[linux-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/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 <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_export.h"
#include "rgrp.h"
#include "util.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_fh_obj fh_obj;
	struct gfs2_inum *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 *fh, int *len,
			  int connectable)
{
	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] = 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 = 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] = 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]);

	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 inum;
	char *name;
};

static int get_name_filldir(void *opaque, const char *name, unsigned int length,
			    u64 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;
	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);
	}

	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 *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 | GL_LOCAL_EXCL,
				  &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);
	}

	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	*/
	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>
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"
	25	#include "ops_export.h"
	26	#include "rgrp.h"
c752666c	27	#include "util.h"
b3b94faa DT	28
	29	static struct dentry gfs2_decode_fh(struct super_block sb,
	30	__u32 *fh,
	31	int fh_len,
	32	int fh_type,
	33	int (acceptable)(void context,
	34	struct dentry *dentry),
	35	void *context)
	36	{
2eb168ca WC	37	struct gfs2_fh_obj fh_obj;
2eb168ca WC	38	struct gfs2_inum *this, parent;
b3b94faa	39
b3b94faa DT	40	if (fh_type != fh_len)
	41	return NULL;
	42
2eb168ca WC	43	this = &fh_obj.this;
2eb168ca WC	44	fh_obj.imode = DT_UNKNOWN;
b3b94faa DT	45	memset(&parent, 0, sizeof(struct gfs2_inum));
	46
	47	switch (fh_type) {
5acd3967	48	case GFS2_LARGE_FH_SIZE:
cd915493	49	parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
b3b94faa	50	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
cd915493	51	parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
b3b94faa	52	parent.no_addr \|= be32_to_cpu(fh[7]);
2eb168ca	53	fh_obj.imode = be32_to_cpu(fh[8]);
5acd3967	54	case GFS2_SMALL_FH_SIZE:
cd915493	55	this->no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
2eb168ca	56	this->no_formal_ino \|= be32_to_cpu(fh[1]);
cd915493	57	this->no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
2eb168ca	58	this->no_addr \|= be32_to_cpu(fh[3]);
b3b94faa DT	59	break;
	60	default:
	61	return NULL;
	62	}
	63
2eb168ca	64	return gfs2_export_ops.find_exported_dentry(sb, &fh_obj, &parent,
b3b94faa DT	65	acceptable, context);
	66	}
	67
	68	static int gfs2_encode_fh(struct dentry dentry, __u32 fh, int *len,
	69	int connectable)
	70	{
	71	struct inode *inode = dentry->d_inode;
c9fd4307	72	struct super_block *sb = inode->i_sb;
feaa7bba	73	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa	74
5acd3967 SW	75	if (*len < GFS2_SMALL_FH_SIZE \|\|
5acd3967 SW	76	(connectable && *len < GFS2_LARGE_FH_SIZE))
b3b94faa DT	77	return 255;
	78
	79	fh[0] = ip->i_num.no_formal_ino >> 32;
	80	fh[0] = cpu_to_be32(fh[0]);
	81	fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	82	fh[1] = cpu_to_be32(fh[1]);
	83	fh[2] = ip->i_num.no_addr >> 32;
	84	fh[2] = cpu_to_be32(fh[2]);
	85	fh[3] = ip->i_num.no_addr & 0xFFFFFFFF;
	86	fh[3] = cpu_to_be32(fh[3]);
5acd3967	87	*len = GFS2_SMALL_FH_SIZE;
b3b94faa	88
c9fd4307	89	if (!connectable \|\| inode == sb->s_root->d_inode)
b3b94faa DT	90	return *len;
	91
	92	spin_lock(&dentry->d_lock);
	93	inode = dentry->d_parent->d_inode;
feaa7bba SW	94	ip = GFS2_I(inode);
feaa7bba SW	95	igrab(inode);
b3b94faa DT	96	spin_unlock(&dentry->d_lock);
	97
	98	fh[4] = ip->i_num.no_formal_ino >> 32;
	99	fh[4] = cpu_to_be32(fh[4]);
	100	fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
	101	fh[5] = cpu_to_be32(fh[5]);
	102	fh[6] = ip->i_num.no_addr >> 32;
	103	fh[6] = cpu_to_be32(fh[6]);
	104	fh[7] = ip->i_num.no_addr & 0xFFFFFFFF;
	105	fh[7] = cpu_to_be32(fh[7]);
2eb168ca WC	106
	107	fh[8] = cpu_to_be32(inode->i_mode);
	108	fh[9] = 0; /* pad to double word */
5acd3967	109	*len = GFS2_LARGE_FH_SIZE;
b3b94faa	110
feaa7bba	111	iput(inode);
b3b94faa DT	112
	113	return *len;
	114	}
	115
	116	struct get_name_filldir {
	117	struct gfs2_inum inum;
	118	char *name;
	119	};
	120
	121	static int get_name_filldir(void opaque, const char name, unsigned int length,
cd915493	122	u64 offset, struct gfs2_inum *inum,
b3b94faa DT	123	unsigned int type)
	124	{
	125	struct get_name_filldir gnfd = (struct get_name_filldir )opaque;
	126
	127	if (!gfs2_inum_equal(inum, &gnfd->inum))
	128	return 0;
	129
	130	memcpy(gnfd->name, name, length);
	131	gnfd->name[length] = 0;
	132
	133	return 1;
	134	}
	135
	136	static int gfs2_get_name(struct dentry parent, char name,
	137	struct dentry *child)
	138	{
	139	struct inode *dir = parent->d_inode;
	140	struct inode *inode = child->d_inode;
	141	struct gfs2_inode dip, ip;
	142	struct get_name_filldir gnfd;
	143	struct gfs2_holder gh;
cd915493	144	u64 offset = 0;
b3b94faa DT	145	int error;
	146
	147	if (!dir)
	148	return -EINVAL;
	149
b3b94faa DT	150	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	151	return -EINVAL;
	152
feaa7bba SW	153	dip = GFS2_I(dir);
feaa7bba SW	154	ip = GFS2_I(inode);
b3b94faa DT	155
	156	*name = 0;
	157	gnfd.inum = ip->i_num;
	158	gnfd.name = name;
	159
	160	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	161	if (error)
	162	return error;
	163
71b86f56	164	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
b3b94faa DT	165
	166	gfs2_glock_dq_uninit(&gh);
	167
	168	if (!error && !*name)
	169	error = -ENOENT;
	170
	171	return error;
	172	}
	173
	174	static struct dentry gfs2_get_parent(struct dentry child)
	175	{
71b86f56	176	struct qstr dotdot;
b3b94faa DT	177	struct inode *inode;
b3b94faa DT	178	struct dentry *dentry;
b3b94faa	179
71b86f56	180	gfs2_str2qstr(&dotdot, "..");
c752666c SW	181	inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
	182
	183	if (!inode)
	184	return ERR_PTR(-ENOENT);
7b625361 SW	185	/*
	186	* In case of an error, @inode carries the error value, and we
	187	* have to return that as a(n invalid) pointer to dentry.
	188	*/
c752666c SW	189	if (IS_ERR(inode))
c752666c SW	190	return ERR_PTR(PTR_ERR(inode));
b3b94faa	191
b3b94faa DT	192	dentry = d_alloc_anon(inode);
	193	if (!dentry) {
	194	iput(inode);
	195	return ERR_PTR(-ENOMEM);
	196	}
	197
	198	return dentry;
	199	}
	200
2eb168ca	201	static struct dentry gfs2_get_dentry(struct super_block sb, void *inum_obj)
b3b94faa	202	{
5c676f6d	203	struct gfs2_sbd *sdp = sb->s_fs_info;
2eb168ca WC	204	struct gfs2_fh_obj fh_obj = (struct gfs2_fh_obj )inum_obj;
2eb168ca WC	205	struct gfs2_inum *inum = &fh_obj->this;
b3b94faa DT	206	struct gfs2_holder i_gh, ri_gh, rgd_gh;
b3b94faa DT	207	struct gfs2_rgrpd *rgd;
b3b94faa DT	208	struct inode *inode;
	209	struct dentry *dentry;
	210	int error;
	211
b3b94faa DT	212	/* System files? */
b3b94faa DT	213
feaa7bba	214	inode = gfs2_ilookup(sb, inum);
b3b94faa	215	if (inode) {
feaa7bba	216	if (GFS2_I(inode)->i_num.no_formal_ino != inum->no_formal_ino) {
b3b94faa DT	217	iput(inode);
	218	return ERR_PTR(-ESTALE);
	219	}
	220	goto out_inode;
	221	}
	222
feaa7bba	223	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
b3b94faa DT	224	LM_ST_SHARED, LM_FLAG_ANY \| GL_LOCAL_EXCL,
	225	&i_gh);
	226	if (error)
	227	return ERR_PTR(error);
	228
b3b94faa DT	229	error = gfs2_rindex_hold(sdp, &ri_gh);
	230	if (error)
	231	goto fail;
	232
	233	error = -EINVAL;
	234	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	235	if (!rgd)
	236	goto fail_rindex;
	237
	238	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	239	if (error)
	240	goto fail_rindex;
	241
	242	error = -ESTALE;
	243	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	244	goto fail_rgd;
	245
	246	gfs2_glock_dq_uninit(&rgd_gh);
	247	gfs2_glock_dq_uninit(&ri_gh);
	248
2eb168ca	249	inode = gfs2_inode_lookup(sb, inum, fh_obj->imode);
feaa7bba SW	250	if (!inode)
	251	goto fail;
	252	if (IS_ERR(inode)) {
	253	error = PTR_ERR(inode);
b3b94faa	254	goto fail;
feaa7bba	255	}
b3b94faa	256
feaa7bba	257	error = gfs2_inode_refresh(GFS2_I(inode));
b3b94faa	258	if (error) {
feaa7bba	259	iput(inode);
b3b94faa DT	260	goto fail;
	261	}
	262
b3b94faa	263	error = -EIO;
feaa7bba SW	264	if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
feaa7bba SW	265	iput(inode);
b3b94faa DT	266	goto fail;
	267	}
	268
	269	gfs2_glock_dq_uninit(&i_gh);
	270
feaa7bba	271	out_inode:
b3b94faa DT	272	dentry = d_alloc_anon(inode);
	273	if (!dentry) {
	274	iput(inode);
	275	return ERR_PTR(-ENOMEM);
	276	}
	277
	278	return dentry;
	279
feaa7bba	280	fail_rgd:
b3b94faa DT	281	gfs2_glock_dq_uninit(&rgd_gh);
b3b94faa DT	282
feaa7bba	283	fail_rindex:
b3b94faa DT	284	gfs2_glock_dq_uninit(&ri_gh);
b3b94faa DT	285
feaa7bba	286	fail:
b3b94faa DT	287	gfs2_glock_dq_uninit(&i_gh);
	288	return ERR_PTR(error);
	289	}
	290
	291	struct export_operations gfs2_export_ops = {
	292	.decode_fh = gfs2_decode_fh,
	293	.encode_fh = gfs2_encode_fh,
	294	.get_name = gfs2_get_name,
	295	.get_parent = gfs2_get_parent,
	296	.get_dentry = gfs2_get_dentry,
	297	};
	298