1 /* 2 * linux/fs/nfsd/nfs4recover.c 3 * 4 * Copyright (c) 2004 The Regents of the University of Michigan. 5 * All rights reserved. 6 * 7 * Andy Adamson <andros@citi.umich.edu> 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 25 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 * 34 */ 35 36 #include <linux/err.h> 37 #include <linux/sunrpc/svc.h> 38 #include <linux/nfsd/nfsd.h> 39 #include <linux/nfs4.h> 40 #include <linux/nfsd/state.h> 41 #include <linux/nfsd/xdr4.h> 42 #include <linux/param.h> 43 #include <linux/file.h> 44 #include <linux/namei.h> 45 #include <asm/uaccess.h> 46 #include <linux/scatterlist.h> 47 #include <linux/crypto.h> 48 #include <linux/sched.h> 49 #include <linux/mount.h> 50 51 #define NFSDDBG_FACILITY NFSDDBG_PROC 52 53 /* Globals */ 54 static struct nameidata rec_dir; 55 static int rec_dir_init = 0; 56 57 static void 58 nfs4_save_user(uid_t *saveuid, gid_t *savegid) 59 { 60 *saveuid = current->fsuid; 61 *savegid = current->fsgid; 62 current->fsuid = 0; 63 current->fsgid = 0; 64 } 65 66 static void 67 nfs4_reset_user(uid_t saveuid, gid_t savegid) 68 { 69 current->fsuid = saveuid; 70 current->fsgid = savegid; 71 } 72 73 static void 74 md5_to_hex(char *out, char *md5) 75 { 76 int i; 77 78 for (i=0; i<16; i++) { 79 unsigned char c = md5[i]; 80 81 *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 82 *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 83 } 84 *out = '\0'; 85 } 86 87 __be32 88 nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname) 89 { 90 struct xdr_netobj cksum; 91 struct hash_desc desc; 92 struct scatterlist sg; 93 __be32 status = nfserr_resource; 94 95 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n", 96 clname->len, clname->data); 97 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; 98 desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 99 if (IS_ERR(desc.tfm)) 100 goto out_no_tfm; 101 cksum.len = crypto_hash_digestsize(desc.tfm); 102 cksum.data = kmalloc(cksum.len, GFP_KERNEL); 103 if (cksum.data == NULL) 104 goto out; 105 106 sg_init_one(&sg, clname->data, clname->len); 107 108 if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data)) 109 goto out; 110 111 md5_to_hex(dname, cksum.data); 112 113 kfree(cksum.data); 114 status = nfs_ok; 115 out: 116 crypto_free_hash(desc.tfm); 117 out_no_tfm: 118 return status; 119 } 120 121 static void 122 nfsd4_sync_rec_dir(void) 123 { 124 mutex_lock(&rec_dir.path.dentry->d_inode->i_mutex); 125 nfsd_sync_dir(rec_dir.path.dentry); 126 mutex_unlock(&rec_dir.path.dentry->d_inode->i_mutex); 127 } 128 129 int 130 nfsd4_create_clid_dir(struct nfs4_client *clp) 131 { 132 char *dname = clp->cl_recdir; 133 struct dentry *dentry; 134 uid_t uid; 135 gid_t gid; 136 int status; 137 138 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); 139 140 if (!rec_dir_init || clp->cl_firststate) 141 return 0; 142 143 nfs4_save_user(&uid, &gid); 144 145 /* lock the parent */ 146 mutex_lock(&rec_dir.path.dentry->d_inode->i_mutex); 147 148 dentry = lookup_one_len(dname, rec_dir.path.dentry, HEXDIR_LEN-1); 149 if (IS_ERR(dentry)) { 150 status = PTR_ERR(dentry); 151 goto out_unlock; 152 } 153 status = -EEXIST; 154 if (dentry->d_inode) { 155 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n"); 156 goto out_put; 157 } 158 status = mnt_want_write(rec_dir.path.mnt); 159 if (status) 160 goto out_put; 161 status = vfs_mkdir(rec_dir.path.dentry->d_inode, dentry, S_IRWXU); 162 mnt_drop_write(rec_dir.path.mnt); 163 out_put: 164 dput(dentry); 165 out_unlock: 166 mutex_unlock(&rec_dir.path.dentry->d_inode->i_mutex); 167 if (status == 0) { 168 clp->cl_firststate = 1; 169 nfsd4_sync_rec_dir(); 170 } 171 nfs4_reset_user(uid, gid); 172 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); 173 return status; 174 } 175 176 typedef int (recdir_func)(struct dentry *, struct dentry *); 177 178 struct dentry_list { 179 struct dentry *dentry; 180 struct list_head list; 181 }; 182 183 struct dentry_list_arg { 184 struct list_head dentries; 185 struct dentry *parent; 186 }; 187 188 static int 189 nfsd4_build_dentrylist(void *arg, const char *name, int namlen, 190 loff_t offset, u64 ino, unsigned int d_type) 191 { 192 struct dentry_list_arg *dla = arg; 193 struct list_head *dentries = &dla->dentries; 194 struct dentry *parent = dla->parent; 195 struct dentry *dentry; 196 struct dentry_list *child; 197 198 if (name && isdotent(name, namlen)) 199 return 0; 200 dentry = lookup_one_len(name, parent, namlen); 201 if (IS_ERR(dentry)) 202 return PTR_ERR(dentry); 203 child = kmalloc(sizeof(*child), GFP_KERNEL); 204 if (child == NULL) 205 return -ENOMEM; 206 child->dentry = dentry; 207 list_add(&child->list, dentries); 208 return 0; 209 } 210 211 static int 212 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) 213 { 214 struct file *filp; 215 struct dentry_list_arg dla = { 216 .parent = dir, 217 }; 218 struct list_head *dentries = &dla.dentries; 219 struct dentry_list *child; 220 uid_t uid; 221 gid_t gid; 222 int status; 223 224 if (!rec_dir_init) 225 return 0; 226 227 nfs4_save_user(&uid, &gid); 228 229 filp = dentry_open(dget(dir), mntget(rec_dir.path.mnt), O_RDONLY); 230 status = PTR_ERR(filp); 231 if (IS_ERR(filp)) 232 goto out; 233 INIT_LIST_HEAD(dentries); 234 status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla); 235 fput(filp); 236 while (!list_empty(dentries)) { 237 child = list_entry(dentries->next, struct dentry_list, list); 238 status = f(dir, child->dentry); 239 if (status) 240 goto out; 241 list_del(&child->list); 242 dput(child->dentry); 243 kfree(child); 244 } 245 out: 246 while (!list_empty(dentries)) { 247 child = list_entry(dentries->next, struct dentry_list, list); 248 list_del(&child->list); 249 dput(child->dentry); 250 kfree(child); 251 } 252 nfs4_reset_user(uid, gid); 253 return status; 254 } 255 256 static int 257 nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry) 258 { 259 int status; 260 261 if (!S_ISREG(dir->d_inode->i_mode)) { 262 printk("nfsd4: non-file found in client recovery directory\n"); 263 return -EINVAL; 264 } 265 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); 266 status = vfs_unlink(dir->d_inode, dentry); 267 mutex_unlock(&dir->d_inode->i_mutex); 268 return status; 269 } 270 271 static int 272 nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry) 273 { 274 int status; 275 276 /* For now this directory should already be empty, but we empty it of 277 * any regular files anyway, just in case the directory was created by 278 * a kernel from the future.... */ 279 nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file); 280 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); 281 status = vfs_rmdir(dir->d_inode, dentry); 282 mutex_unlock(&dir->d_inode->i_mutex); 283 return status; 284 } 285 286 static int 287 nfsd4_unlink_clid_dir(char *name, int namlen) 288 { 289 struct dentry *dentry; 290 int status; 291 292 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); 293 294 mutex_lock(&rec_dir.path.dentry->d_inode->i_mutex); 295 dentry = lookup_one_len(name, rec_dir.path.dentry, namlen); 296 mutex_unlock(&rec_dir.path.dentry->d_inode->i_mutex); 297 if (IS_ERR(dentry)) { 298 status = PTR_ERR(dentry); 299 return status; 300 } 301 status = -ENOENT; 302 if (!dentry->d_inode) 303 goto out; 304 305 status = nfsd4_clear_clid_dir(rec_dir.path.dentry, dentry); 306 out: 307 dput(dentry); 308 return status; 309 } 310 311 void 312 nfsd4_remove_clid_dir(struct nfs4_client *clp) 313 { 314 uid_t uid; 315 gid_t gid; 316 int status; 317 318 if (!rec_dir_init || !clp->cl_firststate) 319 return; 320 321 status = mnt_want_write(rec_dir.path.mnt); 322 if (status) 323 goto out; 324 clp->cl_firststate = 0; 325 nfs4_save_user(&uid, &gid); 326 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); 327 nfs4_reset_user(uid, gid); 328 if (status == 0) 329 nfsd4_sync_rec_dir(); 330 mnt_drop_write(rec_dir.path.mnt); 331 out: 332 if (status) 333 printk("NFSD: Failed to remove expired client state directory" 334 " %.*s\n", HEXDIR_LEN, clp->cl_recdir); 335 return; 336 } 337 338 static int 339 purge_old(struct dentry *parent, struct dentry *child) 340 { 341 int status; 342 343 if (nfs4_has_reclaimed_state(child->d_name.name)) 344 return 0; 345 346 status = nfsd4_clear_clid_dir(parent, child); 347 if (status) 348 printk("failed to remove client recovery directory %s\n", 349 child->d_name.name); 350 /* Keep trying, success or failure: */ 351 return 0; 352 } 353 354 void 355 nfsd4_recdir_purge_old(void) { 356 int status; 357 358 if (!rec_dir_init) 359 return; 360 status = mnt_want_write(rec_dir.path.mnt); 361 if (status) 362 goto out; 363 status = nfsd4_list_rec_dir(rec_dir.path.dentry, purge_old); 364 if (status == 0) 365 nfsd4_sync_rec_dir(); 366 mnt_drop_write(rec_dir.path.mnt); 367 out: 368 if (status) 369 printk("nfsd4: failed to purge old clients from recovery" 370 " directory %s\n", rec_dir.path.dentry->d_name.name); 371 } 372 373 static int 374 load_recdir(struct dentry *parent, struct dentry *child) 375 { 376 if (child->d_name.len != HEXDIR_LEN - 1) { 377 printk("nfsd4: illegal name %s in recovery directory\n", 378 child->d_name.name); 379 /* Keep trying; maybe the others are OK: */ 380 return 0; 381 } 382 nfs4_client_to_reclaim(child->d_name.name); 383 return 0; 384 } 385 386 int 387 nfsd4_recdir_load(void) { 388 int status; 389 390 status = nfsd4_list_rec_dir(rec_dir.path.dentry, load_recdir); 391 if (status) 392 printk("nfsd4: failed loading clients from recovery" 393 " directory %s\n", rec_dir.path.dentry->d_name.name); 394 return status; 395 } 396 397 /* 398 * Hold reference to the recovery directory. 399 */ 400 401 void 402 nfsd4_init_recdir(char *rec_dirname) 403 { 404 uid_t uid = 0; 405 gid_t gid = 0; 406 int status; 407 408 printk("NFSD: Using %s as the NFSv4 state recovery directory\n", 409 rec_dirname); 410 411 BUG_ON(rec_dir_init); 412 413 nfs4_save_user(&uid, &gid); 414 415 status = path_lookup(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, 416 &rec_dir); 417 if (status) 418 printk("NFSD: unable to find recovery directory %s\n", 419 rec_dirname); 420 421 if (!status) 422 rec_dir_init = 1; 423 nfs4_reset_user(uid, gid); 424 } 425 426 void 427 nfsd4_shutdown_recdir(void) 428 { 429 if (!rec_dir_init) 430 return; 431 rec_dir_init = 0; 432 path_put(&rec_dir.path); 433 } 434