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 unsigned int retry_cnt = 0; 49 const char *name; 50 char *value = NULL; 51 struct posix_acl *acl; 52 53 switch (type) { 54 case ACL_TYPE_ACCESS: 55 name = XATTR_NAME_POSIX_ACL_ACCESS; 56 break; 57 case ACL_TYPE_DEFAULT: 58 name = XATTR_NAME_POSIX_ACL_DEFAULT; 59 break; 60 default: 61 BUG(); 62 } 63 64 retry: 65 size = __ceph_getxattr(inode, name, "", 0); 66 if (size > 0) { 67 value = kzalloc(size, GFP_NOFS); 68 if (!value) 69 return ERR_PTR(-ENOMEM); 70 size = __ceph_getxattr(inode, name, value, size); 71 } 72 73 if (size == -ERANGE && retry_cnt < 10) { 74 retry_cnt++; 75 kfree(value); 76 value = NULL; 77 goto retry; 78 } 79 80 if (size > 0) { 81 acl = posix_acl_from_xattr(&init_user_ns, value, size); 82 } else if (size == -ENODATA || size == 0) { 83 acl = NULL; 84 } else { 85 pr_err_ratelimited("get acl %llx.%llx failed, err=%d\n", 86 ceph_vinop(inode), size); 87 acl = ERR_PTR(-EIO); 88 } 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; 105 106 switch (type) { 107 case ACL_TYPE_ACCESS: 108 name = XATTR_NAME_POSIX_ACL_ACCESS; 109 if (acl) { 110 ret = posix_acl_update_mode(inode, &new_mode, &acl); 111 if (ret) 112 goto out; 113 } 114 break; 115 case ACL_TYPE_DEFAULT: 116 if (!S_ISDIR(inode->i_mode)) { 117 ret = acl ? -EINVAL : 0; 118 goto out; 119 } 120 name = XATTR_NAME_POSIX_ACL_DEFAULT; 121 break; 122 default: 123 ret = -EINVAL; 124 goto out; 125 } 126 127 if (acl) { 128 size = posix_acl_xattr_size(acl->a_count); 129 value = kmalloc(size, GFP_NOFS); 130 if (!value) { 131 ret = -ENOMEM; 132 goto out; 133 } 134 135 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 136 if (ret < 0) 137 goto out_free; 138 } 139 140 if (ceph_snap(inode) != CEPH_NOSNAP) { 141 ret = -EROFS; 142 goto out_free; 143 } 144 145 if (new_mode != old_mode) { 146 newattrs.ia_ctime = current_time(inode); 147 newattrs.ia_mode = new_mode; 148 newattrs.ia_valid = ATTR_MODE; 149 ret = __ceph_setattr(inode, &newattrs); 150 if (ret) 151 goto out_free; 152 } 153 154 ret = __ceph_setxattr(inode, name, value, size, 0); 155 if (ret) { 156 if (new_mode != old_mode) { 157 newattrs.ia_mode = old_mode; 158 newattrs.ia_valid = ATTR_MODE; 159 __ceph_setattr(inode, &newattrs); 160 } 161 goto out_free; 162 } 163 164 ceph_set_cached_acl(inode, type, acl); 165 166 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_KERNEL); 205 if (!tmp_buf) 206 goto out_err; 207 pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL); 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(XATTR_NAME_POSIX_ACL_ACCESS); 220 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 221 if (err) 222 goto out_err; 223 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_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(XATTR_NAME_POSIX_ACL_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 XATTR_NAME_POSIX_ACL_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 } 278