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 FILEID_INVALID;
41 } else if (*len < GFS2_SMALL_FH_SIZE) {
42 *len = GFS2_SMALL_FH_SIZE;
43 return FILEID_INVALID;
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 dir_context ctx;
68 struct gfs2_inum_host inum;
69 char *name;
70};
71
72static int get_name_filldir(void *opaque, const char *name, int length,
73 loff_t offset, u64 inum, unsigned int type)
74{
75 struct get_name_filldir *gnfd = opaque;
76
77 if (inum != gnfd->inum.no_addr)
78 return 0;
79
80 memcpy(gnfd->name, name, length);
81 gnfd->name[length] = 0;
82
83 return 1;
84}
85
86static int gfs2_get_name(struct dentry *parent, char *name,
87 struct dentry *child)
88{
89 struct inode *dir = parent->d_inode;
90 struct inode *inode = child->d_inode;
91 struct gfs2_inode *dip, *ip;
92 struct get_name_filldir gnfd = {
93 .ctx.actor = get_name_filldir,
94 .name = name
95 };
96 struct gfs2_holder gh;
97 int error;
98 struct file_ra_state f_ra = { .start = 0 };
99
100 if (!dir)
101 return -EINVAL;
102
103 if (!S_ISDIR(dir->i_mode) || !inode)
104 return -EINVAL;
105
106 dip = GFS2_I(dir);
107 ip = GFS2_I(inode);
108
109 *name = 0;
110 gnfd.inum.no_addr = ip->i_no_addr;
111 gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
112
113 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
114 if (error)
115 return error;
116
117 error = gfs2_dir_read(dir, &gnfd.ctx, &f_ra);
118
119 gfs2_glock_dq_uninit(&gh);
120
121 if (!error && !*name)
122 error = -ENOENT;
123
124 return error;
125}
126
127static struct dentry *gfs2_get_parent(struct dentry *child)
128{
129 return d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
130}
131
132static struct dentry *gfs2_get_dentry(struct super_block *sb,
133 struct gfs2_inum_host *inum)
134{
135 struct gfs2_sbd *sdp = sb->s_fs_info;
136 struct inode *inode;
137
138 inode = gfs2_ilookup(sb, inum->no_addr, 0);
139 if (inode) {
140 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
141 iput(inode);
142 return ERR_PTR(-ESTALE);
143 }
144 goto out_inode;
145 }
146
147 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino,
148 GFS2_BLKST_DINODE);
149 if (IS_ERR(inode))
150 return ERR_CAST(inode);
151
152out_inode:
153 return d_obtain_alias(inode);
154}
155
156static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
157 int fh_len, int fh_type)
158{
159 struct gfs2_inum_host this;
160 __be32 *fh = (__force __be32 *)fid->raw;
161
162 switch (fh_type) {
163 case GFS2_SMALL_FH_SIZE:
164 case GFS2_LARGE_FH_SIZE:
165 case GFS2_OLD_FH_SIZE:
166 if (fh_len < GFS2_SMALL_FH_SIZE)
167 return NULL;
168 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
169 this.no_formal_ino |= be32_to_cpu(fh[1]);
170 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
171 this.no_addr |= be32_to_cpu(fh[3]);
172 return gfs2_get_dentry(sb, &this);
173 default:
174 return NULL;
175 }
176}
177
178static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
179 int fh_len, int fh_type)
180{
181 struct gfs2_inum_host parent;
182 __be32 *fh = (__force __be32 *)fid->raw;
183
184 switch (fh_type) {
185 case GFS2_LARGE_FH_SIZE:
186 case GFS2_OLD_FH_SIZE:
187 if (fh_len < GFS2_LARGE_FH_SIZE)
188 return NULL;
189 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
190 parent.no_formal_ino |= be32_to_cpu(fh[5]);
191 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
192 parent.no_addr |= be32_to_cpu(fh[7]);
193 return gfs2_get_dentry(sb, &parent);
194 default:
195 return NULL;
196 }
197}
198
199const struct export_operations gfs2_export_ops = {
200 .encode_fh = gfs2_encode_fh,
201 .fh_to_dentry = gfs2_fh_to_dentry,
202 .fh_to_parent = gfs2_fh_to_parent,
203 .get_name = gfs2_get_name,
204 .get_parent = gfs2_get_parent,
205};
206