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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 inode *inode, __u32 *p, int *len,
32 struct inode *parent)
33{
34 __be32 *fh = (__force __be32 *)p;
35 struct super_block *sb = inode->i_sb;
36 struct gfs2_inode *ip = GFS2_I(inode);
37
38 if (parent && (*len < GFS2_LARGE_FH_SIZE)) {
39 *len = GFS2_LARGE_FH_SIZE;
40 return FILEID_INVALID;
41 } else if (*len < GFS2_SMALL_FH_SIZE) {
42 *len = GFS2_SMALL_FH_SIZE;
43 return FILEID_INVALID;
44 }
45
46 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
47 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
48 fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
49 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
50 *len = GFS2_SMALL_FH_SIZE;
51
52 if (!parent || inode == d_inode(sb->s_root))
53 return *len;
54
55 ip = GFS2_I(parent);
56
57 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
58 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
59 fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
60 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
61 *len = GFS2_LARGE_FH_SIZE;
62
63 return *len;
64}
65
66struct get_name_filldir {
67 struct dir_context ctx;
68 struct gfs2_inum_host inum;
69 char *name;
70};
71
72static int get_name_filldir(struct dir_context *ctx, const char *name,
73 int length, loff_t offset, u64 inum,
74 unsigned int type)
75{
76 struct get_name_filldir *gnfd =
77 container_of(ctx, struct get_name_filldir, ctx);
78
79 if (inum != gnfd->inum.no_addr)
80 return 0;
81
82 memcpy(gnfd->name, name, length);
83 gnfd->name[length] = 0;
84
85 return 1;
86}
87
88static int gfs2_get_name(struct dentry *parent, char *name,
89 struct dentry *child)
90{
91 struct inode *dir = d_inode(parent);
92 struct inode *inode = d_inode(child);
93 struct gfs2_inode *dip, *ip;
94 struct get_name_filldir gnfd = {
95 .ctx.actor = get_name_filldir,
96 .name = name
97 };
98 struct gfs2_holder gh;
99 int error;
100 struct file_ra_state f_ra = { .start = 0 };
101
102 if (!dir)
103 return -EINVAL;
104
105 if (!S_ISDIR(dir->i_mode) || !inode)
106 return -EINVAL;
107
108 dip = GFS2_I(dir);
109 ip = GFS2_I(inode);
110
111 *name = 0;
112 gnfd.inum.no_addr = ip->i_no_addr;
113 gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
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, &gnfd.ctx, &f_ra);
120
121 gfs2_glock_dq_uninit(&gh);
122
123 if (!error && !*name)
124 error = -ENOENT;
125
126 return error;
127}
128
129static struct dentry *gfs2_get_parent(struct dentry *child)
130{
131 return d_obtain_alias(gfs2_lookupi(d_inode(child), &gfs2_qdotdot, 1));
132}
133
134static struct dentry *gfs2_get_dentry(struct super_block *sb,
135 struct gfs2_inum_host *inum)
136{
137 struct gfs2_sbd *sdp = sb->s_fs_info;
138 struct inode *inode;
139
140 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino,
141 GFS2_BLKST_DINODE);
142 if (IS_ERR(inode))
143 return ERR_CAST(inode);
144 return d_obtain_alias(inode);
145}
146
147static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
148 int fh_len, int fh_type)
149{
150 struct gfs2_inum_host this;
151 __be32 *fh = (__force __be32 *)fid->raw;
152
153 switch (fh_type) {
154 case GFS2_SMALL_FH_SIZE:
155 case GFS2_LARGE_FH_SIZE:
156 case GFS2_OLD_FH_SIZE:
157 if (fh_len < GFS2_SMALL_FH_SIZE)
158 return NULL;
159 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
160 this.no_formal_ino |= be32_to_cpu(fh[1]);
161 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
162 this.no_addr |= be32_to_cpu(fh[3]);
163 return gfs2_get_dentry(sb, &this);
164 default:
165 return NULL;
166 }
167}
168
169static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
170 int fh_len, int fh_type)
171{
172 struct gfs2_inum_host parent;
173 __be32 *fh = (__force __be32 *)fid->raw;
174
175 switch (fh_type) {
176 case GFS2_LARGE_FH_SIZE:
177 case GFS2_OLD_FH_SIZE:
178 if (fh_len < GFS2_LARGE_FH_SIZE)
179 return NULL;
180 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
181 parent.no_formal_ino |= be32_to_cpu(fh[5]);
182 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
183 parent.no_addr |= be32_to_cpu(fh[7]);
184 return gfs2_get_dentry(sb, &parent);
185 default:
186 return NULL;
187 }
188}
189
190const struct export_operations gfs2_export_ops = {
191 .encode_fh = gfs2_encode_fh,
192 .fh_to_dentry = gfs2_fh_to_dentry,
193 .fh_to_parent = gfs2_fh_to_parent,
194 .get_name = gfs2_get_name,
195 .get_parent = gfs2_get_parent,
196};
197
198
