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", 0);
  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         if (tfm)
 118                 crypto_free_tfm(tfm);
 119         return status;
 120 }
 121
 122 static int
 123 nfsd4_rec_fsync(struct dentry *dentry)
 124 {
 125         struct file *filp;
 126         int status = nfs_ok;
 127
 128         dprintk("NFSD: nfs4_fsync_rec_dir\n");
 129         filp = dentry_open(dget(dentry), mntget(rec_dir.mnt), O_RDWR);
 130         if (IS_ERR(filp)) {
 131                 status = PTR_ERR(filp);
 132                 goto out;
 133         }
 134         if (filp->f_op && filp->f_op->fsync)
 135                 status = filp->f_op->fsync(filp, filp->f_dentry, 0);
 136         fput(filp);
 137 out:
 138         if (status)
 139                 printk("nfsd4: unable to sync recovery directory\n");
 140         return status;
 141 }
 142
 143 int
 144 nfsd4_create_clid_dir(struct nfs4_client *clp)
 145 {
 146         char *dname = clp->cl_recdir;
 147         struct dentry *dentry;
 148         uid_t uid;
 149         gid_t gid;
 150         int status;
 151
 152         dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
 153
 154         if (!rec_dir_init || clp->cl_firststate)
 155                 return 0;
 156
 157         nfs4_save_user(&uid, &gid);
 158
 159         /* lock the parent */
 160         down(&rec_dir.dentry->d_inode->i_sem);
 161
 162         dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
 163         if (IS_ERR(dentry)) {
 164                 status = PTR_ERR(dentry);
 165                 goto out_unlock;
 166         }
 167         status = -EEXIST;
 168         if (dentry->d_inode) {
 169                 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
 170                 goto out_put;
 171         }
 172         status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
 173 out_put:
 174         dput(dentry);
 175 out_unlock:
 176         up(&rec_dir.dentry->d_inode->i_sem);
 177         if (status == 0) {
 178                 clp->cl_firststate = 1;
 179                 status = nfsd4_rec_fsync(rec_dir.dentry);
 180         }
 181         nfs4_reset_user(uid, gid);
 182         dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
 183         return status;
 184 }
 185
 186 typedef int (recdir_func)(struct dentry *, struct dentry *);
 187
 188 struct dentry_list {
 189         struct dentry *dentry;
 190         struct list_head list;
 191 };
 192
 193 struct dentry_list_arg {
 194         struct list_head dentries;
 195         struct dentry *parent;
 196 };
 197
 198 static int
 199 nfsd4_build_dentrylist(void *arg, const char *name, int namlen,
 200                 loff_t offset, ino_t ino, unsigned int d_type)
 201 {
 202         struct dentry_list_arg *dla = arg;
 203         struct list_head *dentries = &dla->dentries;
 204         struct dentry *parent = dla->parent;
 205         struct dentry *dentry;
 206         struct dentry_list *child;
 207
 208         if (name && isdotent(name, namlen))
 209                 return nfs_ok;
 210         dentry = lookup_one_len(name, parent, namlen);
 211         if (IS_ERR(dentry))
 212                 return PTR_ERR(dentry);
 213         child = kmalloc(sizeof(*child), GFP_KERNEL);
 214         if (child == NULL)
 215                 return -ENOMEM;
 216         child->dentry = dentry;
 217         list_add(&child->list, dentries);
 218         return 0;
 219 }
 220
 221 static int
 222 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f)
 223 {
 224         struct file *filp;
 225         struct dentry_list_arg dla = {
 226                 .parent = dir,
 227         };
 228         struct list_head *dentries = &dla.dentries;
 229         struct dentry_list *child;
 230         uid_t uid;
 231         gid_t gid;
 232         int status;
 233
 234         if (!rec_dir_init)
 235                 return 0;
 236
 237         nfs4_save_user(&uid, &gid);
 238
 239         filp = dentry_open(dget(dir), mntget(rec_dir.mnt),
 240                         O_RDWR);
 241         status = PTR_ERR(filp);
 242         if (IS_ERR(filp))
 243                 goto out;
 244         INIT_LIST_HEAD(dentries);
 245         status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla);
 246         fput(filp);
 247         while (!list_empty(dentries)) {
 248                 child = list_entry(dentries->next, struct dentry_list, list);
 249                 status = f(dir, child->dentry);
 250                 if (status)
 251                         goto out;
 252                 list_del(&child->list);
 253                 dput(child->dentry);
 254                 kfree(child);
 255         }
 256 out:
 257         while (!list_empty(dentries)) {
 258                 child = list_entry(dentries->next, struct dentry_list, list);
 259                 list_del(&child->list);
 260                 dput(child->dentry);
 261                 kfree(child);
 262         }
 263         nfs4_reset_user(uid, gid);
 264         return status;
 265 }
 266
 267 static int
 268 nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
 269 {
 270         int status;
 271
 272         if (!S_ISREG(dir->d_inode->i_mode)) {
 273                 printk("nfsd4: non-file found in client recovery directory\n");
 274                 return -EINVAL;
 275         }
 276         down(&dir->d_inode->i_sem);
 277         status = vfs_unlink(dir->d_inode, dentry);
 278         up(&dir->d_inode->i_sem);
 279         return status;
 280 }
 281
 282 static int
 283 nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
 284 {
 285         int status;
 286
 287         /* For now this directory should already be empty, but we empty it of
 288          * any regular files anyway, just in case the directory was created by
 289          * a kernel from the future.... */
 290         nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
 291         down(&dir->d_inode->i_sem);
 292         status = vfs_rmdir(dir->d_inode, dentry);
 293         up(&dir->d_inode->i_sem);
 294         return status;
 295 }
 296
 297 static int
 298 nfsd4_unlink_clid_dir(char *name, int namlen)
 299 {
 300         struct dentry *dentry;
 301         int status;
 302
 303         dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
 304
 305         dentry = lookup_one_len(name, rec_dir.dentry, namlen);
 306         if (IS_ERR(dentry)) {
 307                 status = PTR_ERR(dentry);
 308                 return status;
 309         }
 310         status = -ENOENT;
 311         if (!dentry->d_inode)
 312                 goto out;
 313
 314         status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
 315 out:
 316         dput(dentry);
 317         return status;
 318 }
 319
 320 void
 321 nfsd4_remove_clid_dir(struct nfs4_client *clp)
 322 {
 323         uid_t uid;
 324         gid_t gid;
 325         int status;
 326
 327         if (!rec_dir_init || !clp->cl_firststate)
 328                 return;
 329
 330         nfs4_save_user(&uid, &gid);
 331         status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
 332         nfs4_reset_user(uid, gid);
 333         if (status == 0)
 334                 status = nfsd4_rec_fsync(rec_dir.dentry);
 335         if (status)
 336                 printk("NFSD: Failed to remove expired client state directory"
 337                                 " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
 338         return;
 339 }
 340
 341 static int
 342 purge_old(struct dentry *parent, struct dentry *child)
 343 {
 344         int status;
 345
 346         if (nfs4_has_reclaimed_state(child->d_name.name))
 347                 return nfs_ok;
 348
 349         status = nfsd4_clear_clid_dir(parent, child);
 350         if (status)
 351                 printk("failed to remove client recovery directory %s\n",
 352                                 child->d_name.name);
 353         /* Keep trying, success or failure: */
 354         return nfs_ok;
 355 }
 356
 357 void
 358 nfsd4_recdir_purge_old(void) {
 359         int status;
 360
 361         if (!rec_dir_init)
 362                 return;
 363         status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
 364         if (status == 0)
 365                 status = nfsd4_rec_fsync(rec_dir.dentry);
 366         if (status)
 367                 printk("nfsd4: failed to purge old clients from recovery"
 368                         " directory %s\n", rec_dir.dentry->d_name.name);
 369         return;
 370 }
 371
 372 static int
 373 load_recdir(struct dentry *parent, struct dentry *child)
 374 {
 375         if (child->d_name.len != HEXDIR_LEN - 1) {
 376                 printk("nfsd4: illegal name %s in recovery directory\n",
 377                                 child->d_name.name);
 378                 /* Keep trying; maybe the others are OK: */
 379                 return nfs_ok;
 380         }
 381         nfs4_client_to_reclaim(child->d_name.name);
 382         return nfs_ok;
 383 }
 384
 385 int
 386 nfsd4_recdir_load(void) {
 387         int status;
 388
 389         status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir);
 390         if (status)
 391                 printk("nfsd4: failed loading clients from recovery"
 392                         " directory %s\n", rec_dir.dentry->d_name.name);
 393         return status;
 394 }
 395
 396 /*
 397  * Hold reference to the recovery directory.
 398  */
 399
 400 void
 401 nfsd4_init_recdir(char *rec_dirname)
 402 {
 403         uid_t                   uid = 0;
 404         gid_t                   gid = 0;
 405         int                     status;
 406
 407         printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
 408                         rec_dirname);
 409
 410         BUG_ON(rec_dir_init);
 411
 412         nfs4_save_user(&uid, &gid);
 413
 414         status = path_lookup(rec_dirname, LOOKUP_FOLLOW, &rec_dir);
 415         if (status == -ENOENT)
 416                 printk("NFSD: recovery directory %s doesn't exist\n",
 417                                 rec_dirname);
 418
 419         if (!status)
 420                 rec_dir_init = 1;
 421         nfs4_reset_user(uid, gid);
 422 }
 423
 424 void
 425 nfsd4_shutdown_recdir(void)
 426 {
 427         if (!rec_dir_init)
 428                 return;
 429         rec_dir_init = 0;
 430         path_release(&rec_dir);
 431 }