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 static inline struct posix_acl *ceph_get_cached_acl(struct inode *inode,
  44                                                         int type)
  45 {
  46         struct ceph_inode_info *ci = ceph_inode(inode);
  47         struct posix_acl *acl = ACL_NOT_CACHED;
  48
  49         spin_lock(&ci->i_ceph_lock);
  50         if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0))
  51                 acl = get_cached_acl(inode, type);
  52         spin_unlock(&ci->i_ceph_lock);
  53
  54         return acl;
  55 }
  56
  57 struct posix_acl *ceph_get_acl(struct inode *inode, int type)
  58 {
  59         int size;
  60         const char *name;
  61         char *value = NULL;
  62         struct posix_acl *acl;
  63
  64         switch (type) {
  65         case ACL_TYPE_ACCESS:
  66                 name = POSIX_ACL_XATTR_ACCESS;
  67                 break;
  68         case ACL_TYPE_DEFAULT:
  69                 name = POSIX_ACL_XATTR_DEFAULT;
  70                 break;
  71         default:
  72                 BUG();
  73         }
  74
  75         size = __ceph_getxattr(inode, name, "", 0);
  76         if (size > 0) {
  77                 value = kzalloc(size, GFP_NOFS);
  78                 if (!value)
  79                         return ERR_PTR(-ENOMEM);
  80                 size = __ceph_getxattr(inode, name, value, size);
  81         }
  82
  83         if (size > 0)
  84                 acl = posix_acl_from_xattr(&init_user_ns, value, size);
  85         else if (size == -ERANGE || size == -ENODATA || size == 0)
  86                 acl = NULL;
  87         else
  88                 acl = ERR_PTR(-EIO);
  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         umode_t new_mode = inode->i_mode, old_mode = inode->i_mode;
 105         struct dentry *dentry;
 106
 107         switch (type) {
 108         case ACL_TYPE_ACCESS:
 109                 name = POSIX_ACL_XATTR_ACCESS;
 110                 if (acl) {
 111                         ret = posix_acl_equiv_mode(acl, &new_mode);
 112                         if (ret < 0)
 113                                 goto out;
 114                         if (ret == 0)
 115                                 acl = NULL;
 116                 }
 117                 break;
 118         case ACL_TYPE_DEFAULT:
 119                 if (!S_ISDIR(inode->i_mode)) {
 120                         ret = acl ? -EINVAL : 0;
 121                         goto out;
 122                 }
 123                 name = POSIX_ACL_XATTR_DEFAULT;
 124                 break;
 125         default:
 126                 ret = -EINVAL;
 127                 goto out;
 128         }
 129
 130         if (acl) {
 131                 size = posix_acl_xattr_size(acl->a_count);
 132                 value = kmalloc(size, GFP_NOFS);
 133                 if (!value) {
 134                         ret = -ENOMEM;
 135                         goto out;
 136                 }
 137
 138                 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
 139                 if (ret < 0)
 140                         goto out_free;
 141         }
 142
 143         dentry = d_find_alias(inode);
 144         if (new_mode != old_mode) {
 145                 newattrs.ia_mode = new_mode;
 146                 newattrs.ia_valid = ATTR_MODE;
 147                 ret = ceph_setattr(dentry, &newattrs);
 148                 if (ret)
 149                         goto out_dput;
 150         }
 151
 152         ret = __ceph_setxattr(dentry, name, value, size, 0);
 153         if (ret) {
 154                 if (new_mode != old_mode) {
 155                         newattrs.ia_mode = old_mode;
 156                         newattrs.ia_valid = ATTR_MODE;
 157                         ceph_setattr(dentry, &newattrs);
 158                 }
 159                 goto out_dput;
 160         }
 161
 162         ceph_set_cached_acl(inode, type, acl);
 163
 164 out_dput:
 165         dput(dentry);
 166 out_free:
 167         kfree(value);
 168 out:
 169         return ret;
 170 }
 171
 172 int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
 173                        struct ceph_acls_info *info)
 174 {
 175         struct posix_acl *acl, *default_acl;
 176         size_t val_size1 = 0, val_size2 = 0;
 177         struct ceph_pagelist *pagelist = NULL;
 178         void *tmp_buf = NULL;
 179         int err;
 180
 181         err = posix_acl_create(dir, mode, &default_acl, &acl);
 182         if (err)
 183                 return err;
 184
 185         if (acl) {
 186                 int ret = posix_acl_equiv_mode(acl, mode);
 187                 if (ret < 0)
 188                         goto out_err;
 189                 if (ret == 0) {
 190                         posix_acl_release(acl);
 191                         acl = NULL;
 192                 }
 193         }
 194
 195         if (!default_acl && !acl)
 196                 return 0;
 197
 198         if (acl)
 199                 val_size1 = posix_acl_xattr_size(acl->a_count);
 200         if (default_acl)
 201                 val_size2 = posix_acl_xattr_size(default_acl->a_count);
 202
 203         err = -ENOMEM;
 204         tmp_buf = kmalloc(max(val_size1, val_size2), GFP_NOFS);
 205         if (!tmp_buf)
 206                 goto out_err;
 207         pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_NOFS);
 208         if (!pagelist)
 209                 goto out_err;
 210         ceph_pagelist_init(pagelist);
 211
 212         err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
 213         if (err)
 214                 goto out_err;
 215
 216         ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1);
 217
 218         if (acl) {
 219                 size_t len = strlen(POSIX_ACL_XATTR_ACCESS);
 220                 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8);
 221                 if (err)
 222                         goto out_err;
 223                 ceph_pagelist_encode_string(pagelist, POSIX_ACL_XATTR_ACCESS,
 224                                             len);
 225                 err = posix_acl_to_xattr(&init_user_ns, acl,
 226                                          tmp_buf, val_size1);
 227                 if (err < 0)
 228                         goto out_err;
 229                 ceph_pagelist_encode_32(pagelist, val_size1);
 230                 ceph_pagelist_append(pagelist, tmp_buf, val_size1);
 231         }
 232         if (default_acl) {
 233                 size_t len = strlen(POSIX_ACL_XATTR_DEFAULT);
 234                 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8);
 235                 if (err)
 236                         goto out_err;
 237                 err = ceph_pagelist_encode_string(pagelist,
 238                                                   POSIX_ACL_XATTR_DEFAULT, len);
 239                 err = posix_acl_to_xattr(&init_user_ns, default_acl,
 240                                          tmp_buf, val_size2);
 241                 if (err < 0)
 242                         goto out_err;
 243                 ceph_pagelist_encode_32(pagelist, val_size2);
 244                 ceph_pagelist_append(pagelist, tmp_buf, val_size2);
 245         }
 246
 247         kfree(tmp_buf);
 248
 249         info->acl = acl;
 250         info->default_acl = default_acl;
 251         info->pagelist = pagelist;
 252         return 0;
 253
 254 out_err:
 255         posix_acl_release(acl);
 256         posix_acl_release(default_acl);
 257         kfree(tmp_buf);
 258         if (pagelist)
 259                 ceph_pagelist_release(pagelist);
 260         return err;
 261 }
 262
 263 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info)
 264 {
 265         if (!inode)
 266                 return;
 267         ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl);
 268         ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl);
 269 }
 270
 271 void ceph_release_acls_info(struct ceph_acls_info *info)
 272 {
 273         posix_acl_release(info->acl);
 274         posix_acl_release(info->default_acl);
 275         if (info->pagelist)
 276                 ceph_pagelist_release(info->pagelist);
 277 }