Linux 2.6.23-rc1
[usb.git] / fs / gfs2 / ops_export.c
blobb8312edee0e45dc89787f042b350c679e85a6ac6
1 /*
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.
8 */
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>
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 "ops_dentry.h"
26 #include "ops_fstype.h"
27 #include "rgrp.h"
28 #include "util.h"
30 #define GFS2_SMALL_FH_SIZE 4
31 #define GFS2_LARGE_FH_SIZE 8
32 #define GFS2_OLD_FH_SIZE 10
34 static struct dentry *gfs2_decode_fh(struct super_block *sb,
35 __u32 *p,
36 int fh_len,
37 int fh_type,
38 int (*acceptable)(void *context,
39 struct dentry *dentry),
40 void *context)
42 __be32 *fh = (__force __be32 *)p;
43 struct gfs2_inum_host inum, parent;
45 memset(&parent, 0, sizeof(struct gfs2_inum));
47 switch (fh_len) {
48 case GFS2_LARGE_FH_SIZE:
49 case GFS2_OLD_FH_SIZE:
50 parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
51 parent.no_formal_ino |= be32_to_cpu(fh[5]);
52 parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
53 parent.no_addr |= be32_to_cpu(fh[7]);
54 case GFS2_SMALL_FH_SIZE:
55 inum.no_formal_ino = ((u64)be32_to_cpu(fh[0])) << 32;
56 inum.no_formal_ino |= be32_to_cpu(fh[1]);
57 inum.no_addr = ((u64)be32_to_cpu(fh[2])) << 32;
58 inum.no_addr |= be32_to_cpu(fh[3]);
59 break;
60 default:
61 return NULL;
64 return gfs2_export_ops.find_exported_dentry(sb, &inum, &parent,
65 acceptable, context);
68 static int gfs2_encode_fh(struct dentry *dentry, __u32 *p, int *len,
69 int connectable)
71 __be32 *fh = (__force __be32 *)p;
72 struct inode *inode = dentry->d_inode;
73 struct super_block *sb = inode->i_sb;
74 struct gfs2_inode *ip = GFS2_I(inode);
76 if (*len < GFS2_SMALL_FH_SIZE ||
77 (connectable && *len < GFS2_LARGE_FH_SIZE))
78 return 255;
80 fh[0] = cpu_to_be32(ip->i_no_formal_ino >> 32);
81 fh[1] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
82 fh[2] = cpu_to_be32(ip->i_no_addr >> 32);
83 fh[3] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
84 *len = GFS2_SMALL_FH_SIZE;
86 if (!connectable || inode == sb->s_root->d_inode)
87 return *len;
89 spin_lock(&dentry->d_lock);
90 inode = dentry->d_parent->d_inode;
91 ip = GFS2_I(inode);
92 igrab(inode);
93 spin_unlock(&dentry->d_lock);
95 fh[4] = cpu_to_be32(ip->i_no_formal_ino >> 32);
96 fh[5] = cpu_to_be32(ip->i_no_formal_ino & 0xFFFFFFFF);
97 fh[6] = cpu_to_be32(ip->i_no_addr >> 32);
98 fh[7] = cpu_to_be32(ip->i_no_addr & 0xFFFFFFFF);
99 *len = GFS2_LARGE_FH_SIZE;
101 iput(inode);
103 return *len;
106 struct get_name_filldir {
107 struct gfs2_inum_host inum;
108 char *name;
111 static int get_name_filldir(void *opaque, const char *name, int length,
112 loff_t offset, u64 inum, unsigned int type)
114 struct get_name_filldir *gnfd = opaque;
116 if (inum != gnfd->inum.no_addr)
117 return 0;
119 memcpy(gnfd->name, name, length);
120 gnfd->name[length] = 0;
122 return 1;
125 static int gfs2_get_name(struct dentry *parent, char *name,
126 struct dentry *child)
128 struct inode *dir = parent->d_inode;
129 struct inode *inode = child->d_inode;
130 struct gfs2_inode *dip, *ip;
131 struct get_name_filldir gnfd;
132 struct gfs2_holder gh;
133 u64 offset = 0;
134 int error;
136 if (!dir)
137 return -EINVAL;
139 if (!S_ISDIR(dir->i_mode) || !inode)
140 return -EINVAL;
142 dip = GFS2_I(dir);
143 ip = GFS2_I(inode);
145 *name = 0;
146 gnfd.inum.no_addr = ip->i_no_addr;
147 gnfd.inum.no_formal_ino = ip->i_no_formal_ino;
148 gnfd.name = name;
150 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &gh);
151 if (error)
152 return error;
154 error = gfs2_dir_read(dir, &offset, &gnfd, get_name_filldir);
156 gfs2_glock_dq_uninit(&gh);
158 if (!error && !*name)
159 error = -ENOENT;
161 return error;
164 static struct dentry *gfs2_get_parent(struct dentry *child)
166 struct qstr dotdot;
167 struct inode *inode;
168 struct dentry *dentry;
170 gfs2_str2qstr(&dotdot, "..");
171 inode = gfs2_lookupi(child->d_inode, &dotdot, 1, NULL);
173 if (!inode)
174 return ERR_PTR(-ENOENT);
176 * In case of an error, @inode carries the error value, and we
177 * have to return that as a(n invalid) pointer to dentry.
179 if (IS_ERR(inode))
180 return ERR_PTR(PTR_ERR(inode));
182 dentry = d_alloc_anon(inode);
183 if (!dentry) {
184 iput(inode);
185 return ERR_PTR(-ENOMEM);
188 dentry->d_op = &gfs2_dops;
189 return dentry;
192 static struct dentry *gfs2_get_dentry(struct super_block *sb, void *inum_obj)
194 struct gfs2_sbd *sdp = sb->s_fs_info;
195 struct gfs2_inum_host *inum = inum_obj;
196 struct gfs2_holder i_gh, ri_gh, rgd_gh;
197 struct gfs2_rgrpd *rgd;
198 struct inode *inode;
199 struct dentry *dentry;
200 int error;
202 /* System files? */
204 inode = gfs2_ilookup(sb, inum->no_addr);
205 if (inode) {
206 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
207 iput(inode);
208 return ERR_PTR(-ESTALE);
210 goto out_inode;
213 error = gfs2_glock_nq_num(sdp, inum->no_addr, &gfs2_inode_glops,
214 LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
215 if (error)
216 return ERR_PTR(error);
218 error = gfs2_rindex_hold(sdp, &ri_gh);
219 if (error)
220 goto fail;
222 error = -EINVAL;
223 rgd = gfs2_blk2rgrpd(sdp, inum->no_addr);
224 if (!rgd)
225 goto fail_rindex;
227 error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_SHARED, 0, &rgd_gh);
228 if (error)
229 goto fail_rindex;
231 error = -ESTALE;
232 if (gfs2_get_block_type(rgd, inum->no_addr) != GFS2_BLKST_DINODE)
233 goto fail_rgd;
235 gfs2_glock_dq_uninit(&rgd_gh);
236 gfs2_glock_dq_uninit(&ri_gh);
238 inode = gfs2_inode_lookup(sb, DT_UNKNOWN,
239 inum->no_addr,
241 if (!inode)
242 goto fail;
243 if (IS_ERR(inode)) {
244 error = PTR_ERR(inode);
245 goto fail;
248 error = gfs2_inode_refresh(GFS2_I(inode));
249 if (error) {
250 iput(inode);
251 goto fail;
254 /* Pick up the works we bypass in gfs2_inode_lookup */
255 if (inode->i_state & I_NEW)
256 gfs2_set_iop(inode);
258 if (GFS2_I(inode)->i_no_formal_ino != inum->no_formal_ino) {
259 iput(inode);
260 goto fail;
263 error = -EIO;
264 if (GFS2_I(inode)->i_di.di_flags & GFS2_DIF_SYSTEM) {
265 iput(inode);
266 goto fail;
269 gfs2_glock_dq_uninit(&i_gh);
271 out_inode:
272 dentry = d_alloc_anon(inode);
273 if (!dentry) {
274 iput(inode);
275 return ERR_PTR(-ENOMEM);
278 dentry->d_op = &gfs2_dops;
279 return dentry;
281 fail_rgd:
282 gfs2_glock_dq_uninit(&rgd_gh);
284 fail_rindex:
285 gfs2_glock_dq_uninit(&ri_gh);
287 fail:
288 gfs2_glock_dq_uninit(&i_gh);
289 return ERR_PTR(error);
292 struct export_operations gfs2_export_ops = {
293 .decode_fh = gfs2_decode_fh,
294 .encode_fh = gfs2_encode_fh,
295 .get_name = gfs2_get_name,
296 .get_parent = gfs2_get_parent,
297 .get_dentry = gfs2_get_dentry,