fs/ceph/acl.c

   1 /*
   2  * linux/fs/ceph/acl.c
   3  *
   4  * Copyright (C) 2013 Guangliang Zhao, <lucienchao@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public
   8  * License v2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public
  16  * License along with this program; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18  * Boston, MA 021110-1307, USA.
  19  */
  20
  21 #include <linux/ceph/ceph_debug.h>
  22 #include <linux/fs.h>
  23 #include <linux/string.h>
  24 #include <linux/xattr.h>
  25 #include <linux/posix_acl_xattr.h>
  26 #include <linux/posix_acl.h>
  27 #include <linux/sched.h>
  28 #include <linux/slab.h>
  29
  30 #include "super.h"
  31
  32 static inline void ceph_set_cached_acl(struct inode *inode,
  33                                         int type, struct posix_acl *acl)
  34 {
  35         struct ceph_inode_info *ci = ceph_inode(inode);
  36
  37         spin_lock(&ci->i_ceph_lock);
  38         if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
  39                 set_cached_acl(inode, type, acl);
  40         else
  41                 forget_cached_acl(inode, type);
  42         spin_unlock(&ci->i_ceph_lock);
  43 }
  44
  45 struct posix_acl *ceph_get_acl(struct inode *inode, int type)
  46 {
  47         int size;
  48         unsigned int retry_cnt = 0;
  49         const char *name;
  50         char *value = NULL;
  51         struct posix_acl *acl;
  52
  53         switch (type) {
  54         case ACL_TYPE_ACCESS:
  55                 name = XATTR_NAME_POSIX_ACL_ACCESS;
  56                 break;
  57         case ACL_TYPE_DEFAULT:
  58                 name = XATTR_NAME_POSIX_ACL_DEFAULT;
  59                 break;
  60         default:
  61                 BUG();
  62         }
  63
  64 retry:
  65         size = __ceph_getxattr(inode, name, "", 0);
  66         if (size > 0) {
  67                 value = kzalloc(size, GFP_NOFS);
  68                 if (!value)
  69                         return ERR_PTR(-ENOMEM);
  70                 size = __ceph_getxattr(inode, name, value, size);
  71         }
  72
  73         if (size == -ERANGE && retry_cnt < 10) {
  74                 retry_cnt++;
  75                 kfree(value);
  76                 value = NULL;
  77                 goto retry;
  78         }
  79
  80         if (size > 0) {
  81                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
  82         } else if (size == -ENODATA || size == 0) {
  83                 acl = NULL;
  84         } else {
  85                 pr_err_ratelimited("get acl %llx.%llx failed, err=%d\n",
  86                                    ceph_vinop(inode), size);
  87                 acl = ERR_PTR(-EIO);
  88         }
  89
  90         kfree(value);
  91
  92         if (!IS_ERR(acl))
  93                 ceph_set_cached_acl(inode, type, acl);
  94
  95         return acl;
  96 }
  97
  98 int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
  99 {
 100         int ret = 0, size = 0;
 101         const char *name = NULL;
 102         char *value = NULL;
 103         struct iattr newattrs;
 104         struct timespec64 old_ctime = inode->i_ctime;
 105         umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
 106
 107         switch (type) {
 108         case ACL_TYPE_ACCESS:
 109                 name = XATTR_NAME_POSIX_ACL_ACCESS;
 110                 if (acl) {
 111                         ret = posix_acl_update_mode(inode, &new_mode, &acl);
 112                         if (ret)
 113                                 goto out;
 114                 }
 115                 break;
 116         case ACL_TYPE_DEFAULT:
 117                 if (!S_ISDIR(inode->i_mode)) {
 118                         ret = acl ? -EINVAL : 0;
 119                         goto out;
 120                 }
 121                 name = XATTR_NAME_POSIX_ACL_DEFAULT;
 122                 break;
 123         default:
 124                 ret = -EINVAL;
 125                 goto out;
 126         }
 127
 128         if (acl) {
 129                 size = posix_acl_xattr_size(acl->a_count);
 130                 value = kmalloc(size, GFP_NOFS);
 131                 if (!value) {
 132                         ret = -ENOMEM;
 133                         goto out;
 134                 }
 135
 136                 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 137                 if (ret < 0)
 138                         goto out_free;
 139         }
 140
 141         if (ceph_snap(inode) != CEPH_NOSNAP) {
 142                 ret = -EROFS;
 143                 goto out_free;
 144         }
 145
 146         if (new_mode != old_mode) {
 147                 newattrs.ia_ctime = current_time(inode);
 148                 newattrs.ia_mode = new_mode;
 149                 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
 150                 ret = __ceph_setattr(inode, &newattrs);
 151                 if (ret)
 152                         goto out_free;
 153         }
 154
 155         ret = __ceph_setxattr(inode, name, value, size, 0);
 156         if (ret) {
 157                 if (new_mode != old_mode) {
 158                         newattrs.ia_ctime = old_ctime;
 159                         newattrs.ia_mode = old_mode;
 160                         newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
 161                         __ceph_setattr(inode, &newattrs);
 162                 }
 163                 goto out_free;
 164         }
 165
 166         ceph_set_cached_acl(inode, type, acl);
 167
 168 out_free:
 169         kfree(value);
 170 out:
 171         return ret;
 172 }
 173
 174 int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
 175                        struct ceph_acls_info *info)
 176 {
 177         struct posix_acl *acl, *default_acl;
 178         size_t val_size1 = 0, val_size2 = 0;
 179         struct ceph_pagelist *pagelist = NULL;
 180         void *tmp_buf = NULL;
 181         int err;
 182
 183         err = posix_acl_create(dir, mode, &default_acl, &acl);
 184         if (err)
 185                 return err;
 186
 187         if (acl) {
 188                 err = posix_acl_equiv_mode(acl, mode);
 189                 if (err < 0)
 190                         goto out_err;
 191                 if (err == 0) {
 192                         posix_acl_release(acl);
 193                         acl = NULL;
 194                 }
 195         }
 196
 197         if (!default_acl && !acl)
 198                 return 0;
 199
 200         if (acl)
 201                 val_size1 = posix_acl_xattr_size(acl->a_count);
 202         if (default_acl)
 203                 val_size2 = posix_acl_xattr_size(default_acl->a_count);
 204
 205         err = -ENOMEM;
 206         tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL);
 207         if (!tmp_buf)
 208                 goto out_err;
 209         pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL);
 210         if (!pagelist)
 211                 goto out_err;
 212         ceph_pagelist_init(pagelist);
 213
 214         err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
 215         if (err)
 216                 goto out_err;
 217
 218         ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1);
 219
 220         if (acl) {
 221                 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS);
 222                 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8);
 223                 if (err)
 224                         goto out_err;
 225                 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS,
 226                                             len);
 227                 err = posix_acl_to_xattr(&init_user_ns, acl,
 228                                          tmp_buf, val_size1);
 229                 if (err < 0)
 230                         goto out_err;
 231                 ceph_pagelist_encode_32(pagelist, val_size1);
 232                 ceph_pagelist_append(pagelist, tmp_buf, val_size1);
 233         }
 234         if (default_acl) {
 235                 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT);
 236                 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8);
 237                 if (err)
 238                         goto out_err;
 239                 err = ceph_pagelist_encode_string(pagelist,
 240                                                   XATTR_NAME_POSIX_ACL_DEFAULT, len);
 241                 err = posix_acl_to_xattr(&init_user_ns, default_acl,
 242                                          tmp_buf, val_size2);
 243                 if (err < 0)
 244                         goto out_err;
 245                 ceph_pagelist_encode_32(pagelist, val_size2);
 246                 ceph_pagelist_append(pagelist, tmp_buf, val_size2);
 247         }
 248
 249         kfree(tmp_buf);
 250
 251         info->acl = acl;
 252         info->default_acl = default_acl;
 253         info->pagelist = pagelist;
 254         return 0;
 255
 256 out_err:
 257         posix_acl_release(acl);
 258         posix_acl_release(default_acl);
 259         kfree(tmp_buf);
 260         if (pagelist)
 261                 ceph_pagelist_release(pagelist);
 262         return err;
 263 }
 264
 265 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info)
 266 {
 267         if (!inode)
 268                 return;
 269         ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl);
 270         ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl);
 271 }
 272
 273 void ceph_release_acls_info(struct ceph_acls_info *info)
 274 {
 275         posix_acl_release(info->acl);
 276         posix_acl_release(info->default_acl);
 277         if (info->pagelist)
 278                 ceph_pagelist_release(info->pagelist);
 279 }