fs/nfsd/nfs4recover.c

   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
  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 <asm/scatterlist.h>
  47 #include <linux/crypto.h>
  48
  49
  50 #define NFSDDBG_FACILITY                NFSDDBG_PROC
  51
  52 /* Globals */
  53 static struct nameidata rec_dir;
  54 static int rec_dir_init = 0;
  55
  56 static void
  57 nfs4_save_user(uid_t *saveuid, gid_t *savegid)
  58 {
  59         *saveuid = current->fsuid;
  60         *savegid = current->fsgid;
  61         current->fsuid = 0;
  62         current->fsgid = 0;
  63 }
  64
  65 static void
  66 nfs4_reset_user(uid_t saveuid, gid_t savegid)
  67 {
  68         current->fsuid = saveuid;
  69         current->fsgid = savegid;
  70 }
  71
  72 static void
  73 md5_to_hex(char *out, char *md5)
  74 {
  75         int i;
  76
  77         for (i=0; i<16; i++) {
  78                 unsigned char c = md5[i];
  79
  80                 *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
  81                 *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
  82         }
  83         *out = '\0';
  84 }
  85
  86 int
  87 nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
  88 {
  89         struct xdr_netobj cksum;
  90         struct crypto_tfm *tfm;
  91         struct scatterlist sg[1];
  92         int status = nfserr_resource;
  93
  94         dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
  95                         clname->len, clname->data);
  96         tfm = crypto_alloc_tfm("md5", CRYPTO_TFM_REQ_MAY_SLEEP);
  97         if (tfm == NULL)
  98                 goto out;
  99         cksum.len = crypto_tfm_alg_digestsize(tfm);
 100         cksum.data = kmalloc(cksum.len, GFP_KERNEL);
 101         if (cksum.data == NULL)
 102                 goto out;
 103         crypto_digest_init(tfm);
 104
 105         sg[0].page = virt_to_page(clname->data);
 106         sg[0].offset = offset_in_page(clname->data);
 107         sg[0].length = clname->len;
 108
 109         crypto_digest_update(tfm, sg, 1);
 110         crypto_digest_final(tfm, cksum.data);
 111
 112         md5_to_hex(dname, cksum.data);
 113
 114         kfree(cksum.data);
 115         status = nfs_ok;
 116 out:
 117         crypto_free_tfm(tfm);
 118         return status;
 119 }
 120
 121 static void
 122 nfsd4_sync_rec_dir(void)
 123 {
 124         mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
 125         nfsd_sync_dir(rec_dir.dentry);
 126         mutex_unlock(&rec_dir.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.dentry->d_inode->i_mutex);
 147
 148         dentry = lookup_one_len(dname, rec_dir.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 = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
 159 out_put:
 160         dput(dentry);
 161 out_unlock:
 162         mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
 163         if (status == 0) {
 164                 clp->cl_firststate = 1;
 165                 nfsd4_sync_rec_dir();
 166         }
 167         nfs4_reset_user(uid, gid);
 168         dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
 169         return status;
 170 }
 171
 172 typedef int (recdir_func)(struct dentry *, struct dentry *);
 173
 174 struct dentry_list {
 175         struct dentry *dentry;
 176         struct list_head list;
 177 };
 178
 179 struct dentry_list_arg {
 180         struct list_head dentries;
 181         struct dentry *parent;
 182 };
 183
 184 static int
 185 nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
 186                 loff_t offset, ino_t ino, unsigned int d_type)
 187 {
 188         struct dentry_list_arg *dla = arg;
 189         struct list_head *dentries = &dla->dentries;
 190         struct dentry *parent = dla->parent;
 191         struct dentry *dentry;
 192         struct dentry_list *child;
 193
 194         if (name && isdotent(name, namlen))
 195                 return nfs_ok;
 196         dentry = lookup_one_len(name, parent, namlen);
 197         if (IS_ERR(dentry))
 198                 return PTR_ERR(dentry);
 199         child = kmalloc(sizeof(*child), GFP_KERNEL);
 200         if (child == NULL)
 201                 return -ENOMEM;
 202         child->dentry = dentry;
 203         list_add(&child->list, dentries);
 204         return 0;
 205 }
 206
 207 static int
 208 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
 209 {
 210         struct file *filp;
 211         struct dentry_list_arg dla = {
 212                 .parent = dir,
 213         };
 214         struct list_head *dentries = &dla.dentries;
 215         struct dentry_list *child;
 216         uid_t uid;
 217         gid_t gid;
 218         int status;
 219
 220         if (!rec_dir_init)
 221                 return 0;
 222
 223         nfs4_save_user(&uid, &gid);
 224
 225         filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY);
 226         status = PTR_ERR(filp);
 227         if (IS_ERR(filp))
 228                 goto out;
 229         INIT_LIST_HEAD(dentries);
 230         status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
 231         fput(filp);
 232         while (!list_empty(dentries)) {
 233                 child = list_entry(dentries->next, struct dentry_list, list);
 234                 status = f(dir, child->dentry);
 235                 if (status)
 236                         goto out;
 237                 list_del(&child->list);
 238                 dput(child->dentry);
 239                 kfree(child);
 240         }
 241 out:
 242         while (!list_empty(dentries)) {
 243                 child = list_entry(dentries->next, struct dentry_list, list);
 244                 list_del(&child->list);
 245                 dput(child->dentry);
 246                 kfree(child);
 247         }
 248         nfs4_reset_user(uid, gid);
 249         return status;
 250 }
 251
 252 static int
 253 nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
 254 {
 255         int status;
 256
 257         if (!S_ISREG(dir->d_inode->i_mode)) {
 258                 printk("nfsd4: non-file found in client recovery directory\n");
 259                 return -EINVAL;
 260         }
 261         mutex_lock(&dir->d_inode->i_mutex);
 262         status = vfs_unlink(dir->d_inode, dentry);
 263         mutex_unlock(&dir->d_inode->i_mutex);
 264         return status;
 265 }
 266
 267 static int
 268 nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
 269 {
 270         int status;
 271
 272         /* For now this directory should already be empty, but we empty it of
 273          * any regular files anyway, just in case the directory was created by
 274          * a kernel from the future.... */
 275         nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
 276         mutex_lock(&dir->d_inode->i_mutex);
 277         status = vfs_rmdir(dir->d_inode, dentry);
 278         mutex_unlock(&dir->d_inode->i_mutex);
 279         return status;
 280 }
 281
 282 static int
 283 nfsd4_unlink_clid_dir(char *name, int namlen)
 284 {
 285         struct dentry *dentry;
 286         int status;
 287
 288         dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 289
 290         mutex_lock(&rec_dir.dentry->d_inode->i_mutex);
 291         dentry = lookup_one_len(name, rec_dir.dentry, namlen);
 292         mutex_unlock(&rec_dir.dentry->d_inode->i_mutex);
 293         if (IS_ERR(dentry)) {
 294                 status = PTR_ERR(dentry);
 295                 return status;
 296         }
 297         status = -ENOENT;
 298         if (!dentry->d_inode)
 299                 goto out;
 300
 301         status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
 302 out:
 303         dput(dentry);
 304         return status;
 305 }
 306
 307 void
 308 nfsd4_remove_clid_dir(struct nfs4_client *clp)
 309 {
 310         uid_t uid;
 311         gid_t gid;
 312         int status;
 313
 314         if (!rec_dir_init || !clp->cl_firststate)
 315                 return;
 316
 317         clp->cl_firststate = 0;
 318         nfs4_save_user(&uid, &gid);
 319         status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
 320         nfs4_reset_user(uid, gid);
 321         if (status == 0)
 322                 nfsd4_sync_rec_dir();
 323         if (status)
 324                 printk("NFSD: Failed to remove expired client state directory"
 325                                 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
 326         return;
 327 }
 328
 329 static int
 330 purge_old(struct dentry *parent, struct dentry *child)
 331 {
 332         int status;
 333
 334         if (nfs4_has_reclaimed_state(child->d_name.name))
 335                 return nfs_ok;
 336
 337         status = nfsd4_clear_clid_dir(parent, child);
 338         if (status)
 339                 printk("failed to remove client recovery directory %s\n",
 340                                 child->d_name.name);
 341         /* Keep trying, success or failure: */
 342         return nfs_ok;
 343 }
 344
 345 void
 346 nfsd4_recdir_purge_old(void) {
 347         int status;
 348
 349         if (!rec_dir_init)
 350                 return;
 351         status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
 352         if (status == 0)
 353                 nfsd4_sync_rec_dir();
 354         if (status)
 355                 printk("nfsd4: failed to purge old clients from recovery"
 356                         " directory %s\n", rec_dir.dentry->d_name.name);
 357         return;
 358 }
 359
 360 static int
 361 load_recdir(struct dentry *parent, struct dentry *child)
 362 {
 363         if (child->d_name.len != HEXDIR_LEN - 1) {
 364                 printk("nfsd4: illegal name %s in recovery directory\n",
 365                                 child->d_name.name);
 366                 /* Keep trying; maybe the others are OK: */
 367                 return nfs_ok;
 368         }
 369         nfs4_client_to_reclaim(child->d_name.name);
 370         return nfs_ok;
 371 }
 372
 373 int
 374 nfsd4_recdir_load(void) {
 375         int status;
 376
 377         status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
 378         if (status)
 379                 printk("nfsd4: failed loading clients from recovery"
 380                         " directory %s\n", rec_dir.dentry->d_name.name);
 381         return status;
 382 }
 383
 384 /*
 385  * Hold reference to the recovery directory.
 386  */
 387
 388 void
 389 nfsd4_init_recdir(char *rec_dirname)
 390 {
 391         uid_t                   uid = 0;
 392         gid_t                   gid = 0;
 393         int                     status;
 394
 395         printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 396                         rec_dirname);
 397
 398         BUG_ON(rec_dir_init);
 399
 400         nfs4_save_user(&uid, &gid);
 401
 402         status = path_lookup(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
 403                         &rec_dir);
 404         if (status)
 405                 printk("NFSD: unable to find recovery directory %s\n",
 406                                 rec_dirname);
 407
 408         if (!status)
 409                 rec_dir_init = 1;
 410         nfs4_reset_user(uid, gid);
 411 }
 412
 413 void
 414 nfsd4_shutdown_recdir(void)
 415 {
 416         if (!rec_dir_init)
 417                 return;
 418         rec_dir_init = 0;
 419         path_release(&rec_dir);
 420 }