kernel-ark/fs/gfs2/ops_export.c
Christoph Hellwig a569425512 knfsd: exportfs: add exportfs.h header
currently the export_operation structure and helpers related to it are in
fs.h.  fs.h is already far too large and there are very few places needing the
export bits, so split them off into a separate header.

[akpm@linux-foundation.org: fix cifs build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:06 -07:00

300 lines
6.6 KiB
C

/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 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 version 2.
*/
#include <linux/slab.h>
#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 <linux/lm_interface.h>
#include "gfs2.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "ops_dentry.h"
#include "ops_fstype.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 struct dentry *gfs2_decode_fh(struct super_block *sb,
__u32 *p,
int fh_len,
int fh_type,
int (*acceptable)(void *context,
struct dentry *dentry),
void *context)
{
__be32 *fh = (__force __be32 *)p;
struct gfs2_inum_host inum, parent;
memset(&parent, 0, sizeof(struct gfs2_inum));
switch (fh_len) {
case GFS2_LARGE_FH_SIZE:
case GFS2_OLD_FH_SIZE:
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]);
case GFS2_SMALL_FH_SIZE:
inum.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
inum.no_formal_ino |= be32_to_cpu(fh[1]);
inum.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
inum.no_addr |= be32_to_cpu(fh[3]);
break;
default:
return NULL;
}
return gfs2_export_ops.find_exported_dentry(sb, &inum, &parent,
acceptable, context);
}
static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
int connectable)
{
__be32 *fh = (__force __be32 *)p;
struct inode *inode = dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct gfs2_inode *ip = GFS2_I(inode);
if (*len < GFS2_SMALL_FH_SIZE ||
(connectable && *len < GFS2_LARGE_FH_SIZE))
return 255;
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 (!connectable || inode == sb->s_root->d_inode)
return *len;
spin_lock(&dentry->d_lock);
inode = dentry->d_parent->d_inode;
ip = GFS2_I(inode);
igrab(inode);
spin_unlock(&dentry->d_lock);
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;
iput(inode);
return *len;
}
struct get_name_filldir {
struct gfs2_inum_host inum;
char *name;
};
static int get_name_filldir(void *opaque, const char *name, int length,
loff_t offset, u64 inum, unsigned int type)
{
struct get_name_filldir *gnfd = opaque;
if (inum != gnfd->inum.no_addr)
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;
u64 offset = 0;
int error;
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;
gnfd.name = name;
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
if (error)
return error;
error = gfs2_dir_read(dir, &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;
struct inode *inode;
struct dentry *dentry;
gfs2_str2qstr(&dotdot, "..");
inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
if (!inode)
return ERR_PTR(-ENOENT);
/*
* In case of an error, @inode carries the error value, and we
* have to return that as a(n invalid) pointer to dentry.
*/
if (IS_ERR(inode))
return ERR_PTR(PTR_ERR(inode));
dentry = d_alloc_anon(inode);
if (!dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
dentry->d_op = &gfs2_dops;
return dentry;
}
static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_obj)
{
struct gfs2_sbd *sdp = sb->s_fs_info;
struct gfs2_inum_host *inum = inum_obj;
struct gfs2_holder i_gh, ri_gh, rgd_gh;
struct gfs2_rgrpd *rgd;
struct inode *inode;
struct dentry *dentry;
int error;
/* System files? */
inode = gfs2_ilookup(sb, inum->no_addr);
if (inode) {
if (GFS2_I(inode)->i_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, &i_gh);
if (error)
return ERR_PTR(error);
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);
inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
inum->no_addr,
0);
if (!inode)
goto fail;
if (IS_ERR(inode)) {
error = PTR_ERR(inode);
goto fail;
}
error = gfs2_inode_refresh(GFS2_I(inode));
if (error) {
iput(inode);
goto fail;
}
/* Pick up the works we bypass in gfs2_inode_lookup */
if (inode->i_state & I_NEW)
gfs2_set_iop(inode);
if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
iput(inode);
goto fail;
}
error = -EIO;
if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
iput(inode);
goto fail;
}
gfs2_glock_dq_uninit(&i_gh);
out_inode:
dentry = d_alloc_anon(inode);
if (!dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
dentry->d_op = &gfs2_dops;
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,
};