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