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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 dentry *dentry, __u32 *p, int *len,
32 int connectable)
33{
34 __be32 *fh = (__force __be32 *)p;
35 struct inode *inode = dentry->d_inode;
36 struct super_block *sb = inode->i_sb;
37 struct gfs2_inode *ip = GFS2_I(inode);
38
39 if (connectable && (*len < GFS2_LARGE_FH_SIZE)) {
40 *len = GFS2_LARGE_FH_SIZE;
41 return 255;
42 } else if (*len < GFS2_SMALL_FH_SIZE) {
43 *len = GFS2_SMALL_FH_SIZE;
44 return 255;
45 }
46
47 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
48 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
49 fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
50 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
51 *len = GFS2_SMALL_FH_SIZE;
52
53 if (!connectable || inode == sb->s_root->d_inode)
54 return *len;
55
56 spin_lock(&dentry->d_lock);
57 inode = dentry->d_parent->d_inode;
58 ip = GFS2_I(inode);
59 igrab(inode);
60 spin_unlock(&dentry->d_lock);
61
62 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
63 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
64 fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
65 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
66 *len = GFS2_LARGE_FH_SIZE;
67
68 iput(inode);
69
70 return *len;
71}
72
73struct get_name_filldir {
74 struct gfs2_inum_host inum;
75 char *name;
76};
77
78static int get_name_filldir(void *opaque, const char *name, int length,
79 loff_t offset, u64 inum, unsigned int type)
80{
81 struct get_name_filldir *gnfd = opaque;
82
83 if (inum != gnfd->inum.no_addr)
84 return 0;
85
86 memcpy(gnfd->name, name, length);
87 gnfd->name[length] = 0;
88
89 return 1;
90}
91
92static int gfs2_get_name(struct dentry *parent, char *name,
93 struct dentry *child)
94{
95 struct inode *dir = parent->d_inode;
96 struct inode *inode = child->d_inode;
97 struct gfs2_inode *dip, *ip;
98 struct get_name_filldir gnfd;
99 struct gfs2_holder gh;
100 u64 offset = 0;
101 int error;
102
103 if (!dir)
104 return -EINVAL;
105
106 if (!S_ISDIR(dir->i_mode) || !inode)
107 return -EINVAL;
108
109 dip = GFS2_I(dir);
110 ip = GFS2_I(inode);
111
112 *name = 0;
113 gnfd.inum.no_addr = ip->i_no_addr;
114 gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
115 gnfd.name = name;
116
117 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
118 if (error)
119 return error;
120
121 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
122
123 gfs2_glock_dq_uninit(&gh);
124
125 if (!error && !*name)
126 error = -ENOENT;
127
128 return error;
129}
130
131static struct dentry *gfs2_get_parent(struct dentry *child)
132{
133 return d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
134}
135
136static struct dentry *gfs2_get_dentry(struct super_block *sb,
137 struct gfs2_inum_host *inum)
138{
139 struct gfs2_sbd *sdp = sb->s_fs_info;
140 struct inode *inode;
141
142 inode = gfs2_ilookup(sb, inum->no_addr, 0);
143 if (inode) {
144 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
145 iput(inode);
146 return ERR_PTR(-ESTALE);
147 }
148 goto out_inode;
149 }
150
151 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino,
152 GFS2_BLKST_DINODE);
153 if (IS_ERR(inode))
154 return ERR_CAST(inode);
155
156out_inode:
157 return d_obtain_alias(inode);
158}
159
160static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
161 int fh_len, int fh_type)
162{
163 struct gfs2_inum_host this;
164 __be32 *fh = (__force __be32 *)fid->raw;
165
166 switch (fh_type) {
167 case GFS2_SMALL_FH_SIZE:
168 case GFS2_LARGE_FH_SIZE:
169 case GFS2_OLD_FH_SIZE:
170 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
171 this.no_formal_ino |= be32_to_cpu(fh[1]);
172 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
173 this.no_addr |= be32_to_cpu(fh[3]);
174 return gfs2_get_dentry(sb, &this);
175 default:
176 return NULL;
177 }
178}
179
180static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
181 int fh_len, int fh_type)
182{
183 struct gfs2_inum_host parent;
184 __be32 *fh = (__force __be32 *)fid->raw;
185
186 switch (fh_type) {
187 case GFS2_LARGE_FH_SIZE:
188 case GFS2_OLD_FH_SIZE:
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
207
