2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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.
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>
27 #define GFS2_SMALL_FH_SIZE 4
28 #define GFS2_LARGE_FH_SIZE 8
29 #define GFS2_OLD_FH_SIZE 10
31 static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
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);
39 if (*len < GFS2_SMALL_FH_SIZE ||
40 (connectable && *len < GFS2_LARGE_FH_SIZE))
43 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
44 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
45 fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
46 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
47 *len = GFS2_SMALL_FH_SIZE;
49 if (!connectable || inode == sb->s_root->d_inode)
52 spin_lock(&dentry->d_lock);
53 inode = dentry->d_parent->d_inode;
56 spin_unlock(&dentry->d_lock);
58 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
59 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
60 fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
61 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
62 *len = GFS2_LARGE_FH_SIZE;
69 struct get_name_filldir {
70 struct gfs2_inum_host inum;
74 static int get_name_filldir(void *opaque, const char *name, int length,
75 loff_t offset, u64 inum, unsigned int type)
77 struct get_name_filldir *gnfd = opaque;
79 if (inum != gnfd->inum.no_addr)
82 memcpy(gnfd->name, name, length);
83 gnfd->name[length] = 0;
88 static int gfs2_get_name(struct dentry *parent, char *name,
91 struct inode *dir = parent->d_inode;
92 struct inode *inode = child->d_inode;
93 struct gfs2_inode *dip, *ip;
94 struct get_name_filldir gnfd;
95 struct gfs2_holder gh;
102 if (!S_ISDIR(dir->i_mode) || !inode)
109 gnfd.inum.no_addr = ip->i_no_addr;
110 gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
113 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
117 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
119 gfs2_glock_dq_uninit(&gh);
121 if (!error && !*name)
127 static struct dentry *gfs2_get_parent(struct dentry *child)
129 struct dentry *dentry;
131 dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
133 dentry->d_op = &gfs2_dops;
137 static struct dentry *gfs2_get_dentry(struct super_block *sb,
138 struct gfs2_inum_host *inum)
140 struct gfs2_sbd *sdp = sb->s_fs_info;
142 struct dentry *dentry;
144 inode = gfs2_ilookup(sb, inum->no_addr);
146 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
148 return ERR_PTR(-ESTALE);
153 inode = gfs2_lookup_by_inum(sdp, inum->no_addr, &inum->no_formal_ino,
156 return ERR_CAST(inode);
159 dentry = d_obtain_alias(inode);
161 dentry->d_op = &gfs2_dops;
165 static struct dentry *gfs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
166 int fh_len, int fh_type)
168 struct gfs2_inum_host this;
169 __be32 *fh = (__force __be32 *)fid->raw;
172 case GFS2_SMALL_FH_SIZE:
173 case GFS2_LARGE_FH_SIZE:
174 case GFS2_OLD_FH_SIZE:
175 this.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
176 this.no_formal_ino |= be32_to_cpu(fh[1]);
177 this.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
178 this.no_addr |= be32_to_cpu(fh[3]);
179 return gfs2_get_dentry(sb, &this);
185 static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
186 int fh_len, int fh_type)
188 struct gfs2_inum_host parent;
189 __be32 *fh = (__force __be32 *)fid->raw;
192 case GFS2_LARGE_FH_SIZE:
193 case GFS2_OLD_FH_SIZE:
194 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
195 parent.no_formal_ino |= be32_to_cpu(fh[5]);
196 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
197 parent.no_addr |= be32_to_cpu(fh[7]);
198 return gfs2_get_dentry(sb, &parent);
204 const struct export_operations gfs2_export_ops = {
205 .encode_fh = gfs2_encode_fh,
206 .fh_to_dentry = gfs2_fh_to_dentry,
207 .fh_to_parent = gfs2_fh_to_parent,
208 .get_name = gfs2_get_name,
209 .get_parent = gfs2_get_parent,