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_mode = new_mode; 135 newattrs.ia_valid = ATTR_MODE; 136 ret = __ceph_setattr(inode, &newattrs); 137 if (ret) 138 goto out_free; 139 } 140 141 ret = __ceph_setxattr(inode, name, value, size, 0); 142 if (ret) { 143 if (new_mode != old_mode) { 144 newattrs.ia_mode = old_mode; 145 newattrs.ia_valid = ATTR_MODE; 146 __ceph_setattr(inode, &newattrs); 147 } 148 goto out_free; 149 } 150 151 ceph_set_cached_acl(inode, type, acl); 152 153 out_free: 154 kfree(value); 155 out: 156 return ret; 157 } 158 159 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 160 struct ceph_acls_info *info) 161 { 162 struct posix_acl *acl, *default_acl; 163 size_t val_size1 = 0, val_size2 = 0; 164 struct ceph_pagelist *pagelist = NULL; 165 void *tmp_buf = NULL; 166 int err; 167 168 err = posix_acl_create(dir, mode, &default_acl, &acl); 169 if (err) 170 return err; 171 172 if (acl) { 173 int ret = posix_acl_equiv_mode(acl, mode); 174 if (ret < 0) 175 goto out_err; 176 if (ret == 0) { 177 posix_acl_release(acl); 178 acl = NULL; 179 } 180 } 181 182 if (!default_acl && !acl) 183 return 0; 184 185 if (acl) 186 val_size1 = posix_acl_xattr_size(acl->a_count); 187 if (default_acl) 188 val_size2 = posix_acl_xattr_size(default_acl->a_count); 189 190 err = -ENOMEM; 191 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 192 if (!tmp_buf) 193 goto out_err; 194 pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL); 195 if (!pagelist) 196 goto out_err; 197 ceph_pagelist_init(pagelist); 198 199 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 200 if (err) 201 goto out_err; 202 203 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 204 205 if (acl) { 206 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 207 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 208 if (err) 209 goto out_err; 210 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 211 len); 212 err = posix_acl_to_xattr(&init_user_ns, acl, 213 tmp_buf, val_size1); 214 if (err < 0) 215 goto out_err; 216 ceph_pagelist_encode_32(pagelist, val_size1); 217 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 218 } 219 if (default_acl) { 220 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 221 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 222 if (err) 223 goto out_err; 224 err = ceph_pagelist_encode_string(pagelist, 225 XATTR_NAME_POSIX_ACL_DEFAULT, len); 226 err = posix_acl_to_xattr(&init_user_ns, default_acl, 227 tmp_buf, val_size2); 228 if (err < 0) 229 goto out_err; 230 ceph_pagelist_encode_32(pagelist, val_size2); 231 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 232 } 233 234 kfree(tmp_buf); 235 236 info->acl = acl; 237 info->default_acl = default_acl; 238 info->pagelist = pagelist; 239 return 0; 240 241 out_err: 242 posix_acl_release(acl); 243 posix_acl_release(default_acl); 244 kfree(tmp_buf); 245 if (pagelist) 246 ceph_pagelist_release(pagelist); 247 return err; 248 } 249 250 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info) 251 { 252 if (!inode) 253 return; 254 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl); 255 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl); 256 } 257 258 void ceph_release_acls_info(struct ceph_acls_info *info) 259 { 260 posix_acl_release(info->acl); 261 posix_acl_release(info->default_acl); 262 if (info->pagelist) 263 ceph_pagelist_release(info->pagelist); 264 } 265