[GFS2] Update copyright date to 2006
[linux-2.6.git] / fs / gfs2 / ops_export.c
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 v.2.
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>
15 #include <linux/gfs2_ondisk.h>
16 #include <linux/crc32.h>
17
18 #include "gfs2.h"
19 #include "lm_interface.h"
20 #include "incore.h"
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"
27 #include "util.h"
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 {
37         struct gfs2_inum this, parent;
38
39         if (fh_type != fh_len)
40                 return NULL;
41
42         memset(&parent, 0, sizeof(struct gfs2_inum));
43
44         switch (fh_type) {
45         case 8:
46                 parent.no_formal_ino = ((uint64_t)be32_to_cpu(fh[4])) << 32;
47                 parent.no_formal_ino |= be32_to_cpu(fh[5]);
48                 parent.no_addr = ((uint64_t)be32_to_cpu(fh[6])) << 32;
49                 parent.no_addr |= be32_to_cpu(fh[7]);
50         case 4:
51                 this.no_formal_ino = ((uint64_t)be32_to_cpu(fh[0])) << 32;
52                 this.no_formal_ino |= be32_to_cpu(fh[1]);
53                 this.no_addr = ((uint64_t)be32_to_cpu(fh[2])) << 32;
54                 this.no_addr |= be32_to_cpu(fh[3]);
55                 break;
56         default:
57                 return NULL;
58         }
59
60         return gfs2_export_ops.find_exported_dentry(sb, &this, &parent,
61                                                     acceptable, context);
62 }
63
64 static int gfs2_encode_fh(struct dentry *dentry, __u32 *fh, int *len,
65                           int connectable)
66 {
67         struct inode *inode = dentry->d_inode;
68         struct super_block *sb = inode->i_sb;
69         struct gfs2_inode *ip = inode->u.generic_ip;
70
71         if (*len < 4 || (connectable && *len < 8))
72                 return 255;
73
74         fh[0] = ip->i_num.no_formal_ino >> 32;
75         fh[0] = cpu_to_be32(fh[0]);
76         fh[1] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
77         fh[1] = cpu_to_be32(fh[1]);
78         fh[2] = ip->i_num.no_addr >> 32;
79         fh[2] = cpu_to_be32(fh[2]);
80         fh[3] = ip->i_num.no_addr & 0xFFFFFFFF;
81         fh[3] = cpu_to_be32(fh[3]);
82         *len = 4;
83
84         if (!connectable || inode == sb->s_root->d_inode)
85                 return *len;
86
87         spin_lock(&dentry->d_lock);
88         inode = dentry->d_parent->d_inode;
89         ip = inode->u.generic_ip;
90         gfs2_inode_hold(ip);
91         spin_unlock(&dentry->d_lock);
92
93         fh[4] = ip->i_num.no_formal_ino >> 32;
94         fh[4] = cpu_to_be32(fh[4]);
95         fh[5] = ip->i_num.no_formal_ino & 0xFFFFFFFF;
96         fh[5] = cpu_to_be32(fh[5]);
97         fh[6] = ip->i_num.no_addr >> 32;
98         fh[6] = cpu_to_be32(fh[6]);
99         fh[7] = ip->i_num.no_addr & 0xFFFFFFFF;
100         fh[7] = cpu_to_be32(fh[7]);
101         *len = 8;
102
103         gfs2_inode_put(ip);
104
105         return *len;
106 }
107
108 struct get_name_filldir {
109         struct gfs2_inum inum;
110         char *name;
111 };
112
113 static int get_name_filldir(void *opaque, const char *name, unsigned int length,
114                             uint64_t offset, struct gfs2_inum *inum,
115                             unsigned int type)
116 {
117         struct get_name_filldir *gnfd = (struct get_name_filldir *)opaque;
118
119         if (!gfs2_inum_equal(inum, &gnfd->inum))
120                 return 0;
121
122         memcpy(gnfd->name, name, length);
123         gnfd->name[length] = 0;
124
125         return 1;
126 }
127
128 static int gfs2_get_name(struct dentry *parent, char *name,
129                          struct dentry *child)
130 {
131         struct inode *dir = parent->d_inode;
132         struct inode *inode = child->d_inode;
133         struct gfs2_inode *dip, *ip;
134         struct get_name_filldir gnfd;
135         struct gfs2_holder gh;
136         uint64_t offset = 0;
137         int error;
138
139         if (!dir)
140                 return -EINVAL;
141
142         if (!S_ISDIR(dir->i_mode) || !inode)
143                 return -EINVAL;
144
145         dip = dir->u.generic_ip;
146         ip = inode->u.generic_ip;
147
148         *name = 0;
149         gnfd.inum = ip->i_num;
150         gnfd.name = name;
151
152         error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
153         if (error)
154                 return error;
155
156         error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
157
158         gfs2_glock_dq_uninit(&gh);
159
160         if (!error && !*name)
161                 error = -ENOENT;
162
163         return error;
164 }
165
166 static struct dentry *gfs2_get_parent(struct dentry *child)
167 {
168         struct qstr dotdot;
169         struct inode *inode;
170         struct dentry *dentry;
171
172         gfs2_str2qstr(&dotdot, "..");
173         inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
174
175         if (!inode)
176                 return ERR_PTR(-ENOENT);
177         if (IS_ERR(inode))
178                 return ERR_PTR(PTR_ERR(inode));
179
180         dentry = d_alloc_anon(inode);
181         if (!dentry) {
182                 iput(inode);
183                 return ERR_PTR(-ENOMEM);
184         }
185
186         return dentry;
187 }
188
189 static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_p)
190 {
191         struct gfs2_sbd *sdp = sb->s_fs_info;
192         struct gfs2_inum *inum = (struct gfs2_inum *)inum_p;
193         struct gfs2_holder i_gh, ri_gh, rgd_gh;
194         struct gfs2_rgrpd *rgd;
195         struct gfs2_inode *ip;
196         struct inode *inode;
197         struct dentry *dentry;
198         int error;
199
200         /* System files? */
201
202         inode = gfs2_iget(sb, inum);
203         if (inode) {
204                 ip = inode->u.generic_ip;
205                 if (ip->i_num.no_formal_ino != inum->no_formal_ino) {
206                         iput(inode);
207                         return ERR_PTR(-ESTALE);
208                 }
209                 goto out_inode;
210         }
211
212         error = gfs2_glock_nq_num(sdp,
213                                   inum->no_addr, &gfs2_inode_glops,
214                                   LM_ST_SHARED, LM_FLAG_ANY | GL_LOCAL_EXCL,
215                                   &i_gh);
216         if (error)
217                 return ERR_PTR(error);
218
219         error = gfs2_inode_get(i_gh.gh_gl, inum, NO_CREATE, &ip);
220         if (error)
221                 goto fail;
222         if (ip)
223                 goto out_ip;
224
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
245         error = gfs2_inode_get(i_gh.gh_gl, inum, CREATE, &ip);
246         if (error)
247                 goto fail;
248
249         error = gfs2_inode_refresh(ip);
250         if (error) {
251                 gfs2_inode_put(ip);
252                 goto fail;
253         }
254
255  out_ip:
256         error = -EIO;
257         if (ip->i_di.di_flags & GFS2_DIF_SYSTEM) {
258                 gfs2_inode_put(ip);
259                 goto fail;
260         }
261
262         gfs2_glock_dq_uninit(&i_gh);
263
264         inode = gfs2_ip2v(ip);
265         gfs2_inode_put(ip);
266
267         if (!inode)
268                 return ERR_PTR(-ENOMEM);
269
270  out_inode:
271         dentry = d_alloc_anon(inode);
272         if (!dentry) {
273                 iput(inode);
274                 return ERR_PTR(-ENOMEM);
275         }
276
277         return dentry;
278
279  fail_rgd:
280         gfs2_glock_dq_uninit(&rgd_gh);
281
282  fail_rindex:
283         gfs2_glock_dq_uninit(&ri_gh);
284
285  fail:
286         gfs2_glock_dq_uninit(&i_gh);
287         return ERR_PTR(error);
288 }
289
290 struct export_operations gfs2_export_ops = {
291         .decode_fh = gfs2_decode_fh,
292         .encode_fh = gfs2_encode_fh,
293         .get_name = gfs2_get_name,
294         .get_parent = gfs2_get_parent,
295         .get_dentry = gfs2_get_dentry,
296 };
297