Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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
7 * of the GNU General Public License version 2.
8 */
9
10#include <linux/spinlock.h>
11#include <linux/completion.h>
12#include <linux/buffer_head.h>
13#include <linux/exportfs.h>
14#include <linux/gfs2_ondisk.h>
15#include <linux/crc32.h>
16
17#include "gfs2.h"
18#include "incore.h"
19#include "dir.h"
20#include "glock.h"
21#include "glops.h"
22#include "inode.h"
23#include "super.h"
24#include "rgrp.h"
25#include "util.h"
26
27#define GFS2_SMALL_FH_SIZE 4
28#define GFS2_LARGE_FH_SIZE 8
29#define GFS2_OLD_FH_SIZE 10
30
31static int gfs2_encode_fh(struct inode *inode, __u32 *p, int *len,
32 struct inode *parent)
33{
34 __be32 *fh = (__force __be32 *)p;
35 struct super_block *sb = inode->i_sb;
36 struct gfs2_inode *ip = GFS2_I(inode);
37
38 if (parent && (*len < GFS2_LARGE_FH_SIZE)) {
39 *len = GFS2_LARGE_FH_SIZE;
40 return 255;
41 } else if (*len < GFS2_SMALL_FH_SIZE) {
42 *len = GFS2_SMALL_FH_SIZE;
43 return 255;
44 }
45
46 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
47 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
48 fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
49 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
50 *len = GFS2_SMALL_FH_SIZE;
51
52 if (!parent || inode == sb->s_root->d_inode)
53 return *len;
54
55 ip = GFS2_I(parent);
56
57 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
58 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
59 fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
60 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
61 *len = GFS2_LARGE_FH_SIZE;
62
63 return *len;
64}
65
66struct get_name_filldir {
67 struct gfs2_inum_host inum;
68 char *name;
69};
70
71static int get_name_filldir(void *opaque, const char *name, int length,
72 loff_t offset, u64 inum, unsigned int type)
73{
74 struct get_name_filldir *gnfd = opaque;
75
76 if (inum != gnfd->inum.no_addr)
77 return 0;
78
79 memcpy(gnfd->name, name, length);
80 gnfd->name[length] = 0;
81
82 return 1;
83}
84
85static int gfs2_get_name(struct dentry *parent, char *name,
86 struct dentry *child)
87{
88 struct inode *dir = parent->d_inode;
89 struct inode *inode = child->d_inode;
90 struct gfs2_inode *dip, *ip;
91 struct get_name_filldir gnfd;
92 struct gfs2_holder gh;
93 u64 offset = 0;
94 int error;
95 struct file_ra_state f_ra = { .start = 0 };
96
97 if (!dir)
98 return -EINVAL;
99
100 if (!S_ISDIR(dir->i_mode) || !inode)
101 return -EINVAL;
102
103 dip = GFS2_I(dir);
104 ip = GFS2_I(inode);
105
106 *name = 0;
107 gnfd.inum.no_addr = ip->i_no_addr;
108 gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
109 gnfd.name = name;
110
111 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
112 if (error)
113 return error;
114
115 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir, &f_ra);
116
117 gfs2_glock_dq_uninit(&gh);
118
119 if (!error && !*name)
120 error = -ENOENT;
121
122 return error;
123}
124
125static struct dentry *gfs2_get_parent(struct dentry *child)
126{
127 return d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
128}
129
130static struct dentry *gfs2_get_dentry(struct super_block *sb,
131 struct gfs2_inum_host *inum)
132{
133 struct gfs2_sbd *sdp = sb->s_fs_info;
134 struct inode *inode;
135
136 inode = gfs2_ilookup(sb, inum->no_addr, 0);
137 if (inode) {
138 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
139 iput(inode);
140 return ERR_PTR(-ESTALE);
141 }
142 goto out_inode;
143 }
144
145 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino,
146 GFS2_BLKST_DINODE);
147 if (IS_ERR(inode))
148 return ERR_CAST(inode);
149
150out_inode:
151 return d_obtain_alias(inode);
152}
153
154static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
155 int fh_len, int fh_type)
156{
157 struct gfs2_inum_host this;
158 __be32 *fh = (__force __be32 *)fid->raw;
159
160 switch (fh_type) {
161 case GFS2_SMALL_FH_SIZE:
162 case GFS2_LARGE_FH_SIZE:
163 case GFS2_OLD_FH_SIZE:
164 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
165 this.no_formal_ino |= be32_to_cpu(fh[1]);
166 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
167 this.no_addr |= be32_to_cpu(fh[3]);
168 return gfs2_get_dentry(sb, &this);
169 default:
170 return NULL;
171 }
172}
173
174static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
175 int fh_len, int fh_type)
176{
177 struct gfs2_inum_host parent;
178 __be32 *fh = (__force __be32 *)fid->raw;
179
180 switch (fh_type) {
181 case GFS2_LARGE_FH_SIZE:
182 case GFS2_OLD_FH_SIZE:
183 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
184 parent.no_formal_ino |= be32_to_cpu(fh[5]);
185 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
186 parent.no_addr |= be32_to_cpu(fh[7]);
187 return gfs2_get_dentry(sb, &parent);
188 default:
189 return NULL;
190 }
191}
192
193const struct export_operations gfs2_export_ops = {
194 .encode_fh = gfs2_encode_fh,
195 .fh_to_dentry = gfs2_fh_to_dentry,
196 .fh_to_parent = gfs2_fh_to_parent,
197 .get_name = gfs2_get_name,
198 .get_parent = gfs2_get_parent,
199};
200