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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
18#include "gfs2.h"
19#include "incore.h"
20#include "dir.h"
21#include "glock.h"
22#include "glops.h"
23#include "inode.h"
24#include "super.h"
25#include "rgrp.h"
26#include "util.h"
27
28#define GFS2_SMALL_FH_SIZE 4
29#define GFS2_LARGE_FH_SIZE 8
30#define GFS2_OLD_FH_SIZE 10
31
32static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
33 int connectable)
34{
35 __be32 *fh = (__force __be32 *)p;
36 struct inode *inode = dentry->d_inode;
37 struct super_block *sb = inode->i_sb;
38 struct gfs2_inode *ip = GFS2_I(inode);
39
40 if (*len < GFS2_SMALL_FH_SIZE ||
41 (connectable && *len < GFS2_LARGE_FH_SIZE))
42 return 255;
43
44 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
45 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
46 fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
47 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
48 *len = GFS2_SMALL_FH_SIZE;
49
50 if (!connectable || inode == sb->s_root->d_inode)
51 return *len;
52
53 spin_lock(&dentry->d_lock);
54 inode = dentry->d_parent->d_inode;
55 ip = GFS2_I(inode);
56 igrab(inode);
57 spin_unlock(&dentry->d_lock);
58
59 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
60 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
61 fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
62 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
63 *len = GFS2_LARGE_FH_SIZE;
64
65 iput(inode);
66
67 return *len;
68}
69
70struct get_name_filldir {
71 struct gfs2_inum_host inum;
72 char *name;
73};
74
75static int get_name_filldir(void *opaque, const char *name, int length,
76 loff_t offset, u64 inum, unsigned int type)
77{
78 struct get_name_filldir *gnfd = opaque;
79
80 if (inum != gnfd->inum.no_addr)
81 return 0;
82
83 memcpy(gnfd->name, name, length);
84 gnfd->name[length] = 0;
85
86 return 1;
87}
88
89static int gfs2_get_name(struct dentry *parent, char *name,
90 struct dentry *child)
91{
92 struct inode *dir = parent->d_inode;
93 struct inode *inode = child->d_inode;
94 struct gfs2_inode *dip, *ip;
95 struct get_name_filldir gnfd;
96 struct gfs2_holder gh;
97 u64 offset = 0;
98 int error;
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 gnfd.name = name;
113
114 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
115 if (error)
116 return error;
117
118 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
119
120 gfs2_glock_dq_uninit(&gh);
121
122 if (!error && !*name)
123 error = -ENOENT;
124
125 return error;
126}
127
128static struct dentry *gfs2_get_parent(struct dentry *child)
129{
130 struct qstr dotdot;
131 struct dentry *dentry;
132
133
134
135
136
137 gfs2_str2qstr(&dotdot, "..");
138
139 dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &dotdot, 1));
140 if (!IS_ERR(dentry))
141 dentry->d_op = &gfs2_dops;
142 return dentry;
143}
144
145static struct dentry *gfs2_get_dentry(struct super_block *sb,
146 struct gfs2_inum_host *inum)
147{
148 struct gfs2_sbd *sdp = sb->s_fs_info;
149 struct gfs2_holder i_gh;
150 struct inode *inode;
151 struct dentry *dentry;
152 int error;
153
154 inode = gfs2_ilookup(sb, inum->no_addr);
155 if (inode) {
156 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
157 iput(inode);
158 return ERR_PTR(-ESTALE);
159 }
160 goto out_inode;
161 }
162
163 error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
164 LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
165 if (error)
166 return ERR_PTR(error);
167
168 error = gfs2_check_blk_type(sdp, inum->no_addr, GFS2_BLKST_DINODE);
169 if (error)
170 goto fail;
171
172 inode = gfs2_inode_lookup(sb, DT_UNKNOWN, inum->no_addr, 0, 0);
173 if (IS_ERR(inode)) {
174 error = PTR_ERR(inode);
175 goto fail;
176 }
177
178 error = gfs2_inode_refresh(GFS2_I(inode));
179 if (error) {
180 iput(inode);
181 goto fail;
182 }
183
184
185 if (inode->i_state & I_NEW)
186 gfs2_set_iop(inode);
187
188 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
189 iput(inode);
190 goto fail;
191 }
192
193 error = -EIO;
194 if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM) {
195 iput(inode);
196 goto fail;
197 }
198
199 gfs2_glock_dq_uninit(&i_gh);
200
201out_inode:
202 dentry = d_obtain_alias(inode);
203 if (!IS_ERR(dentry))
204 dentry->d_op = &gfs2_dops;
205 return dentry;
206fail:
207 gfs2_glock_dq_uninit(&i_gh);
208 return ERR_PTR(error);
209}
210
211static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
212 int fh_len, int fh_type)
213{
214 struct gfs2_inum_host this;
215 __be32 *fh = (__force __be32 *)fid->raw;
216
217 switch (fh_type) {
218 case GFS2_SMALL_FH_SIZE:
219 case GFS2_LARGE_FH_SIZE:
220 case GFS2_OLD_FH_SIZE:
221 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
222 this.no_formal_ino |= be32_to_cpu(fh[1]);
223 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
224 this.no_addr |= be32_to_cpu(fh[3]);
225 return gfs2_get_dentry(sb, &this);
226 default:
227 return NULL;
228 }
229}
230
231static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
232 int fh_len, int fh_type)
233{
234 struct gfs2_inum_host parent;
235 __be32 *fh = (__force __be32 *)fid->raw;
236
237 switch (fh_type) {
238 case GFS2_LARGE_FH_SIZE:
239 case GFS2_OLD_FH_SIZE:
240 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
241 parent.no_formal_ino |= be32_to_cpu(fh[5]);
242 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
243 parent.no_addr |= be32_to_cpu(fh[7]);
244 return gfs2_get_dentry(sb, &parent);
245 default:
246 return NULL;
247 }
248}
249
250const struct export_operations gfs2_export_ops = {
251 .encode_fh = gfs2_encode_fh,
252 .fh_to_dentry = gfs2_fh_to_dentry,
253 .fh_to_parent = gfs2_fh_to_parent,
254 .get_name = gfs2_get_name,
255 .get_parent = gfs2_get_parent,
256};
257
258
