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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, 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_dir2.h"
#include "xfs_dir2_priv.h"
/*
* Directory data block operations
*/
/*
* For special situations, the dirent size ends up fixed because we always know
* what the size of the entry is. That's true for the "." and "..", and
* therefore we know that they are a fixed size and hence their offsets are
* constant, as is the first entry.
*
* Hence, this calculation is written as a macro to be able to be calculated at
* compile time and so certain offsets can be calculated directly in the
* structure initaliser via the macro. There are two macros - one for dirents
* with ftype and without so there are no unresolvable conditionals in the
* calculations. We also use round_up() as XFS_DIR2_DATA_ALIGN is always a power
* of 2 and the compiler doesn't reject it (unlike roundup()).
*/
#define XFS_DIR2_DATA_ENTSIZE(n) \
round_up((offsetof(struct xfs_dir2_data_entry, name[0]) + (n) + \
sizeof(xfs_dir2_data_off_t)), XFS_DIR2_DATA_ALIGN)
#define XFS_DIR3_DATA_ENTSIZE(n) \
round_up((offsetof(struct xfs_dir2_data_entry, name[0]) + (n) + \
sizeof(xfs_dir2_data_off_t) + sizeof(uint8_t)), \
XFS_DIR2_DATA_ALIGN)
int
xfs_dir2_data_entsize(
struct xfs_mount *mp,
int n)
{
if (xfs_sb_version_hasftype(&mp->m_sb))
return XFS_DIR3_DATA_ENTSIZE(n);
else
return XFS_DIR2_DATA_ENTSIZE(n);
}
static uint8_t
xfs_dir2_data_get_ftype(
struct xfs_dir2_data_entry *dep)
{
return XFS_DIR3_FT_UNKNOWN;
}
static void
xfs_dir2_data_put_ftype(
struct xfs_dir2_data_entry *dep,
uint8_t ftype)
{
ASSERT(ftype < XFS_DIR3_FT_MAX);
}
static uint8_t
xfs_dir3_data_get_ftype(
struct xfs_dir2_data_entry *dep)
{
uint8_t ftype = dep->name[dep->namelen];
if (ftype >= XFS_DIR3_FT_MAX)
return XFS_DIR3_FT_UNKNOWN;
return ftype;
}
static void
xfs_dir3_data_put_ftype(
struct xfs_dir2_data_entry *dep,
uint8_t type)
{
ASSERT(type < XFS_DIR3_FT_MAX);
ASSERT(dep->namelen != 0);
dep->name[dep->namelen] = type;
}
/*
* Pointer to an entry's tag word.
*/
static __be16 *
xfs_dir2_data_entry_tag_p(
struct xfs_dir2_data_entry *dep)
{
return (__be16 *)((char *)dep +
XFS_DIR2_DATA_ENTSIZE(dep->namelen) - sizeof(__be16));
}
static __be16 *
xfs_dir3_data_entry_tag_p(
struct xfs_dir2_data_entry *dep)
{
return (__be16 *)((char *)dep +
XFS_DIR3_DATA_ENTSIZE(dep->namelen) - sizeof(__be16));
}
static struct xfs_dir2_data_free *
xfs_dir2_data_bestfree_p(struct xfs_dir2_data_hdr *hdr)
{
return hdr->bestfree;
}
static struct xfs_dir2_data_free *
xfs_dir3_data_bestfree_p(struct xfs_dir2_data_hdr *hdr)
{
return ((struct xfs_dir3_data_hdr *)hdr)->best_free;
}
static const struct xfs_dir_ops xfs_dir2_ops = {
.data_get_ftype = xfs_dir2_data_get_ftype,
.data_put_ftype = xfs_dir2_data_put_ftype,
.data_entry_tag_p = xfs_dir2_data_entry_tag_p,
.data_bestfree_p = xfs_dir2_data_bestfree_p,
.data_first_offset = sizeof(struct xfs_dir2_data_hdr) +
XFS_DIR2_DATA_ENTSIZE(1) +
XFS_DIR2_DATA_ENTSIZE(2),
.data_entry_offset = sizeof(struct xfs_dir2_data_hdr),
};
static const struct xfs_dir_ops xfs_dir2_ftype_ops = {
.data_get_ftype = xfs_dir3_data_get_ftype,
.data_put_ftype = xfs_dir3_data_put_ftype,
.data_entry_tag_p = xfs_dir3_data_entry_tag_p,
.data_bestfree_p = xfs_dir2_data_bestfree_p,
.data_first_offset = sizeof(struct xfs_dir2_data_hdr) +
XFS_DIR3_DATA_ENTSIZE(1) +
XFS_DIR3_DATA_ENTSIZE(2),
.data_entry_offset = sizeof(struct xfs_dir2_data_hdr),
};
static const struct xfs_dir_ops xfs_dir3_ops = {
.data_get_ftype = xfs_dir3_data_get_ftype,
.data_put_ftype = xfs_dir3_data_put_ftype,
.data_entry_tag_p = xfs_dir3_data_entry_tag_p,
.data_bestfree_p = xfs_dir3_data_bestfree_p,
.data_first_offset = sizeof(struct xfs_dir3_data_hdr) +
XFS_DIR3_DATA_ENTSIZE(1) +
XFS_DIR3_DATA_ENTSIZE(2),
.data_entry_offset = sizeof(struct xfs_dir3_data_hdr),
};
/*
* Return the ops structure according to the current config. If we are passed
* an inode, then that overrides the default config we use which is based on
* feature bits.
*/
const struct xfs_dir_ops *
xfs_dir_get_ops(
struct xfs_mount *mp,
struct xfs_inode *dp)
{
if (dp)
return dp->d_ops;
if (mp->m_dir_inode_ops)
return mp->m_dir_inode_ops;
if (xfs_sb_version_hascrc(&mp->m_sb))
return &xfs_dir3_ops;
if (xfs_sb_version_hasftype(&mp->m_sb))
return &xfs_dir2_ftype_ops;
return &xfs_dir2_ops;
}
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