[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_fstype.h"
#include "rgrp.h"
#include "util.h"

#define GFS2_SMALL_FH_SIZE 4
#define GFS2_LARGE_FH_SIZE 8

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:
		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,
};
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"
bb8d8a6f	25	#include "ops_fstype.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
bb8d8a6f	31
b3b94faa	32	static struct dentry gfs2_decode_fh(struct super_block sb,
b44b84d7	33	__u32 *p,
b3b94faa DT	34	int fh_len,
	35	int fh_type,
	36	int (acceptable)(void context,
	37	struct dentry *dentry),
	38	void *context)
	39	{
b44b84d7	40	__be32 fh = (__force __be32 )p;
35dcc52e	41	struct gfs2_inum_host inum, parent;
b3b94faa	42
b3b94faa DT	43	memset(&parent, 0, sizeof(struct gfs2_inum));
b3b94faa DT	44
a7d2b2bd	45	switch (fh_len) {
5acd3967	46	case GFS2_LARGE_FH_SIZE:
cd915493	47	parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
b3b94faa	48	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
cd915493	49	parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
b3b94faa	50	parent.no_addr \|= be32_to_cpu(fh[7]);
5acd3967	51	case GFS2_SMALL_FH_SIZE:
35dcc52e WC	52	inum.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
	53	inum.no_formal_ino \|= be32_to_cpu(fh[1]);
	54	inum.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
	55	inum.no_addr \|= be32_to_cpu(fh[3]);
b3b94faa DT	56	break;
	57	default:
	58	return NULL;
	59	}
	60
35dcc52e	61	return gfs2_export_ops.find_exported_dentry(sb, &inum, &parent,
b3b94faa DT	62	acceptable, context);
	63	}
	64
b44b84d7	65	static int gfs2_encode_fh(struct dentry dentry, __u32 p, int *len,
b3b94faa DT	66	int connectable)
b3b94faa DT	67	{
b44b84d7	68	__be32 fh = (__force __be32 )p;
b3b94faa	69	struct inode *inode = dentry->d_inode;
c9fd4307	70	struct super_block *sb = inode->i_sb;
feaa7bba	71	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa	72
5acd3967 SW	73	if (*len < GFS2_SMALL_FH_SIZE \|\|
5acd3967 SW	74	(connectable && *len < GFS2_LARGE_FH_SIZE))
b3b94faa DT	75	return 255;
b3b94faa DT	76
dbb7cae2 SW	77	fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	78	fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	79	fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
	80	fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
5acd3967	81	*len = GFS2_SMALL_FH_SIZE;
b3b94faa	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;
feaa7bba SW	88	ip = GFS2_I(inode);
feaa7bba SW	89	igrab(inode);
b3b94faa DT	90	spin_unlock(&dentry->d_lock);
b3b94faa DT	91
dbb7cae2 SW	92	fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
	93	fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
	94	fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
	95	fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
5acd3967	96	*len = GFS2_LARGE_FH_SIZE;
b3b94faa	97
feaa7bba	98	iput(inode);
b3b94faa DT	99
	100	return *len;
	101	}
	102
	103	struct get_name_filldir {
629a21e7	104	struct gfs2_inum_host inum;
b3b94faa DT	105	char *name;
	106	};
	107
3699e3a4 SW	108	static int get_name_filldir(void opaque, const char name, int length,
3699e3a4 SW	109	loff_t offset, u64 inum, unsigned int type)
b3b94faa	110	{
3699e3a4	111	struct get_name_filldir *gnfd = opaque;
b3b94faa	112
3699e3a4	113	if (inum != gnfd->inum.no_addr)
b3b94faa DT	114	return 0;
	115
	116	memcpy(gnfd->name, name, length);
	117	gnfd->name[length] = 0;
	118
	119	return 1;
	120	}
	121
	122	static int gfs2_get_name(struct dentry parent, char name,
	123	struct dentry *child)
	124	{
	125	struct inode *dir = parent->d_inode;
	126	struct inode *inode = child->d_inode;
	127	struct gfs2_inode dip, ip;
	128	struct get_name_filldir gnfd;
	129	struct gfs2_holder gh;
cd915493	130	u64 offset = 0;
b3b94faa DT	131	int error;
	132
	133	if (!dir)
	134	return -EINVAL;
	135
b3b94faa DT	136	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	137	return -EINVAL;
	138
feaa7bba SW	139	dip = GFS2_I(dir);
feaa7bba SW	140	ip = GFS2_I(inode);
b3b94faa DT	141
b3b94faa DT	142	*name = 0;
dbb7cae2 SW	143	gnfd.inum.no_addr = ip->i_no_addr;
dbb7cae2 SW	144	gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
b3b94faa DT	145	gnfd.name = name;
	146
	147	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	148	if (error)
	149	return error;
	150
71b86f56	151	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
b3b94faa DT	152
	153	gfs2_glock_dq_uninit(&gh);
	154
	155	if (!error && !*name)
	156	error = -ENOENT;
	157
	158	return error;
	159	}
	160
	161	static struct dentry gfs2_get_parent(struct dentry child)
	162	{
71b86f56	163	struct qstr dotdot;
b3b94faa DT	164	struct inode *inode;
b3b94faa DT	165	struct dentry *dentry;
b3b94faa	166
71b86f56	167	gfs2_str2qstr(&dotdot, "..");
c752666c SW	168	inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
	169
	170	if (!inode)
	171	return ERR_PTR(-ENOENT);
7b625361 SW	172	/*
	173	* In case of an error, @inode carries the error value, and we
	174	* have to return that as a(n invalid) pointer to dentry.
	175	*/
c752666c SW	176	if (IS_ERR(inode))
c752666c SW	177	return ERR_PTR(PTR_ERR(inode));
b3b94faa	178
b3b94faa DT	179	dentry = d_alloc_anon(inode);
	180	if (!dentry) {
	181	iput(inode);
	182	return ERR_PTR(-ENOMEM);
	183	}
	184
70831465	185	dentry->d_op = &gfs2_dops;
b3b94faa DT	186	return dentry;
	187	}
	188
2eb168ca	189	static struct dentry gfs2_get_dentry(struct super_block sb, void *inum_obj)
b3b94faa	190	{
5c676f6d	191	struct gfs2_sbd *sdp = sb->s_fs_info;
35dcc52e	192	struct gfs2_inum_host *inum = inum_obj;
b3b94faa DT	193	struct gfs2_holder i_gh, ri_gh, rgd_gh;
b3b94faa DT	194	struct gfs2_rgrpd *rgd;
b3b94faa DT	195	struct inode *inode;
	196	struct dentry *dentry;
	197	int error;
	198
b3b94faa DT	199	/* System files? */
b3b94faa DT	200
dbb7cae2	201	inode = gfs2_ilookup(sb, inum->no_addr);
b3b94faa	202	if (inode) {
dbb7cae2	203	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
b3b94faa DT	204	iput(inode);
	205	return ERR_PTR(-ESTALE);
	206	}
	207	goto out_inode;
	208	}
	209
feaa7bba	210	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
1c0f4872	211	LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
b3b94faa DT	212	if (error)
	213	return ERR_PTR(error);
	214
b3b94faa DT	215	error = gfs2_rindex_hold(sdp, &ri_gh);
	216	if (error)
	217	goto fail;
	218
	219	error = -EINVAL;
	220	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	221	if (!rgd)
	222	goto fail_rindex;
	223
	224	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	225	if (error)
	226	goto fail_rindex;
	227
	228	error = -ESTALE;
	229	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	230	goto fail_rgd;
	231
	232	gfs2_glock_dq_uninit(&rgd_gh);
	233	gfs2_glock_dq_uninit(&ri_gh);
	234
35dcc52e	235	inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
bb9bcf06	236	inum->no_addr,
35dcc52e	237	0);
feaa7bba SW	238	if (!inode)
	239	goto fail;
	240	if (IS_ERR(inode)) {
	241	error = PTR_ERR(inode);
b3b94faa	242	goto fail;
feaa7bba	243	}
b3b94faa	244
feaa7bba	245	error = gfs2_inode_refresh(GFS2_I(inode));
b3b94faa	246	if (error) {
feaa7bba	247	iput(inode);
b3b94faa DT	248	goto fail;
b3b94faa DT	249	}
35dcc52e WC	250
	251	/* Pick up the works we bypass in gfs2_inode_lookup */
	252	if (inode->i_state & I_NEW)
	253	gfs2_set_iop(inode);
	254
dbb7cae2 SW	255	if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
	256	iput(inode);
	257	goto fail;
	258	}
b3b94faa	259
b3b94faa	260	error = -EIO;
feaa7bba SW	261	if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
feaa7bba SW	262	iput(inode);
b3b94faa DT	263	goto fail;
	264	}
	265
	266	gfs2_glock_dq_uninit(&i_gh);
	267
feaa7bba	268	out_inode:
b3b94faa DT	269	dentry = d_alloc_anon(inode);
	270	if (!dentry) {
	271	iput(inode);
	272	return ERR_PTR(-ENOMEM);
	273	}
	274
70831465	275	dentry->d_op = &gfs2_dops;
b3b94faa DT	276	return dentry;
b3b94faa DT	277
feaa7bba	278	fail_rgd:
b3b94faa DT	279	gfs2_glock_dq_uninit(&rgd_gh);
b3b94faa DT	280
feaa7bba	281	fail_rindex:
b3b94faa DT	282	gfs2_glock_dq_uninit(&ri_gh);
b3b94faa DT	283
feaa7bba	284	fail:
b3b94faa DT	285	gfs2_glock_dq_uninit(&i_gh);
	286	return ERR_PTR(error);
	287	}
	288
	289	struct export_operations gfs2_export_ops = {
	290	.decode_fh = gfs2_decode_fh,
	291	.encode_fh = gfs2_encode_fh,
	292	.get_name = gfs2_get_name,
	293	.get_parent = gfs2_get_parent,
	294	.get_dentry = gfs2_get_dentry,
	295	};
	296