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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*/
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include "gfs2.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "super.h"
#include "rgrp.h"
#include "util.h"
#define GFS2_SMALL_FH_SIZE 4
#define GFS2_LARGE_FH_SIZE 8
#define GFS2_OLD_FH_SIZE 10
static int gfs2_encode_fh(struct inode *inode, __u32 *p, int *len,
struct inode *parent)
{
__be32 *fh = (__force __be32 *)p;
struct super_block *sb = inode->i_sb;
struct gfs2_inode *ip = GFS2_I(inode);
if (parent && (*len < GFS2_LARGE_FH_SIZE)) {
*len = GFS2_LARGE_FH_SIZE;
return FILEID_INVALID;
} else if (*len < GFS2_SMALL_FH_SIZE) {
*len = GFS2_SMALL_FH_SIZE;
return FILEID_INVALID;
}
fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
*len = GFS2_SMALL_FH_SIZE;
if (!parent || inode == d_inode(sb->s_root))
return *len;
ip = GFS2_I(parent);
fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
*len = GFS2_LARGE_FH_SIZE;
return *len;
}
struct get_name_filldir {
struct dir_context ctx;
struct gfs2_inum_host inum;
char *name;
};
static bool get_name_filldir(struct dir_context *ctx, const char *name,
int length, loff_t offset, u64 inum,
unsigned int type)
{
struct get_name_filldir *gnfd =
container_of(ctx, struct get_name_filldir, ctx);
if (inum != gnfd->inum.no_addr)
return true;
memcpy(gnfd->name, name, length);
gnfd->name[length] = 0;
return false;
}
static int gfs2_get_name(struct dentry *parent, char *name,
struct dentry *child)
{
struct inode *dir = d_inode(parent);
struct inode *inode = d_inode(child);
struct gfs2_inode *dip, *ip;
struct get_name_filldir gnfd = {
.ctx.actor = get_name_filldir,
.name = name
};
struct gfs2_holder gh;
int error;
struct file_ra_state f_ra = { .start = 0 };
if (!dir)
return -EINVAL;
if (!S_ISDIR(dir->i_mode) || !inode)
return -EINVAL;
dip = GFS2_I(dir);
ip = GFS2_I(inode);
*name = 0;
gnfd.inum.no_addr = ip->i_no_addr;
gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
if (error)
return error;
error = gfs2_dir_read(dir, &gnfd.ctx, &f_ra);
gfs2_glock_dq_uninit(&gh);
if (!error && !*name)
error = -ENOENT;
return error;
}
static struct dentry *gfs2_get_parent(struct dentry *child)
{
return d_obtain_alias(gfs2_lookupi(d_inode(child), &gfs2_qdotdot, 1));
}
static struct dentry *gfs2_get_dentry(struct super_block *sb,
struct gfs2_inum_host *inum)
{
struct gfs2_sbd *sdp = sb->s_fs_info;
struct inode *inode;
if (!inum->no_formal_ino)
return ERR_PTR(-ESTALE);
inode = gfs2_lookup_by_inum(sdp, inum->no_addr, inum->no_formal_ino,
GFS2_BLKST_DINODE);
if (IS_ERR(inode))
return ERR_CAST(inode);
return d_obtain_alias(inode);
}
static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
int fh_len, int fh_type)
{
struct gfs2_inum_host this;
__be32 *fh = (__force __be32 *)fid->raw;
switch (fh_type) {
case GFS2_SMALL_FH_SIZE:
case GFS2_LARGE_FH_SIZE:
case GFS2_OLD_FH_SIZE:
if (fh_len < GFS2_SMALL_FH_SIZE)
return NULL;
this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
this.no_formal_ino |= be32_to_cpu(fh[1]);
this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
this.no_addr |= be32_to_cpu(fh[3]);
return gfs2_get_dentry(sb, &this);
default:
return NULL;
}
}
static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
int fh_len, int fh_type)
{
struct gfs2_inum_host parent;
__be32 *fh = (__force __be32 *)fid->raw;
switch (fh_type) {
case GFS2_LARGE_FH_SIZE:
case GFS2_OLD_FH_SIZE:
if (fh_len < GFS2_LARGE_FH_SIZE)
return NULL;
parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
parent.no_formal_ino |= be32_to_cpu(fh[5]);
parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
parent.no_addr |= be32_to_cpu(fh[7]);
return gfs2_get_dentry(sb, &parent);
default:
return NULL;
}
}
const struct export_operations gfs2_export_ops = {
.encode_fh = gfs2_encode_fh,
.fh_to_dentry = gfs2_fh_to_dentry,
.fh_to_parent = gfs2_fh_to_parent,
.get_name = gfs2_get_name,
.get_parent = gfs2_get_parent,
};
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