avr32: fix out-of-range rjmp instruction on large kernels
[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/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/exportfs.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 "super.h"
26 #include "rgrp.h"
27 #include "util.h"
28
29 #define GFS2_SMALL_FH_SIZE 4
30 #define GFS2_LARGE_FH_SIZE 8
31 #define GFS2_OLD_FH_SIZE 10
32
33 static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
34                           int connectable)
35 {
36         __be32 *fh = (__force __be32 *)p;
37         struct inode *inode = dentry->d_inode;
38         struct super_block *sb = inode->i_sb;
39         struct gfs2_inode *ip = GFS2_I(inode);
40
41         if (*len < GFS2_SMALL_FH_SIZE ||
42             (connectable && *len < GFS2_LARGE_FH_SIZE))
43                 return 255;
44
45         fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
46         fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
47         fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
48         fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
49         *len = GFS2_SMALL_FH_SIZE;
50
51         if (!connectable || inode == sb->s_root->d_inode)
52                 return *len;
53
54         spin_lock(&dentry->d_lock);
55         inode = dentry->d_parent->d_inode;
56         ip = GFS2_I(inode);
57         igrab(inode);
58         spin_unlock(&dentry->d_lock);
59
60         fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
61         fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
62         fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
63         fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
64         *len = GFS2_LARGE_FH_SIZE;
65
66         iput(inode);
67
68         return *len;
69 }
70
71 struct get_name_filldir {
72         struct gfs2_inum_host inum;
73         char *name;
74 };
75
76 static int get_name_filldir(void *opaque, const char *name, int length,
77                             loff_t offset, u64 inum, unsigned int type)
78 {
79         struct get_name_filldir *gnfd = opaque;
80
81         if (inum != gnfd->inum.no_addr)
82                 return 0;
83
84         memcpy(gnfd->name, name, length);
85         gnfd->name[length] = 0;
86
87         return 1;
88 }
89
90 static int gfs2_get_name(struct dentry *parent, char *name,
91                          struct dentry *child)
92 {
93         struct inode *dir = parent->d_inode;
94         struct inode *inode = child->d_inode;
95         struct gfs2_inode *dip, *ip;
96         struct get_name_filldir gnfd;
97         struct gfs2_holder gh;
98         u64 offset = 0;
99         int error;
100
101         if (!dir)
102                 return -EINVAL;
103
104         if (!S_ISDIR(dir->i_mode) || !inode)
105                 return -EINVAL;
106
107         dip = GFS2_I(dir);
108         ip = GFS2_I(inode);
109
110         *name = 0;
111         gnfd.inum.no_addr = ip->i_no_addr;
112         gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
113         gnfd.name = name;
114
115         error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
116         if (error)
117                 return error;
118
119         error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
120
121         gfs2_glock_dq_uninit(&gh);
122
123         if (!error && !*name)
124                 error = -ENOENT;
125
126         return error;
127 }
128
129 static struct dentry *gfs2_get_parent(struct dentry *child)
130 {
131         struct qstr dotdot;
132         struct dentry *dentry;
133
134         /*
135          * XXX(hch): it would be a good idea to keep this around as a
136          *           static variable.
137          */
138         gfs2_str2qstr(&dotdot, "..");
139
140         dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
141         if (!IS_ERR(dentry))
142                 dentry->d_op = &gfs2_dops;
143         return dentry;
144 }
145
146 static struct dentry *gfs2_get_dentry(struct super_block *sb,
147                 struct gfs2_inum_host *inum)
148 {
149         struct gfs2_sbd *sdp = sb->s_fs_info;
150         struct gfs2_holder i_gh, ri_gh, rgd_gh;
151         struct gfs2_rgrpd *rgd;
152         struct inode *inode;
153         struct dentry *dentry;
154         int error;
155
156         /* System files? */
157
158         inode = gfs2_ilookup(sb, inum->no_addr);
159         if (inode) {
160                 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
161                         iput(inode);
162                         return ERR_PTR(-ESTALE);
163                 }
164                 goto out_inode;
165         }
166
167         error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
168                                   LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
169         if (error)
170                 return ERR_PTR(error);
171
172         error = gfs2_rindex_hold(sdp, &ri_gh);
173         if (error)
174                 goto fail;
175
176         error = -EINVAL;
177         rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
178         if (!rgd)
179                 goto fail_rindex;
180
181         error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
182         if (error)
183                 goto fail_rindex;
184
185         error = -ESTALE;
186         if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
187                 goto fail_rgd;
188
189         gfs2_glock_dq_uninit(&rgd_gh);
190         gfs2_glock_dq_uninit(&ri_gh);
191
192         inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
193                                         inum->no_addr,
194                                         0, 0);
195         if (IS_ERR(inode)) {
196                 error = PTR_ERR(inode);
197                 goto fail;
198         }
199
200         error = gfs2_inode_refresh(GFS2_I(inode));
201         if (error) {
202                 iput(inode);
203                 goto fail;
204         }
205
206         /* Pick up the works we bypass in gfs2_inode_lookup */
207         if (inode->i_state & I_NEW) 
208                 gfs2_set_iop(inode);
209
210         if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
211                 iput(inode);
212                 goto fail;
213         }
214
215         error = -EIO;
216         if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) {
217                 iput(inode);
218                 goto fail;
219         }
220
221         gfs2_glock_dq_uninit(&i_gh);
222
223 out_inode:
224         dentry = d_obtain_alias(inode);
225         if (!IS_ERR(dentry))
226                 dentry->d_op = &gfs2_dops;
227         return dentry;
228
229 fail_rgd:
230         gfs2_glock_dq_uninit(&rgd_gh);
231
232 fail_rindex:
233         gfs2_glock_dq_uninit(&ri_gh);
234
235 fail:
236         gfs2_glock_dq_uninit(&i_gh);
237         return ERR_PTR(error);
238 }
239
240 static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
241                 int fh_len, int fh_type)
242 {
243         struct gfs2_inum_host this;
244         __be32 *fh = (__force __be32 *)fid->raw;
245
246         switch (fh_type) {
247         case GFS2_SMALL_FH_SIZE:
248         case GFS2_LARGE_FH_SIZE:
249         case GFS2_OLD_FH_SIZE:
250                 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
251                 this.no_formal_ino |= be32_to_cpu(fh[1]);
252                 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
253                 this.no_addr |= be32_to_cpu(fh[3]);
254                 return gfs2_get_dentry(sb, &this);
255         default:
256                 return NULL;
257         }
258 }
259
260 static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
261                 int fh_len, int fh_type)
262 {
263         struct gfs2_inum_host parent;
264         __be32 *fh = (__force __be32 *)fid->raw;
265
266         switch (fh_type) {
267         case GFS2_LARGE_FH_SIZE:
268         case GFS2_OLD_FH_SIZE:
269                 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
270                 parent.no_formal_ino |= be32_to_cpu(fh[5]);
271                 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
272                 parent.no_addr |= be32_to_cpu(fh[7]);
273                 return gfs2_get_dentry(sb, &parent);
274         default:
275                 return NULL;
276         }
277 }
278
279 const struct export_operations gfs2_export_ops = {
280         .encode_fh = gfs2_encode_fh,
281         .fh_to_dentry = gfs2_fh_to_dentry,
282         .fh_to_parent = gfs2_fh_to_parent,
283         .get_name = gfs2_get_name,
284         .get_parent = gfs2_get_parent,
285 };
286