1/* 2 * Copyright IBM Corporation, 2010 3 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of version 2.1 of the GNU Lesser General Public License 7 * as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, but 10 * WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 12 * 13 */ 14 15#include <linux/module.h> 16#include <linux/fs.h> 17#include <net/9p/9p.h> 18#include <net/9p/client.h> 19#include <linux/slab.h> 20#include <linux/sched.h> 21#include <linux/posix_acl_xattr.h> 22#include "xattr.h" 23#include "acl.h" 24#include "v9fs.h" 25#include "v9fs_vfs.h" 26#include "fid.h" 27 28static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name) 29{ 30 ssize_t size; 31 void *value = NULL; 32 struct posix_acl *acl = NULL; 33 34 size = v9fs_fid_xattr_get(fid, name, NULL, 0); 35 if (size > 0) { 36 value = kzalloc(size, GFP_NOFS); 37 if (!value) 38 return ERR_PTR(-ENOMEM); 39 size = v9fs_fid_xattr_get(fid, name, value, size); 40 if (size > 0) { 41 acl = posix_acl_from_xattr(&init_user_ns, value, size); 42 if (IS_ERR(acl)) 43 goto err_out; 44 } 45 } else if (size == -ENODATA || size == 0 || 46 size == -ENOSYS || size == -EOPNOTSUPP) { 47 acl = NULL; 48 } else 49 acl = ERR_PTR(-EIO); 50 51err_out: 52 kfree(value); 53 return acl; 54} 55 56int v9fs_get_acl(struct inode *inode, struct p9_fid *fid) 57{ 58 int retval = 0; 59 struct posix_acl *pacl, *dacl; 60 struct v9fs_session_info *v9ses; 61 62 v9ses = v9fs_inode2v9ses(inode); 63 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) || 64 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) { 65 set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL); 66 set_cached_acl(inode, ACL_TYPE_ACCESS, NULL); 67 return 0; 68 } 69 /* get the default/access acl values and cache them */ 70 dacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_DEFAULT); 71 pacl = __v9fs_get_acl(fid, XATTR_NAME_POSIX_ACL_ACCESS); 72 73 if (!IS_ERR(dacl) && !IS_ERR(pacl)) { 74 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); 75 set_cached_acl(inode, ACL_TYPE_ACCESS, pacl); 76 } else 77 retval = -EIO; 78 79 if (!IS_ERR(dacl)) 80 posix_acl_release(dacl); 81 82 if (!IS_ERR(pacl)) 83 posix_acl_release(pacl); 84 85 return retval; 86} 87 88static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) 89{ 90 struct posix_acl *acl; 91 /* 92 * 9p Always cache the acl value when 93 * instantiating the inode (v9fs_inode_from_fid) 94 */ 95 acl = get_cached_acl(inode, type); 96 BUG_ON(is_uncached_acl(acl)); 97 return acl; 98} 99 100struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type) 101{ 102 struct v9fs_session_info *v9ses; 103 104 v9ses = v9fs_inode2v9ses(inode); 105 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) || 106 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) { 107 /* 108 * On access = client and acl = on mode get the acl 109 * values from the server 110 */ 111 return NULL; 112 } 113 return v9fs_get_cached_acl(inode, type); 114 115} 116 117static int v9fs_set_acl(struct p9_fid *fid, int type, struct posix_acl *acl) 118{ 119 int retval; 120 char *name; 121 size_t size; 122 void *buffer; 123 if (!acl) 124 return 0; 125 126 /* Set a setxattr request to server */ 127 size = posix_acl_xattr_size(acl->a_count); 128 buffer = kmalloc(size, GFP_KERNEL); 129 if (!buffer) 130 return -ENOMEM; 131 retval = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); 132 if (retval < 0) 133 goto err_free_out; 134 switch (type) { 135 case ACL_TYPE_ACCESS: 136 name = XATTR_NAME_POSIX_ACL_ACCESS; 137 break; 138 case ACL_TYPE_DEFAULT: 139 name = XATTR_NAME_POSIX_ACL_DEFAULT; 140 break; 141 default: 142 BUG(); 143 } 144 retval = v9fs_fid_xattr_set(fid, name, buffer, size, 0); 145err_free_out: 146 kfree(buffer); 147 return retval; 148} 149 150int v9fs_acl_chmod(struct inode *inode, struct p9_fid *fid) 151{ 152 int retval = 0; 153 struct posix_acl *acl; 154 155 if (S_ISLNK(inode->i_mode)) 156 return -EOPNOTSUPP; 157 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); 158 if (acl) { 159 retval = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); 160 if (retval) 161 return retval; 162 set_cached_acl(inode, ACL_TYPE_ACCESS, acl); 163 retval = v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl); 164 posix_acl_release(acl); 165 } 166 return retval; 167} 168 169int v9fs_set_create_acl(struct inode *inode, struct p9_fid *fid, 170 struct posix_acl *dacl, struct posix_acl *acl) 171{ 172 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); 173 set_cached_acl(inode, ACL_TYPE_ACCESS, acl); 174 v9fs_set_acl(fid, ACL_TYPE_DEFAULT, dacl); 175 v9fs_set_acl(fid, ACL_TYPE_ACCESS, acl); 176 return 0; 177} 178 179void v9fs_put_acl(struct posix_acl *dacl, 180 struct posix_acl *acl) 181{ 182 posix_acl_release(dacl); 183 posix_acl_release(acl); 184} 185 186int v9fs_acl_mode(struct inode *dir, umode_t *modep, 187 struct posix_acl **dpacl, struct posix_acl **pacl) 188{ 189 int retval = 0; 190 umode_t mode = *modep; 191 struct posix_acl *acl = NULL; 192 193 if (!S_ISLNK(mode)) { 194 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT); 195 if (IS_ERR(acl)) 196 return PTR_ERR(acl); 197 if (!acl) 198 mode &= ~current_umask(); 199 } 200 if (acl) { 201 if (S_ISDIR(mode)) 202 *dpacl = posix_acl_dup(acl); 203 retval = __posix_acl_create(&acl, GFP_NOFS, &mode); 204 if (retval < 0) 205 return retval; 206 if (retval > 0) 207 *pacl = acl; 208 else 209 posix_acl_release(acl); 210 } 211 *modep = mode; 212 return 0; 213} 214 215static int v9fs_xattr_get_acl(const struct xattr_handler *handler, 216 struct dentry *dentry, struct inode *inode, 217 const char *name, void *buffer, size_t size) 218{ 219 struct v9fs_session_info *v9ses; 220 struct posix_acl *acl; 221 int error; 222 223 v9ses = v9fs_dentry2v9ses(dentry); 224 /* 225 * We allow set/get/list of acl when access=client is not specified 226 */ 227 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) 228 return v9fs_xattr_get(dentry, handler->name, buffer, size); 229 230 acl = v9fs_get_cached_acl(inode, handler->flags); 231 if (IS_ERR(acl)) 232 return PTR_ERR(acl); 233 if (acl == NULL) 234 return -ENODATA; 235 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); 236 posix_acl_release(acl); 237 238 return error; 239} 240 241static int v9fs_xattr_set_acl(const struct xattr_handler *handler, 242 struct dentry *dentry, struct inode *inode, 243 const char *name, const void *value, 244 size_t size, int flags) 245{ 246 int retval; 247 struct posix_acl *acl; 248 struct v9fs_session_info *v9ses; 249 250 v9ses = v9fs_dentry2v9ses(dentry); 251 /* 252 * set the attribute on the remote. Without even looking at the 253 * xattr value. We leave it to the server to validate 254 */ 255 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) 256 return v9fs_xattr_set(dentry, handler->name, value, size, 257 flags); 258 259 if (S_ISLNK(inode->i_mode)) 260 return -EOPNOTSUPP; 261 if (!inode_owner_or_capable(inode)) 262 return -EPERM; 263 if (value) { 264 /* update the cached acl value */ 265 acl = posix_acl_from_xattr(&init_user_ns, value, size); 266 if (IS_ERR(acl)) 267 return PTR_ERR(acl); 268 else if (acl) { 269 retval = posix_acl_valid(inode->i_sb->s_user_ns, acl); 270 if (retval) 271 goto err_out; 272 } 273 } else 274 acl = NULL; 275 276 switch (handler->flags) { 277 case ACL_TYPE_ACCESS: 278 if (acl) { 279 struct iattr iattr = { 0 }; 280 struct posix_acl *old_acl = acl; 281 282 retval = posix_acl_update_mode(inode, &iattr.ia_mode, &acl); 283 if (retval) 284 goto err_out; 285 if (!acl) { 286 /* 287 * ACL can be represented 288 * by the mode bits. So don't 289 * update ACL. 290 */ 291 posix_acl_release(old_acl); 292 value = NULL; 293 size = 0; 294 } 295 iattr.ia_valid = ATTR_MODE; 296 /* FIXME should we update ctime ? 297 * What is the following setxattr update the 298 * mode ? 299 */ 300 v9fs_vfs_setattr_dotl(dentry, &iattr); 301 } 302 break; 303 case ACL_TYPE_DEFAULT: 304 if (!S_ISDIR(inode->i_mode)) { 305 retval = acl ? -EINVAL : 0; 306 goto err_out; 307 } 308 break; 309 default: 310 BUG(); 311 } 312 retval = v9fs_xattr_set(dentry, handler->name, value, size, flags); 313 if (!retval) 314 set_cached_acl(inode, handler->flags, acl); 315err_out: 316 posix_acl_release(acl); 317 return retval; 318} 319 320const struct xattr_handler v9fs_xattr_acl_access_handler = { 321 .name = XATTR_NAME_POSIX_ACL_ACCESS, 322 .flags = ACL_TYPE_ACCESS, 323 .get = v9fs_xattr_get_acl, 324 .set = v9fs_xattr_set_acl, 325}; 326 327const struct xattr_handler v9fs_xattr_acl_default_handler = { 328 .name = XATTR_NAME_POSIX_ACL_DEFAULT, 329 .flags = ACL_TYPE_DEFAULT, 330 .get = v9fs_xattr_get_acl, 331 .set = v9fs_xattr_set_acl, 332}; 333