[net-next-2.6.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/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_export.h"
#include "rgrp.h"
#include "util.h"

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_fh_obj fh_obj;
	struct gfs2_inum_host *this, parent;

	if (fh_type != fh_len)
		return NULL;

	this 		= &fh_obj.this;
	fh_obj.imode 	= DT_UNKNOWN;
	memset(&parent, 0, sizeof(struct gfs2_inum));

	switch (fh_type) {
	case GFS2_LARGE_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]);
		fh_obj.imode = be32_to_cpu(fh[8]);
	case GFS2_SMALL_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]);
		break;
	default:
		return NULL;
	}

	return gfs2_export_ops.find_exported_dentry(sb, &fh_obj, &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_num.no_formal_ino >> 32);
	fh[1] = cpu_to_be32(ip->i_num.no_formal_ino & 0xFFFFFFFF);
	fh[2] = cpu_to_be32(ip->i_num.no_addr >> 32);
	fh[3] = cpu_to_be32(ip->i_num.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_num.no_formal_ino >> 32);
	fh[5] = cpu_to_be32(ip->i_num.no_formal_ino & 0xFFFFFFFF);
	fh[6] = cpu_to_be32(ip->i_num.no_addr >> 32);
	fh[7] = cpu_to_be32(ip->i_num.no_addr & 0xFFFFFFFF);

	fh[8]  = cpu_to_be32(inode->i_mode);
	fh[9]  = 0;	/* pad to double word */
	*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 = 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(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_fh_obj *fh_obj = (struct gfs2_fh_obj *)inum_obj;
	struct gfs2_inum_host *inum = &fh_obj->this;
	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);
	if (inode) {
		if (GFS2_I(inode)->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, &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, inum, fh_obj->imode);
	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;
	}

	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,
};
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>
5c676f6d	14	#include <linux/gfs2_ondisk.h>
71b86f56	15	#include <linux/crc32.h>
7d308590	16	#include <linux/lm_interface.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"
70831465	24	#include "ops_dentry.h"
b3b94faa DT	25	#include "ops_export.h"
b3b94faa DT	26	#include "rgrp.h"
c752666c	27	#include "util.h"
b3b94faa DT	28
b3b94faa DT	29	static struct dentry gfs2_decode_fh(struct super_block sb,
b44b84d7	30	__u32 *p,
b3b94faa DT	31	int fh_len,
	32	int fh_type,
	33	int (acceptable)(void context,
	34	struct dentry *dentry),
	35	void *context)
	36	{
b44b84d7	37	__be32 fh = (__force __be32 )p;
2eb168ca	38	struct gfs2_fh_obj fh_obj;
629a21e7	39	struct gfs2_inum_host *this, parent;
b3b94faa	40
b3b94faa DT	41	if (fh_type != fh_len)
	42	return NULL;
	43
2eb168ca WC	44	this = &fh_obj.this;
2eb168ca WC	45	fh_obj.imode = DT_UNKNOWN;
b3b94faa DT	46	memset(&parent, 0, sizeof(struct gfs2_inum));
	47
	48	switch (fh_type) {
5acd3967	49	case GFS2_LARGE_FH_SIZE:
cd915493	50	parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
b3b94faa	51	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
cd915493	52	parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
b3b94faa	53	parent.no_addr \|= be32_to_cpu(fh[7]);
2eb168ca	54	fh_obj.imode = be32_to_cpu(fh[8]);
5acd3967	55	case GFS2_SMALL_FH_SIZE:
cd915493	56	this->no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
2eb168ca	57	this->no_formal_ino \|= be32_to_cpu(fh[1]);
cd915493	58	this->no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
2eb168ca	59	this->no_addr \|= be32_to_cpu(fh[3]);
b3b94faa DT	60	break;
	61	default:
	62	return NULL;
	63	}
	64
2eb168ca	65	return gfs2_export_ops.find_exported_dentry(sb, &fh_obj, &parent,
b3b94faa DT	66	acceptable, context);
	67	}
	68
b44b84d7	69	static int gfs2_encode_fh(struct dentry dentry, __u32 p, int *len,
b3b94faa DT	70	int connectable)
b3b94faa DT	71	{
b44b84d7	72	__be32 fh = (__force __be32 )p;
b3b94faa	73	struct inode *inode = dentry->d_inode;
c9fd4307	74	struct super_block *sb = inode->i_sb;
feaa7bba	75	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa	76
5acd3967 SW	77	if (*len < GFS2_SMALL_FH_SIZE \|\|
5acd3967 SW	78	(connectable && *len < GFS2_LARGE_FH_SIZE))
b3b94faa DT	79	return 255;
b3b94faa DT	80
b44b84d7 AV	81	fh[0] = cpu_to_be32(ip->i_num.no_formal_ino >> 32);
	82	fh[1] = cpu_to_be32(ip->i_num.no_formal_ino & 0xFFFFFFFF);
	83	fh[2] = cpu_to_be32(ip->i_num.no_addr >> 32);
	84	fh[3] = cpu_to_be32(ip->i_num.no_addr & 0xFFFFFFFF);
5acd3967	85	*len = GFS2_SMALL_FH_SIZE;
b3b94faa	86
c9fd4307	87	if (!connectable \|\| inode == sb->s_root->d_inode)
b3b94faa DT	88	return *len;
	89
	90	spin_lock(&dentry->d_lock);
	91	inode = dentry->d_parent->d_inode;
feaa7bba SW	92	ip = GFS2_I(inode);
feaa7bba SW	93	igrab(inode);
b3b94faa DT	94	spin_unlock(&dentry->d_lock);
b3b94faa DT	95
b44b84d7 AV	96	fh[4] = cpu_to_be32(ip->i_num.no_formal_ino >> 32);
	97	fh[5] = cpu_to_be32(ip->i_num.no_formal_ino & 0xFFFFFFFF);
	98	fh[6] = cpu_to_be32(ip->i_num.no_addr >> 32);
	99	fh[7] = cpu_to_be32(ip->i_num.no_addr & 0xFFFFFFFF);
2eb168ca WC	100
	101	fh[8] = cpu_to_be32(inode->i_mode);
	102	fh[9] = 0; /* pad to double word */
5acd3967	103	*len = GFS2_LARGE_FH_SIZE;
b3b94faa	104
feaa7bba	105	iput(inode);
b3b94faa DT	106
	107	return *len;
	108	}
	109
	110	struct get_name_filldir {
629a21e7	111	struct gfs2_inum_host inum;
b3b94faa DT	112	char *name;
	113	};
	114
3699e3a4 SW	115	static int get_name_filldir(void opaque, const char name, int length,
3699e3a4 SW	116	loff_t offset, u64 inum, unsigned int type)
b3b94faa	117	{
3699e3a4	118	struct get_name_filldir *gnfd = opaque;
b3b94faa	119
3699e3a4	120	if (inum != gnfd->inum.no_addr)
b3b94faa DT	121	return 0;
	122
	123	memcpy(gnfd->name, name, length);
	124	gnfd->name[length] = 0;
	125
	126	return 1;
	127	}
	128
	129	static int gfs2_get_name(struct dentry parent, char name,
	130	struct dentry *child)
	131	{
	132	struct inode *dir = parent->d_inode;
	133	struct inode *inode = child->d_inode;
	134	struct gfs2_inode dip, ip;
	135	struct get_name_filldir gnfd;
	136	struct gfs2_holder gh;
cd915493	137	u64 offset = 0;
b3b94faa DT	138	int error;
	139
	140	if (!dir)
	141	return -EINVAL;
	142
b3b94faa DT	143	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	144	return -EINVAL;
	145
feaa7bba SW	146	dip = GFS2_I(dir);
feaa7bba SW	147	ip = GFS2_I(inode);
b3b94faa DT	148
	149	*name = 0;
	150	gnfd.inum = ip->i_num;
	151	gnfd.name = name;
	152
	153	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	154	if (error)
	155	return error;
	156
71b86f56	157	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
b3b94faa DT	158
	159	gfs2_glock_dq_uninit(&gh);
	160
	161	if (!error && !*name)
	162	error = -ENOENT;
	163
	164	return error;
	165	}
	166
	167	static struct dentry gfs2_get_parent(struct dentry child)
	168	{
71b86f56	169	struct qstr dotdot;
b3b94faa DT	170	struct inode *inode;
b3b94faa DT	171	struct dentry *dentry;
b3b94faa	172
71b86f56	173	gfs2_str2qstr(&dotdot, "..");
c752666c SW	174	inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
	175
	176	if (!inode)
	177	return ERR_PTR(-ENOENT);
7b625361 SW	178	/*
	179	* In case of an error, @inode carries the error value, and we
	180	* have to return that as a(n invalid) pointer to dentry.
	181	*/
c752666c SW	182	if (IS_ERR(inode))
c752666c SW	183	return ERR_PTR(PTR_ERR(inode));
b3b94faa	184
b3b94faa DT	185	dentry = d_alloc_anon(inode);
	186	if (!dentry) {
	187	iput(inode);
	188	return ERR_PTR(-ENOMEM);
	189	}
	190
70831465	191	dentry->d_op = &gfs2_dops;
b3b94faa DT	192	return dentry;
	193	}
	194
2eb168ca	195	static struct dentry gfs2_get_dentry(struct super_block sb, void *inum_obj)
b3b94faa	196	{
5c676f6d	197	struct gfs2_sbd *sdp = sb->s_fs_info;
2eb168ca	198	struct gfs2_fh_obj fh_obj = (struct gfs2_fh_obj )inum_obj;
629a21e7	199	struct gfs2_inum_host *inum = &fh_obj->this;
b3b94faa DT	200	struct gfs2_holder i_gh, ri_gh, rgd_gh;
b3b94faa DT	201	struct gfs2_rgrpd *rgd;
b3b94faa DT	202	struct inode *inode;
	203	struct dentry *dentry;
	204	int error;
	205
b3b94faa DT	206	/* System files? */
b3b94faa DT	207
feaa7bba	208	inode = gfs2_ilookup(sb, inum);
b3b94faa	209	if (inode) {
feaa7bba	210	if (GFS2_I(inode)->i_num.no_formal_ino != inum->no_formal_ino) {
b3b94faa DT	211	iput(inode);
	212	return ERR_PTR(-ESTALE);
	213	}
	214	goto out_inode;
	215	}
	216
feaa7bba	217	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
1c0f4872	218	LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
b3b94faa DT	219	if (error)
	220	return ERR_PTR(error);
	221
b3b94faa DT	222	error = gfs2_rindex_hold(sdp, &ri_gh);
	223	if (error)
	224	goto fail;
	225
	226	error = -EINVAL;
	227	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	228	if (!rgd)
	229	goto fail_rindex;
	230
	231	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	232	if (error)
	233	goto fail_rindex;
	234
	235	error = -ESTALE;
	236	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	237	goto fail_rgd;
	238
	239	gfs2_glock_dq_uninit(&rgd_gh);
	240	gfs2_glock_dq_uninit(&ri_gh);
	241
2eb168ca	242	inode = gfs2_inode_lookup(sb, inum, fh_obj->imode);
feaa7bba SW	243	if (!inode)
	244	goto fail;
	245	if (IS_ERR(inode)) {
	246	error = PTR_ERR(inode);
b3b94faa	247	goto fail;
feaa7bba	248	}
b3b94faa	249
feaa7bba	250	error = gfs2_inode_refresh(GFS2_I(inode));
b3b94faa	251	if (error) {
feaa7bba	252	iput(inode);
b3b94faa DT	253	goto fail;
	254	}
	255
b3b94faa	256	error = -EIO;
feaa7bba SW	257	if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
feaa7bba SW	258	iput(inode);
b3b94faa DT	259	goto fail;
	260	}
	261
	262	gfs2_glock_dq_uninit(&i_gh);
	263
feaa7bba	264	out_inode:
b3b94faa DT	265	dentry = d_alloc_anon(inode);
	266	if (!dentry) {
	267	iput(inode);
	268	return ERR_PTR(-ENOMEM);
	269	}
	270
70831465	271	dentry->d_op = &gfs2_dops;
b3b94faa DT	272	return dentry;
b3b94faa DT	273
feaa7bba	274	fail_rgd:
b3b94faa DT	275	gfs2_glock_dq_uninit(&rgd_gh);
b3b94faa DT	276
feaa7bba	277	fail_rindex:
b3b94faa DT	278	gfs2_glock_dq_uninit(&ri_gh);
b3b94faa DT	279
feaa7bba	280	fail:
b3b94faa DT	281	gfs2_glock_dq_uninit(&i_gh);
	282	return ERR_PTR(error);
	283	}
	284
	285	struct export_operations gfs2_export_ops = {
	286	.decode_fh = gfs2_decode_fh,
	287	.encode_fh = gfs2_encode_fh,
	288	.get_name = gfs2_get_name,
	289	.get_parent = gfs2_get_parent,
	290	.get_dentry = gfs2_get_dentry,
	291	};
	292