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         if (!IS_ERR(acl))
 176                 nfsi->acl_access = posix_acl_dup(acl);
 177         if (!IS_ERR(dfacl))
 178                 nfsi->acl_default = posix_acl_dup(dfacl);
 179         spin_unlock(&inode->i_lock);
 180 }
 181
 182 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
 183 {
 184         struct nfs_server *server = NFS_SERVER(inode);
 185         struct nfs_fattr fattr;
 186         struct page *pages[NFSACL_MAXPAGES] = { };
 187         struct nfs3_getaclargs args = {
 188                 .fh = NFS_FH(inode),
 189                 /* The xdr layer may allocate pages here. */
 190                 .pages = pages,
 191         };
 192         struct nfs3_getaclres res = {
 193                 .fattr =        &fattr,
 194         };
 195         struct rpc_message msg = {
 196                 .rpc_argp       = &args,
 197                 .rpc_resp       = &res,
 198         };
 199         struct posix_acl *acl;
 200         int status, count;
 201
 202         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 203                 return ERR_PTR(-EOPNOTSUPP);
 204
 205         status = nfs_revalidate_inode(server, inode);
 206         if (status < 0)
 207                 return ERR_PTR(status);
 208         acl = nfs3_get_cached_acl(inode, type);
 209         if (acl != ERR_PTR(-EAGAIN))
 210                 return acl;
 211         acl = NULL;
 212
 213         /*
 214          * Only get the access acl when explicitly requested: We don't
 215          * need it for access decisions, and only some applications use
 216          * it. Applications which request the access acl first are not
 217          * penalized from this optimization.
 218          */
 219         if (type == ACL_TYPE_ACCESS)
 220                 args.mask |= NFS_ACLCNT|NFS_ACL;
 221         if (S_ISDIR(inode->i_mode))
 222                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
 223         if (args.mask == 0)
 224                 return NULL;
 225
 226         dprintk("NFS call getacl\n");
 227         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
 228         status = rpc_call_sync(server->client_acl, &msg, 0);
 229         dprintk("NFS reply getacl: %d\n", status);
 230
 231         /* pages may have been allocated at the xdr layer. */
 232         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 233                 __free_page(args.pages[count]);
 234
 235         switch (status) {
 236                 case 0:
 237                         status = nfs_refresh_inode(inode, &fattr);
 238                         break;
 239                 case -EPFNOSUPPORT:
 240                 case -EPROTONOSUPPORT:
 241                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
 242                         server->caps &= ~NFS_CAP_ACLS;
 243                 case -ENOTSUPP:
 244                         status = -EOPNOTSUPP;
 245                 default:
 246                         goto getout;
 247         }
 248         if ((args.mask & res.mask) != args.mask) {
 249                 status = -EIO;
 250                 goto getout;
 251         }
 252
 253         if (res.acl_access != NULL) {
 254                 if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
 255                         posix_acl_release(res.acl_access);
 256                         res.acl_access = NULL;
 257                 }
 258         }
 259         nfs3_cache_acls(inode,
 260                 (res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
 261                 (res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
 262
 263         switch(type) {
 264                 case ACL_TYPE_ACCESS:
 265                         acl = res.acl_access;
 266                         res.acl_access = NULL;
 267                         break;
 268
 269                 case ACL_TYPE_DEFAULT:
 270                         acl = res.acl_default;
 271                         res.acl_default = NULL;
 272         }
 273
 274 getout:
 275         posix_acl_release(res.acl_access);
 276         posix_acl_release(res.acl_default);
 277
 278         if (status != 0) {
 279                 posix_acl_release(acl);
 280                 acl = ERR_PTR(status);
 281         }
 282         return acl;
 283 }
 284
 285 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 286                   struct posix_acl *dfacl)
 287 {
 288         struct nfs_server *server = NFS_SERVER(inode);
 289         struct nfs_fattr fattr;
 290         struct page *pages[NFSACL_MAXPAGES] = { };
 291         struct nfs3_setaclargs args = {
 292                 .inode = inode,
 293                 .mask = NFS_ACL,
 294                 .acl_access = acl,
 295                 .pages = pages,
 296         };
 297         struct rpc_message msg = {
 298                 .rpc_argp       = &args,
 299                 .rpc_resp       = &fattr,
 300         };
 301         int status, count;
 302
 303         status = -EOPNOTSUPP;
 304         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 305                 goto out;
 306
 307         /* We are doing this here, because XDR marshalling can only
 308            return -ENOMEM. */
 309         status = -ENOSPC;
 310         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
 311                 goto out;
 312         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
 313                 goto out;
 314         if (S_ISDIR(inode->i_mode)) {
 315                 args.mask |= NFS_DFACL;
 316                 args.acl_default = dfacl;
 317         }
 318
 319         dprintk("NFS call setacl\n");
 320         nfs_begin_data_update(inode);
 321         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
 322         status = rpc_call_sync(server->client_acl, &msg, 0);
 323         spin_lock(&inode->i_lock);
 324         NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ACCESS;
 325         spin_unlock(&inode->i_lock);
 326         nfs_end_data_update(inode);
 327         dprintk("NFS reply setacl: %d\n", status);
 328
 329         /* pages may have been allocated at the xdr layer. */
 330         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 331                 __free_page(args.pages[count]);
 332
 333         switch (status) {
 334                 case 0:
 335                         status = nfs_refresh_inode(inode, &fattr);
 336                         nfs3_cache_acls(inode, acl, dfacl);
 337                         break;
 338                 case -EPFNOSUPPORT:
 339                 case -EPROTONOSUPPORT:
 340                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 341                                         "(will not retry)\n");
 342                         server->caps &= ~NFS_CAP_ACLS;
 343                 case -ENOTSUPP:
 344                         status = -EOPNOTSUPP;
 345         }
 346 out:
 347         return status;
 348 }
 349
 350 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
 351 {
 352         struct posix_acl *alloc = NULL, *dfacl = NULL;
 353         int status;
 354
 355         if (S_ISDIR(inode->i_mode)) {
 356                 switch(type) {
 357                         case ACL_TYPE_ACCESS:
 358                                 alloc = dfacl = nfs3_proc_getacl(inode,
 359                                                 ACL_TYPE_DEFAULT);
 360                                 if (IS_ERR(alloc))
 361                                         goto fail;
 362                                 break;
 363
 364                         case ACL_TYPE_DEFAULT:
 365                                 dfacl = acl;
 366                                 alloc = acl = nfs3_proc_getacl(inode,
 367                                                 ACL_TYPE_ACCESS);
 368                                 if (IS_ERR(alloc))
 369                                         goto fail;
 370                                 break;
 371
 372                         default:
 373                                 return -EINVAL;
 374                 }
 375         } else if (type != ACL_TYPE_ACCESS)
 376                         return -EINVAL;
 377
 378         if (acl == NULL) {
 379                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 380                 if (IS_ERR(alloc))
 381                         goto fail;
 382         }
 383         status = nfs3_proc_setacls(inode, acl, dfacl);
 384         posix_acl_release(alloc);
 385         return status;
 386
 387 fail:
 388         return PTR_ERR(alloc);
 389 }
 390
 391 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 392                 mode_t mode)
 393 {
 394         struct posix_acl *dfacl, *acl;
 395         int error = 0;
 396
 397         dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
 398         if (IS_ERR(dfacl)) {
 399                 error = PTR_ERR(dfacl);
 400                 return (error == -EOPNOTSUPP) ? 0 : error;
 401         }
 402         if (!dfacl)
 403                 return 0;
 404         acl = posix_acl_clone(dfacl, GFP_KERNEL);
 405         error = -ENOMEM;
 406         if (!acl)
 407                 goto out_release_dfacl;
 408         error = posix_acl_create_masq(acl, &mode);
 409         if (error < 0)
 410                 goto out_release_acl;
 411         error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
 412                                                       dfacl : NULL);
 413 out_release_acl:
 414         posix_acl_release(acl);
 415 out_release_dfacl:
 416         posix_acl_release(dfacl);
 417         return error;
 418 }