fs/nfs/nfs3acl.c

   1 #include <linux/fs.h>
   2 #include <linux/gfp.h>
   3 #include <linux/nfs.h>
   4 #include <linux/nfs3.h>
   5 #include <linux/nfs_fs.h>
   6 #include <linux/posix_acl_xattr.h>
   7 #include <linux/nfsacl.h>
   8
   9 #include "internal.h"
  10
  11 #define NFSDBG_FACILITY NFSDBG_PROC
  12
  13 ssize_t nfs3_listxattr(struct dentry *dentry, char *buffer, size_t size)
  14 {
  15         struct inode *inode = dentry->d_inode;
  16         struct posix_acl *acl;
  17         int pos=0, len=0;
  18
  19 #       define output(s) do {                                           \
  20                         if (pos + sizeof(s) <= size) {                  \
  21                                 memcpy(buffer + pos, s, sizeof(s));     \
  22                                 pos += sizeof(s);                       \
  23                         }                                               \
  24                         len += sizeof(s);                               \
  25                 } while(0)
  26
  27         acl = nfs3_proc_getacl(inode, ACL_TYPE_ACCESS);
  28         if (IS_ERR(acl))
  29                 return PTR_ERR(acl);
  30         if (acl) {
  31                 output("system.posix_acl_access");
  32                 posix_acl_release(acl);
  33         }
  34
  35         if (S_ISDIR(inode->i_mode)) {
  36                 acl = nfs3_proc_getacl(inode, ACL_TYPE_DEFAULT);
  37                 if (IS_ERR(acl))
  38                         return PTR_ERR(acl);
  39                 if (acl) {
  40                         output("system.posix_acl_default");
  41                         posix_acl_release(acl);
  42                 }
  43         }
  44
  45 #       undef output
  46
  47         if (!buffer || len <= size)
  48                 return len;
  49         return -ERANGE;
  50 }
  51
  52 ssize_t nfs3_getxattr(struct dentry *dentry, const char *name,
  53                 void *buffer, size_t size)
  54 {
  55         struct inode *inode = dentry->d_inode;
  56         struct posix_acl *acl;
  57         int type, error = 0;
  58
  59         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
  60                 type = ACL_TYPE_ACCESS;
  61         else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
  62                 type = ACL_TYPE_DEFAULT;
  63         else
  64                 return -EOPNOTSUPP;
  65
  66         acl = nfs3_proc_getacl(inode, type);
  67         if (IS_ERR(acl))
  68                 return PTR_ERR(acl);
  69         else if (acl) {
  70                 if (type == ACL_TYPE_ACCESS && acl->a_count == 0)
  71                         error = -ENODATA;
  72                 else
  73                         error = posix_acl_to_xattr(acl, buffer, size);
  74                 posix_acl_release(acl);
  75         } else
  76                 error = -ENODATA;
  77
  78         return error;
  79 }
  80
  81 int nfs3_setxattr(struct dentry *dentry, const char *name,
  82              const void *value, size_t size, int flags)
  83 {
  84         struct inode *inode = dentry->d_inode;
  85         struct posix_acl *acl;
  86         int type, error;
  87
  88         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
  89                 type = ACL_TYPE_ACCESS;
  90         else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
  91                 type = ACL_TYPE_DEFAULT;
  92         else
  93                 return -EOPNOTSUPP;
  94
  95         acl = posix_acl_from_xattr(value, size);
  96         if (IS_ERR(acl))
  97                 return PTR_ERR(acl);
  98         error = nfs3_proc_setacl(inode, type, acl);
  99         posix_acl_release(acl);
 100
 101         return error;
 102 }
 103
 104 int nfs3_removexattr(struct dentry *dentry, const char *name)
 105 {
 106         struct inode *inode = dentry->d_inode;
 107         int type;
 108
 109         if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0)
 110                 type = ACL_TYPE_ACCESS;
 111         else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0)
 112                 type = ACL_TYPE_DEFAULT;
 113         else
 114                 return -EOPNOTSUPP;
 115
 116         return nfs3_proc_setacl(inode, type, NULL);
 117 }
 118
 119 static void __nfs3_forget_cached_acls(struct nfs_inode *nfsi)
 120 {
 121         if (!IS_ERR(nfsi->acl_access)) {
 122                 posix_acl_release(nfsi->acl_access);
 123                 nfsi->acl_access = ERR_PTR(-EAGAIN);
 124         }
 125         if (!IS_ERR(nfsi->acl_default)) {
 126                 posix_acl_release(nfsi->acl_default);
 127                 nfsi->acl_default = ERR_PTR(-EAGAIN);
 128         }
 129 }
 130
 131 void nfs3_forget_cached_acls(struct inode *inode)
 132 {
 133         dprintk("NFS: nfs3_forget_cached_acls(%s/%ld)\n", inode->i_sb->s_id,
 134                 inode->i_ino);
 135         spin_lock(&inode->i_lock);
 136         __nfs3_forget_cached_acls(NFS_I(inode));
 137         spin_unlock(&inode->i_lock);
 138 }
 139
 140 static struct posix_acl *nfs3_get_cached_acl(struct inode *inode, int type)
 141 {
 142         struct nfs_inode *nfsi = NFS_I(inode);
 143         struct posix_acl *acl = ERR_PTR(-EINVAL);
 144
 145         spin_lock(&inode->i_lock);
 146         switch(type) {
 147                 case ACL_TYPE_ACCESS:
 148                         acl = nfsi->acl_access;
 149                         break;
 150
 151                 case ACL_TYPE_DEFAULT:
 152                         acl = nfsi->acl_default;
 153                         break;
 154
 155                 default:
 156                         goto out;
 157         }
 158         if (IS_ERR(acl))
 159                 acl = ERR_PTR(-EAGAIN);
 160         else
 161                 acl = posix_acl_dup(acl);
 162 out:
 163         spin_unlock(&inode->i_lock);
 164         dprintk("NFS: nfs3_get_cached_acl(%s/%ld, %d) = %p\n", inode->i_sb->s_id,
 165                 inode->i_ino, type, acl);
 166         return acl;
 167 }
 168
 169 static void nfs3_cache_acls(struct inode *inode, struct posix_acl *acl,
 170                     struct posix_acl *dfacl)
 171 {
 172         struct nfs_inode *nfsi = NFS_I(inode);
 173
 174         dprintk("nfs3_cache_acls(%s/%ld, %p, %p)\n", inode->i_sb->s_id,
 175                 inode->i_ino, acl, dfacl);
 176         spin_lock(&inode->i_lock);
 177         __nfs3_forget_cached_acls(NFS_I(inode));
 178         if (!IS_ERR(acl))
 179                 nfsi->acl_access = posix_acl_dup(acl);
 180         if (!IS_ERR(dfacl))
 181                 nfsi->acl_default = posix_acl_dup(dfacl);
 182         spin_unlock(&inode->i_lock);
 183 }
 184
 185 struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type)
 186 {
 187         struct nfs_server *server = NFS_SERVER(inode);
 188         struct page *pages[NFSACL_MAXPAGES] = { };
 189         struct nfs3_getaclargs args = {
 190                 .fh = NFS_FH(inode),
 191                 /* The xdr layer may allocate pages here. */
 192                 .pages = pages,
 193         };
 194         struct nfs3_getaclres res = {
 195                 0
 196         };
 197         struct rpc_message msg = {
 198                 .rpc_argp       = &args,
 199                 .rpc_resp       = &res,
 200         };
 201         struct posix_acl *acl;
 202         int status, count;
 203
 204         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 205                 return ERR_PTR(-EOPNOTSUPP);
 206
 207         status = nfs_revalidate_inode(server, inode);
 208         if (status < 0)
 209                 return ERR_PTR(status);
 210         acl = nfs3_get_cached_acl(inode, type);
 211         if (acl != ERR_PTR(-EAGAIN))
 212                 return acl;
 213         acl = NULL;
 214
 215         /*
 216          * Only get the access acl when explicitly requested: We don't
 217          * need it for access decisions, and only some applications use
 218          * it. Applications which request the access acl first are not
 219          * penalized from this optimization.
 220          */
 221         if (type == ACL_TYPE_ACCESS)
 222                 args.mask |= NFS_ACLCNT|NFS_ACL;
 223         if (S_ISDIR(inode->i_mode))
 224                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
 225         if (args.mask == 0)
 226                 return NULL;
 227
 228         dprintk("NFS call getacl\n");
 229         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
 230         res.fattr = nfs_alloc_fattr();
 231         if (res.fattr == NULL)
 232                 return ERR_PTR(-ENOMEM);
 233
 234         status = rpc_call_sync(server->client_acl, &msg, 0);
 235         dprintk("NFS reply getacl: %d\n", status);
 236
 237         /* pages may have been allocated at the xdr layer. */
 238         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 239                 __free_page(args.pages[count]);
 240
 241         switch (status) {
 242                 case 0:
 243                         status = nfs_refresh_inode(inode, res.fattr);
 244                         break;
 245                 case -EPFNOSUPPORT:
 246                 case -EPROTONOSUPPORT:
 247                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
 248                         server->caps &= ~NFS_CAP_ACLS;
 249                 case -ENOTSUPP:
 250                         status = -EOPNOTSUPP;
 251                 default:
 252                         goto getout;
 253         }
 254         if ((args.mask & res.mask) != args.mask) {
 255                 status = -EIO;
 256                 goto getout;
 257         }
 258
 259         if (res.acl_access != NULL) {
 260                 if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
 261                         posix_acl_release(res.acl_access);
 262                         res.acl_access = NULL;
 263                 }
 264         }
 265         nfs3_cache_acls(inode,
 266                 (res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
 267                 (res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
 268
 269         switch(type) {
 270                 case ACL_TYPE_ACCESS:
 271                         acl = res.acl_access;
 272                         res.acl_access = NULL;
 273                         break;
 274
 275                 case ACL_TYPE_DEFAULT:
 276                         acl = res.acl_default;
 277                         res.acl_default = NULL;
 278         }
 279
 280 getout:
 281         posix_acl_release(res.acl_access);
 282         posix_acl_release(res.acl_default);
 283         nfs_free_fattr(res.fattr);
 284
 285         if (status != 0) {
 286                 posix_acl_release(acl);
 287                 acl = ERR_PTR(status);
 288         }
 289         return acl;
 290 }
 291
 292 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 293                   struct posix_acl *dfacl)
 294 {
 295         struct nfs_server *server = NFS_SERVER(inode);
 296         struct nfs_fattr *fattr;
 297         struct page *pages[NFSACL_MAXPAGES];
 298         struct nfs3_setaclargs args = {
 299                 .inode = inode,
 300                 .mask = NFS_ACL,
 301                 .acl_access = acl,
 302                 .pages = pages,
 303         };
 304         struct rpc_message msg = {
 305                 .rpc_argp       = &args,
 306                 .rpc_resp       = &fattr,
 307         };
 308         int status;
 309
 310         status = -EOPNOTSUPP;
 311         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 312                 goto out;
 313
 314         /* We are doing this here, because XDR marshalling can only
 315            return -ENOMEM. */
 316         status = -ENOSPC;
 317         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
 318                 goto out;
 319         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
 320                 goto out;
 321         if (S_ISDIR(inode->i_mode)) {
 322                 args.mask |= NFS_DFACL;
 323                 args.acl_default = dfacl;
 324                 args.len = nfsacl_size(acl, dfacl);
 325         } else
 326                 args.len = nfsacl_size(acl, NULL);
 327
 328         if (args.len > NFS_ACL_INLINE_BUFSIZE) {
 329                 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
 330
 331                 status = -ENOMEM;
 332                 do {
 333                         args.pages[args.npages] = alloc_page(GFP_KERNEL);
 334                         if (args.pages[args.npages] == NULL)
 335                                 goto out_freepages;
 336                         args.npages++;
 337                 } while (args.npages < npages);
 338         }
 339
 340         dprintk("NFS call setacl\n");
 341         status = -ENOMEM;
 342         fattr = nfs_alloc_fattr();
 343         if (fattr == NULL)
 344                 goto out_freepages;
 345
 346         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
 347         msg.rpc_resp = fattr;
 348         status = rpc_call_sync(server->client_acl, &msg, 0);
 349         nfs_access_zap_cache(inode);
 350         nfs_zap_acl_cache(inode);
 351         dprintk("NFS reply setacl: %d\n", status);
 352
 353         switch (status) {
 354                 case 0:
 355                         status = nfs_refresh_inode(inode, fattr);
 356                         nfs3_cache_acls(inode, acl, dfacl);
 357                         break;
 358                 case -EPFNOSUPPORT:
 359                 case -EPROTONOSUPPORT:
 360                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 361                                         "(will not retry)\n");
 362                         server->caps &= ~NFS_CAP_ACLS;
 363                 case -ENOTSUPP:
 364                         status = -EOPNOTSUPP;
 365         }
 366         nfs_free_fattr(fattr);
 367 out_freepages:
 368         while (args.npages != 0) {
 369                 args.npages--;
 370                 __free_page(args.pages[args.npages]);
 371         }
 372 out:
 373         return status;
 374 }
 375
 376 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
 377 {
 378         struct posix_acl *alloc = NULL, *dfacl = NULL;
 379         int status;
 380
 381         if (S_ISDIR(inode->i_mode)) {
 382                 switch(type) {
 383                         case ACL_TYPE_ACCESS:
 384                                 alloc = dfacl = nfs3_proc_getacl(inode,
 385                                                 ACL_TYPE_DEFAULT);
 386                                 if (IS_ERR(alloc))
 387                                         goto fail;
 388                                 break;
 389
 390                         case ACL_TYPE_DEFAULT:
 391                                 dfacl = acl;
 392                                 alloc = acl = nfs3_proc_getacl(inode,
 393                                                 ACL_TYPE_ACCESS);
 394                                 if (IS_ERR(alloc))
 395                                         goto fail;
 396                                 break;
 397
 398                         default:
 399                                 return -EINVAL;
 400                 }
 401         } else if (type != ACL_TYPE_ACCESS)
 402                         return -EINVAL;
 403
 404         if (acl == NULL) {
 405                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 406                 if (IS_ERR(alloc))
 407                         goto fail;
 408         }
 409         status = nfs3_proc_setacls(inode, acl, dfacl);
 410         posix_acl_release(alloc);
 411         return status;
 412
 413 fail:
 414         return PTR_ERR(alloc);
 415 }
 416
 417 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 418                 mode_t mode)
 419 {
 420         struct posix_acl *dfacl, *acl;
 421         int error = 0;
 422
 423         dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
 424         if (IS_ERR(dfacl)) {
 425                 error = PTR_ERR(dfacl);
 426                 return (error == -EOPNOTSUPP) ? 0 : error;
 427         }
 428         if (!dfacl)
 429                 return 0;
 430         acl = posix_acl_clone(dfacl, GFP_KERNEL);
 431         error = -ENOMEM;
 432         if (!acl)
 433                 goto out_release_dfacl;
 434         error = posix_acl_create_masq(acl, &mode);
 435         if (error < 0)
 436                 goto out_release_acl;
 437         error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
 438                                                       dfacl : NULL);
 439 out_release_acl:
 440         posix_acl_release(acl);
 441 out_release_dfacl:
 442         posix_acl_release(dfacl);
 443         return error;
 444 }