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 const char *name; 49 char *value = NULL; 50 struct posix_acl *acl; 51 52 switch (type) { 53 case ACL_TYPE_ACCESS: 54 name = XATTR_NAME_POSIX_ACL_ACCESS; 55 break; 56 case ACL_TYPE_DEFAULT: 57 name = XATTR_NAME_POSIX_ACL_DEFAULT; 58 break; 59 default: 60 BUG(); 61 } 62 63 size = __ceph_getxattr(inode, name, "", 0); 64 if (size > 0) { 65 value = kzalloc(size, GFP_NOFS); 66 if (!value) 67 return ERR_PTR(-ENOMEM); 68 size = __ceph_getxattr(inode, name, value, size); 69 } 70 71 if (size > 0) 72 acl = posix_acl_from_xattr(&init_user_ns, value, size); 73 else if (size == -ERANGE || size == -ENODATA || size == 0) 74 acl = NULL; 75 else 76 acl = ERR_PTR(-EIO); 77 78 kfree(value); 79 80 if (!IS_ERR(acl)) 81 ceph_set_cached_acl(inode, type, acl); 82 83 return acl; 84 } 85 86 int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type) 87 { 88 int ret = 0, size = 0; 89 const char *name = NULL; 90 char *value = NULL; 91 struct iattr newattrs; 92 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 93 94 switch (type) { 95 case ACL_TYPE_ACCESS: 96 name = XATTR_NAME_POSIX_ACL_ACCESS; 97 if (acl) { 98 ret = posix_acl_update_mode(inode, &new_mode, &acl); 99 if (ret) 100 goto out; 101 } 102 break; 103 case ACL_TYPE_DEFAULT: 104 if (!S_ISDIR(inode->i_mode)) { 105 ret = acl ? -EINVAL : 0; 106 goto out; 107 } 108 name = XATTR_NAME_POSIX_ACL_DEFAULT; 109 break; 110 default: 111 ret = -EINVAL; 112 goto out; 113 } 114 115 if (acl) { 116 size = posix_acl_xattr_size(acl->a_count); 117 value = kmalloc(size, GFP_NOFS); 118 if (!value) { 119 ret = -ENOMEM; 120 goto out; 121 } 122 123 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 124 if (ret < 0) 125 goto out_free; 126 } 127 128 if (ceph_snap(inode) != CEPH_NOSNAP) { 129 ret = -EROFS; 130 goto out_free; 131 } 132 133 if (new_mode != old_mode) { 134 newattrs.ia_ctime = current_time(inode); 135 newattrs.ia_mode = new_mode; 136 newattrs.ia_valid = ATTR_MODE; 137 ret = __ceph_setattr(inode, &newattrs); 138 if (ret) 139 goto out_free; 140 } 141 142 ret = __ceph_setxattr(inode, name, value, size, 0); 143 if (ret) { 144 if (new_mode != old_mode) { 145 newattrs.ia_mode = old_mode; 146 newattrs.ia_valid = ATTR_MODE; 147 __ceph_setattr(inode, &newattrs); 148 } 149 goto out_free; 150 } 151 152 ceph_set_cached_acl(inode, type, acl); 153 154 out_free: 155 kfree(value); 156 out: 157 return ret; 158 } 159 160 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 161 struct ceph_acls_info *info) 162 { 163 struct posix_acl *acl, *default_acl; 164 size_t val_size1 = 0, val_size2 = 0; 165 struct ceph_pagelist *pagelist = NULL; 166 void *tmp_buf = NULL; 167 int err; 168 169 err = posix_acl_create(dir, mode, &default_acl, &acl); 170 if (err) 171 return err; 172 173 if (acl) { 174 int ret = posix_acl_equiv_mode(acl, mode); 175 if (ret < 0) 176 goto out_err; 177 if (ret == 0) { 178 posix_acl_release(acl); 179 acl = NULL; 180 } 181 } 182 183 if (!default_acl && !acl) 184 return 0; 185 186 if (acl) 187 val_size1 = posix_acl_xattr_size(acl->a_count); 188 if (default_acl) 189 val_size2 = posix_acl_xattr_size(default_acl->a_count); 190 191 err = -ENOMEM; 192 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 193 if (!tmp_buf) 194 goto out_err; 195 pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL); 196 if (!pagelist) 197 goto out_err; 198 ceph_pagelist_init(pagelist); 199 200 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 201 if (err) 202 goto out_err; 203 204 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 205 206 if (acl) { 207 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 208 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 209 if (err) 210 goto out_err; 211 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 212 len); 213 err = posix_acl_to_xattr(&init_user_ns, acl, 214 tmp_buf, val_size1); 215 if (err < 0) 216 goto out_err; 217 ceph_pagelist_encode_32(pagelist, val_size1); 218 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 219 } 220 if (default_acl) { 221 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 222 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 223 if (err) 224 goto out_err; 225 err = ceph_pagelist_encode_string(pagelist, 226 XATTR_NAME_POSIX_ACL_DEFAULT, len); 227 err = posix_acl_to_xattr(&init_user_ns, default_acl, 228 tmp_buf, val_size2); 229 if (err < 0) 230 goto out_err; 231 ceph_pagelist_encode_32(pagelist, val_size2); 232 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 233 } 234 235 kfree(tmp_buf); 236 237 info->acl = acl; 238 info->default_acl = default_acl; 239 info->pagelist = pagelist; 240 return 0; 241 242 out_err: 243 posix_acl_release(acl); 244 posix_acl_release(default_acl); 245 kfree(tmp_buf); 246 if (pagelist) 247 ceph_pagelist_release(pagelist); 248 return err; 249 } 250 251 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info) 252 { 253 if (!inode) 254 return; 255 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl); 256 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl); 257 } 258 259 void ceph_release_acls_info(struct ceph_acls_info *info) 260 { 261 posix_acl_release(info->acl); 262 posix_acl_release(info->default_acl); 263 if (info->pagelist) 264 ceph_pagelist_release(info->pagelist); 265 } 266