fs/ocfs2/acl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  * vim: noexpandtab sw=8 ts=8 sts=0:
   4  *
   5  * acl.c
   6  *
   7  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
   8  *
   9  * CREDITS:
  10  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
  11  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/string.h>
  18
  19 #include <cluster/masklog.h>
  20
  21 #include "ocfs2.h"
  22 #include "alloc.h"
  23 #include "dlmglue.h"
  24 #include "file.h"
  25 #include "inode.h"
  26 #include "journal.h"
  27 #include "ocfs2_fs.h"
  28
  29 #include "xattr.h"
  30 #include "acl.h"
  31
  32 /*
  33  * Convert from xattr value to acl struct.
  34  */
  35 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
  36 {
  37         int n, count;
  38         struct posix_acl *acl;
  39
  40         if (!value)
  41                 return NULL;
  42         if (size < sizeof(struct posix_acl_entry))
  43                 return ERR_PTR(-EINVAL);
  44
  45         count = size / sizeof(struct posix_acl_entry);
  46
  47         acl = posix_acl_alloc(count, GFP_NOFS);
  48         if (!acl)
  49                 return ERR_PTR(-ENOMEM);
  50         for (n = 0; n < count; n++) {
  51                 struct ocfs2_acl_entry *entry =
  52                         (struct ocfs2_acl_entry *)value;
  53
  54                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
  55                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
  56                 switch(acl->a_entries[n].e_tag) {
  57                 case ACL_USER:
  58                         acl->a_entries[n].e_uid =
  59                                 make_kuid(&init_user_ns,
  60                                           le32_to_cpu(entry->e_id));
  61                         break;
  62                 case ACL_GROUP:
  63                         acl->a_entries[n].e_gid =
  64                                 make_kgid(&init_user_ns,
  65                                           le32_to_cpu(entry->e_id));
  66                         break;
  67                 default:
  68                         break;
  69                 }
  70                 value += sizeof(struct posix_acl_entry);
  71
  72         }
  73         return acl;
  74 }
  75
  76 /*
  77  * Convert acl struct to xattr value.
  78  */
  79 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
  80 {
  81         struct ocfs2_acl_entry *entry = NULL;
  82         char *ocfs2_acl;
  83         size_t n;
  84
  85         *size = acl->a_count * sizeof(struct posix_acl_entry);
  86
  87         ocfs2_acl = kmalloc(*size, GFP_NOFS);
  88         if (!ocfs2_acl)
  89                 return ERR_PTR(-ENOMEM);
  90
  91         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
  92         for (n = 0; n < acl->a_count; n++, entry++) {
  93                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
  94                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
  95                 switch(acl->a_entries[n].e_tag) {
  96                 case ACL_USER:
  97                         entry->e_id = cpu_to_le32(
  98                                 from_kuid(&init_user_ns,
  99                                           acl->a_entries[n].e_uid));
 100                         break;
 101                 case ACL_GROUP:
 102                         entry->e_id = cpu_to_le32(
 103                                 from_kgid(&init_user_ns,
 104                                           acl->a_entries[n].e_gid));
 105                         break;
 106                 default:
 107                         entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
 108                         break;
 109                 }
 110         }
 111         return ocfs2_acl;
 112 }
 113
 114 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
 115                                               int type,
 116                                               struct buffer_head *di_bh)
 117 {
 118         int name_index;
 119         char *value = NULL;
 120         struct posix_acl *acl;
 121         int retval;
 122
 123         switch (type) {
 124         case ACL_TYPE_ACCESS:
 125                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 126                 break;
 127         case ACL_TYPE_DEFAULT:
 128                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 129                 break;
 130         default:
 131                 return ERR_PTR(-EINVAL);
 132         }
 133
 134         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
 135         if (retval > 0) {
 136                 value = kmalloc(retval, GFP_NOFS);
 137                 if (!value)
 138                         return ERR_PTR(-ENOMEM);
 139                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
 140                                                 "", value, retval);
 141         }
 142
 143         if (retval > 0)
 144                 acl = ocfs2_acl_from_xattr(value, retval);
 145         else if (retval == -ENODATA || retval == 0)
 146                 acl = NULL;
 147         else
 148                 acl = ERR_PTR(retval);
 149
 150         kfree(value);
 151
 152         return acl;
 153 }
 154
 155 /*
 156  * Helper function to set i_mode in memory and disk. Some call paths
 157  * will not have di_bh or a journal handle to pass, in which case it
 158  * will create it's own.
 159  */
 160 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
 161                               handle_t *handle, umode_t new_mode)
 162 {
 163         int ret, commit_handle = 0;
 164         struct ocfs2_dinode *di;
 165
 166         if (di_bh == NULL) {
 167                 ret = ocfs2_read_inode_block(inode, &di_bh);
 168                 if (ret) {
 169                         mlog_errno(ret);
 170                         goto out;
 171                 }
 172         } else
 173                 get_bh(di_bh);
 174
 175         if (handle == NULL) {
 176                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
 177                                            OCFS2_INODE_UPDATE_CREDITS);
 178                 if (IS_ERR(handle)) {
 179                         ret = PTR_ERR(handle);
 180                         mlog_errno(ret);
 181                         goto out_brelse;
 182                 }
 183
 184                 commit_handle = 1;
 185         }
 186
 187         di = (struct ocfs2_dinode *)di_bh->b_data;
 188         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
 189                                       OCFS2_JOURNAL_ACCESS_WRITE);
 190         if (ret) {
 191                 mlog_errno(ret);
 192                 goto out_commit;
 193         }
 194
 195         inode->i_mode = new_mode;
 196         inode->i_ctime = current_time(inode);
 197         di->i_mode = cpu_to_le16(inode->i_mode);
 198         di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 199         di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 200         ocfs2_update_inode_fsync_trans(handle, inode, 0);
 201
 202         ocfs2_journal_dirty(handle, di_bh);
 203
 204 out_commit:
 205         if (commit_handle)
 206                 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
 207 out_brelse:
 208         brelse(di_bh);
 209 out:
 210         return ret;
 211 }
 212
 213 /*
 214  * Set the access or default ACL of an inode.
 215  */
 216 static int ocfs2_set_acl(handle_t *handle,
 217                          struct inode *inode,
 218                          struct buffer_head *di_bh,
 219                          int type,
 220                          struct posix_acl *acl,
 221                          struct ocfs2_alloc_context *meta_ac,
 222                          struct ocfs2_alloc_context *data_ac)
 223 {
 224         int name_index;
 225         void *value = NULL;
 226         size_t size = 0;
 227         int ret;
 228
 229         if (S_ISLNK(inode->i_mode))
 230                 return -EOPNOTSUPP;
 231
 232         switch (type) {
 233         case ACL_TYPE_ACCESS:
 234                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
 235                 break;
 236         case ACL_TYPE_DEFAULT:
 237                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
 238                 if (!S_ISDIR(inode->i_mode))
 239                         return acl ? -EACCES : 0;
 240                 break;
 241         default:
 242                 return -EINVAL;
 243         }
 244
 245         if (acl) {
 246                 value = ocfs2_acl_to_xattr(acl, &size);
 247                 if (IS_ERR(value))
 248                         return (int)PTR_ERR(value);
 249         }
 250
 251         if (handle)
 252                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
 253                                              "", value, size, 0,
 254                                              meta_ac, data_ac);
 255         else
 256                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
 257
 258         kfree(value);
 259         if (!ret)
 260                 set_cached_acl(inode, type, acl);
 261
 262         return ret;
 263 }
 264
 265 int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
 266                       struct posix_acl *acl, int type)
 267 {
 268         struct buffer_head *bh = NULL;
 269         int status, had_lock;
 270         struct ocfs2_lock_holder oh;
 271
 272         had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
 273         if (had_lock < 0)
 274                 return had_lock;
 275         if (type == ACL_TYPE_ACCESS && acl) {
 276                 umode_t mode;
 277
 278                 status = posix_acl_update_mode(&init_user_ns, inode, &mode,
 279                                                &acl);
 280                 if (status)
 281                         goto unlock;
 282
 283                 status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
 284                 if (status)
 285                         goto unlock;
 286         }
 287         status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
 288 unlock:
 289         ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
 290         brelse(bh);
 291         return status;
 292 }
 293
 294 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
 295 {
 296         struct ocfs2_super *osb;
 297         struct buffer_head *di_bh = NULL;
 298         struct posix_acl *acl;
 299         int had_lock;
 300         struct ocfs2_lock_holder oh;
 301
 302         osb = OCFS2_SB(inode->i_sb);
 303         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 304                 return NULL;
 305
 306         had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
 307         if (had_lock < 0)
 308                 return ERR_PTR(had_lock);
 309
 310         down_read(&OCFS2_I(inode)->ip_xattr_sem);
 311         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
 312         up_read(&OCFS2_I(inode)->ip_xattr_sem);
 313
 314         ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
 315         brelse(di_bh);
 316         return acl;
 317 }
 318
 319 int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
 320 {
 321         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 322         struct posix_acl *acl;
 323         int ret;
 324
 325         if (S_ISLNK(inode->i_mode))
 326                 return -EOPNOTSUPP;
 327
 328         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
 329                 return 0;
 330
 331         down_read(&OCFS2_I(inode)->ip_xattr_sem);
 332         acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
 333         up_read(&OCFS2_I(inode)->ip_xattr_sem);
 334         if (IS_ERR_OR_NULL(acl))
 335                 return PTR_ERR_OR_ZERO(acl);
 336         ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
 337         if (ret)
 338                 return ret;
 339         ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
 340                             acl, NULL, NULL);
 341         posix_acl_release(acl);
 342         return ret;
 343 }
 344
 345 /*
 346  * Initialize the ACLs of a new inode. If parent directory has default ACL,
 347  * then clone to new inode. Called from ocfs2_mknod.
 348  */
 349 int ocfs2_init_acl(handle_t *handle,
 350                    struct inode *inode,
 351                    struct inode *dir,
 352                    struct buffer_head *di_bh,
 353                    struct buffer_head *dir_bh,
 354                    struct ocfs2_alloc_context *meta_ac,
 355                    struct ocfs2_alloc_context *data_ac)
 356 {
 357         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 358         struct posix_acl *acl = NULL;
 359         int ret = 0, ret2;
 360         umode_t mode;
 361
 362         if (!S_ISLNK(inode->i_mode)) {
 363                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
 364                         down_read(&OCFS2_I(dir)->ip_xattr_sem);
 365                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
 366                                                    dir_bh);
 367                         up_read(&OCFS2_I(dir)->ip_xattr_sem);
 368                         if (IS_ERR(acl))
 369                                 return PTR_ERR(acl);
 370                 }
 371                 if (!acl) {
 372                         mode = inode->i_mode & ~current_umask();
 373                         ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 374                         if (ret) {
 375                                 mlog_errno(ret);
 376                                 goto cleanup;
 377                         }
 378                 }
 379         }
 380         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
 381                 if (S_ISDIR(inode->i_mode)) {
 382                         ret = ocfs2_set_acl(handle, inode, di_bh,
 383                                             ACL_TYPE_DEFAULT, acl,
 384                                             meta_ac, data_ac);
 385                         if (ret)
 386                                 goto cleanup;
 387                 }
 388                 mode = inode->i_mode;
 389                 ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
 390                 if (ret < 0)
 391                         return ret;
 392
 393                 ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
 394                 if (ret2) {
 395                         mlog_errno(ret2);
 396                         ret = ret2;
 397                         goto cleanup;
 398                 }
 399                 if (ret > 0) {
 400                         ret = ocfs2_set_acl(handle, inode,
 401                                             di_bh, ACL_TYPE_ACCESS,
 402                                             acl, meta_ac, data_ac);
 403                 }
 404         }
 405 cleanup:
 406         posix_acl_release(acl);
 407         return ret;
 408 }