fs/ocfs2/acl.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * acl.c
   5  *
   6  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
   7  *
   8  * CREDITS:
   9  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
  10  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public
  14  * License version 2 as published by the Free Software Foundation.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/string.h>
  26
  27 #include <cluster/masklog.h>
  28
  29 #include "ocfs2.h"
  30 #include "alloc.h"
  31 #include "dlmglue.h"
  32 #include "file.h"
  33 #include "inode.h"
  34 #include "journal.h"
  35 #include "ocfs2_fs.h"
  36
  37 #include "xattr.h"
  38 #include "acl.h"
  39
  40 /*
  41  * Convert from xattr value to acl struct.
  42  */
  43 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  44 {
  45         int n, count;
  46         struct posix_acl *acl;
  47
  48         if (!value)
  49                 return NULL;
  50         if (size < sizeof(struct posix_acl_entry))
  51                 return ERR_PTR(-EINVAL);
  52
  53         count = size / sizeof(struct posix_acl_entry);
  54
  55         acl = posix_acl_alloc(count, GFP_NOFS);
  56         if (!acl)
  57                 return ERR_PTR(-ENOMEM);
  58         for (n = 0; n < count; n++) {
  59                 struct ocfs2_acl_entry *entry =
  60                         (struct ocfs2_acl_entry *)value;
  61
  62                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  63                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  64                 switch(acl->a_entries[n].e_tag) {
  65                 case ACL_USER:
  66                         acl->a_entries[n].e_uid =
  67                                 make_kuid(&init_user_ns,
  68                                           le32_to_cpu(entry->e_id));
  69                         break;
  70                 case ACL_GROUP:
  71                         acl->a_entries[n].e_gid =
  72                                 make_kgid(&init_user_ns,
  73                                           le32_to_cpu(entry->e_id));
  74                         break;
  75                 default:
  76                         break;
  77                 }
  78                 value += sizeof(struct posix_acl_entry);
  79
  80         }
  81         return acl;
  82 }
  83
  84 /*
  85  * Convert acl struct to xattr value.
  86  */
  87 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  88 {
  89         struct ocfs2_acl_entry *entry = NULL;
  90         char *ocfs2_acl;
  91         size_t n;
  92
  93         *size = acl->a_count * sizeof(struct posix_acl_entry);
  94
  95         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  96         if (!ocfs2_acl)
  97                 return ERR_PTR(-ENOMEM);
  98
  99         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
 100         for (n = 0; n < acl->a_count; n++, entry++) {
 101                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
 102                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
 103                 switch(acl->a_entries[n].e_tag) {
 104                 case ACL_USER:
 105                         entry->e_id = cpu_to_le32(
 106                                 from_kuid(&init_user_ns,
 107                                           acl->a_entries[n].e_uid));
 108                         break;
 109                 case ACL_GROUP:
 110                         entry->e_id = cpu_to_le32(
 111                                 from_kgid(&init_user_ns,
 112                                           acl->a_entries[n].e_gid));
 113                         break;
 114                 default:
 115                         entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 116                         break;
 117                 }
 118         }
 119         return ocfs2_acl;
 120 }
 121
 122 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 123                                               int type,
 124                                               struct buffer_head *di_bh)
 125 {
 126         int name_index;
 127         char *value = NULL;
 128         struct posix_acl *acl;
 129         int retval;
 130
 131         switch (type) {
 132         case ACL_TYPE_ACCESS:
 133                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 134                 break;
 135         case ACL_TYPE_DEFAULT:
 136                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 137                 break;
 138         default:
 139                 return ERR_PTR(-EINVAL);
 140         }
 141
 142         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 143         if (retval > 0) {
 144                 value = kmalloc(retval, GFP_NOFS);
 145                 if (!value)
 146                         return ERR_PTR(-ENOMEM);
 147                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 148                                                 "", value, retval);
 149         }
 150
 151         if (retval > 0)
 152                 acl = ocfs2_acl_from_xattr(value, retval);
 153         else if (retval == -ENODATA || retval == 0)
 154                 acl = NULL;
 155         else
 156                 acl = ERR_PTR(retval);
 157
 158         kfree(value);
 159
 160         return acl;
 161 }
 162
 163 /*
 164  * Helper function to set i_mode in memory and disk. Some call paths
 165  * will not have di_bh or a journal handle to pass, in which case it
 166  * will create it's own.
 167  */
 168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 169                               handle_t *handle, umode_t new_mode)
 170 {
 171         int ret, commit_handle = 0;
 172         struct ocfs2_dinode *di;
 173
 174         if (di_bh == NULL) {
 175                 ret = ocfs2_read_inode_block(inode, &di_bh);
 176                 if (ret) {
 177                         mlog_errno(ret);
 178                         goto out;
 179                 }
 180         } else
 181                 get_bh(di_bh);
 182
 183         if (handle == NULL) {
 184                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 185                                            OCFS2_INODE_UPDATE_CREDITS);
 186                 if (IS_ERR(handle)) {
 187                         ret = PTR_ERR(handle);
 188                         mlog_errno(ret);
 189                         goto out_brelse;
 190                 }
 191
 192                 commit_handle = 1;
 193         }
 194
 195         di = (struct ocfs2_dinode *)di_bh->b_data;
 196         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 197                                       OCFS2_JOURNAL_ACCESS_WRITE);
 198         if (ret) {
 199                 mlog_errno(ret);
 200                 goto out_commit;
 201         }
 202
 203         inode->i_mode = new_mode;
 204         inode->i_ctime = CURRENT_TIME;
 205         di->i_mode = cpu_to_le16(inode->i_mode);
 206         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 207         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 208
 209         ocfs2_journal_dirty(handle, di_bh);
 210
 211 out_commit:
 212         if (commit_handle)
 213                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 214 out_brelse:
 215         brelse(di_bh);
 216 out:
 217         return ret;
 218 }
 219
 220 /*
 221  * Set the access or default ACL of an inode.
 222  */
 223 int ocfs2_set_acl(handle_t *handle,
 224                          struct inode *inode,
 225                          struct buffer_head *di_bh,
 226                          int type,
 227                          struct posix_acl *acl,
 228                          struct ocfs2_alloc_context *meta_ac,
 229                          struct ocfs2_alloc_context *data_ac)
 230 {
 231         int name_index;
 232         void *value = NULL;
 233         size_t size = 0;
 234         int ret;
 235
 236         if (S_ISLNK(inode->i_mode))
 237                 return -EOPNOTSUPP;
 238
 239         switch (type) {
 240         case ACL_TYPE_ACCESS:
 241                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 242                 if (acl) {
 243                         umode_t mode = inode->i_mode;
 244                         ret = posix_acl_equiv_mode(acl, &mode);
 245                         if (ret < 0)
 246                                 return ret;
 247                         else {
 248                                 if (ret == 0)
 249                                         acl = NULL;
 250
 251                                 ret = ocfs2_acl_set_mode(inode, di_bh,
 252                                                          handle, mode);
 253                                 if (ret)
 254                                         return ret;
 255
 256                         }
 257                 }
 258                 break;
 259         case ACL_TYPE_DEFAULT:
 260                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 261                 if (!S_ISDIR(inode->i_mode))
 262                         return acl ? -EACCES : 0;
 263                 break;
 264         default:
 265                 return -EINVAL;
 266         }
 267
 268         if (acl) {
 269                 value = ocfs2_acl_to_xattr(acl, &size);
 270                 if (IS_ERR(value))
 271                         return (int)PTR_ERR(value);
 272         }
 273
 274         if (handle)
 275                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 276                                              "", value, size, 0,
 277                                              meta_ac, data_ac);
 278         else
 279                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 280
 281         kfree(value);
 282
 283         return ret;
 284 }
 285
 286 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 287 {
 288         return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
 289 }
 290
 291 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
 292 {
 293         struct ocfs2_super *osb;
 294         struct buffer_head *di_bh = NULL;
 295         struct posix_acl *acl;
 296         int ret = -EAGAIN;
 297
 298         osb = OCFS2_SB(inode->i_sb);
 299         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 300                 return NULL;
 301
 302         ret = ocfs2_read_inode_block(inode, &di_bh);
 303         if (ret < 0)
 304                 return ERR_PTR(ret);
 305
 306         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 307
 308         brelse(di_bh);
 309
 310         return acl;
 311 }