path: root/fs/xfs/libxfs/xfs_dir2_sf.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2003,2005 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_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_trace.h"

/*
 * Prototypes for internal functions.
 */
static void xfs_dir2_sf_addname_easy(xfs_da_args_t *args,
				     xfs_dir2_sf_entry_t *sfep,
				     xfs_dir2_data_aoff_t offset,
				     int new_isize);
static void xfs_dir2_sf_addname_hard(xfs_da_args_t *args, int objchange,
				     int new_isize);
static int xfs_dir2_sf_addname_pick(xfs_da_args_t *args, int objchange,
				    xfs_dir2_sf_entry_t **sfepp,
				    xfs_dir2_data_aoff_t *offsetp);
#ifdef DEBUG
static void xfs_dir2_sf_check(xfs_da_args_t *args);
#else
#define	xfs_dir2_sf_check(args)
#endif /* DEBUG */

static void xfs_dir2_sf_toino4(xfs_da_args_t *args);
static void xfs_dir2_sf_toino8(xfs_da_args_t *args);

int
xfs_dir2_sf_entsize(
	struct xfs_mount	*mp,
	struct xfs_dir2_sf_hdr	*hdr,
	int			len)
{
	int			count = len;

	count += sizeof(struct xfs_dir2_sf_entry);	/* namelen + offset */
	count += hdr->i8count ? XFS_INO64_SIZE : XFS_INO32_SIZE; /* ino # */

	if (xfs_has_ftype(mp))
		count += sizeof(uint8_t);
	return count;
}

struct xfs_dir2_sf_entry *
xfs_dir2_sf_nextentry(
	struct xfs_mount	*mp,
	struct xfs_dir2_sf_hdr	*hdr,
	struct xfs_dir2_sf_entry *sfep)
{
	return (void *)sfep + xfs_dir2_sf_entsize(mp, hdr, sfep->namelen);
}

/*
 * In short-form directory entries the inode numbers are stored at variable
 * offset behind the entry name. If the entry stores a filetype value, then it
 * sits between the name and the inode number.  The actual inode numbers can
 * come in two formats as well, either 4 bytes or 8 bytes wide.
 */
xfs_ino_t
xfs_dir2_sf_get_ino(
	struct xfs_mount		*mp,
	struct xfs_dir2_sf_hdr		*hdr,
	struct xfs_dir2_sf_entry	*sfep)
{
	uint8_t				*from = sfep->name + sfep->namelen;

	if (xfs_has_ftype(mp))
		from++;

	if (!hdr->i8count)
		return get_unaligned_be32(from);
	return get_unaligned_be64(from) & XFS_MAXINUMBER;
}

void
xfs_dir2_sf_put_ino(
	struct xfs_mount		*mp,
	struct xfs_dir2_sf_hdr		*hdr,
	struct xfs_dir2_sf_entry	*sfep,
	xfs_ino_t			ino)
{
	uint8_t				*to = sfep->name + sfep->namelen;

	ASSERT(ino <= XFS_MAXINUMBER);

	if (xfs_has_ftype(mp))
		to++;

	if (hdr->i8count)
		put_unaligned_be64(ino, to);
	else
		put_unaligned_be32(ino, to);
}

xfs_ino_t
xfs_dir2_sf_get_parent_ino(
	struct xfs_dir2_sf_hdr	*hdr)
{
	if (!hdr->i8count)
		return get_unaligned_be32(hdr->parent);
	return get_unaligned_be64(hdr->parent) & XFS_MAXINUMBER;
}

void
xfs_dir2_sf_put_parent_ino(
	struct xfs_dir2_sf_hdr		*hdr,
	xfs_ino_t			ino)
{
	ASSERT(ino <= XFS_MAXINUMBER);

	if (hdr->i8count)
		put_unaligned_be64(ino, hdr->parent);
	else
		put_unaligned_be32(ino, hdr->parent);
}

/*
 * The file type field is stored at the end of the name for filetype enabled
 * shortform directories, or not at all otherwise.