[mirror_ubuntu-zesty-kernel.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_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, unsigned int length,
			    u64 offset, struct gfs2_inum_host *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);
	}

	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 | 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);
	}

	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	*/
	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"
70831465	25	#include "ops_dentry.h"
b3b94faa DT	26	#include "ops_export.h"
b3b94faa DT	27	#include "rgrp.h"
c752666c	28	#include "util.h"
b3b94faa DT	29
b3b94faa DT	30	static struct dentry gfs2_decode_fh(struct super_block sb,
b44b84d7	31	__u32 *p,
b3b94faa DT	32	int fh_len,
	33	int fh_type,
	34	int (acceptable)(void context,
	35	struct dentry *dentry),
	36	void *context)
	37	{
b44b84d7	38	__be32 fh = (__force __be32 )p;
2eb168ca	39	struct gfs2_fh_obj fh_obj;
629a21e7	40	struct gfs2_inum_host *this, parent;
b3b94faa	41
b3b94faa DT	42	if (fh_type != fh_len)
	43	return NULL;
	44
2eb168ca WC	45	this = &fh_obj.this;
2eb168ca WC	46	fh_obj.imode = DT_UNKNOWN;
b3b94faa DT	47	memset(&parent, 0, sizeof(struct gfs2_inum));
	48
	49	switch (fh_type) {
5acd3967	50	case GFS2_LARGE_FH_SIZE:
cd915493	51	parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
b3b94faa	52	parent.no_formal_ino \|= be32_to_cpu(fh[5]);
cd915493	53	parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
b3b94faa	54	parent.no_addr \|= be32_to_cpu(fh[7]);
2eb168ca	55	fh_obj.imode = be32_to_cpu(fh[8]);
5acd3967	56	case GFS2_SMALL_FH_SIZE:
cd915493	57	this->no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
2eb168ca	58	this->no_formal_ino \|= be32_to_cpu(fh[1]);
cd915493	59	this->no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
2eb168ca	60	this->no_addr \|= be32_to_cpu(fh[3]);
b3b94faa DT	61	break;
	62	default:
	63	return NULL;
	64	}
	65
2eb168ca	66	return gfs2_export_ops.find_exported_dentry(sb, &fh_obj, &parent,
b3b94faa DT	67	acceptable, context);
	68	}
	69
b44b84d7	70	static int gfs2_encode_fh(struct dentry dentry, __u32 p, int *len,
b3b94faa DT	71	int connectable)
b3b94faa DT	72	{
b44b84d7	73	__be32 fh = (__force __be32 )p;
b3b94faa	74	struct inode *inode = dentry->d_inode;
c9fd4307	75	struct super_block *sb = inode->i_sb;
feaa7bba	76	struct gfs2_inode *ip = GFS2_I(inode);
b3b94faa	77
5acd3967 SW	78	if (*len < GFS2_SMALL_FH_SIZE \|\|
5acd3967 SW	79	(connectable && *len < GFS2_LARGE_FH_SIZE))
b3b94faa DT	80	return 255;
b3b94faa DT	81
b44b84d7 AV	82	fh[0] = cpu_to_be32(ip->i_num.no_formal_ino >> 32);
	83	fh[1] = cpu_to_be32(ip->i_num.no_formal_ino & 0xFFFFFFFF);
	84	fh[2] = cpu_to_be32(ip->i_num.no_addr >> 32);
	85	fh[3] = cpu_to_be32(ip->i_num.no_addr & 0xFFFFFFFF);
5acd3967	86	*len = GFS2_SMALL_FH_SIZE;
b3b94faa	87
c9fd4307	88	if (!connectable \|\| inode == sb->s_root->d_inode)
b3b94faa DT	89	return *len;
	90
	91	spin_lock(&dentry->d_lock);
	92	inode = dentry->d_parent->d_inode;
feaa7bba SW	93	ip = GFS2_I(inode);
feaa7bba SW	94	igrab(inode);
b3b94faa DT	95	spin_unlock(&dentry->d_lock);
b3b94faa DT	96
b44b84d7 AV	97	fh[4] = cpu_to_be32(ip->i_num.no_formal_ino >> 32);
	98	fh[5] = cpu_to_be32(ip->i_num.no_formal_ino & 0xFFFFFFFF);
	99	fh[6] = cpu_to_be32(ip->i_num.no_addr >> 32);
	100	fh[7] = cpu_to_be32(ip->i_num.no_addr & 0xFFFFFFFF);
2eb168ca WC	101
	102	fh[8] = cpu_to_be32(inode->i_mode);
	103	fh[9] = 0; /* pad to double word */
5acd3967	104	*len = GFS2_LARGE_FH_SIZE;
b3b94faa	105
feaa7bba	106	iput(inode);
b3b94faa DT	107
	108	return *len;
	109	}
	110
	111	struct get_name_filldir {
629a21e7	112	struct gfs2_inum_host inum;
b3b94faa DT	113	char *name;
	114	};
	115
	116	static int get_name_filldir(void opaque, const char name, unsigned int length,
629a21e7	117	u64 offset, struct gfs2_inum_host *inum,
b3b94faa DT	118	unsigned int type)
	119	{
	120	struct get_name_filldir gnfd = (struct get_name_filldir )opaque;
	121
	122	if (!gfs2_inum_equal(inum, &gnfd->inum))
	123	return 0;
	124
	125	memcpy(gnfd->name, name, length);
	126	gnfd->name[length] = 0;
	127
	128	return 1;
	129	}
	130
	131	static int gfs2_get_name(struct dentry parent, char name,
	132	struct dentry *child)
	133	{
	134	struct inode *dir = parent->d_inode;
	135	struct inode *inode = child->d_inode;
	136	struct gfs2_inode dip, ip;
	137	struct get_name_filldir gnfd;
	138	struct gfs2_holder gh;
cd915493	139	u64 offset = 0;
b3b94faa DT	140	int error;
	141
	142	if (!dir)
	143	return -EINVAL;
	144
b3b94faa DT	145	if (!S_ISDIR(dir->i_mode) \|\| !inode)
	146	return -EINVAL;
	147
feaa7bba SW	148	dip = GFS2_I(dir);
feaa7bba SW	149	ip = GFS2_I(inode);
b3b94faa DT	150
	151	*name = 0;
	152	gnfd.inum = ip->i_num;
	153	gnfd.name = name;
	154
	155	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
	156	if (error)
	157	return error;
	158
71b86f56	159	error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
b3b94faa DT	160
	161	gfs2_glock_dq_uninit(&gh);
	162
	163	if (!error && !*name)
	164	error = -ENOENT;
	165
	166	return error;
	167	}
	168
	169	static struct dentry gfs2_get_parent(struct dentry child)
	170	{
71b86f56	171	struct qstr dotdot;
b3b94faa DT	172	struct inode *inode;
b3b94faa DT	173	struct dentry *dentry;
b3b94faa	174
71b86f56	175	gfs2_str2qstr(&dotdot, "..");
c752666c SW	176	inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
	177
	178	if (!inode)
	179	return ERR_PTR(-ENOENT);
7b625361 SW	180	/*
	181	* In case of an error, @inode carries the error value, and we
	182	* have to return that as a(n invalid) pointer to dentry.
	183	*/
c752666c SW	184	if (IS_ERR(inode))
c752666c SW	185	return ERR_PTR(PTR_ERR(inode));
b3b94faa	186
b3b94faa DT	187	dentry = d_alloc_anon(inode);
	188	if (!dentry) {
	189	iput(inode);
	190	return ERR_PTR(-ENOMEM);
	191	}
	192
70831465	193	dentry->d_op = &gfs2_dops;
b3b94faa DT	194	return dentry;
	195	}
	196
2eb168ca	197	static struct dentry gfs2_get_dentry(struct super_block sb, void *inum_obj)
b3b94faa	198	{
5c676f6d	199	struct gfs2_sbd *sdp = sb->s_fs_info;
2eb168ca	200	struct gfs2_fh_obj fh_obj = (struct gfs2_fh_obj )inum_obj;
629a21e7	201	struct gfs2_inum_host *inum = &fh_obj->this;
b3b94faa DT	202	struct gfs2_holder i_gh, ri_gh, rgd_gh;
b3b94faa DT	203	struct gfs2_rgrpd *rgd;
b3b94faa DT	204	struct inode *inode;
	205	struct dentry *dentry;
	206	int error;
	207
b3b94faa DT	208	/* System files? */
b3b94faa DT	209
feaa7bba	210	inode = gfs2_ilookup(sb, inum);
b3b94faa	211	if (inode) {
feaa7bba	212	if (GFS2_I(inode)->i_num.no_formal_ino != inum->no_formal_ino) {
b3b94faa DT	213	iput(inode);
	214	return ERR_PTR(-ESTALE);
	215	}
	216	goto out_inode;
	217	}
	218
feaa7bba	219	error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
b3b94faa DT	220	LM_ST_SHARED, LM_FLAG_ANY \| GL_LOCAL_EXCL,
	221	&i_gh);
	222	if (error)
	223	return ERR_PTR(error);
	224
b3b94faa DT	225	error = gfs2_rindex_hold(sdp, &ri_gh);
	226	if (error)
	227	goto fail;
	228
	229	error = -EINVAL;
	230	rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
	231	if (!rgd)
	232	goto fail_rindex;
	233
	234	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
	235	if (error)
	236	goto fail_rindex;
	237
	238	error = -ESTALE;
	239	if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
	240	goto fail_rgd;
	241
	242	gfs2_glock_dq_uninit(&rgd_gh);
	243	gfs2_glock_dq_uninit(&ri_gh);
	244
2eb168ca	245	inode = gfs2_inode_lookup(sb, inum, fh_obj->imode);
feaa7bba SW	246	if (!inode)
	247	goto fail;
	248	if (IS_ERR(inode)) {
	249	error = PTR_ERR(inode);
b3b94faa	250	goto fail;
feaa7bba	251	}
b3b94faa	252
feaa7bba	253	error = gfs2_inode_refresh(GFS2_I(inode));
b3b94faa	254	if (error) {
feaa7bba	255	iput(inode);
b3b94faa DT	256	goto fail;
	257	}
	258
b3b94faa	259	error = -EIO;
feaa7bba SW	260	if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
feaa7bba SW	261	iput(inode);
b3b94faa DT	262	goto fail;
	263	}
	264
	265	gfs2_glock_dq_uninit(&i_gh);
	266
feaa7bba	267	out_inode:
b3b94faa DT	268	dentry = d_alloc_anon(inode);
	269	if (!dentry) {
	270	iput(inode);
	271	return ERR_PTR(-ENOMEM);
	272	}
	273
70831465	274	dentry->d_op = &gfs2_dops;
b3b94faa DT	275	return dentry;
b3b94faa DT	276
feaa7bba	277	fail_rgd:
b3b94faa DT	278	gfs2_glock_dq_uninit(&rgd_gh);
b3b94faa DT	279
feaa7bba	280	fail_rindex:
b3b94faa DT	281	gfs2_glock_dq_uninit(&ri_gh);
b3b94faa DT	282
feaa7bba	283	fail:
b3b94faa DT	284	gfs2_glock_dq_uninit(&i_gh);
	285	return ERR_PTR(error);
	286	}
	287
	288	struct export_operations gfs2_export_ops = {
	289	.decode_fh = gfs2_decode_fh,
	290	.encode_fh = gfs2_encode_fh,
	291	.get_name = gfs2_get_name,
	292	.get_parent = gfs2_get_parent,
	293	.get_dentry = gfs2_get_dentry,
	294	};
	295