namei.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 *   Portions Copyright (C) Christoph Hellwig, 2001-2002
 */

#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/ctype.h>
#include <linux/quotaops.h>
#include <linux/exportfs.h>
#include "jfs_incore.h"
#include "jfs_superblock.h"
#include "jfs_inode.h"
#include "jfs_dinode.h"
#include "jfs_dmap.h"
#include "jfs_unicode.h"
#include "jfs_metapage.h"
#include "jfs_xattr.h"
#include "jfs_acl.h"
#include "jfs_debug.h"

/*
 * forward references
 */
const struct dentry_operations jfs_ci_dentry_operations;

static s64 commitZeroLink(tid_t, struct inode *);

/*
 * NAME:	free_ea_wmap(inode)
 *
 * FUNCTION:	free uncommitted extended attributes from working map
 *
 */
static inline void free_ea_wmap(struct inode *inode)
{ … }

/*
 * NAME:	jfs_create(dip, dentry, mode)
 *
 * FUNCTION:	create a regular file in the parent directory <dip>
 *		with name = <from dentry> and mode = <mode>
 *
 * PARAMETER:	dip	- parent directory vnode
 *		dentry	- dentry of new file
 *		mode	- create mode (rwxrwxrwx).
 *		nd- nd struct
 *
 * RETURN:	Errors from subroutines
 *
 */
static int jfs_create(struct mnt_idmap *idmap, struct inode *dip,
		      struct dentry *dentry, umode_t mode, bool excl)
{ … }


/*
 * NAME:	jfs_mkdir(dip, dentry, mode)
 *
 * FUNCTION:	create a child directory in the parent directory <dip>
 *		with name = <from dentry> and mode = <mode>
 *
 * PARAMETER:	dip	- parent directory vnode
 *		dentry	- dentry of child directory
 *		mode	- create mode (rwxrwxrwx).
 *
 * RETURN:	Errors from subroutines
 *
 * note:
 * EACCES: user needs search+write permission on the parent directory
 */
static int jfs_mkdir(struct mnt_idmap *idmap, struct inode *dip,
		     struct dentry *dentry, umode_t mode)
{ … }

/*
 * NAME:	jfs_rmdir(dip, dentry)
 *
 * FUNCTION:	remove a link to child directory
 *
 * PARAMETER:	dip	- parent inode
 *		dentry	- child directory dentry
 *
 * RETURN:	-EINVAL	- if name is . or ..
 *		-EINVAL - if . or .. exist but are invalid.
 *		errors from subroutines
 *
 * note:
 * if other threads have the directory open when the last link
 * is removed, the "." and ".." entries, if present, are removed before
 * rmdir() returns and no new entries may be created in the directory,
 * but the directory is not removed until the last reference to
 * the directory is released (cf.unlink() of regular file).
 */
static int jfs_rmdir(struct inode *dip, struct dentry *dentry)
{ … }

/*
 * NAME:	jfs_unlink(dip, dentry)
 *
 * FUNCTION:	remove a link to object <vp> named by <name>
 *		from parent directory <dvp>
 *
 * PARAMETER:	dip	- inode of parent directory
 *		dentry	- dentry of object to be removed
 *
 * RETURN:	errors from subroutines
 *
 * note:
 * temporary file: if one or more processes have the file open
 * when the last link is removed, the link will be removed before
 * unlink() returns, but the removal of the file contents will be
 * postponed until all references to the files are closed.
 *
 * JFS does NOT support unlink() on directories.
 *
 */
static int jfs_unlink(struct inode *dip, struct dentry *dentry)
{ … }

/*
 * NAME:	commitZeroLink()
 *
 * FUNCTION:	for non-directory, called by jfs_remove(),
 *		truncate a regular file, directory or symbolic
 *		link to zero length. return 0 if type is not
 *		one of these.
 *
 *		if the file is currently associated with a VM segment
 *		only permanent disk and inode map resources are freed,
 *		and neither the inode nor indirect blocks are modified
 *		so that the resources can be later freed in the work
 *		map by ctrunc1.
 *		if there is no VM segment on entry, the resources are
 *		freed in both work and permanent map.
 *		(? for temporary file - memory object is cached even
 *		after no reference:
 *		reference count > 0 -   )
 *
 * PARAMETERS:	cd	- pointer to commit data structure.
 *			  current inode is the one to truncate.
 *
 * RETURN:	Errors from subroutines
 */
static s64 commitZeroLink(tid_t tid, struct inode *ip)
{ … }


/*
 * NAME:	jfs_free_zero_link()
 *
 * FUNCTION:	for non-directory, called by iClose(),
 *		free resources of a file from cache and WORKING map
 *		for a file previously committed with zero link count
 *		while associated with a pager object,
 *
 * PARAMETER:	ip	- pointer to inode of file.
 */
void jfs_free_zero_link(struct inode *ip)
{ … }

/*
 * NAME:	jfs_link(vp, dvp, name, crp)
 *
 * FUNCTION:	create a link to <vp> by the name = <name>
 *		in the parent directory <dvp>
 *
 * PARAMETER:	vp	- target object
 *		dvp	- parent directory of new link
 *		name	- name of new link to target object
 *		crp	- credential
 *
 * RETURN:	Errors from subroutines
 *
 * note:
 * JFS does NOT support link() on directories (to prevent circular
 * path in the directory hierarchy);
 * EPERM: the target object is a directory, and either the caller
 * does not have appropriate privileges or the implementation prohibits
 * using link() on directories [XPG4.2].
 *
 * JFS does NOT support links between file systems:
 * EXDEV: target object and new link are on different file systems and
 * implementation does not support links between file systems [XPG4.2].
 */
static int jfs_link(struct dentry *old_dentry,
	     struct inode *dir, struct dentry *dentry)
{ … }

/*
 * NAME:	jfs_symlink(dip, dentry, name)
 *
 * FUNCTION:	creates a symbolic link to <symlink> by name <name>
 *			in directory <dip>
 *
 * PARAMETER:	dip	- parent directory vnode
 *		dentry	- dentry of symbolic link
 *		name	- the path name of the existing object
 *			  that will be the source of the link
 *
 * RETURN:	errors from subroutines
 *
 * note:
 * ENAMETOOLONG: pathname resolution of a symbolic link produced
 * an intermediate result whose length exceeds PATH_MAX [XPG4.2]
*/

static int jfs_symlink(struct mnt_idmap *idmap, struct inode *dip,
		       struct dentry *dentry, const char *name)
{ … }


/*
 * NAME:	jfs_rename
 *
 * FUNCTION:	rename a file or directory
 */
static int jfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
		      struct dentry *old_dentry, struct inode *new_dir,
		      struct dentry *new_dentry, unsigned int flags)
{ … }


/*
 * NAME:	jfs_mknod
 *
 * FUNCTION:	Create a special file (device)
 */
static int jfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
		     struct dentry *dentry, umode_t mode, dev_t rdev)
{ … }

static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, unsigned int flags)
{ … }

static struct inode *jfs_nfs_get_inode(struct super_block *sb,
		u64 ino, u32 generation)
{ … }

struct dentry *jfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{ … }

struct dentry *jfs_fh_to_parent(struct super_block *sb, struct fid *fid,
		int fh_len, int fh_type)
{ … }

struct dentry *jfs_get_parent(struct dentry *dentry)
{ … }

const struct inode_operations jfs_dir_inode_operations = …;

WRAP_DIR_ITER(…) // FIXME!
const struct file_operations jfs_dir_operations = …;

static int jfs_ci_hash(const struct dentry *dir, struct qstr *this)
{ … }

static int jfs_ci_compare(const struct dentry *dentry,
		unsigned int len, const char *str, const struct qstr *name)
{ … }

static int jfs_ci_revalidate(struct dentry *dentry, unsigned int flags)
{ … }

const struct dentry_operations jfs_ci_dentry_operations = …;
linux/fs/jfs/namei.c
