fs/ocfs2/acl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * acl.c
   4  *
   5  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
   6  *
   7  * CREDITS:
   8  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
   9  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/string.h>
  16
  17 #include <cluster/masklog.h>
  18
  19 #include "ocfs2.h"
  20 #include "alloc.h"
  21 #include "dlmglue.h"
  22 #include "file.h"
  23 #include "inode.h"
  24 #include "journal.h"
  25 #include "ocfs2_fs.h"
  26
  27 #include "xattr.h"
  28 #include "acl.h"
  29
  30 /*
  31  * Convert from xattr value to acl struct.
  32  */
  33 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  34 {
  35         int n, count;
  36         struct posix_acl *acl;
  37
  38         if (!value)
  39                 return NULL;
  40         if (size < sizeof(struct posix_acl_entry))
  41                 return ERR_PTR(-EINVAL);
  42
  43         count = size / sizeof(struct posix_acl_entry);
  44
  45         acl = posix_acl_alloc(count, GFP_NOFS);
  46         if (!acl)
  47                 return ERR_PTR(-ENOMEM);
  48         for (n = 0; n < count; n++) {
  49                 struct ocfs2_acl_entry *entry =
  50                         (struct ocfs2_acl_entry *)value;
  51
  52                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  53                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  54                 switch(acl->a_entries[n].e_tag) {
  55                 case ACL_USER:
  56                         acl->a_entries[n].e_uid =
  57                                 make_kuid(&init_user_ns,
  58                                           le32_to_cpu(entry->e_id));
  59                         break;
  60                 case ACL_GROUP:
  61                         acl->a_entries[n].e_gid =
  62                                 make_kgid(&init_user_ns,
  63                                           le32_to_cpu(entry->e_id));
  64                         break;
  65                 default:
  66                         break;
  67                 }
  68                 value += sizeof(struct posix_acl_entry);
  69
  70         }
  71         return acl;
  72 }
  73
  74 /*
  75  * Convert acl struct to xattr value.
  76  */
  77 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  78 {
  79         struct ocfs2_acl_entry *entry = NULL;
  80         char *ocfs2_acl;
  81         size_t n;
  82
  83         *size = acl->a_count * sizeof(struct posix_acl_entry);
  84
  85         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  86         if (!ocfs2_acl)
  87                 return ERR_PTR(-ENOMEM);
  88
  89         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  90         for (n = 0; n < acl->a_count; n++, entry++) {
  91                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  92                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  93                 switch(acl->a_entries[n].e_tag) {
  94                 case ACL_USER:
  95                         entry->e_id = cpu_to_le32(
  96                                 from_kuid(&init_user_ns,
  97                                           acl->a_entries[n].e_uid));
  98                         break;
  99                 case ACL_GROUP:
 100                         entry->e_id = cpu_to_le32(
 101                                 from_kgid(&init_user_ns,
 102                                           acl->a_entries[n].e_gid));
 103                         break;
 104                 default:
 105                         entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 106                         break;
 107                 }
 108         }
 109         return ocfs2_acl;
 110 }
 111
 112 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 113                                               int type,
 114                                               struct buffer_head *di_bh)
 115 {
 116         int name_index;
 117         char *value = NULL;
 118         struct posix_acl *acl;
 119         int retval;
 120
 121         switch (type) {
 122         case ACL_TYPE_ACCESS:
 123                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 124                 break;
 125         case ACL_TYPE_DEFAULT:
 126                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 127                 break;
 128         default:
 129                 return ERR_PTR(-EINVAL);
 130         }
 131
 132         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 133         if (retval > 0) {
 134                 value = kmalloc(retval, GFP_NOFS);
 135                 if (!value)
 136                         return ERR_PTR(-ENOMEM);
 137                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 138                                                 "", value, retval);
 139         }
 140
 141         if (retval > 0)
 142                 acl = ocfs2_acl_from_xattr(value, retval);
 143         else if (retval == -ENODATA || retval == 0)
 144                 acl = NULL;
 145         else
 146                 acl = ERR_PTR(retval);
 147
 148         kfree(value);
 149
 150         return acl;
 151 }
 152
 153 /*
 154  * Helper function to set i_mode in memory and disk. Some call paths
 155  * will not have di_bh or a journal handle to pass, in which case it
 156  * will create it's own.
 157  */
 158 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 159                               handle_t *handle, umode_t new_mode)
 160 {
 161         int ret, commit_handle = 0;
 162         struct ocfs2_dinode *di;
 163
 164         if (di_bh == NULL) {
 165                 ret = ocfs2_read_inode_block(inode, &di_bh);
 166                 if (ret) {
 167                         mlog_errno(ret);
 168                         goto out;
 169                 }
 170         } else
 171                 get_bh(di_bh);
 172
 173         if (handle == NULL) {
 174                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 175                                            OCFS2_INODE_UPDATE_CREDITS);
 176                 if (IS_ERR(handle)) {
 177                         ret = PTR_ERR(handle);
 178                         mlog_errno(ret);
 179                         goto out_brelse;
 180                 }
 181
 182                 commit_handle = 1;
 183         }
 184
 185         di = (struct ocfs2_dinode *)di_bh->b_data;
 186         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 187                                       OCFS2_JOURNAL_ACCESS_WRITE);
 188         if (ret) {
 189                 mlog_errno(ret);
 190                 goto out_commit;
 191         }
 192
 193         inode->i_mode = new_mode;
 194         inode->i_ctime = current_time(inode);
 195         di->i_mode = cpu_to_le16(inode->i_mode);
 196         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 197         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 198         ocfs2_update_inode_fsync_trans(handle, inode, 0);
 199
 200         ocfs2_journal_dirty(handle, di_bh);
 201
 202 out_commit:
 203         if (commit_handle)
 204                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 205 out_brelse:
 206         brelse(di_bh);
 207 out:
 208         return ret;
 209 }
 210
 211 /*
 212  * Set the access or default ACL of an inode.
 213  */
 214 static int ocfs2_set_acl(handle_t *handle,
 215                          struct inode *inode,
 216                          struct buffer_head *di_bh,
 217                          int type,
 218                          struct posix_acl *acl,
 219                          struct ocfs2_alloc_context *meta_ac,
 220                          struct ocfs2_alloc_context *data_ac)
 221 {
 222         int name_index;
 223         void *value = NULL;
 224         size_t size = 0;
 225         int ret;
 226
 227         if (S_ISLNK(inode->i_mode))
 228                 return -EOPNOTSUPP;
 229
 230         switch (type) {
 231         case ACL_TYPE_ACCESS:
 232                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 233                 break;
 234         case ACL_TYPE_DEFAULT:
 235                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 236                 if (!S_ISDIR(inode->i_mode))
 237                         return acl ? -EACCES : 0;
 238                 break;
 239         default:
 240                 return -EINVAL;
 241         }
 242
 243         if (acl) {
 244                 value = ocfs2_acl_to_xattr(acl, &size);
 245                 if (IS_ERR(value))
 246                         return (int)PTR_ERR(value);
 247         }
 248
 249         if (handle)
 250                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 251                                              "", value, size, 0,
 252                                              meta_ac, data_ac);
 253         else
 254                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 255
 256         kfree(value);
 257         if (!ret)
 258                 set_cached_acl(inode, type, acl);
 259
 260         return ret;
 261 }
 262
 263 int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
 264                       struct posix_acl *acl, int type)
 265 {
 266         struct buffer_head *bh = NULL;
 267         int status, had_lock;
 268         struct ocfs2_lock_holder oh;
 269
 270         had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
 271         if (had_lock < 0)
 272                 return had_lock;
 273         if (type == ACL_TYPE_ACCESS && acl) {
 274                 umode_t mode;
 275
 276                 status = posix_acl_update_mode(&init_user_ns, inode, &mode,
 277                                                &acl);
 278                 if (status)
 279                         goto unlock;
 280
 281                 status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
 282                 if (status)
 283                         goto unlock;
 284         }
 285         status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
 286 unlock:
 287         ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
 288         brelse(bh);
 289         return status;
 290 }
 291
 292 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
 293 {
 294         struct ocfs2_super *osb;
 295         struct buffer_head *di_bh = NULL;
 296         struct posix_acl *acl;
 297         int had_lock;
 298         struct ocfs2_lock_holder oh;
 299
 300         osb = OCFS2_SB(inode->i_sb);
 301         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 302                 return NULL;
 303
 304         had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
 305         if (had_lock < 0)
 306                 return ERR_PTR(had_lock);
 307
 308         down_read(&OCFS2_I(inode)->ip_xattr_sem);
 309         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 310         up_read(&OCFS2_I(inode)->ip_xattr_sem);
 311
 312         ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
 313         brelse(di_bh);
 314         return acl;
 315 }
 316
 317 int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
 318 {
 319         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 320         struct posix_acl *acl;
 321         int ret;
 322
 323         if (S_ISLNK(inode->i_mode))
 324                 return -EOPNOTSUPP;
 325
 326         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 327                 return 0;
 328
 329         down_read(&OCFS2_I(inode)->ip_xattr_sem);
 330         acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
 331         up_read(&OCFS2_I(inode)->ip_xattr_sem);
 332         if (IS_ERR_OR_NULL(acl))
 333                 return PTR_ERR_OR_ZERO(acl);
 334         ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
 335         if (ret)
 336                 return ret;
 337         ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 338                             acl, NULL, NULL);
 339         posix_acl_release(acl);
 340         return ret;
 341 }
 342
 343 /*
 344  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 345  * then clone to new inode. Called from ocfs2_mknod.
 346  */
 347 int ocfs2_init_acl(handle_t *handle,
 348                    struct inode *inode,
 349                    struct inode *dir,
 350                    struct buffer_head *di_bh,
 351                    struct buffer_head *dir_bh,
 352                    struct ocfs2_alloc_context *meta_ac,
 353                    struct ocfs2_alloc_context *data_ac)
 354 {
 355         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 356         struct posix_acl *acl = NULL;
 357         int ret = 0, ret2;
 358         umode_t mode;
 359
 360         if (!S_ISLNK(inode->i_mode)) {
 361                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 362                         down_read(&OCFS2_I(dir)->ip_xattr_sem);
 363                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 364                                                    dir_bh);
 365                         up_read(&OCFS2_I(dir)->ip_xattr_sem);
 366                         if (IS_ERR(acl))
 367                                 return PTR_ERR(acl);
 368                 }
 369                 if (!acl) {
 370                         mode = inode->i_mode & ~current_umask();
 371                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 372                         if (ret) {
 373                                 mlog_errno(ret);
 374                                 goto cleanup;
 375                         }
 376                 }
 377         }
 378         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 379                 if (S_ISDIR(inode->i_mode)) {
 380                         ret = ocfs2_set_acl(handle, inode, di_bh,
 381                                             ACL_TYPE_DEFAULT, acl,
 382                                             meta_ac, data_ac);
 383                         if (ret)
 384                                 goto cleanup;
 385                 }
 386                 mode = inode->i_mode;
 387                 ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
 388                 if (ret < 0)
 389                         return ret;
 390
 391                 ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 392                 if (ret2) {
 393                         mlog_errno(ret2);
 394                         ret = ret2;
 395                         goto cleanup;
 396                 }
 397                 if (ret > 0) {
 398                         ret = ocfs2_set_acl(handle, inode,
 399                                             di_bh, ACL_TYPE_ACCESS,
 400                                             acl, meta_ac, data_ac);
 401                 }
 402         }
 403 cleanup:
 404         posix_acl_release(acl);
 405         return ret;
 406 }