:	path of the base directory
  * @mode:	mode of the new tmpfile
@@ -3714,24 +3714,26 @@ static int vfs_tmpfile(struct mnt_idmap *idmap,
  * hence this is only for kernel internal use, and must not be installed into
  * file tables or such.
  */
-struct file *vfs_tmpfile_open(struct mnt_idmap *idmap,
-			  const struct path *parentpath,
-			  umode_t mode, int open_flag, const struct cred *cred)
+struct file *kernel_tmpfile_open(struct mnt_idmap *idmap,
+				 const struct path *parentpath,
+				 umode_t mode, int open_flag,
+				 const struct cred *cred)
 {
 	struct file *file;
 	int error;
 
 	file = alloc_empty_file_noaccount(open_flag, cred);
-	if (!IS_ERR(file)) {
-		error = vfs_tmpfile(idmap, parentpath, file, mode);
-		if (error) {
-			fput(file);
-			file = ERR_PTR(error);
-		}
+	if (IS_ERR(file))
+		return file;
+
+	error = vfs_tmpfile(idmap, parentpath, file, mode);
+	if (error) {
+		fput(file);
+		file = ERR_PTR(error);
 	}
 	return file;
 }
-EXPORT_SYMBOL(vfs_tmpfile_open);
+EXPORT_SYMBOL(kernel_tmpfile_open);
 
 static int do_tmpfile(struct nameidata *nd, unsigned flags,
 		const struct open_flags *op,

fs/overlayfs/overlayfs.h

@@ -329,8 +329,9 @@ static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs,
 					  struct dentry *dentry, umode_t mode)
 {
 	struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = dentry };
-	struct file *file = vfs_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path, mode,
-					O_LARGEFILE | O_WRONLY, current_cred());
+	struct file *file = kernel_tmpfile_open(ovl_upper_mnt_idmap(ofs), &path,
+						mode, O_LARGEFILE | O_WRONLY,
+						current_cred());
 	int err = PTR_ERR_OR_ZERO(file);
 
 	pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);

include/linux/fs.h

@@ -1672,9 +1672,10 @@ static inline int vfs_whiteout(struct mnt_idmap *idmap,
 			 WHITEOUT_DEV);
 }
 
-struct file *vfs_tmpfile_open(struct mnt_idmap *idmap,
-			const struct path *parentpath,
-			umode_t mode, int open_flag, const struct cred *cred);
+struct file *kernel_tmpfile_open(struct mnt_idmap *idmap,
+				 const struct path *parentpath,
+				 umode_t mode, int open_flag,
+				 const struct cred *cred);
 
 int vfs_mkobj(struct dentry *, umode_t,
 		int (*f)(struct dentry *, umode_t, void *),