diff options
Diffstat (limited to 'fs/open.c')
-rw-r--r-- | fs/open.c | 76 |
1 files changed, 65 insertions, 11 deletions
diff --git a/fs/open.c b/fs/open.c index fa5d53282dfe..fb07b2840eb4 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1108,23 +1108,77 @@ struct file *dentry_create(const struct path *path, int flags, umode_t mode, } EXPORT_SYMBOL(dentry_create); -struct file *open_with_fake_path(const struct path *path, int flags, +/** + * 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 = alloc_empty_file_noaccount(flags, cred); - if (!IS_ERR(f)) { - int error; + struct file *f; + int error; - f->f_path = *path; - error = do_dentry_open(f, inode, NULL); - if (error) { - fput(f); - f = ERR_PTR(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(open_with_fake_path); +EXPORT_SYMBOL_GPL(kernel_file_open); + +/** + * backing_file_open - open a backing file for kernel internal use + * @path: path of the file to open + * @flags: open flags + * @path: path of the backing file + * @cred: credentials for open + * + * Open a backing file for a stackable filesystem (e.g., overlayfs). + * @path may be on the stackable filesystem and backing inode on the + * underlying filesystem. In this case, we want to be able to return + * the @real_path of the backing inode. This is done by embedding the + * returned file into a container structure that also stores the path of + * the backing inode on the underlying filesystem, which can be + * retrieved using backing_file_real_path(). + */ +struct file *backing_file_open(const struct path *path, int flags, + const struct path *real_path, + const struct cred *cred) +{ + struct file *f; + int error; + + f = alloc_empty_backing_file(flags, cred); + if (IS_ERR(f)) + return f; + + f->f_path = *path; + path_get(real_path); + *backing_file_real_path(f) = *real_path; + error = do_dentry_open(f, d_inode(real_path->dentry), NULL); + if (error) { + fput(f); + f = ERR_PTR(error); + } + + return f; +} +EXPORT_SYMBOL_GPL(backing_file_open); #define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE)) #define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC) |