fs/nfs/nfs3acl.c

   1 #include <linux/fs.h>
   2 #include <linux/nfs.h>
   3 #include <linux/nfs3.h>
   4 #include <linux/nfs_fs.h>
   5 #include <linux/posix_acl_xattr.h>
   6 #include <linux/nfsacl.h>
   7
   8 #define NFSDBG_FACILITY NFSDBG_PROC
   9
  10 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
  11 {
  12         struct inode *inode = dentry->d_inode;
  13         struct posix_acl *acl;
  14         int pos=0, len=0;
  15
  16 #       define output(s) do {                                           \
  17                         if (pos + sizeof(s) <= size) {                  \
  18                                 memcpy(buffer + pos, s, sizeof(s));     \
  19                                 pos += sizeof(s);                       \
  20                         }                                               \
  21                         len += sizeof(s);                               \
  22                 } while(0)
  23
  24         acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
  25         if (IS_ERR(acl))
  26                 return PTR_ERR(acl);
  27         if (acl) {
  28                 output("system.posix_acl_access");
  29                 posix_acl_release(acl);
  30         }
  31
  32         if (S_ISDIR(inode->i_mode)) {
  33                 acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
  34                 if (IS_ERR(acl))
  35                         return PTR_ERR(acl);
  36                 if (acl) {
  37                         output("system.posix_acl_default");
  38                         posix_acl_release(acl);
  39                 }
  40         }
  41
  42 #       undef output
  43
  44         if (!buffer || len <= size)
  45                 return len;
  46         return -ERANGE;
  47 }
  48
  49 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
  50                 void *buffer, size_t size)
  51 {
  52         struct inode *inode = dentry->d_inode;
  53         struct posix_acl *acl;
  54         int type, error = 0;
  55
  56         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
  57                 type = ACL_TYPE_ACCESS;
  58         else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
  59                 type = ACL_TYPE_DEFAULT;
  60         else
  61                 return -EOPNOTSUPP;
  62
  63         acl = nfs3_proc_getacl(inode, type);
  64         if (IS_ERR(acl))
  65                 return PTR_ERR(acl);
  66         else if (acl) {
  67                 if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
  68                         error = -ENODATA;
  69                 else
  70                         error = posix_acl_to_xattr(acl, buffer, size);
  71                 posix_acl_release(acl);
  72         } else
  73                 error = -ENODATA;
  74
  75         return error;
  76 }
  77
  78 int nfs3_setxattr(struct dentry *dentry, const char *name,
  79              const void *value, size_t size, int flags)
  80 {
  81         struct inode *inode = dentry->d_inode;
  82         struct posix_acl *acl;
  83         int type, error;
  84
  85         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
  86                 type = ACL_TYPE_ACCESS;
  87         else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
  88                 type = ACL_TYPE_DEFAULT;
  89         else
  90                 return -EOPNOTSUPP;
  91
  92         acl = posix_acl_from_xattr(value, size);
  93         if (IS_ERR(acl))
  94                 return PTR_ERR(acl);
  95         error = nfs3_proc_setacl(inode, type, acl);
  96         posix_acl_release(acl);
  97
  98         return error;
  99 }
 100
 101 int nfs3_removexattr(struct dentry *dentry, const char *name)
 102 {
 103         struct inode *inode = dentry->d_inode;
 104         int type;
 105
 106         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
 107                 type = ACL_TYPE_ACCESS;
 108         else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
 109                 type = ACL_TYPE_DEFAULT;
 110         else
 111                 return -EOPNOTSUPP;
 112
 113         return nfs3_proc_setacl(inode, type, NULL);
 114 }
 115
 116 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
 117 {
 118         if (!IS_ERR(nfsi->acl_access)) {
 119                 posix_acl_release(nfsi->acl_access);
 120                 nfsi->acl_access = ERR_PTR(-EAGAIN);
 121         }
 122         if (!IS_ERR(nfsi->acl_default)) {
 123                 posix_acl_release(nfsi->acl_default);
 124                 nfsi->acl_default = ERR_PTR(-EAGAIN);
 125         }
 126 }
 127
 128 void nfs3_forget_cached_acls(struct inode *inode)
 129 {
 130         dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
 131                 inode->i_ino);
 132         spin_lock(&inode->i_lock);
 133         __nfs3_forget_cached_acls(NFS_I(inode));
 134         spin_unlock(&inode->i_lock);
 135 }
 136
 137 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
 138 {
 139         struct nfs_inode *nfsi = NFS_I(inode);
 140         struct posix_acl *acl = ERR_PTR(-EINVAL);
 141
 142         spin_lock(&inode->i_lock);
 143         switch(type) {
 144                 case ACL_TYPE_ACCESS:
 145                         acl = nfsi->acl_access;
 146                         break;
 147
 148                 case ACL_TYPE_DEFAULT:
 149                         acl = nfsi->acl_default;
 150                         break;
 151
 152                 default:
 153                         goto out;
 154         }
 155         if (IS_ERR(acl))
 156                 acl = ERR_PTR(-EAGAIN);
 157         else
 158                 acl = posix_acl_dup(acl);
 159 out:
 160         spin_unlock(&inode->i_lock);
 161         dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
 162                 inode->i_ino, type, acl);
 163         return acl;
 164 }
 165
 166 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
 167                     struct posix_acl *dfacl)
 168 {
 169         struct nfs_inode *nfsi = NFS_I(inode);
 170
 171         dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
 172                 inode->i_ino, acl, dfacl);
 173         spin_lock(&inode->i_lock);
 174         __nfs3_forget_cached_acls(NFS_I(inode));
 175         nfsi->acl_access = posix_acl_dup(acl);
 176         nfsi->acl_default = posix_acl_dup(dfacl);
 177         spin_unlock(&inode->i_lock);
 178 }
 179
 180 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
 181 {
 182         struct nfs_server *server = NFS_SERVER(inode);
 183         struct nfs_fattr fattr;
 184         struct page *pages[NFSACL_MAXPAGES] = { };
 185         struct nfs3_getaclargs args = {
 186                 .fh = NFS_FH(inode),
 187                 /* The xdr layer may allocate pages here. */
 188                 .pages = pages,
 189         };
 190         struct nfs3_getaclres res = {
 191                 .fattr =        &fattr,
 192         };
 193         struct posix_acl *acl;
 194         int status, count;
 195
 196         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 197                 return ERR_PTR(-EOPNOTSUPP);
 198
 199         status = nfs_revalidate_inode(server, inode);
 200         if (status < 0)
 201                 return ERR_PTR(status);
 202         acl = nfs3_get_cached_acl(inode, type);
 203         if (acl != ERR_PTR(-EAGAIN))
 204                 return acl;
 205         acl = NULL;
 206
 207         /*
 208          * Only get the access acl when explicitly requested: We don't
 209          * need it for access decisions, and only some applications use
 210          * it. Applications which request the access acl first are not
 211          * penalized from this optimization.
 212          */
 213         if (type == ACL_TYPE_ACCESS)
 214                 args.mask |= NFS_ACLCNT|NFS_ACL;
 215         if (S_ISDIR(inode->i_mode))
 216                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
 217         if (args.mask == 0)
 218                 return NULL;
 219
 220         dprintk("NFS call getacl\n");
 221         status = rpc_call(server->client_acl, ACLPROC3_GETACL,
 222                           &args, &res, 0);
 223         dprintk("NFS reply getacl: %d\n", status);
 224
 225         /* pages may have been allocated at the xdr layer. */
 226         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 227                 __free_page(args.pages[count]);
 228
 229         switch (status) {
 230                 case 0:
 231                         status = nfs_refresh_inode(inode, &fattr);
 232                         break;
 233                 case -EPFNOSUPPORT:
 234                 case -EPROTONOSUPPORT:
 235                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
 236                         server->caps &= ~NFS_CAP_ACLS;
 237                 case -ENOTSUPP:
 238                         status = -EOPNOTSUPP;
 239                 default:
 240                         goto getout;
 241         }
 242         if ((args.mask & res.mask) != args.mask) {
 243                 status = -EIO;
 244                 goto getout;
 245         }
 246
 247         if (res.acl_access != NULL) {
 248                 if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
 249                         posix_acl_release(res.acl_access);
 250                         res.acl_access = NULL;
 251                 }
 252         }
 253         nfs3_cache_acls(inode, res.acl_access, res.acl_default);
 254
 255         switch(type) {
 256                 case ACL_TYPE_ACCESS:
 257                         acl = res.acl_access;
 258                         res.acl_access = NULL;
 259                         break;
 260
 261                 case ACL_TYPE_DEFAULT:
 262                         acl = res.acl_default;
 263                         res.acl_default = NULL;
 264         }
 265
 266 getout:
 267         posix_acl_release(res.acl_access);
 268         posix_acl_release(res.acl_default);
 269
 270         if (status != 0) {
 271                 posix_acl_release(acl);
 272                 acl = ERR_PTR(status);
 273         }
 274         return acl;
 275 }
 276
 277 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 278                   struct posix_acl *dfacl)
 279 {
 280         struct nfs_server *server = NFS_SERVER(inode);
 281         struct nfs_fattr fattr;
 282         struct page *pages[NFSACL_MAXPAGES] = { };
 283         struct nfs3_setaclargs args = {
 284                 .inode = inode,
 285                 .mask = NFS_ACL,
 286                 .acl_access = acl,
 287                 .pages = pages,
 288         };
 289         int status, count;
 290
 291         status = -EOPNOTSUPP;
 292         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 293                 goto out;
 294
 295         /* We are doing this here, because XDR marshalling can only
 296            return -ENOMEM. */
 297         status = -ENOSPC;
 298         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
 299                 goto out;
 300         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
 301                 goto out;
 302         if (S_ISDIR(inode->i_mode)) {
 303                 args.mask |= NFS_DFACL;
 304                 args.acl_default = dfacl;
 305         }
 306
 307         dprintk("NFS call setacl\n");
 308         nfs_begin_data_update(inode);
 309         status = rpc_call(server->client_acl, ACLPROC3_SETACL,
 310                           &args, &fattr, 0);
 311         spin_lock(&inode->i_lock);
 312         NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS;
 313         spin_unlock(&inode->i_lock);
 314         nfs_end_data_update(inode);
 315         dprintk("NFS reply setacl: %d\n", status);
 316
 317         /* pages may have been allocated at the xdr layer. */
 318         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 319                 __free_page(args.pages[count]);
 320
 321         switch (status) {
 322                 case 0:
 323                         status = nfs_refresh_inode(inode, &fattr);
 324                         break;
 325                 case -EPFNOSUPPORT:
 326                 case -EPROTONOSUPPORT:
 327                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 328                                         "(will not retry)\n");
 329                         server->caps &= ~NFS_CAP_ACLS;
 330                 case -ENOTSUPP:
 331                         status = -EOPNOTSUPP;
 332         }
 333 out:
 334         return status;
 335 }
 336
 337 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
 338 {
 339         struct posix_acl *alloc = NULL, *dfacl = NULL;
 340         int status;
 341
 342         if (S_ISDIR(inode->i_mode)) {
 343                 switch(type) {
 344                         case ACL_TYPE_ACCESS:
 345                                 alloc = dfacl = nfs3_proc_getacl(inode,
 346                                                 ACL_TYPE_DEFAULT);
 347                                 if (IS_ERR(alloc))
 348                                         goto fail;
 349                                 break;
 350
 351                         case ACL_TYPE_DEFAULT:
 352                                 dfacl = acl;
 353                                 alloc = acl = nfs3_proc_getacl(inode,
 354                                                 ACL_TYPE_ACCESS);
 355                                 if (IS_ERR(alloc))
 356                                         goto fail;
 357                                 break;
 358
 359                         default:
 360                                 return -EINVAL;
 361                 }
 362         } else if (type != ACL_TYPE_ACCESS)
 363                         return -EINVAL;
 364
 365         if (acl == NULL) {
 366                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 367                 if (IS_ERR(alloc))
 368                         goto fail;
 369         }
 370         status = nfs3_proc_setacls(inode, acl, dfacl);
 371         posix_acl_release(alloc);
 372         return status;
 373
 374 fail:
 375         return PTR_ERR(alloc);
 376 }
 377
 378 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 379                 mode_t mode)
 380 {
 381         struct posix_acl *dfacl, *acl;
 382         int error = 0;
 383
 384         dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
 385         if (IS_ERR(dfacl)) {
 386                 error = PTR_ERR(dfacl);
 387                 return (error == -EOPNOTSUPP) ? 0 : error;
 388         }
 389         if (!dfacl)
 390                 return 0;
 391         acl = posix_acl_clone(dfacl, GFP_KERNEL);
 392         error = -ENOMEM;
 393         if (!acl)
 394                 goto out_release_dfacl;
 395         error = posix_acl_create_masq(acl, &mode);
 396         if (error < 0)
 397                 goto out_release_acl;
 398         error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
 399                                                       dfacl : NULL);
 400 out_release_acl:
 401         posix_acl_release(acl);
 402 out_release_dfacl:
 403         posix_acl_release(dfacl);
 404         return error;
 405 }