Unverified Commit cbb0b9d4 authored by Amir Goldstein's avatar Amir Goldstein Committed by Christian Brauner
Browse files

fs: use a helper for opening kernel internal files 



cachefiles uses kernel_open_tmpfile() to open kernel internal tmpfile
without accounting for nr_files.

cachefiles uses open_with_fake_path() for the same reason without the
need for a fake path.

Fork open_with_fake_path() to kernel_file_open() which only does the
noaccount part and use it in cachefiles.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Message-Id: <20230615112229.2143178-3-amir73il@gmail.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent d56e0ddb

fs/cachefiles/namei.c

+2 −2
Original line number Diff line number Diff line
@@ -560,7 +560,7 @@ static bool cachefiles_open_file(struct cachefiles_object *object, 
	 */

	path.mnt = cache->mnt;

	path.dentry = dentry;

	file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT,

	file = kernel_file_open(&path, O_RDWR | O_LARGEFILE | O_DIRECT,

				d_backing_inode(dentry), cache->cache_cred);

	if (IS_ERR(file)) {

		trace_cachefiles_vfs_error(object, d_backing_inode(dentry),

fs/open.c

+33 −0
Original line number Diff line number Diff line
@@ -1116,6 +1116,39 @@ struct file *dentry_create(const struct path *path, int flags, umode_t mode, 
}

EXPORT_SYMBOL(dentry_create);



/**

 * kernel_file_open - open a file for kernel internal use

 * @path:	path of the file to open

 * @flags:	open flags

 * @inode:	the inode

 * @cred:	credentials for open

 *

 * Open a file for use by in-kernel consumers. The file is not accounted

 * against nr_files and must not be installed into the file descriptor

 * table.

 *

 * Return: Opened file on success, an error pointer on failure.

 */

struct file *kernel_file_open(const struct path *path, int flags,

				struct inode *inode, const struct cred *cred)

{

	struct file *f;

	int error;



	f = alloc_empty_file_noaccount(flags, cred);

	if (IS_ERR(f))

		return f;



	f->f_path = *path;

	error = do_dentry_open(f, inode, NULL);

	if (error) {

		fput(f);

		f = ERR_PTR(error);

	}

	return f;

}

EXPORT_SYMBOL_GPL(kernel_file_open);



struct file *open_with_fake_path(const struct path *path, int flags,

				struct inode *inode, const struct cred *cred)

{

include/linux/fs.h

+2 −0
Original line number Diff line number Diff line
@@ -1676,6 +1676,8 @@ 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 *kernel_file_open(const struct path *path, int flags,

			      struct inode *inode, const struct cred *cred);



int vfs_mkobj(struct dentry *, umode_t,

		int (*f)(struct dentry *, umode_t, void *),