1 /* 2 * Copyright (c) 2002 Red Hat, Inc. All rights reserved. 3 * 4 * This software may be freely redistributed under the terms of the 5 * GNU General Public License. 6 * 7 * You should have received a copy of the GNU General Public License 8 * along with this program; if not, write to the Free Software 9 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 10 * 11 * Authors: David Woodhouse <dwmw2@cambridge.redhat.com> 12 * David Howells <dhowells@redhat.com> 13 * 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/slab.h> 20 #include <linux/fs.h> 21 #include <linux/pagemap.h> 22 #include "internal.h" 23 24 struct afs_iget_data { 25 struct afs_fid fid; 26 struct afs_volume *volume; /* volume on which resides */ 27 }; 28 29 /* 30 * map the AFS file status to the inode member variables 31 */ 32 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key) 33 { 34 struct inode *inode = AFS_VNODE_TO_I(vnode); 35 36 _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu", 37 vnode->status.type, 38 vnode->status.nlink, 39 (unsigned long long) vnode->status.size, 40 vnode->status.data_version, 41 vnode->status.mode); 42 43 switch (vnode->status.type) { 44 case AFS_FTYPE_FILE: 45 inode->i_mode = S_IFREG | vnode->status.mode; 46 inode->i_op = &afs_file_inode_operations; 47 inode->i_fop = &afs_file_operations; 48 break; 49 case AFS_FTYPE_DIR: 50 inode->i_mode = S_IFDIR | vnode->status.mode; 51 inode->i_op = &afs_dir_inode_operations; 52 inode->i_fop = &afs_dir_file_operations; 53 break; 54 case AFS_FTYPE_SYMLINK: 55 inode->i_mode = S_IFLNK | vnode->status.mode; 56 inode->i_op = &page_symlink_inode_operations; 57 break; 58 default: 59 printk("kAFS: AFS vnode with undefined type\n"); 60 return -EBADMSG; 61 } 62 63 inode->i_nlink = vnode->status.nlink; 64 inode->i_uid = vnode->status.owner; 65 inode->i_gid = 0; 66 inode->i_size = vnode->status.size; 67 inode->i_ctime.tv_sec = vnode->status.mtime_server; 68 inode->i_ctime.tv_nsec = 0; 69 inode->i_atime = inode->i_mtime = inode->i_ctime; 70 inode->i_blocks = 0; 71 inode->i_version = vnode->fid.unique; 72 inode->i_mapping->a_ops = &afs_fs_aops; 73 74 /* check to see whether a symbolic link is really a mountpoint */ 75 if (vnode->status.type == AFS_FTYPE_SYMLINK) { 76 afs_mntpt_check_symlink(vnode, key); 77 78 if (test_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags)) { 79 inode->i_mode = S_IFDIR | vnode->status.mode; 80 inode->i_op = &afs_mntpt_inode_operations; 81 inode->i_fop = &afs_mntpt_file_operations; 82 } 83 } 84 85 return 0; 86 } 87 88 /* 89 * iget5() comparator 90 */ 91 static int afs_iget5_test(struct inode *inode, void *opaque) 92 { 93 struct afs_iget_data *data = opaque; 94 95 return inode->i_ino == data->fid.vnode && 96 inode->i_version == data->fid.unique; 97 } 98 99 /* 100 * iget5() inode initialiser 101 */ 102 static int afs_iget5_set(struct inode *inode, void *opaque) 103 { 104 struct afs_iget_data *data = opaque; 105 struct afs_vnode *vnode = AFS_FS_I(inode); 106 107 inode->i_ino = data->fid.vnode; 108 inode->i_version = data->fid.unique; 109 vnode->fid = data->fid; 110 vnode->volume = data->volume; 111 112 return 0; 113 } 114 115 /* 116 * inode retrieval 117 */ 118 struct inode *afs_iget(struct super_block *sb, struct key *key, 119 struct afs_fid *fid, struct afs_file_status *status, 120 struct afs_callback *cb) 121 { 122 struct afs_iget_data data = { .fid = *fid }; 123 struct afs_super_info *as; 124 struct afs_vnode *vnode; 125 struct inode *inode; 126 int ret; 127 128 _enter(",{%u,%u,%u},,", fid->vid, fid->vnode, fid->unique); 129 130 as = sb->s_fs_info; 131 data.volume = as->volume; 132 133 inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set, 134 &data); 135 if (!inode) { 136 _leave(" = -ENOMEM"); 137 return ERR_PTR(-ENOMEM); 138 } 139 140 _debug("GOT INODE %p { vl=%x vn=%x, u=%x }", 141 inode, fid->vid, fid->vnode, fid->unique); 142 143 vnode = AFS_FS_I(inode); 144 145 /* deal with an existing inode */ 146 if (!(inode->i_state & I_NEW)) { 147 _leave(" = %p", inode); 148 return inode; 149 } 150 151 #ifdef AFS_CACHING_SUPPORT 152 /* set up caching before reading the status, as fetch-status reads the 153 * first page of symlinks to see if they're really mntpts */ 154 cachefs_acquire_cookie(vnode->volume->cache, 155 NULL, 156 vnode, 157 &vnode->cache); 158 #endif 159 160 if (!status) { 161 /* it's a remotely extant inode */ 162 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 163 ret = afs_vnode_fetch_status(vnode, NULL, key); 164 if (ret < 0) 165 goto bad_inode; 166 } else { 167 /* it's an inode we just created */ 168 memcpy(&vnode->status, status, sizeof(vnode->status)); 169 170 if (!cb) { 171 /* it's a symlink we just created (the fileserver 172 * didn't give us a callback) */ 173 vnode->cb_version = 0; 174 vnode->cb_expiry = 0; 175 vnode->cb_type = 0; 176 vnode->cb_expires = get_seconds(); 177 } else { 178 vnode->cb_version = cb->version; 179 vnode->cb_expiry = cb->expiry; 180 vnode->cb_type = cb->type; 181 vnode->cb_expires = vnode->cb_expiry + get_seconds(); 182 } 183 } 184 185 ret = afs_inode_map_status(vnode, key); 186 if (ret < 0) 187 goto bad_inode; 188 189 /* success */ 190 clear_bit(AFS_VNODE_UNSET, &vnode->flags); 191 inode->i_flags |= S_NOATIME; 192 unlock_new_inode(inode); 193 _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type); 194 return inode; 195 196 /* failure */ 197 bad_inode: 198 make_bad_inode(inode); 199 unlock_new_inode(inode); 200 iput(inode); 201 202 _leave(" = %d [bad]", ret); 203 return ERR_PTR(ret); 204 } 205 206 /* 207 * validate a vnode/inode 208 * - there are several things we need to check 209 * - parent dir data changes (rm, rmdir, rename, mkdir, create, link, 210 * symlink) 211 * - parent dir metadata changed (security changes) 212 * - dentry data changed (write, truncate) 213 * - dentry metadata changed (security changes) 214 */ 215 int afs_validate(struct afs_vnode *vnode, struct key *key) 216 { 217 int ret; 218 219 _enter("{v={%x:%u} fl=%lx},%x", 220 vnode->fid.vid, vnode->fid.vnode, vnode->flags, 221 key_serial(key)); 222 223 if (vnode->cb_promised && 224 !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) && 225 !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) && 226 !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) { 227 if (vnode->cb_expires < get_seconds() + 10) { 228 _debug("callback expired"); 229 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); 230 } else { 231 goto valid; 232 } 233 } 234 235 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) 236 goto valid; 237 238 mutex_lock(&vnode->validate_lock); 239 240 /* if the promise has expired, we need to check the server again to get 241 * a new promise - note that if the (parent) directory's metadata was 242 * changed then the security may be different and we may no longer have 243 * access */ 244 if (!vnode->cb_promised || 245 test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) { 246 _debug("not promised"); 247 ret = afs_vnode_fetch_status(vnode, NULL, key); 248 if (ret < 0) 249 goto error_unlock; 250 _debug("new promise [fl=%lx]", vnode->flags); 251 } 252 253 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { 254 _debug("file already deleted"); 255 ret = -ESTALE; 256 goto error_unlock; 257 } 258 259 /* if the vnode's data version number changed then its contents are 260 * different */ 261 if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) { 262 _debug("zap data {%x:%d}", vnode->fid.vid, vnode->fid.vnode); 263 invalidate_remote_inode(&vnode->vfs_inode); 264 } 265 266 clear_bit(AFS_VNODE_MODIFIED, &vnode->flags); 267 mutex_unlock(&vnode->validate_lock); 268 valid: 269 _leave(" = 0"); 270 return 0; 271 272 error_unlock: 273 mutex_unlock(&vnode->validate_lock); 274 _leave(" = %d", ret); 275 return ret; 276 } 277 278 /* 279 * read the attributes of an inode 280 */ 281 int afs_inode_getattr(struct vfsmount *mnt, struct dentry *dentry, 282 struct kstat *stat) 283 { 284 struct inode *inode; 285 286 inode = dentry->d_inode; 287 288 _enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version); 289 290 generic_fillattr(inode, stat); 291 return 0; 292 } 293 294 /* 295 * clear an AFS inode 296 */ 297 void afs_clear_inode(struct inode *inode) 298 { 299 struct afs_permits *permits; 300 struct afs_vnode *vnode; 301 302 vnode = AFS_FS_I(inode); 303 304 _enter("{%x:%d.%d} v=%u x=%u t=%u }", 305 vnode->fid.vid, 306 vnode->fid.vnode, 307 vnode->fid.unique, 308 vnode->cb_version, 309 vnode->cb_expiry, 310 vnode->cb_type); 311 312 _debug("CLEAR INODE %p", inode); 313 314 ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode); 315 316 afs_give_up_callback(vnode); 317 318 if (vnode->server) { 319 spin_lock(&vnode->server->fs_lock); 320 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes); 321 spin_unlock(&vnode->server->fs_lock); 322 afs_put_server(vnode->server); 323 vnode->server = NULL; 324 } 325 326 ASSERT(!vnode->cb_promised); 327 328 #ifdef AFS_CACHING_SUPPORT 329 cachefs_relinquish_cookie(vnode->cache, 0); 330 vnode->cache = NULL; 331 #endif 332 333 mutex_lock(&vnode->permits_lock); 334 permits = vnode->permits; 335 rcu_assign_pointer(vnode->permits, NULL); 336 mutex_unlock(&vnode->permits_lock); 337 if (permits) 338 call_rcu(&permits->rcu, afs_zap_permits); 339 340 _leave(""); 341 } 342