[PATCH] fix v850 compilation
[linux-2.6] / 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 version 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 #include <linux/lm_interface.h>
18
19 #include "gfs2.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_fh_obj fh_obj;
38         struct gfs2_inum *this, parent;
39
40         if (fh_type != fh_len)
41                 return NULL;
42
43         this            = &fh_obj.this;
44         fh_obj.imode    = DT_UNKNOWN;
45         memset(&parent, 0, sizeof(struct gfs2_inum));
46
47         switch (fh_type) {
48         case GFS2_LARGE_FH_SIZE:
49                 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
50                 parent.no_formal_ino |= be32_to_cpu(fh[5]);
51                 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
52                 parent.no_addr |= be32_to_cpu(fh[7]);
53                 fh_obj.imode = be32_to_cpu(fh[8]);
54         case GFS2_SMALL_FH_SIZE:
55                 this->no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
56                 this->no_formal_ino |= be32_to_cpu(fh[1]);
57                 this->no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
58                 this->no_addr |= be32_to_cpu(fh[3]);
59                 break;
60         default:
61                 return NULL;
62         }
63
64         return gfs2_export_ops.find_exported_dentry(sb, &fh_obj, &parent,
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;
72         struct super_block *sb = inode->i_sb;
73         struct gfs2_inode *ip = GFS2_I(inode);
74
75         if (*len < GFS2_SMALL_FH_SIZE ||
76             (connectable && *len < GFS2_LARGE_FH_SIZE))
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]);
87         *len = GFS2_SMALL_FH_SIZE;
88
89         if (!connectable || inode == sb->s_root->d_inode)
90                 return *len;
91
92         spin_lock(&dentry->d_lock);
93         inode = dentry->d_parent->d_inode;
94         ip = GFS2_I(inode);
95         igrab(inode);
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]);
106
107         fh[8]  = cpu_to_be32(inode->i_mode);
108         fh[9]  = 0;     /* pad to double word */
109         *len = GFS2_LARGE_FH_SIZE;
110
111         iput(inode);
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,
122                             u64 offset, struct gfs2_inum *inum,
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;
144         u64 offset = 0;
145         int error;
146
147         if (!dir)
148                 return -EINVAL;
149
150         if (!S_ISDIR(dir->i_mode) || !inode)
151                 return -EINVAL;
152
153         dip = GFS2_I(dir);
154         ip = GFS2_I(inode);
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
164         error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
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 {
176         struct qstr dotdot;
177         struct inode *inode;
178         struct dentry *dentry;
179
180         gfs2_str2qstr(&dotdot, "..");
181         inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
182
183         if (!inode)
184                 return ERR_PTR(-ENOENT);
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          */
189         if (IS_ERR(inode))
190                 return ERR_PTR(PTR_ERR(inode));
191
192         dentry = d_alloc_anon(inode);
193         if (!dentry) {
194                 iput(inode);
195                 return ERR_PTR(-ENOMEM);
196         }
197
198         return dentry;
199 }
200
201 static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_obj)
202 {
203         struct gfs2_sbd *sdp = sb->s_fs_info;
204         struct gfs2_fh_obj *fh_obj = (struct gfs2_fh_obj *)inum_obj;
205         struct gfs2_inum *inum = &fh_obj->this;
206         struct gfs2_holder i_gh, ri_gh, rgd_gh;
207         struct gfs2_rgrpd *rgd;
208         struct inode *inode;
209         struct dentry *dentry;
210         int error;
211
212         /* System files? */
213
214         inode = gfs2_ilookup(sb, inum);
215         if (inode) {
216                 if (GFS2_I(inode)->i_num.no_formal_ino != inum->no_formal_ino) {
217                         iput(inode);
218                         return ERR_PTR(-ESTALE);
219                 }
220                 goto out_inode;
221         }
222
223         error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
224                                   LM_ST_SHARED, LM_FLAG_ANY | GL_LOCAL_EXCL,
225                                   &i_gh);
226         if (error)
227                 return ERR_PTR(error);
228
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
249         inode = gfs2_inode_lookup(sb, inum, fh_obj->imode);
250         if (!inode)
251                 goto fail;
252         if (IS_ERR(inode)) {
253                 error = PTR_ERR(inode);
254                 goto fail;
255         }
256
257         error = gfs2_inode_refresh(GFS2_I(inode));
258         if (error) {
259                 iput(inode);
260                 goto fail;
261         }
262
263         error = -EIO;
264         if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
265                 iput(inode);
266                 goto fail;
267         }
268
269         gfs2_glock_dq_uninit(&i_gh);
270
271 out_inode:
272         dentry = d_alloc_anon(inode);
273         if (!dentry) {
274                 iput(inode);
275                 return ERR_PTR(-ENOMEM);
276         }
277
278         return dentry;
279
280 fail_rgd:
281         gfs2_glock_dq_uninit(&rgd_gh);
282
283 fail_rindex:
284         gfs2_glock_dq_uninit(&ri_gh);
285
286 fail:
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