linux/fs/xfs/libxfs/xfs_dir2.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_health.h"
#include "xfs_bmap_btree.h"
#include "xfs_trans_space.h"
#include "xfs_parent.h"
#include "xfs_ag.h"
#include "xfs_ialloc.h"

const struct xfs_name xfs_name_dotdot = …;

const struct xfs_name xfs_name_dot = …;

/*
 * Convert inode mode to directory entry filetype
 */
unsigned char
xfs_mode_to_ftype(
	int		mode)
{ … }

/*
 * ASCII case-insensitive (ie. A-Z) support for directories that was
 * used in IRIX.
 */
xfs_dahash_t
xfs_ascii_ci_hashname(
	const struct xfs_name	*name)
{ … }

enum xfs_dacmp
xfs_ascii_ci_compname(
	struct xfs_da_args	*args,
	const unsigned char	*name,
	int			len)
{ … }

int
xfs_da_mount(
	struct xfs_mount	*mp)
{ … }

void
xfs_da_unmount(
	struct xfs_mount	*mp)
{ … }

/*
 * Return 1 if directory contains only "." and "..".
 */
int
xfs_dir_isempty(
	xfs_inode_t	*dp)
{ … }

/*
 * Validate a given inode number.
 */
int
xfs_dir_ino_validate(
	xfs_mount_t	*mp,
	xfs_ino_t	ino)
{ … }

/*
 * Initialize a directory with its "." and ".." entries.
 */
int
xfs_dir_init(
	xfs_trans_t	*tp,
	xfs_inode_t	*dp,
	xfs_inode_t	*pdp)
{ … }

enum xfs_dir2_fmt
xfs_dir2_format(
	struct xfs_da_args	*args,
	int			*error)
{ … }

int
xfs_dir_createname_args(
	struct xfs_da_args	*args)
{ … }

/*
 * Enter a name in a directory, or check for available space.
 * If inum is 0, only the available space test is performed.
 */
int
xfs_dir_createname(
	struct xfs_trans	*tp,
	struct xfs_inode	*dp,
	const struct xfs_name	*name,
	xfs_ino_t		inum,		/* new entry inode number */
	xfs_extlen_t		total)		/* bmap's total block count */
{ … }

/*
 * If doing a CI lookup and case-insensitive match, dup actual name into
 * args.value. Return EEXIST for success (ie. name found) or an error.
 */
int
xfs_dir_cilookup_result(
	struct xfs_da_args *args,
	const unsigned char *name,
	int		len)
{ … }

int
xfs_dir_lookup_args(
	struct xfs_da_args	*args)
{ … }

/*
 * Lookup a name in a directory, give back the inode number.
 * If ci_name is not NULL, returns the actual name in ci_name if it differs
 * to name, or ci_name->name is set to NULL for an exact match.
 */

int
xfs_dir_lookup(
	struct xfs_trans	*tp,
	struct xfs_inode	*dp,
	const struct xfs_name	*name,
	xfs_ino_t		*inum,	  /* out: inode number */
	struct xfs_name		*ci_name) /* out: actual name if CI match */
{ … }

int
xfs_dir_removename_args(
	struct xfs_da_args	*args)
{ … }

/*
 * Remove an entry from a directory.
 */
int
xfs_dir_removename(
	struct xfs_trans	*tp,
	struct xfs_inode	*dp,
	const struct xfs_name	*name,
	xfs_ino_t		ino,
	xfs_extlen_t		total)		/* bmap's total block count */
{ … }

int
xfs_dir_replace_args(
	struct xfs_da_args	*args)
{ … }

/*
 * Replace the inode number of a directory entry.
 */
int
xfs_dir_replace(
	struct xfs_trans	*tp,
	struct xfs_inode	*dp,
	const struct xfs_name	*name,		/* name of entry to replace */
	xfs_ino_t		inum,		/* new inode number */
	xfs_extlen_t		total)		/* bmap's total block count */
{ … }

/*
 * See if this entry can be added to the directory without allocating space.
 */
int
xfs_dir_canenter(
	struct xfs_trans	*tp,
	struct xfs_inode	*dp,
	const struct xfs_name	*name)		/* name of entry to add */
{ … }

/*
 * Utility routines.
 */

/*
 * Add a block to the directory.
 *
 * This routine is for data and free blocks, not leaf/node blocks which are
 * handled by xfs_da_grow_inode.
 */
int
xfs_dir2_grow_inode(
	struct xfs_da_args	*args,
	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
	xfs_dir2_db_t		*dbp)	/* out: block number added */
{ … }

/*
 * Remove the given block from the directory.
 * This routine is used for data and free blocks, leaf/node are done
 * by xfs_da_shrink_inode.
 */
int
xfs_dir2_shrink_inode(
	struct xfs_da_args	*args,
	xfs_dir2_db_t		db,
	struct xfs_buf		*bp)
{ … }

/* Returns true if the directory entry name is valid. */
bool
xfs_dir2_namecheck(
	const void	*name,
	size_t		length)
{ … }

xfs_dahash_t
xfs_dir2_hashname(
	struct xfs_mount	*mp,
	const struct xfs_name	*name)
{ … }

enum xfs_dacmp
xfs_dir2_compname(
	struct xfs_da_args	*args,
	const unsigned char	*name,
	int			len)
{ … }

#ifdef CONFIG_XFS_LIVE_HOOKS
/*
 * Use a static key here to reduce the overhead of directory live update hooks.
 * If the compiler supports jump labels, the static branch will be replaced by
 * a nop sled when there are no hook users.  Online fsck is currently the only
 * caller, so this is a reasonable tradeoff.
 *
 * Note: Patching the kernel code requires taking the cpu hotplug lock.  Other
 * parts of the kernel allocate memory with that lock held, which means that
 * XFS callers cannot hold any locks that might be used by memory reclaim or
 * writeback when calling the static_branch_{inc,dec} functions.
 */
DEFINE_STATIC_XFS_HOOK_SWITCH(xfs_dir_hooks_switch);

void
xfs_dir_hook_disable(void)
{ … }

void
xfs_dir_hook_enable(void)
{ … }

/* Call hooks for a directory update relating to a child dirent update. */
inline void
xfs_dir_update_hook(
	struct xfs_inode		*dp,
	struct xfs_inode		*ip,
	int				delta,
	const struct xfs_name		*name)
{ … }

/* Call the specified function during a directory update. */
int
xfs_dir_hook_add(
	struct xfs_mount	*mp,
	struct xfs_dir_hook	*hook)
{ … }

/* Stop calling the specified function during a directory update. */
void
xfs_dir_hook_del(
	struct xfs_mount	*mp,
	struct xfs_dir_hook	*hook)
{ … }

/* Configure directory update hook functions. */
void
xfs_dir_hook_setup(
	struct xfs_dir_hook	*hook,
	notifier_fn_t		mod_fn)
{ … }
#endif /* CONFIG_XFS_LIVE_HOOKS */

/*
 * Given a directory @dp, a newly allocated inode @ip, and a @name, link @ip
 * into @dp under the given @name.  If @ip is a directory, it will be
 * initialized.  Both inodes must have the ILOCK held and the transaction must
 * have sufficient blocks reserved.
 */
int
xfs_dir_create_child(
	struct xfs_trans	*tp,
	unsigned int		resblks,
	struct xfs_dir_update	*du)
{ … }

/*
 * Given a directory @dp, an existing non-directory inode @ip, and a @name,
 * link @ip into @dp under the given @name.  Both inodes must have the ILOCK
 * held.
 */
int
xfs_dir_add_child(
	struct xfs_trans	*tp,
	unsigned int		resblks,
	struct xfs_dir_update	*du)
{ … }

/*
 * Given a directory @dp, a child @ip, and a @name, remove the (@name, @ip)
 * entry from the directory.  Both inodes must have the ILOCK held.
 */
int
xfs_dir_remove_child(
	struct xfs_trans	*tp,
	unsigned int		resblks,
	struct xfs_dir_update	*du)
{ … }

/*
 * Exchange the entry (@name1, @ip1) in directory @dp1 with the entry (@name2,
 * @ip2) in directory @dp2, and update '..' @ip1 and @ip2's entries as needed.
 * @ip1 and @ip2 need not be of the same type.
 *
 * All inodes must have the ILOCK held, and both entries must already exist.
 */
int
xfs_dir_exchange_children(
	struct xfs_trans	*tp,
	struct xfs_dir_update	*du1,
	struct xfs_dir_update	*du2,
	unsigned int		spaceres)
{ … }

/*
 * Given an entry (@src_name, @src_ip) in directory @src_dp, make the entry
 * @target_name in directory @target_dp point to @src_ip and remove the
 * original entry, cleaning up everything left behind.
 *
 * Cleanup involves dropping a link count on @target_ip, and either removing
 * the (@src_name, @src_ip) entry from @src_dp or simply replacing the entry
 * with (@src_name, @wip) if a whiteout inode @wip is supplied.
 *
 * All inodes must have the ILOCK held.  We assume that if @src_ip is a
 * directory then its '..' doesn't already point to @target_dp, and that @wip
 * is a freshly allocated whiteout.
 */
int
xfs_dir_rename_children(
	struct xfs_trans	*tp,
	struct xfs_dir_update	*du_src,
	struct xfs_dir_update	*du_tgt,
	unsigned int		spaceres,
	struct xfs_dir_update	*du_wip)
{ … }