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_equiv_mode(acl, &new_mode); 99 if (ret < 0) 100 goto out; 101 if (ret == 0) 102 acl = NULL; 103 } 104 break; 105 case ACL_TYPE_DEFAULT: 106 if (!S_ISDIR(inode->i_mode)) { 107 ret = acl ? -EINVAL : 0; 108 goto out; 109 } 110 name = XATTR_NAME_POSIX_ACL_DEFAULT; 111 break; 112 default: 113 ret = -EINVAL; 114 goto out; 115 } 116 117 if (acl) { 118 size = posix_acl_xattr_size(acl->a_count); 119 value = kmalloc(size, GFP_NOFS); 120 if (!value) { 121 ret = -ENOMEM; 122 goto out; 123 } 124 125 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 126 if (ret < 0) 127 goto out_free; 128 } 129 130 if (new_mode != old_mode) { 131 newattrs.ia_mode = new_mode; 132 newattrs.ia_valid = ATTR_MODE; 133 ret = __ceph_setattr(inode, &newattrs); 134 if (ret) 135 goto out_free; 136 } 137 138 ret = __ceph_setxattr(inode, 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(inode, &newattrs); 144 } 145 goto out_free; 146 } 147 148 ceph_set_cached_acl(inode, type, acl); 149 150 out_free: 151 kfree(value); 152 out: 153 return ret; 154 } 155 156 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 157 struct ceph_acls_info *info) 158 { 159 struct posix_acl *acl, *default_acl; 160 size_t val_size1 = 0, val_size2 = 0; 161 struct ceph_pagelist *pagelist = NULL; 162 void *tmp_buf = NULL; 163 int err; 164 165 err = posix_acl_create(dir, mode, &default_acl, &acl); 166 if (err) 167 return err; 168 169 if (acl) { 170 int ret = posix_acl_equiv_mode(acl, mode); 171 if (ret < 0) 172 goto out_err; 173 if (ret == 0) { 174 posix_acl_release(acl); 175 acl = NULL; 176 } 177 } 178 179 if (!default_acl && !acl) 180 return 0; 181 182 if (acl) 183 val_size1 = posix_acl_xattr_size(acl->a_count); 184 if (default_acl) 185 val_size2 = posix_acl_xattr_size(default_acl->a_count); 186 187 err = -ENOMEM; 188 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 189 if (!tmp_buf) 190 goto out_err; 191 pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL); 192 if (!pagelist) 193 goto out_err; 194 ceph_pagelist_init(pagelist); 195 196 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 197 if (err) 198 goto out_err; 199 200 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 201 202 if (acl) { 203 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 204 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 205 if (err) 206 goto out_err; 207 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 208 len); 209 err = posix_acl_to_xattr(&init_user_ns, acl, 210 tmp_buf, val_size1); 211 if (err < 0) 212 goto out_err; 213 ceph_pagelist_encode_32(pagelist, val_size1); 214 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 215 } 216 if (default_acl) { 217 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 218 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 219 if (err) 220 goto out_err; 221 err = ceph_pagelist_encode_string(pagelist, 222 XATTR_NAME_POSIX_ACL_DEFAULT, len); 223 err = posix_acl_to_xattr(&init_user_ns, default_acl, 224 tmp_buf, val_size2); 225 if (err < 0) 226 goto out_err; 227 ceph_pagelist_encode_32(pagelist, val_size2); 228 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 229 } 230 231 kfree(tmp_buf); 232 233 info->acl = acl; 234 info->default_acl = default_acl; 235 info->pagelist = pagelist; 236 return 0; 237 238 out_err: 239 posix_acl_release(acl); 240 posix_acl_release(default_acl); 241 kfree(tmp_buf); 242 if (pagelist) 243 ceph_pagelist_release(pagelist); 244 return err; 245 } 246 247 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info) 248 { 249 if (!inode) 250 return; 251 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl); 252 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl); 253 } 254 255 void ceph_release_acls_info(struct ceph_acls_info *info) 256 { 257 posix_acl_release(info->acl); 258 posix_acl_release(info->default_acl); 259 if (info->pagelist) 260 ceph_pagelist_release(info->pagelist); 261 } 262