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 char recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
  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 int
  88 nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname)
  89 {
  90         struct xdr_netobj cksum;
  91         struct crypto_tfm *tfm;
  92         struct scatterlist sg[1];
  93         int status = nfserr_resource;
  94
  95         dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
  96                         clname->len, clname->data);
  97         tfm = crypto_alloc_tfm("md5", 0);
  98         if (tfm == NULL)
  99                 goto out;
 100         cksum.len = crypto_tfm_alg_digestsize(tfm);
 101         cksum.data = kmalloc(cksum.len, GFP_KERNEL);
 102         if (cksum.data == NULL)
 103                 goto out;
 104         crypto_digest_init(tfm);
 105
 106         sg[0].page = virt_to_page(clname->data);
 107         sg[0].offset = offset_in_page(clname->data);
 108         sg[0].length = clname->len;
 109
 110         crypto_digest_update(tfm, sg, 1);
 111         crypto_digest_final(tfm, cksum.data);
 112
 113         md5_to_hex(dname, cksum.data);
 114
 115         kfree(cksum.data);
 116         status = nfs_ok;
 117 out:
 118         if (tfm)
 119                 crypto_free_tfm(tfm);
 120         return status;
 121 }
 122
 123 static int
 124 nfsd4_rec_fsync(struct dentry *dentry)
 125 {
 126         struct file *filp;
 127         int status = nfs_ok;
 128
 129         dprintk("NFSD: nfs4_fsync_rec_dir\n");
 130         filp = dentry_open(dget(dentry), mntget(rec_dir.mnt), O_RDWR);
 131         if (IS_ERR(filp)) {
 132                 status = PTR_ERR(filp);
 133                 goto out;
 134         }
 135         if (filp->f_op && filp->f_op->fsync)
 136                 status = filp->f_op->fsync(filp, filp->f_dentry, 0);
 137         fput(filp);
 138 out:
 139         if (status)
 140                 printk("nfsd4: unable to sync recovery directory\n");
 141         return status;
 142 }
 143
 144 int
 145 nfsd4_create_clid_dir(struct nfs4_client *clp)
 146 {
 147         char *dname = clp->cl_recdir;
 148         struct dentry *dentry;
 149         uid_t uid;
 150         gid_t gid;
 151         int status;
 152
 153         dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
 154
 155         if (!rec_dir_init || clp->cl_firststate)
 156                 return 0;
 157
 158         nfs4_save_user(&uid, &gid);
 159
 160         /* lock the parent */
 161         down(&rec_dir.dentry->d_inode->i_sem);
 162
 163         dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
 164         if (IS_ERR(dentry)) {
 165                 status = PTR_ERR(dentry);
 166                 goto out_unlock;
 167         }
 168         status = -EEXIST;
 169         if (dentry->d_inode) {
 170                 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
 171                 goto out_put;
 172         }
 173         status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
 174 out_put:
 175         dput(dentry);
 176 out_unlock:
 177         up(&rec_dir.dentry->d_inode->i_sem);
 178         if (status == 0) {
 179                 clp->cl_firststate = 1;
 180                 status = nfsd4_rec_fsync(rec_dir.dentry);
 181         }
 182         nfs4_reset_user(uid, gid);
 183         dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
 184         return status;
 185 }
 186
 187 typedef int (recdir_func)(struct dentry *, struct dentry *);
 188
 189 struct dentry_list {
 190         struct dentry *dentry;
 191         struct list_head list;
 192 };
 193
 194 struct dentry_list_arg {
 195         struct list_head dentries;
 196         struct dentry *parent;
 197 };
 198
 199 static int
 200 nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
 201                 loff_t offset, ino_t ino, unsigned int d_type)
 202 {
 203         struct dentry_list_arg *dla = arg;
 204         struct list_head *dentries = &dla->dentries;
 205         struct dentry *parent = dla->parent;
 206         struct dentry *dentry;
 207         struct dentry_list *child;
 208
 209         if (name && isdotent(name, namlen))
 210                 return nfs_ok;
 211         dentry = lookup_one_len(name, parent, namlen);
 212         if (IS_ERR(dentry))
 213                 return PTR_ERR(dentry);
 214         child = kmalloc(sizeof(*child), GFP_KERNEL);
 215         if (child == NULL)
 216                 return -ENOMEM;
 217         child->dentry = dentry;
 218         list_add(&child->list, dentries);
 219         return 0;
 220 }
 221
 222 static int
 223 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
 224 {
 225         struct file *filp;
 226         struct dentry_list_arg dla = {
 227                 .parent = dir,
 228         };
 229         struct list_head *dentries = &dla.dentries;
 230         struct dentry_list *child;
 231         uid_t uid;
 232         gid_t gid;
 233         int status;
 234
 235         if (!rec_dir_init)
 236                 return 0;
 237
 238         nfs4_save_user(&uid, &gid);
 239
 240         filp = dentry_open(dget(dir), mntget(rec_dir.mnt),
 241                         O_RDWR);
 242         status = PTR_ERR(filp);
 243         if (IS_ERR(filp))
 244                 goto out;
 245         INIT_LIST_HEAD(dentries);
 246         status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
 247         fput(filp);
 248         while (!list_empty(dentries)) {
 249                 child = list_entry(dentries->next, struct dentry_list, list);
 250                 status = f(dir, child->dentry);
 251                 if (status)
 252                         goto out;
 253                 list_del(&child->list);
 254                 dput(child->dentry);
 255                 kfree(child);
 256         }
 257 out:
 258         while (!list_empty(dentries)) {
 259                 child = list_entry(dentries->next, struct dentry_list, list);
 260                 list_del(&child->list);
 261                 dput(child->dentry);
 262                 kfree(child);
 263         }
 264         nfs4_reset_user(uid, gid);
 265         return status;
 266 }
 267
 268 static int
 269 nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
 270 {
 271         int status;
 272
 273         if (!S_ISREG(dir->d_inode->i_mode)) {
 274                 printk("nfsd4: non-file found in client recovery directory\n");
 275                 return -EINVAL;
 276         }
 277         down(&dir->d_inode->i_sem);
 278         status = vfs_unlink(dir->d_inode, dentry);
 279         up(&dir->d_inode->i_sem);
 280         return status;
 281 }
 282
 283 static int
 284 nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
 285 {
 286         int status;
 287
 288         /* For now this directory should already be empty, but we empty it of
 289          * any regular files anyway, just in case the directory was created by
 290          * a kernel from the future.... */
 291         nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
 292         down(&dir->d_inode->i_sem);
 293         status = vfs_rmdir(dir->d_inode, dentry);
 294         up(&dir->d_inode->i_sem);
 295         return status;
 296 }
 297
 298 static int
 299 nfsd4_unlink_clid_dir(char *name, int namlen)
 300 {
 301         struct dentry *dentry;
 302         int status;
 303
 304         dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 305
 306         dentry = lookup_one_len(name, rec_dir.dentry, namlen);
 307         if (IS_ERR(dentry)) {
 308                 status = PTR_ERR(dentry);
 309                 return status;
 310         }
 311         status = -ENOENT;
 312         if (!dentry->d_inode)
 313                 goto out;
 314
 315         status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
 316 out:
 317         dput(dentry);
 318         return status;
 319 }
 320
 321 void
 322 nfsd4_remove_clid_dir(struct nfs4_client *clp)
 323 {
 324         uid_t uid;
 325         gid_t gid;
 326         int status;
 327
 328         if (!rec_dir_init || !clp->cl_firststate)
 329                 return;
 330
 331         nfs4_save_user(&uid, &gid);
 332         status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
 333         nfs4_reset_user(uid, gid);
 334         if (status == 0)
 335                 status = nfsd4_rec_fsync(rec_dir.dentry);
 336         if (status)
 337                 printk("NFSD: Failed to remove expired client state directory"
 338                                 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
 339         return;
 340 }
 341
 342 static int
 343 purge_old(struct dentry *parent, struct dentry *child)
 344 {
 345         int status;
 346
 347         if (nfs4_has_reclaimed_state(child->d_name.name))
 348                 return nfs_ok;
 349
 350         status = nfsd4_clear_clid_dir(parent, child);
 351         if (status)
 352                 printk("failed to remove client recovery directory %s\n",
 353                                 child->d_name.name);
 354         /* Keep trying, success or failure: */
 355         return nfs_ok;
 356 }
 357
 358 void
 359 nfsd4_recdir_purge_old(void) {
 360         int status;
 361
 362         if (!rec_dir_init)
 363                 return;
 364         status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
 365         if (status == 0)
 366                 status = nfsd4_rec_fsync(rec_dir.dentry);
 367         if (status)
 368                 printk("nfsd4: failed to purge old clients from recovery"
 369                         " directory %s\n", rec_dir.dentry->d_name.name);
 370         return;
 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 nfs_ok;
 381         }
 382         nfs4_client_to_reclaim(child->d_name.name);
 383         return nfs_ok;
 384 }
 385
 386 int
 387 nfsd4_recdir_load(void) {
 388         int status;
 389
 390         status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
 391         if (status)
 392                 printk("nfsd4: failed loading clients from recovery"
 393                         " directory %s\n", rec_dir.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, &rec_dir);
 416         if (status == -ENOENT)
 417                 printk("NFSD: recovery directory %s doesn't exist\n",
 418                                 rec_dirname);
 419
 420         if (!status)
 421                 rec_dir_init = 1;
 422         nfs4_reset_user(uid, gid);
 423 }
 424
 425 void
 426 nfsd4_shutdown_recdir(void)
 427 {
 428         if (!rec_dir_init)
 429                 return;
 430         rec_dir_init = 0;
 431         path_release(&rec_dir);
 432 }