drivers/staging/lustre/lustre/llite/remote_perm.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/llite/remote_perm.c
  37  *
  38  * Lustre Permission Cache for Remote Client
  39  *
  40  * Author: Lai Siyao <lsy@clusterfs.com>
  41  * Author: Fan Yong <fanyong@clusterfs.com>
  42  */
  43
  44 #define DEBUG_SUBSYSTEM S_LLITE
  45
  46 #include <linux/module.h>
  47 #include <linux/types.h>
  48
  49 #include "../include/lustre_lite.h"
  50 #include "../include/lustre_ha.h"
  51 #include "../include/lustre_dlm.h"
  52 #include "../include/lprocfs_status.h"
  53 #include "../include/lustre_disk.h"
  54 #include "../include/lustre_param.h"
  55 #include "llite_internal.h"
  56
  57 struct kmem_cache *ll_remote_perm_cachep = NULL;
  58 struct kmem_cache *ll_rmtperm_hash_cachep = NULL;
  59
  60 static inline struct ll_remote_perm *alloc_ll_remote_perm(void)
  61 {
  62         struct ll_remote_perm *lrp;
  63
  64         OBD_SLAB_ALLOC_PTR_GFP(lrp, ll_remote_perm_cachep, GFP_KERNEL);
  65         if (lrp)
  66                 INIT_HLIST_NODE(&lrp->lrp_list);
  67         return lrp;
  68 }
  69
  70 static inline void free_ll_remote_perm(struct ll_remote_perm *lrp)
  71 {
  72         if (!lrp)
  73                 return;
  74
  75         if (!hlist_unhashed(&lrp->lrp_list))
  76                 hlist_del(&lrp->lrp_list);
  77         OBD_SLAB_FREE(lrp, ll_remote_perm_cachep, sizeof(*lrp));
  78 }
  79
  80 static struct hlist_head *alloc_rmtperm_hash(void)
  81 {
  82         struct hlist_head *hash;
  83         int i;
  84
  85         OBD_SLAB_ALLOC_GFP(hash, ll_rmtperm_hash_cachep,
  86                            REMOTE_PERM_HASHSIZE * sizeof(*hash),
  87                            GFP_IOFS);
  88         if (!hash)
  89                 return NULL;
  90
  91         for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
  92                 INIT_HLIST_HEAD(hash + i);
  93
  94         return hash;
  95 }
  96
  97 void free_rmtperm_hash(struct hlist_head *hash)
  98 {
  99         int i;
 100         struct ll_remote_perm *lrp;
 101         struct hlist_node *next;
 102
 103         if(!hash)
 104                 return;
 105
 106         for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
 107                 hlist_for_each_entry_safe(lrp, next, hash + i,
 108                                               lrp_list)
 109                         free_ll_remote_perm(lrp);
 110         OBD_SLAB_FREE(hash, ll_rmtperm_hash_cachep,
 111                       REMOTE_PERM_HASHSIZE * sizeof(*hash));
 112 }
 113
 114 static inline int remote_perm_hashfunc(uid_t uid)
 115 {
 116         return uid & (REMOTE_PERM_HASHSIZE - 1);
 117 }
 118
 119 /* NB: setxid permission is not checked here, instead it's done on
 120  * MDT when client get remote permission. */
 121 static int do_check_remote_perm(struct ll_inode_info *lli, int mask)
 122 {
 123         struct hlist_head *head;
 124         struct ll_remote_perm *lrp;
 125         int found = 0, rc;
 126
 127         if (!lli->lli_remote_perms)
 128                 return -ENOENT;
 129
 130         head = lli->lli_remote_perms +
 131                 remote_perm_hashfunc(from_kuid(&init_user_ns, current_uid()));
 132
 133         spin_lock(&lli->lli_lock);
 134         hlist_for_each_entry(lrp, head, lrp_list) {
 135                 if (lrp->lrp_uid != from_kuid(&init_user_ns, current_uid()))
 136                         continue;
 137                 if (lrp->lrp_gid != from_kgid(&init_user_ns, current_gid()))
 138                         continue;
 139                 if (lrp->lrp_fsuid != from_kuid(&init_user_ns, current_fsuid()))
 140                         continue;
 141                 if (lrp->lrp_fsgid != from_kgid(&init_user_ns, current_fsgid()))
 142                         continue;
 143                 found = 1;
 144                 break;
 145         }
 146
 147         if (!found)
 148                 GOTO(out, rc = -ENOENT);
 149
 150         CDEBUG(D_SEC, "found remote perm: %u/%u/%u/%u - %#x\n",
 151                lrp->lrp_uid, lrp->lrp_gid, lrp->lrp_fsuid, lrp->lrp_fsgid,
 152                lrp->lrp_access_perm);
 153         rc = ((lrp->lrp_access_perm & mask) == mask) ? 0 : -EACCES;
 154
 155 out:
 156         spin_unlock(&lli->lli_lock);
 157         return rc;
 158 }
 159
 160 int ll_update_remote_perm(struct inode *inode, struct mdt_remote_perm *perm)
 161 {
 162         struct ll_inode_info *lli = ll_i2info(inode);
 163         struct ll_remote_perm *lrp = NULL, *tmp = NULL;
 164         struct hlist_head *head, *perm_hash = NULL;
 165
 166         LASSERT(ll_i2sbi(inode)->ll_flags & LL_SBI_RMT_CLIENT);
 167
 168 #if 0
 169         if (perm->rp_uid != current->uid ||
 170             perm->rp_gid != current->gid ||
 171             perm->rp_fsuid != current->fsuid ||
 172             perm->rp_fsgid != current->fsgid) {
 173                 /* user might setxid in this small period */
 174                 CDEBUG(D_SEC,
 175                        "remote perm user %u/%u/%u/%u != current %u/%u/%u/%u\n",
 176                        perm->rp_uid, perm->rp_gid, perm->rp_fsuid,
 177                        perm->rp_fsgid, current->uid, current->gid,
 178                        current->fsuid, current->fsgid);
 179                 return -EAGAIN;
 180         }
 181 #endif
 182
 183         if (!lli->lli_remote_perms) {
 184                 perm_hash = alloc_rmtperm_hash();
 185                 if (perm_hash == NULL) {
 186                         CERROR("alloc lli_remote_perms failed!\n");
 187                         return -ENOMEM;
 188                 }
 189         }
 190
 191         spin_lock(&lli->lli_lock);
 192
 193         if (!lli->lli_remote_perms)
 194                 lli->lli_remote_perms = perm_hash;
 195         else if (perm_hash)
 196                 free_rmtperm_hash(perm_hash);
 197
 198         head = lli->lli_remote_perms + remote_perm_hashfunc(perm->rp_uid);
 199
 200 again:
 201         hlist_for_each_entry(tmp, head, lrp_list) {
 202                 if (tmp->lrp_uid != perm->rp_uid)
 203                         continue;
 204                 if (tmp->lrp_gid != perm->rp_gid)
 205                         continue;
 206                 if (tmp->lrp_fsuid != perm->rp_fsuid)
 207                         continue;
 208                 if (tmp->lrp_fsgid != perm->rp_fsgid)
 209                         continue;
 210                 if (lrp)
 211                         free_ll_remote_perm(lrp);
 212                 lrp = tmp;
 213                 break;
 214         }
 215
 216         if (!lrp) {
 217                 spin_unlock(&lli->lli_lock);
 218                 lrp = alloc_ll_remote_perm();
 219                 if (!lrp) {
 220                         CERROR("alloc memory for ll_remote_perm failed!\n");
 221                         return -ENOMEM;
 222                 }
 223                 spin_lock(&lli->lli_lock);
 224                 goto again;
 225         }
 226
 227         lrp->lrp_access_perm = perm->rp_access_perm;
 228         if (lrp != tmp) {
 229                 lrp->lrp_uid     = perm->rp_uid;
 230                 lrp->lrp_gid     = perm->rp_gid;
 231                 lrp->lrp_fsuid       = perm->rp_fsuid;
 232                 lrp->lrp_fsgid       = perm->rp_fsgid;
 233                 hlist_add_head(&lrp->lrp_list, head);
 234         }
 235         lli->lli_rmtperm_time = cfs_time_current();
 236         spin_unlock(&lli->lli_lock);
 237
 238         CDEBUG(D_SEC, "new remote perm@%p: %u/%u/%u/%u - %#x\n",
 239                lrp, lrp->lrp_uid, lrp->lrp_gid, lrp->lrp_fsuid, lrp->lrp_fsgid,
 240                lrp->lrp_access_perm);
 241
 242         return 0;
 243 }
 244
 245 int lustre_check_remote_perm(struct inode *inode, int mask)
 246 {
 247         struct ll_inode_info *lli = ll_i2info(inode);
 248         struct ll_sb_info *sbi = ll_i2sbi(inode);
 249         struct ptlrpc_request *req = NULL;
 250         struct mdt_remote_perm *perm;
 251         struct obd_capa *oc;
 252         unsigned long save;
 253         int i = 0, rc;
 254
 255         do {
 256                 save = lli->lli_rmtperm_time;
 257                 rc = do_check_remote_perm(lli, mask);
 258                 if (!rc || (rc != -ENOENT && i))
 259                         break;
 260
 261                 might_sleep();
 262
 263                 mutex_lock(&lli->lli_rmtperm_mutex);
 264                 /* check again */
 265                 if (save != lli->lli_rmtperm_time) {
 266                         rc = do_check_remote_perm(lli, mask);
 267                         if (!rc || (rc != -ENOENT && i)) {
 268                                 mutex_unlock(&lli->lli_rmtperm_mutex);
 269                                 break;
 270                         }
 271                 }
 272
 273                 if (i++ > 5) {
 274                         CERROR("check remote perm falls in dead loop!\n");
 275                         LBUG();
 276                 }
 277
 278                 oc = ll_mdscapa_get(inode);
 279                 rc = md_get_remote_perm(sbi->ll_md_exp, ll_inode2fid(inode), oc,
 280                                         ll_i2suppgid(inode), &req);
 281                 capa_put(oc);
 282                 if (rc) {
 283                         mutex_unlock(&lli->lli_rmtperm_mutex);
 284                         break;
 285                 }
 286
 287                 perm = req_capsule_server_swab_get(&req->rq_pill, &RMF_ACL,
 288                                                    lustre_swab_mdt_remote_perm);
 289                 if (unlikely(perm == NULL)) {
 290                         mutex_unlock(&lli->lli_rmtperm_mutex);
 291                         rc = -EPROTO;
 292                         break;
 293                 }
 294
 295                 rc = ll_update_remote_perm(inode, perm);
 296                 mutex_unlock(&lli->lli_rmtperm_mutex);
 297                 if (rc == -ENOMEM)
 298                         break;
 299
 300                 ptlrpc_req_finished(req);
 301                 req = NULL;
 302         } while (1);
 303         ptlrpc_req_finished(req);
 304         return rc;
 305 }
 306
 307 #if 0  /* NB: remote perms can't be freed in ll_mdc_blocking_ast of UPDATE lock,
 308         * because it will fail sanity test 48.
 309         */
 310 void ll_free_remote_perms(struct inode *inode)
 311 {
 312         struct ll_inode_info *lli = ll_i2info(inode);
 313         struct hlist_head *hash = lli->lli_remote_perms;
 314         struct ll_remote_perm *lrp;
 315         struct hlist_node *node, *next;
 316         int i;
 317
 318         LASSERT(hash);
 319
 320         spin_lock(&lli->lli_lock);
 321
 322         for (i = 0; i < REMOTE_PERM_HASHSIZE; i++) {
 323                 hlist_for_each_entry_safe(lrp, node, next, hash + i,
 324                                               lrp_list)
 325                         free_ll_remote_perm(lrp);
 326         }
 327
 328         spin_unlock(&lli->lli_lock);
 329 }
 330 #endif