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 struct posix_acl *ceph_get_acl(struct inode *inode, int type) 44 { 45 int size; 46 const char *name; 47 char *value = NULL; 48 struct posix_acl *acl; 49 50 switch (type) { 51 case ACL_TYPE_ACCESS: 52 name = POSIX_ACL_XATTR_ACCESS; 53 break; 54 case ACL_TYPE_DEFAULT: 55 name = POSIX_ACL_XATTR_DEFAULT; 56 break; 57 default: 58 BUG(); 59 } 60 61 size = __ceph_getxattr(inode, name, "", 0); 62 if (size > 0) { 63 value = kzalloc(size, GFP_NOFS); 64 if (!value) 65 return ERR_PTR(-ENOMEM); 66 size = __ceph_getxattr(inode, name, value, size); 67 } 68 69 if (size > 0) 70 acl = posix_acl_from_xattr(&init_user_ns, value, size); 71 else if (size == -ERANGE || size == -ENODATA || size == 0) 72 acl = NULL; 73 else 74 acl = ERR_PTR(-EIO); 75 76 kfree(value); 77 78 if (!IS_ERR(acl)) 79 ceph_set_cached_acl(inode, type, acl); 80 81 return acl; 82 } 83 84 int ceph_set_acl(struct inode *inode, struct posix_acl *acl, int type) 85 { 86 int ret = 0, size = 0; 87 const char *name = NULL; 88 char *value = NULL; 89 struct iattr newattrs; 90 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 91 struct dentry *dentry; 92 93 switch (type) { 94 case ACL_TYPE_ACCESS: 95 name = POSIX_ACL_XATTR_ACCESS; 96 if (acl) { 97 ret = posix_acl_equiv_mode(acl, &new_mode); 98 if (ret < 0) 99 goto out; 100 if (ret == 0) 101 acl = NULL; 102 } 103 break; 104 case ACL_TYPE_DEFAULT: 105 if (!S_ISDIR(inode->i_mode)) { 106 ret = acl ? -EINVAL : 0; 107 goto out; 108 } 109 name = POSIX_ACL_XATTR_DEFAULT; 110 break; 111 default: 112 ret = -EINVAL; 113 goto out; 114 } 115 116 if (acl) { 117 size = posix_acl_xattr_size(acl->a_count); 118 value = kmalloc(size, GFP_NOFS); 119 if (!value) { 120 ret = -ENOMEM; 121 goto out; 122 } 123 124 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 125 if (ret < 0) 126 goto out_free; 127 } 128 129 dentry = d_find_alias(inode); 130 if (new_mode != old_mode) { 131 newattrs.ia_mode = new_mode; 132 newattrs.ia_valid = ATTR_MODE; 133 ret = ceph_setattr(dentry, &newattrs); 134 if (ret) 135 goto out_dput; 136 } 137 138 ret = __ceph_setxattr(dentry, 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(dentry, &newattrs); 144 } 145 goto out_dput; 146 } 147 148 ceph_set_cached_acl(inode, type, acl); 149 150 out_dput: 151 dput(dentry); 152 out_free: 153 kfree(value); 154 out: 155 return ret; 156 } 157 158 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 159 struct ceph_acls_info *info) 160 { 161 struct posix_acl *acl, *default_acl; 162 size_t val_size1 = 0, val_size2 = 0; 163 struct ceph_pagelist *pagelist = NULL; 164 void *tmp_buf = NULL; 165 int err; 166 167 err = posix_acl_create(dir, mode, &default_acl, &acl); 168 if (err) 169 return err; 170 171 if (acl) { 172 int ret = posix_acl_equiv_mode(acl, mode); 173 if (ret < 0) 174 goto out_err; 175 if (ret == 0) { 176 posix_acl_release(acl); 177 acl = NULL; 178 } 179 } 180 181 if (!default_acl && !acl) 182 return 0; 183 184 if (acl) 185 val_size1 = posix_acl_xattr_size(acl->a_count); 186 if (default_acl) 187 val_size2 = posix_acl_xattr_size(default_acl->a_count); 188 189 err = -ENOMEM; 190 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 191 if (!tmp_buf) 192 goto out_err; 193 pagelist = kmalloc(sizeof(struct ceph_pagelist), GFP_KERNEL); 194 if (!pagelist) 195 goto out_err; 196 ceph_pagelist_init(pagelist); 197 198 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 199 if (err) 200 goto out_err; 201 202 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 203 204 if (acl) { 205 size_t len = strlen(POSIX_ACL_XATTR_ACCESS); 206 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 207 if (err) 208 goto out_err; 209 ceph_pagelist_encode_string(pagelist, POSIX_ACL_XATTR_ACCESS, 210 len); 211 err = posix_acl_to_xattr(&init_user_ns, acl, 212 tmp_buf, val_size1); 213 if (err < 0) 214 goto out_err; 215 ceph_pagelist_encode_32(pagelist, val_size1); 216 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 217 } 218 if (default_acl) { 219 size_t len = strlen(POSIX_ACL_XATTR_DEFAULT); 220 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 221 if (err) 222 goto out_err; 223 err = ceph_pagelist_encode_string(pagelist, 224 POSIX_ACL_XATTR_DEFAULT, len); 225 err = posix_acl_to_xattr(&init_user_ns, default_acl, 226 tmp_buf, val_size2); 227 if (err < 0) 228 goto out_err; 229 ceph_pagelist_encode_32(pagelist, val_size2); 230 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 231 } 232 233 kfree(tmp_buf); 234 235 info->acl = acl; 236 info->default_acl = default_acl; 237 info->pagelist = pagelist; 238 return 0; 239 240 out_err: 241 posix_acl_release(acl); 242 posix_acl_release(default_acl); 243 kfree(tmp_buf); 244 if (pagelist) 245 ceph_pagelist_release(pagelist); 246 return err; 247 } 248 249 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info) 250 { 251 if (!inode) 252 return; 253 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl); 254 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl); 255 } 256 257 void ceph_release_acls_info(struct ceph_acls_info *info) 258 { 259 posix_acl_release(info->acl); 260 posix_acl_release(info->default_acl); 261 if (info->pagelist) 262 ceph_pagelist_release(info->pagelist); 263 } 264