linux/fs/gfs2/ops_export.c
Steven Whitehouse c9fd43078f [GFS2] Tidy up mount code.
We no longer lookup ".gfs2_admin" in the root directory in order to
find it, but instead use the inode number given in the superblock.
Both the root directory and the admin directory are now looked up using
the same routine, so the redundant code is removed.

Also, there is no longer a reference to the root inode in the
GFS2 super block. When required this can be retreived via
sb->s_root->d_inode instead.

Assuming that we introduce a metadata filesystem type for GFS, then
this is a first step towards that goal.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2006-03-01 15:31:02 -05:00

294 lines
6.3 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <asm/semaphore.h>
#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "ops_export.h"
#include "rgrp.h"
static struct dentry *gfs2_decode_fh(struct super_block *sb,
__u32 *fh,
int fh_len,
int fh_type,
int (*acceptable)(void *context,
struct dentry *dentry),
void *context)
{
struct gfs2_inum this, parent;
if (fh_type != fh_len)
return NULL;
memset(&parent, 0, sizeof(struct gfs2_inum));
switch (fh_type) {
case 8:
parent.no_formal_ino = ((uint64_t)be32_to_cpu(fh[4])) << 32;
parent.no_formal_ino |= be32_to_cpu(fh[5]);
parent.no_addr = ((uint64_t)be32_to_cpu(fh[6])) << 32;
parent.no_addr |= be32_to_cpu(fh[7]);
case 4:
this.no_formal_ino = ((uint64_t)be32_to_cpu(fh[0])) << 32;
this.no_formal_ino |= be32_to_cpu(fh[1]);
this.no_addr = ((uint64_t)be32_to_cpu(fh[2])) << 32;
this.no_addr |= be32_to_cpu(fh[3]);
break;
default:
return NULL;
}
return gfs2_export_ops.find_exported_dentry(sb, &this, &parent,
acceptable, context);
}
static int gfs2_encode_fh(struct dentry *dentry, __u32 *fh, int *len,
int connectable)
{
struct inode *inode = dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct gfs2_inode *ip = inode->u.generic_ip;
if (*len < 4 || (connectable && *len < 8))
return 255;
fh[0] = ip->i_num.no_formal_ino >> 32;
fh[0] = cpu_to_be32(fh[0]);
fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
fh[1] = cpu_to_be32(fh[1]);
fh[2] = ip->i_num.no_addr >> 32;
fh[2] = cpu_to_be32(fh[2]);
fh[3] = ip->i_num.no_addr & 0xFFFFFFFF;
fh[3] = cpu_to_be32(fh[3]);
*len = 4;
if (!connectable || inode == sb->s_root->d_inode)
return *len;
spin_lock(&dentry->d_lock);
inode = dentry->d_parent->d_inode;
ip = inode->u.generic_ip;
gfs2_inode_hold(ip);
spin_unlock(&dentry->d_lock);
fh[4] = ip->i_num.no_formal_ino >> 32;
fh[4] = cpu_to_be32(fh[4]);
fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
fh[5] = cpu_to_be32(fh[5]);
fh[6] = ip->i_num.no_addr >> 32;
fh[6] = cpu_to_be32(fh[6]);
fh[7] = ip->i_num.no_addr & 0xFFFFFFFF;
fh[7] = cpu_to_be32(fh[7]);
*len = 8;
gfs2_inode_put(ip);
return *len;
}
struct get_name_filldir {
struct gfs2_inum inum;
char *name;
};
static int get_name_filldir(void *opaque, const char *name, unsigned int length,
uint64_t offset, struct gfs2_inum *inum,
unsigned int type)
{
struct get_name_filldir *gnfd = (struct get_name_filldir *)opaque;
if (!gfs2_inum_equal(inum, &gnfd->inum))
return 0;
memcpy(gnfd->name, name, length);
gnfd->name[length] = 0;
return 1;
}
static int gfs2_get_name(struct dentry *parent, char *name,
struct dentry *child)
{
struct inode *dir = parent->d_inode;
struct inode *inode = child->d_inode;
struct gfs2_inode *dip, *ip;
struct get_name_filldir gnfd;
struct gfs2_holder gh;
uint64_t offset = 0;
int error;
if (!dir)
return -EINVAL;
if (!S_ISDIR(dir->i_mode) || !inode)
return -EINVAL;
dip = dir->u.generic_ip;
ip = inode->u.generic_ip;
*name = 0;
gnfd.inum = ip->i_num;
gnfd.name = name;
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
if (error)
return error;
error = gfs2_dir_read(dip, &offset, &gnfd, get_name_filldir);
gfs2_glock_dq_uninit(&gh);
if (!error && !*name)
error = -ENOENT;
return error;
}
static struct dentry *gfs2_get_parent(struct dentry *child)
{
struct qstr dotdot = { .name = "..", .len = 2 };
struct inode *inode;
struct dentry *dentry;
int error;
error = gfs2_lookupi(child->d_inode, &dotdot, 1, &inode);
if (error)
return ERR_PTR(error);
dentry = d_alloc_anon(inode);
if (!dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
return dentry;
}
static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_p)
{
struct gfs2_sbd *sdp = sb->s_fs_info;
struct gfs2_inum *inum = (struct gfs2_inum *)inum_p;
struct gfs2_holder i_gh, ri_gh, rgd_gh;
struct gfs2_rgrpd *rgd;
struct gfs2_inode *ip;
struct inode *inode;
struct dentry *dentry;
int error;
/* System files? */
inode = gfs2_iget(sb, inum);
if (inode) {
ip = inode->u.generic_ip;
if (ip->i_num.no_formal_ino != inum->no_formal_ino) {
iput(inode);
return ERR_PTR(-ESTALE);
}
goto out_inode;
}
error = gfs2_glock_nq_num(sdp,
inum->no_addr, &gfs2_inode_glops,
LM_ST_SHARED, LM_FLAG_ANY | GL_LOCAL_EXCL,
&i_gh);
if (error)
return ERR_PTR(error);
error = gfs2_inode_get(i_gh.gh_gl, inum, NO_CREATE, &ip);
if (error)
goto fail;
if (ip)
goto out_ip;
error = gfs2_rindex_hold(sdp, &ri_gh);
if (error)
goto fail;
error = -EINVAL;
rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
if (!rgd)
goto fail_rindex;
error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
if (error)
goto fail_rindex;
error = -ESTALE;
if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
goto fail_rgd;
gfs2_glock_dq_uninit(&rgd_gh);
gfs2_glock_dq_uninit(&ri_gh);
error = gfs2_inode_get(i_gh.gh_gl, inum, CREATE, &ip);
if (error)
goto fail;
error = gfs2_inode_refresh(ip);
if (error) {
gfs2_inode_put(ip);
goto fail;
}
out_ip:
error = -EIO;
if (ip->i_di.di_flags & GFS2_DIF_SYSTEM) {
gfs2_inode_put(ip);
goto fail;
}
gfs2_glock_dq_uninit(&i_gh);
inode = gfs2_ip2v(ip);
gfs2_inode_put(ip);
if (!inode)
return ERR_PTR(-ENOMEM);
out_inode:
dentry = d_alloc_anon(inode);
if (!dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
return dentry;
fail_rgd:
gfs2_glock_dq_uninit(&rgd_gh);
fail_rindex:
gfs2_glock_dq_uninit(&ri_gh);
fail:
gfs2_glock_dq_uninit(&i_gh);
return ERR_PTR(error);
}
struct export_operations gfs2_export_ops = {
.decode_fh = gfs2_decode_fh,
.encode_fh = gfs2_encode_fh,
.get_name = gfs2_get_name,
.get_parent = gfs2_get_parent,
.get_dentry = gfs2_get_dentry,
};