[linux-2.6-block.git] / fs / gfs2 / ops_export.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 "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 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 dentry *dentry;

	/*
	 * XXX(hch): it would be a good idea to keep this around as a
	 *	     static variable.
	 */
	gfs2_str2qstr(&dotdot, "..");

	dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
	if (!IS_ERR(dentry))
		dentry->d_op = &gfs2_dops;
	return dentry;
}

static struct dentry *gfs2_get_dentry(struct super_block *sb,
		struct gfs2_inum_host *inum)
{
	struct gfs2_sbd *sdp = sb->s_fs_info;
	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, 0);
	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_diskflags & GFS2_DIF_SYSTEM) {
		iput(inode);
		goto fail;
	}

	gfs2_glock_dq_uninit(&i_gh);

out_inode:
	dentry = d_obtain_alias(inode);
	if (!IS_ERR(dentry))
		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);
}

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:
		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:
		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,
};
Commit	Line	Data
b3b94faa DT	1	/*
b3b94faa DT	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3a8a9a10	3	* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
b3b94faa DT	4	*
	5	* This copyrighted material is made available to anyone wishing to use,
	6	* modify, copy, or redistribute it subject to the terms and conditions
e9fc2aa0	7	* of the GNU General Public License version 2.
b3b94faa DT	8	*/
b3b94faa DT	9
b3b94faa DT	10	#include <linux/slab.h>
	11	#include <linux/spinlock.h>
	12	#include <linux/completion.h>
	13	#include <linux/buffer_head.h>
a5694255	14	#include <linux/exportfs.h>
5c676f6d	15	#include <linux/gfs2_ondisk.h>
71b86f56	16	#include <linux/crc32.h>
7d308590	17	#include <linux/lm_interface.h>
b3b94faa DT	18
b3b94faa DT	19	#include "gfs2.h"
5c676f6d	20	#include "incore.h"
b3b94faa DT	21	#include "dir.h"
	22	#include "glock.h"
	23	#include "glops.h"
	24	#include "inode.h"
b2760583	25	#include "super.h"
b3b94faa	26	#include "rgrp.h"
c752666c	27	#include "util.h"
b3b94faa	28
bb8d8a6f	29	#define GFS2_SMALL_FH_SIZE 4
35dcc52e	30	#define GFS2_LARGE_FH_SIZE 8
3ebf4490	31	#define GFS2_OLD_FH_SIZE 10
bb8d8a6f	32
b44b84d7	33	static int gfs2_encode_fh(struct dentry dentry, __u32 p, int *len,
b3b94faa DT	34	int connectable)
b3b94faa DT	35	{
b44b84d7	36	__be32 fh = (__force __be32 )p;
b3b94faa	37	struct inode *inode = dentry->d_inode;
c9fd4307	38	struct super_block *sb = inode->i_sb;
feaa7bba	39	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa	40
5acd3967 SW	41	if (*len < GFS2_SMALL_FH_SIZE \|\|
5acd3967 SW	42	(connectable && *len < GFS2_LARGE_FH_SIZE))
b3b94faa DT	43	return 255;
b3b94faa DT	44
dbb7cae2 SW	45	fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	46	fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	47	fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
	48	fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
5acd3967	49	*len = GFS2_SMALL_FH_SIZE;
b3b94faa	50
c9fd4307	51	if (!connectable \|\| inode == sb->s_root->d_inode)
b3b94faa DT	52	return *len;
	53
	54	spin_lock(&dentry->d_lock);
	55	inode = dentry->d_parent->d_inode;
feaa7bba SW	56	ip = GFS2_I(inode);
feaa7bba SW	57	igrab(inode);
b3b94faa DT	58	spin_unlock(&dentry->d_lock);
b3b94faa DT	59
dbb7cae2 SW	60	fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	61	fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	62	fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
	63	fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
5acd3967	64	*len = GFS2_LARGE_FH_SIZE;
b3b94faa	65
feaa7bba	66	iput(inode);
b3b94faa DT	67
	68	return *len;
	69	}
	70
	71	struct get_name_filldir {
629a21e7	72	struct gfs2_inum_host inum;
b3b94faa DT	73	char *name;
	74	};
	75
3699e3a4 SW	76	static int get_name_filldir(void opaque, const char name, int length,
3699e3a4 SW	77	loff_t offset, u64 inum, unsigned int type)
b3b94faa	78	{
3699e3a4	79	struct get_name_filldir *gnfd = opaque;
b3b94faa	80
3699e3a4	81	if (inum != gnfd->inum.no_addr)
b3b94faa DT	82	return 0;
	83
	84	memcpy(gnfd->name, name, length);
	85	gnfd->name[length] = 0;
	86
	87	return 1;
	88	}
	89
	90	static int gfs2_get_name(struct dentry parent, char name,
	91	struct dentry *child)
	92	{
	93	struct inode *dir = parent->d_inode;
	94	struct inode *inode = child->d_inode;
	95	struct gfs2_inode dip, ip;
	96	struct get_name_filldir gnfd;
	97	struct gfs2_holder gh;
cd915493	98	u64 offset = 0;
b3b94faa DT	99	int error;
	100
	101	if (!dir)
	102	return -EINVAL;
	103
b3b94faa DT	104	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	105	return -EINVAL;
	106
feaa7bba SW	107	dip = GFS2_I(dir);
feaa7bba SW	108	ip = GFS2_I(inode);
b3b94faa DT	109
b3b94faa DT	110	*name = 0;
dbb7cae2 SW	111	gnfd.inum.no_addr = ip->i_no_addr;
dbb7cae2 SW	112	gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
b3b94faa DT	113	gnfd.name = name;
	114
	115	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	116	if (error)
	117	return error;
	118
71b86f56	119	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
b3b94faa DT	120
	121	gfs2_glock_dq_uninit(&gh);
	122
	123	if (!error && !*name)
	124	error = -ENOENT;
	125
	126	return error;
	127	}
	128
	129	static struct dentry gfs2_get_parent(struct dentry child)
	130	{
71b86f56	131	struct qstr dotdot;
b3b94faa	132	struct dentry *dentry;
b3b94faa	133
7b625361	134	/*
44003728 CH	135	* XXX(hch): it would be a good idea to keep this around as a
44003728 CH	136	* static variable.
7b625361	137	*/
44003728	138	gfs2_str2qstr(&dotdot, "..");
b3b94faa	139
44003728 CH	140	dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
	141	if (!IS_ERR(dentry))
	142	dentry->d_op = &gfs2_dops;
b3b94faa DT	143	return dentry;
	144	}
	145
34c0d154 CH	146	static struct dentry gfs2_get_dentry(struct super_block sb,
34c0d154 CH	147	struct gfs2_inum_host *inum)
b3b94faa	148	{
5c676f6d	149	struct gfs2_sbd *sdp = sb->s_fs_info;
b3b94faa DT	150	struct gfs2_holder i_gh, ri_gh, rgd_gh;
b3b94faa DT	151	struct gfs2_rgrpd *rgd;
b3b94faa DT	152	struct inode *inode;
	153	struct dentry *dentry;
	154	int error;
	155
b3b94faa DT	156	/* System files? */
b3b94faa DT	157
dbb7cae2	158	inode = gfs2_ilookup(sb, inum->no_addr);
b3b94faa	159	if (inode) {
dbb7cae2	160	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
b3b94faa DT	161	iput(inode);
	162	return ERR_PTR(-ESTALE);
	163	}
	164	goto out_inode;
	165	}
	166
feaa7bba	167	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
1c0f4872	168	LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
b3b94faa DT	169	if (error)
	170	return ERR_PTR(error);
	171
b3b94faa DT	172	error = gfs2_rindex_hold(sdp, &ri_gh);
	173	if (error)
	174	goto fail;
	175
	176	error = -EINVAL;
	177	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	178	if (!rgd)
	179	goto fail_rindex;
	180
	181	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	182	if (error)
	183	goto fail_rindex;
	184
	185	error = -ESTALE;
	186	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	187	goto fail_rgd;
	188
	189	gfs2_glock_dq_uninit(&rgd_gh);
	190	gfs2_glock_dq_uninit(&ri_gh);
	191
35dcc52e	192	inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
bb9bcf06	193	inum->no_addr,
7a9f53b3	194	0, 0);
feaa7bba SW	195	if (IS_ERR(inode)) {
feaa7bba SW	196	error = PTR_ERR(inode);
b3b94faa	197	goto fail;
feaa7bba	198	}
b3b94faa	199
feaa7bba	200	error = gfs2_inode_refresh(GFS2_I(inode));
b3b94faa	201	if (error) {
feaa7bba	202	iput(inode);
b3b94faa DT	203	goto fail;
b3b94faa DT	204	}
35dcc52e WC	205
	206	/* Pick up the works we bypass in gfs2_inode_lookup */
	207	if (inode->i_state & I_NEW)
	208	gfs2_set_iop(inode);
	209
dbb7cae2 SW	210	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
	211	iput(inode);
	212	goto fail;
	213	}
b3b94faa	214
b3b94faa	215	error = -EIO;
383f01fb	216	if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) {
feaa7bba	217	iput(inode);
b3b94faa DT	218	goto fail;
	219	}
	220
	221	gfs2_glock_dq_uninit(&i_gh);
	222
feaa7bba	223	out_inode:
44003728 CH	224	dentry = d_obtain_alias(inode);
	225	if (!IS_ERR(dentry))
	226	dentry->d_op = &gfs2_dops;
b3b94faa DT	227	return dentry;
b3b94faa DT	228
feaa7bba	229	fail_rgd:
b3b94faa DT	230	gfs2_glock_dq_uninit(&rgd_gh);
b3b94faa DT	231
feaa7bba	232	fail_rindex:
b3b94faa DT	233	gfs2_glock_dq_uninit(&ri_gh);
b3b94faa DT	234
feaa7bba	235	fail:
b3b94faa DT	236	gfs2_glock_dq_uninit(&i_gh);
	237	return ERR_PTR(error);
	238	}
	239
34c0d154 CH	240	static struct dentry gfs2_fh_to_dentry(struct super_block sb, struct fid *fid,
	241	int fh_len, int fh_type)
	242	{
	243	struct gfs2_inum_host this;
	244	__be32 fh = (__force __be32 )fid->raw;
	245
	246	switch (fh_type) {
	247	case GFS2_SMALL_FH_SIZE:
	248	case GFS2_LARGE_FH_SIZE:
	249	case GFS2_OLD_FH_SIZE:
	250	this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
	251	this.no_formal_ino \|= be32_to_cpu(fh[1]);
	252	this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
	253	this.no_addr \|= be32_to_cpu(fh[3]);
	254	return gfs2_get_dentry(sb, &this);
	255	default:
	256	return NULL;
	257	}
	258	}
	259
	260	static struct dentry gfs2_fh_to_parent(struct super_block sb, struct fid *fid,
	261	int fh_len, int fh_type)
	262	{
	263	struct gfs2_inum_host parent;
	264	__be32 fh = (__force __be32 )fid->raw;
	265
	266	switch (fh_type) {
	267	case GFS2_LARGE_FH_SIZE:
	268	case GFS2_OLD_FH_SIZE:
	269	parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
	270	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
	271	parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
	272	parent.no_addr \|= be32_to_cpu(fh[7]);
	273	return gfs2_get_dentry(sb, &parent);
	274	default:
	275	return NULL;
	276	}
	277	}
	278
39655164	279	const struct export_operations gfs2_export_ops = {
b3b94faa	280	.encode_fh = gfs2_encode_fh,
34c0d154 CH	281	.fh_to_dentry = gfs2_fh_to_dentry,
34c0d154 CH	282	.fh_to_parent = gfs2_fh_to_parent,
b3b94faa DT	283	.get_name = gfs2_get_name,
b3b94faa DT	284	.get_parent = gfs2_get_parent,
b3b94faa DT	285	};
b3b94faa DT	286