[net-next-2.6.git] / fs / gfs2 / ops_export.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,
};
Commit	Line	Data
b3b94faa DT	1	/*
	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
	3	* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
	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
	7	* of the GNU General Public License v.2.
	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/slab.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/completion.h>
	14	#include <linux/buffer_head.h>
5c676f6d	15	#include <linux/gfs2_ondisk.h>
b3b94faa DT	16	#include <asm/semaphore.h>
	17
	18	#include "gfs2.h"
5c676f6d SW	19	#include "lm_interface.h"
5c676f6d SW	20	#include "incore.h"
b3b94faa DT	21	#include "dir.h"
	22	#include "glock.h"
	23	#include "glops.h"
	24	#include "inode.h"
	25	#include "ops_export.h"
	26	#include "rgrp.h"
	27
	28	static struct dentry gfs2_decode_fh(struct super_block sb,
	29	__u32 *fh,
	30	int fh_len,
	31	int fh_type,
	32	int (acceptable)(void context,
	33	struct dentry *dentry),
	34	void *context)
	35	{
	36	struct gfs2_inum this, parent;
	37
b3b94faa DT	38	if (fh_type != fh_len)
	39	return NULL;
	40
	41	memset(&parent, 0, sizeof(struct gfs2_inum));
	42
	43	switch (fh_type) {
	44	case 8:
	45	parent.no_formal_ino = ((uint64_t)be32_to_cpu(fh[4])) << 32;
	46	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
	47	parent.no_addr = ((uint64_t)be32_to_cpu(fh[6])) << 32;
	48	parent.no_addr \|= be32_to_cpu(fh[7]);
	49	case 4:
	50	this.no_formal_ino = ((uint64_t)be32_to_cpu(fh[0])) << 32;
	51	this.no_formal_ino \|= be32_to_cpu(fh[1]);
	52	this.no_addr = ((uint64_t)be32_to_cpu(fh[2])) << 32;
	53	this.no_addr \|= be32_to_cpu(fh[3]);
	54	break;
	55	default:
	56	return NULL;
	57	}
	58
	59	return gfs2_export_ops.find_exported_dentry(sb, &this, &parent,
	60	acceptable, context);
	61	}
	62
	63	static int gfs2_encode_fh(struct dentry dentry, __u32 fh, int *len,
	64	int connectable)
	65	{
	66	struct inode *inode = dentry->d_inode;
c9fd4307	67	struct super_block *sb = inode->i_sb;
5c676f6d	68	struct gfs2_inode *ip = inode->u.generic_ip;
b3b94faa	69
b3b94faa DT	70	if (len < 4 \|\| (connectable && len < 8))
	71	return 255;
	72
	73	fh[0] = ip->i_num.no_formal_ino >> 32;
	74	fh[0] = cpu_to_be32(fh[0]);
	75	fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	76	fh[1] = cpu_to_be32(fh[1]);
	77	fh[2] = ip->i_num.no_addr >> 32;
	78	fh[2] = cpu_to_be32(fh[2]);
	79	fh[3] = ip->i_num.no_addr & 0xFFFFFFFF;
	80	fh[3] = cpu_to_be32(fh[3]);
	81	*len = 4;
	82
c9fd4307	83	if (!connectable \|\| inode == sb->s_root->d_inode)
b3b94faa DT	84	return *len;
	85
	86	spin_lock(&dentry->d_lock);
	87	inode = dentry->d_parent->d_inode;
5c676f6d	88	ip = inode->u.generic_ip;
b3b94faa DT	89	gfs2_inode_hold(ip);
	90	spin_unlock(&dentry->d_lock);
	91
	92	fh[4] = ip->i_num.no_formal_ino >> 32;
	93	fh[4] = cpu_to_be32(fh[4]);
	94	fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	95	fh[5] = cpu_to_be32(fh[5]);
	96	fh[6] = ip->i_num.no_addr >> 32;
	97	fh[6] = cpu_to_be32(fh[6]);
	98	fh[7] = ip->i_num.no_addr & 0xFFFFFFFF;
	99	fh[7] = cpu_to_be32(fh[7]);
	100	*len = 8;
	101
	102	gfs2_inode_put(ip);
	103
	104	return *len;
	105	}
	106
	107	struct get_name_filldir {
	108	struct gfs2_inum inum;
	109	char *name;
	110	};
	111
	112	static int get_name_filldir(void opaque, const char name, unsigned int length,
	113	uint64_t offset, struct gfs2_inum *inum,
	114	unsigned int type)
	115	{
	116	struct get_name_filldir gnfd = (struct get_name_filldir )opaque;
	117
	118	if (!gfs2_inum_equal(inum, &gnfd->inum))
	119	return 0;
	120
	121	memcpy(gnfd->name, name, length);
	122	gnfd->name[length] = 0;
	123
	124	return 1;
	125	}
	126
	127	static int gfs2_get_name(struct dentry parent, char name,
	128	struct dentry *child)
	129	{
	130	struct inode *dir = parent->d_inode;
	131	struct inode *inode = child->d_inode;
	132	struct gfs2_inode dip, ip;
	133	struct get_name_filldir gnfd;
	134	struct gfs2_holder gh;
	135	uint64_t offset = 0;
	136	int error;
	137
	138	if (!dir)
	139	return -EINVAL;
	140
b3b94faa DT	141	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	142	return -EINVAL;
	143
5c676f6d SW	144	dip = dir->u.generic_ip;
5c676f6d SW	145	ip = inode->u.generic_ip;
b3b94faa DT	146
	147	*name = 0;
	148	gnfd.inum = ip->i_num;
	149	gnfd.name = name;
	150
	151	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	152	if (error)
	153	return error;
	154
	155	error = gfs2_dir_read(dip, &offset, &gnfd, get_name_filldir);
	156
	157	gfs2_glock_dq_uninit(&gh);
	158
	159	if (!error && !*name)
	160	error = -ENOENT;
	161
	162	return error;
	163	}
	164
	165	static struct dentry gfs2_get_parent(struct dentry child)
	166	{
b3b94faa	167	struct qstr dotdot = { .name = "..", .len = 2 };
b3b94faa DT	168	struct inode *inode;
	169	struct dentry *dentry;
	170	int error;
	171
7359a19c	172	error = gfs2_lookupi(child->d_inode, &dotdot, 1, &inode);
b3b94faa DT	173	if (error)
	174	return ERR_PTR(error);
	175
b3b94faa DT	176	dentry = d_alloc_anon(inode);
	177	if (!dentry) {
	178	iput(inode);
	179	return ERR_PTR(-ENOMEM);
	180	}
	181
	182	return dentry;
	183	}
	184
	185	static struct dentry gfs2_get_dentry(struct super_block sb, void *inum_p)
	186	{
5c676f6d	187	struct gfs2_sbd *sdp = sb->s_fs_info;
b3b94faa DT	188	struct gfs2_inum inum = (struct gfs2_inum )inum_p;
	189	struct gfs2_holder i_gh, ri_gh, rgd_gh;
	190	struct gfs2_rgrpd *rgd;
	191	struct gfs2_inode *ip;
	192	struct inode *inode;
	193	struct dentry *dentry;
	194	int error;
	195
b3b94faa DT	196	/* System files? */
	197
	198	inode = gfs2_iget(sb, inum);
	199	if (inode) {
5c676f6d	200	ip = inode->u.generic_ip;
b3b94faa DT	201	if (ip->i_num.no_formal_ino != inum->no_formal_ino) {
	202	iput(inode);
	203	return ERR_PTR(-ESTALE);
	204	}
	205	goto out_inode;
	206	}
	207
	208	error = gfs2_glock_nq_num(sdp,
	209	inum->no_addr, &gfs2_inode_glops,
	210	LM_ST_SHARED, LM_FLAG_ANY \| GL_LOCAL_EXCL,
	211	&i_gh);
	212	if (error)
	213	return ERR_PTR(error);
	214
	215	error = gfs2_inode_get(i_gh.gh_gl, inum, NO_CREATE, &ip);
	216	if (error)
	217	goto fail;
	218	if (ip)
	219	goto out_ip;
	220
	221	error = gfs2_rindex_hold(sdp, &ri_gh);
	222	if (error)
	223	goto fail;
	224
	225	error = -EINVAL;
	226	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	227	if (!rgd)
	228	goto fail_rindex;
	229
	230	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	231	if (error)
	232	goto fail_rindex;
	233
	234	error = -ESTALE;
	235	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	236	goto fail_rgd;
	237
	238	gfs2_glock_dq_uninit(&rgd_gh);
	239	gfs2_glock_dq_uninit(&ri_gh);
	240
	241	error = gfs2_inode_get(i_gh.gh_gl, inum, CREATE, &ip);
	242	if (error)
	243	goto fail;
	244
	245	error = gfs2_inode_refresh(ip);
	246	if (error) {
	247	gfs2_inode_put(ip);
	248	goto fail;
	249	}
	250
b3b94faa DT	251	out_ip:
	252	error = -EIO;
	253	if (ip->i_di.di_flags & GFS2_DIF_SYSTEM) {
	254	gfs2_inode_put(ip);
	255	goto fail;
	256	}
	257
	258	gfs2_glock_dq_uninit(&i_gh);
	259
	260	inode = gfs2_ip2v(ip);
	261	gfs2_inode_put(ip);
	262
	263	if (!inode)
	264	return ERR_PTR(-ENOMEM);
	265
	266	out_inode:
	267	dentry = d_alloc_anon(inode);
	268	if (!dentry) {
	269	iput(inode);
	270	return ERR_PTR(-ENOMEM);
	271	}
	272
	273	return dentry;
	274
	275	fail_rgd:
	276	gfs2_glock_dq_uninit(&rgd_gh);
	277
	278	fail_rindex:
	279	gfs2_glock_dq_uninit(&ri_gh);
	280
	281	fail:
	282	gfs2_glock_dq_uninit(&i_gh);
	283	return ERR_PTR(error);
	284	}
	285
	286	struct export_operations gfs2_export_ops = {
	287	.decode_fh = gfs2_decode_fh,
	288	.encode_fh = gfs2_encode_fh,
	289	.get_name = gfs2_get_name,
	290	.get_parent = gfs2_get_parent,
	291	.get_dentry = gfs2_get_dentry,
	292	};
	293