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         spin_unlock(&ci->i_ceph_lock);
  41 }
  42
  43 struct posix_acl *ceph_get_acl(struct inode *inode, int type)
  44 {
  45         int size;
  46         const char *name;
  47         char *value = NULL;
  48         struct posix_acl *acl;
  49
  50         switch (type) {
  51         case ACL_TYPE_ACCESS:
  52                 name = XATTR_NAME_POSIX_ACL_ACCESS;
  53                 break;
  54         case ACL_TYPE_DEFAULT:
  55                 name = XATTR_NAME_POSIX_ACL_DEFAULT;
  56                 break;
  57         default:
  58                 BUG();
  59         }
  60
  61         size = __ceph_getxattr(inode, name, "", 0);
  62         if (size > 0) {
  63                 value = kzalloc(size, GFP_NOFS);
  64                 if (!value)
  65                         return ERR_PTR(-ENOMEM);
  66                 size = __ceph_getxattr(inode, name, value, size);
  67         }
  68
  69         if (size > 0)
  70                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
  71         else if (size == -ERANGE || size == -ENODATA || size == 0)
  72                 acl = NULL;
  73         else
  74                 acl = ERR_PTR(-EIO);
  75
  76         kfree(value);
  77
  78         if (!IS_ERR(acl))
  79                 ceph_set_cached_acl(inode, type, acl);
  80
  81         return acl;
  82 }
  83
  84 int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type)
  85 {
  86         int ret = 0, size = 0;
  87         const char *name = NULL;
  88         char *value = NULL;
  89         struct iattr newattrs;
  90         umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
  91         struct dentry *dentry;
  92
  93         switch (type) {
  94         case ACL_TYPE_ACCESS:
  95                 name = XATTR_NAME_POSIX_ACL_ACCESS;
  96                 if (acl) {
  97                         ret = posix_acl_equiv_mode(acl, &new_mode);
  98                         if (ret < 0)
  99                                 goto out;
 100                         if (ret == 0)
 101                                 acl = NULL;
 102                 }
 103                 break;
 104         case ACL_TYPE_DEFAULT:
 105                 if (!S_ISDIR(inode->i_mode)) {
 106                         ret = acl ? -EINVAL : 0;
 107                         goto out;
 108                 }
 109                 name = XATTR_NAME_POSIX_ACL_DEFAULT;
 110                 break;
 111         default:
 112                 ret = -EINVAL;
 113                 goto out;
 114         }
 115
 116         if (acl) {
 117                 size = posix_acl_xattr_size(acl->a_count);
 118                 value = kmalloc(size, GFP_NOFS);
 119                 if (!value) {
 120                         ret = -ENOMEM;
 121                         goto out;
 122                 }
 123
 124                 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 125                 if (ret < 0)
 126                         goto out_free;
 127         }
 128
 129         dentry = d_find_alias(inode);
 130         if (new_mode != old_mode) {
 131                 newattrs.ia_mode = new_mode;
 132                 newattrs.ia_valid = ATTR_MODE;
 133                 ret = ceph_setattr(dentry, &newattrs);
 134                 if (ret)
 135                         goto out_dput;
 136         }
 137
 138         ret = __ceph_setxattr(dentry, name, value, size, 0);
 139         if (ret) {
 140                 if (new_mode != old_mode) {
 141                         newattrs.ia_mode = old_mode;
 142                         newattrs.ia_valid = ATTR_MODE;
 143                         ceph_setattr(dentry, &newattrs);
 144                 }
 145                 goto out_dput;
 146         }
 147
 148         ceph_set_cached_acl(inode, type, acl);
 149
 150 out_dput:
 151         dput(dentry);
 152 out_free:
 153         kfree(value);
 154 out:
 155         return ret;
 156 }
 157
 158 int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
 159                        struct ceph_acls_info *info)
 160 {
 161         struct posix_acl *acl, *default_acl;
 162         size_t val_size1 = 0, val_size2 = 0;
 163         struct ceph_pagelist *pagelist = NULL;
 164         void *tmp_buf = NULL;
 165         int err;
 166
 167         err = posix_acl_create(dir, mode, &default_acl, &acl);
 168         if (err)
 169                 return err;
 170
 171         if (acl) {
 172                 int ret = posix_acl_equiv_mode(acl, mode);
 173                 if (ret < 0)
 174                         goto out_err;
 175                 if (ret == 0) {
 176                         posix_acl_release(acl);
 177                         acl = NULL;
 178                 }
 179         }
 180
 181         if (!default_acl && !acl)
 182                 return 0;
 183
 184         if (acl)
 185                 val_size1 = posix_acl_xattr_size(acl->a_count);
 186         if (default_acl)
 187                 val_size2 = posix_acl_xattr_size(default_acl->a_count);
 188
 189         err = -ENOMEM;
 190         tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL);
 191         if (!tmp_buf)
 192                 goto out_err;
 193         pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL);
 194         if (!pagelist)
 195                 goto out_err;
 196         ceph_pagelist_init(pagelist);
 197
 198         err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
 199         if (err)
 200                 goto out_err;
 201
 202         ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1);
 203
 204         if (acl) {
 205                 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS);
 206                 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8);
 207                 if (err)
 208                         goto out_err;
 209                 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS,
 210                                             len);
 211                 err = posix_acl_to_xattr(&init_user_ns, acl,
 212                                          tmp_buf, val_size1);
 213                 if (err < 0)
 214                         goto out_err;
 215                 ceph_pagelist_encode_32(pagelist, val_size1);
 216                 ceph_pagelist_append(pagelist, tmp_buf, val_size1);
 217         }
 218         if (default_acl) {
 219                 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT);
 220                 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8);
 221                 if (err)
 222                         goto out_err;
 223                 err = ceph_pagelist_encode_string(pagelist,
 224                                                   XATTR_NAME_POSIX_ACL_DEFAULT, len);
 225                 err = posix_acl_to_xattr(&init_user_ns, default_acl,
 226                                          tmp_buf, val_size2);
 227                 if (err < 0)
 228                         goto out_err;
 229                 ceph_pagelist_encode_32(pagelist, val_size2);
 230                 ceph_pagelist_append(pagelist, tmp_buf, val_size2);
 231         }
 232
 233         kfree(tmp_buf);
 234
 235         info->acl = acl;
 236         info->default_acl = default_acl;
 237         info->pagelist = pagelist;
 238         return 0;
 239
 240 out_err:
 241         posix_acl_release(acl);
 242         posix_acl_release(default_acl);
 243         kfree(tmp_buf);
 244         if (pagelist)
 245                 ceph_pagelist_release(pagelist);
 246         return err;
 247 }
 248
 249 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info)
 250 {
 251         if (!inode)
 252                 return;
 253         ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl);
 254         ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl);
 255 }
 256
 257 void ceph_release_acls_info(struct ceph_acls_info *info)
 258 {
 259         posix_acl_release(info->acl);
 260         posix_acl_release(info->default_acl);
 261         if (info->pagelist)
 262                 ceph_pagelist_release(info->pagelist);
 263 }