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 struct timespec64 old_ctime = inode->i_ctime; 105 umode_t new_mode = inode->i_mode, old_mode = inode->i_mode; 106 107 if (ceph_snap(inode) != CEPH_NOSNAP) { 108 ret = -EROFS; 109 goto out; 110 } 111 112 switch (type) { 113 case ACL_TYPE_ACCESS: 114 name = XATTR_NAME_POSIX_ACL_ACCESS; 115 if (acl) { 116 ret = posix_acl_update_mode(inode, &new_mode, &acl); 117 if (ret) 118 goto out; 119 } 120 break; 121 case ACL_TYPE_DEFAULT: 122 if (!S_ISDIR(inode->i_mode)) { 123 ret = acl ? -EINVAL : 0; 124 goto out; 125 } 126 name = XATTR_NAME_POSIX_ACL_DEFAULT; 127 break; 128 default: 129 ret = -EINVAL; 130 goto out; 131 } 132 133 if (acl) { 134 size = posix_acl_xattr_size(acl->a_count); 135 value = kmalloc(size, GFP_NOFS); 136 if (!value) { 137 ret = -ENOMEM; 138 goto out; 139 } 140 141 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size); 142 if (ret < 0) 143 goto out_free; 144 } 145 146 if (new_mode != old_mode) { 147 newattrs.ia_ctime = current_time(inode); 148 newattrs.ia_mode = new_mode; 149 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 150 ret = __ceph_setattr(inode, &newattrs); 151 if (ret) 152 goto out_free; 153 } 154 155 ret = __ceph_setxattr(inode, name, value, size, 0); 156 if (ret) { 157 if (new_mode != old_mode) { 158 newattrs.ia_ctime = old_ctime; 159 newattrs.ia_mode = old_mode; 160 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; 161 __ceph_setattr(inode, &newattrs); 162 } 163 goto out_free; 164 } 165 166 ceph_set_cached_acl(inode, type, acl); 167 168 out_free: 169 kfree(value); 170 out: 171 return ret; 172 } 173 174 int ceph_pre_init_acls(struct inode *dir, umode_t *mode, 175 struct ceph_acls_info *info) 176 { 177 struct posix_acl *acl, *default_acl; 178 size_t val_size1 = 0, val_size2 = 0; 179 struct ceph_pagelist *pagelist = NULL; 180 void *tmp_buf = NULL; 181 int err; 182 183 err = posix_acl_create(dir, mode, &default_acl, &acl); 184 if (err) 185 return err; 186 187 if (acl) { 188 err = posix_acl_equiv_mode(acl, mode); 189 if (err < 0) 190 goto out_err; 191 if (err == 0) { 192 posix_acl_release(acl); 193 acl = NULL; 194 } 195 } 196 197 if (!default_acl && !acl) 198 return 0; 199 200 if (acl) 201 val_size1 = posix_acl_xattr_size(acl->a_count); 202 if (default_acl) 203 val_size2 = posix_acl_xattr_size(default_acl->a_count); 204 205 err = -ENOMEM; 206 tmp_buf = kmalloc(max(val_size1, val_size2), GFP_KERNEL); 207 if (!tmp_buf) 208 goto out_err; 209 pagelist = ceph_pagelist_alloc(GFP_KERNEL); 210 if (!pagelist) 211 goto out_err; 212 213 err = ceph_pagelist_reserve(pagelist, PAGE_SIZE); 214 if (err) 215 goto out_err; 216 217 ceph_pagelist_encode_32(pagelist, acl && default_acl ? 2 : 1); 218 219 if (acl) { 220 size_t len = strlen(XATTR_NAME_POSIX_ACL_ACCESS); 221 err = ceph_pagelist_reserve(pagelist, len + val_size1 + 8); 222 if (err) 223 goto out_err; 224 ceph_pagelist_encode_string(pagelist, XATTR_NAME_POSIX_ACL_ACCESS, 225 len); 226 err = posix_acl_to_xattr(&init_user_ns, acl, 227 tmp_buf, val_size1); 228 if (err < 0) 229 goto out_err; 230 ceph_pagelist_encode_32(pagelist, val_size1); 231 ceph_pagelist_append(pagelist, tmp_buf, val_size1); 232 } 233 if (default_acl) { 234 size_t len = strlen(XATTR_NAME_POSIX_ACL_DEFAULT); 235 err = ceph_pagelist_reserve(pagelist, len + val_size2 + 8); 236 if (err) 237 goto out_err; 238 err = ceph_pagelist_encode_string(pagelist, 239 XATTR_NAME_POSIX_ACL_DEFAULT, len); 240 err = posix_acl_to_xattr(&init_user_ns, default_acl, 241 tmp_buf, val_size2); 242 if (err < 0) 243 goto out_err; 244 ceph_pagelist_encode_32(pagelist, val_size2); 245 ceph_pagelist_append(pagelist, tmp_buf, val_size2); 246 } 247 248 kfree(tmp_buf); 249 250 info->acl = acl; 251 info->default_acl = default_acl; 252 info->pagelist = pagelist; 253 return 0; 254 255 out_err: 256 posix_acl_release(acl); 257 posix_acl_release(default_acl); 258 kfree(tmp_buf); 259 if (pagelist) 260 ceph_pagelist_release(pagelist); 261 return err; 262 } 263 264 void ceph_init_inode_acls(struct inode* inode, struct ceph_acls_info *info) 265 { 266 if (!inode) 267 return; 268 ceph_set_cached_acl(inode, ACL_TYPE_ACCESS, info->acl); 269 ceph_set_cached_acl(inode, ACL_TYPE_DEFAULT, info->default_acl); 270 } 271 272 void ceph_release_acls_info(struct ceph_acls_info *info) 273 { 274 posix_acl_release(info->acl); 275 posix_acl_release(info->default_acl); 276 if (info->pagelist) 277 ceph_pagelist_release(info->pagelist); 278 } 279