[linux-2.6-block.git] / fs / gfs2 / 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 "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;
	struct inode *inode;
	struct dentry *dentry;
	int error;

	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_check_blk_type(sdp, inum->no_addr, GFS2_BLKST_DINODE);
	if (error)
		goto fail;

	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:
	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>
b3b94faa DT	17
b3b94faa DT	18	#include "gfs2.h"
5c676f6d	19	#include "incore.h"
b3b94faa DT	20	#include "dir.h"
	21	#include "glock.h"
	22	#include "glops.h"
	23	#include "inode.h"
b2760583	24	#include "super.h"
b3b94faa	25	#include "rgrp.h"
c752666c	26	#include "util.h"
b3b94faa	27
bb8d8a6f	28	#define GFS2_SMALL_FH_SIZE 4
35dcc52e	29	#define GFS2_LARGE_FH_SIZE 8
3ebf4490	30	#define GFS2_OLD_FH_SIZE 10
bb8d8a6f	31
b44b84d7	32	static int gfs2_encode_fh(struct dentry dentry, __u32 p, int *len,
b3b94faa DT	33	int connectable)
b3b94faa DT	34	{
b44b84d7	35	__be32 fh = (__force __be32 )p;
b3b94faa	36	struct inode *inode = dentry->d_inode;
c9fd4307	37	struct super_block *sb = inode->i_sb;
feaa7bba	38	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa	39
5acd3967 SW	40	if (*len < GFS2_SMALL_FH_SIZE \|\|
5acd3967 SW	41	(connectable && *len < GFS2_LARGE_FH_SIZE))
b3b94faa DT	42	return 255;
b3b94faa DT	43
dbb7cae2 SW	44	fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	45	fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	46	fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
	47	fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
5acd3967	48	*len = GFS2_SMALL_FH_SIZE;
b3b94faa	49
c9fd4307	50	if (!connectable \|\| inode == sb->s_root->d_inode)
b3b94faa DT	51	return *len;
	52
	53	spin_lock(&dentry->d_lock);
	54	inode = dentry->d_parent->d_inode;
feaa7bba SW	55	ip = GFS2_I(inode);
feaa7bba SW	56	igrab(inode);
b3b94faa DT	57	spin_unlock(&dentry->d_lock);
b3b94faa DT	58
dbb7cae2 SW	59	fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	60	fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	61	fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
	62	fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
5acd3967	63	*len = GFS2_LARGE_FH_SIZE;
b3b94faa	64
feaa7bba	65	iput(inode);
b3b94faa DT	66
	67	return *len;
	68	}
	69
	70	struct get_name_filldir {
629a21e7	71	struct gfs2_inum_host inum;
b3b94faa DT	72	char *name;
	73	};
	74
3699e3a4 SW	75	static int get_name_filldir(void opaque, const char name, int length,
3699e3a4 SW	76	loff_t offset, u64 inum, unsigned int type)
b3b94faa	77	{
3699e3a4	78	struct get_name_filldir *gnfd = opaque;
b3b94faa	79
3699e3a4	80	if (inum != gnfd->inum.no_addr)
b3b94faa DT	81	return 0;
	82
	83	memcpy(gnfd->name, name, length);
	84	gnfd->name[length] = 0;
	85
	86	return 1;
	87	}
	88
	89	static int gfs2_get_name(struct dentry parent, char name,
	90	struct dentry *child)
	91	{
	92	struct inode *dir = parent->d_inode;
	93	struct inode *inode = child->d_inode;
	94	struct gfs2_inode dip, ip;
	95	struct get_name_filldir gnfd;
	96	struct gfs2_holder gh;
cd915493	97	u64 offset = 0;
b3b94faa DT	98	int error;
	99
	100	if (!dir)
	101	return -EINVAL;
	102
b3b94faa DT	103	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	104	return -EINVAL;
	105
feaa7bba SW	106	dip = GFS2_I(dir);
feaa7bba SW	107	ip = GFS2_I(inode);
b3b94faa DT	108
b3b94faa DT	109	*name = 0;
dbb7cae2 SW	110	gnfd.inum.no_addr = ip->i_no_addr;
dbb7cae2 SW	111	gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
b3b94faa DT	112	gnfd.name = name;
	113
	114	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	115	if (error)
	116	return error;
	117
71b86f56	118	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
b3b94faa DT	119
	120	gfs2_glock_dq_uninit(&gh);
	121
	122	if (!error && !*name)
	123	error = -ENOENT;
	124
	125	return error;
	126	}
	127
	128	static struct dentry gfs2_get_parent(struct dentry child)
	129	{
71b86f56	130	struct qstr dotdot;
b3b94faa	131	struct dentry *dentry;
b3b94faa	132
7b625361	133	/*
44003728 CH	134	* XXX(hch): it would be a good idea to keep this around as a
44003728 CH	135	* static variable.
7b625361	136	*/
44003728	137	gfs2_str2qstr(&dotdot, "..");
b3b94faa	138
44003728 CH	139	dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
	140	if (!IS_ERR(dentry))
	141	dentry->d_op = &gfs2_dops;
b3b94faa DT	142	return dentry;
	143	}
	144
34c0d154	145	static struct dentry gfs2_get_dentry(struct super_block sb,
acf7e244	146	struct gfs2_inum_host *inum)
b3b94faa	147	{
5c676f6d	148	struct gfs2_sbd *sdp = sb->s_fs_info;
acf7e244	149	struct gfs2_holder i_gh;
b3b94faa DT	150	struct inode *inode;
	151	struct dentry *dentry;
	152	int error;
	153
dbb7cae2	154	inode = gfs2_ilookup(sb, inum->no_addr);
b3b94faa	155	if (inode) {
dbb7cae2	156	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
b3b94faa DT	157	iput(inode);
	158	return ERR_PTR(-ESTALE);
	159	}
	160	goto out_inode;
	161	}
	162
feaa7bba	163	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
1c0f4872	164	LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
b3b94faa DT	165	if (error)
	166	return ERR_PTR(error);
	167
acf7e244	168	error = gfs2_check_blk_type(sdp, inum->no_addr, GFS2_BLKST_DINODE);
b3b94faa DT	169	if (error)
	170	goto fail;
	171
acf7e244	172	inode = gfs2_inode_lookup(sb, DT_UNKNOWN, inum->no_addr, 0, 0);
feaa7bba SW	173	if (IS_ERR(inode)) {
feaa7bba SW	174	error = PTR_ERR(inode);
b3b94faa	175	goto fail;
feaa7bba	176	}
b3b94faa	177
feaa7bba	178	error = gfs2_inode_refresh(GFS2_I(inode));
b3b94faa	179	if (error) {
feaa7bba	180	iput(inode);
b3b94faa DT	181	goto fail;
b3b94faa DT	182	}
35dcc52e WC	183
	184	/* Pick up the works we bypass in gfs2_inode_lookup */
	185	if (inode->i_state & I_NEW)
	186	gfs2_set_iop(inode);
	187
dbb7cae2 SW	188	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
	189	iput(inode);
	190	goto fail;
	191	}
b3b94faa	192
b3b94faa	193	error = -EIO;
383f01fb	194	if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) {
feaa7bba	195	iput(inode);
b3b94faa DT	196	goto fail;
	197	}
	198
	199	gfs2_glock_dq_uninit(&i_gh);
	200
feaa7bba	201	out_inode:
44003728 CH	202	dentry = d_obtain_alias(inode);
	203	if (!IS_ERR(dentry))
	204	dentry->d_op = &gfs2_dops;
b3b94faa	205	return dentry;
feaa7bba	206	fail:
b3b94faa DT	207	gfs2_glock_dq_uninit(&i_gh);
	208	return ERR_PTR(error);
	209	}
	210
34c0d154 CH	211	static struct dentry gfs2_fh_to_dentry(struct super_block sb, struct fid *fid,
	212	int fh_len, int fh_type)
	213	{
	214	struct gfs2_inum_host this;
	215	__be32 fh = (__force __be32 )fid->raw;
	216
	217	switch (fh_type) {
	218	case GFS2_SMALL_FH_SIZE:
	219	case GFS2_LARGE_FH_SIZE:
	220	case GFS2_OLD_FH_SIZE:
	221	this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
	222	this.no_formal_ino \|= be32_to_cpu(fh[1]);
	223	this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
	224	this.no_addr \|= be32_to_cpu(fh[3]);
	225	return gfs2_get_dentry(sb, &this);
	226	default:
	227	return NULL;
	228	}
	229	}
	230
	231	static struct dentry gfs2_fh_to_parent(struct super_block sb, struct fid *fid,
	232	int fh_len, int fh_type)
	233	{
	234	struct gfs2_inum_host parent;
	235	__be32 fh = (__force __be32 )fid->raw;
	236
	237	switch (fh_type) {
	238	case GFS2_LARGE_FH_SIZE:
	239	case GFS2_OLD_FH_SIZE:
	240	parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
	241	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
	242	parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
	243	parent.no_addr \|= be32_to_cpu(fh[7]);
	244	return gfs2_get_dentry(sb, &parent);
	245	default:
	246	return NULL;
	247	}
	248	}
	249
39655164	250	const struct export_operations gfs2_export_ops = {
b3b94faa	251	.encode_fh = gfs2_encode_fh,
34c0d154 CH	252	.fh_to_dentry = gfs2_fh_to_dentry,
34c0d154 CH	253	.fh_to_parent = gfs2_fh_to_parent,
b3b94faa DT	254	.get_name = gfs2_get_name,
b3b94faa DT	255	.get_parent = gfs2_get_parent,
b3b94faa DT	256	};
b3b94faa DT	257