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         if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
 211                 nfs_zap_acl_cache(inode);
 212         acl = nfs3_get_cached_acl(inode, type);
 213         if (acl != ERR_PTR(-EAGAIN))
 214                 return acl;
 215         acl = NULL;
 216
 217         /*
 218          * Only get the access acl when explicitly requested: We don't
 219          * need it for access decisions, and only some applications use
 220          * it. Applications which request the access acl first are not
 221          * penalized from this optimization.
 222          */
 223         if (type == ACL_TYPE_ACCESS)
 224                 args.mask |= NFS_ACLCNT|NFS_ACL;
 225         if (S_ISDIR(inode->i_mode))
 226                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
 227         if (args.mask == 0)
 228                 return NULL;
 229
 230         dprintk("NFS call getacl\n");
 231         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
 232         status = rpc_call_sync(server->client_acl, &msg, 0);
 233         dprintk("NFS reply getacl: %d\n", status);
 234
 235         /* pages may have been allocated at the xdr layer. */
 236         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 237                 __free_page(args.pages[count]);
 238
 239         switch (status) {
 240                 case 0:
 241                         status = nfs_refresh_inode(inode, &fattr);
 242                         break;
 243                 case -EPFNOSUPPORT:
 244                 case -EPROTONOSUPPORT:
 245                         dprintk("NFS_V3_ACL extension not supported; disabling\n");
 246                         server->caps &= ~NFS_CAP_ACLS;
 247                 case -ENOTSUPP:
 248                         status = -EOPNOTSUPP;
 249                 default:
 250                         goto getout;
 251         }
 252         if ((args.mask & res.mask) != args.mask) {
 253                 status = -EIO;
 254                 goto getout;
 255         }
 256
 257         if (res.acl_access != NULL) {
 258                 if (posix_acl_equiv_mode(res.acl_access, NULL) == 0) {
 259                         posix_acl_release(res.acl_access);
 260                         res.acl_access = NULL;
 261                 }
 262         }
 263         nfs3_cache_acls(inode,
 264                 (res.mask & NFS_ACL)   ? res.acl_access  : ERR_PTR(-EINVAL),
 265                 (res.mask & NFS_DFACL) ? res.acl_default : ERR_PTR(-EINVAL));
 266
 267         switch(type) {
 268                 case ACL_TYPE_ACCESS:
 269                         acl = res.acl_access;
 270                         res.acl_access = NULL;
 271                         break;
 272
 273                 case ACL_TYPE_DEFAULT:
 274                         acl = res.acl_default;
 275                         res.acl_default = NULL;
 276         }
 277
 278 getout:
 279         posix_acl_release(res.acl_access);
 280         posix_acl_release(res.acl_default);
 281
 282         if (status != 0) {
 283                 posix_acl_release(acl);
 284                 acl = ERR_PTR(status);
 285         }
 286         return acl;
 287 }
 288
 289 static int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
 290                   struct posix_acl *dfacl)
 291 {
 292         struct nfs_server *server = NFS_SERVER(inode);
 293         struct nfs_fattr fattr;
 294         struct page *pages[NFSACL_MAXPAGES] = { };
 295         struct nfs3_setaclargs args = {
 296                 .inode = inode,
 297                 .mask = NFS_ACL,
 298                 .acl_access = acl,
 299                 .pages = pages,
 300         };
 301         struct rpc_message msg = {
 302                 .rpc_argp       = &args,
 303                 .rpc_resp       = &fattr,
 304         };
 305         int status, count;
 306
 307         status = -EOPNOTSUPP;
 308         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 309                 goto out;
 310
 311         /* We are doing this here, because XDR marshalling can only
 312            return -ENOMEM. */
 313         status = -ENOSPC;
 314         if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
 315                 goto out;
 316         if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
 317                 goto out;
 318         if (S_ISDIR(inode->i_mode)) {
 319                 args.mask |= NFS_DFACL;
 320                 args.acl_default = dfacl;
 321         }
 322
 323         dprintk("NFS call setacl\n");
 324         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
 325         status = rpc_call_sync(server->client_acl, &msg, 0);
 326         nfs_access_zap_cache(inode);
 327         nfs_zap_acl_cache(inode);
 328         dprintk("NFS reply setacl: %d\n", status);
 329
 330         /* pages may have been allocated at the xdr layer. */
 331         for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
 332                 __free_page(args.pages[count]);
 333
 334         switch (status) {
 335                 case 0:
 336                         status = nfs_refresh_inode(inode, &fattr);
 337                         nfs3_cache_acls(inode, acl, dfacl);
 338                         break;
 339                 case -EPFNOSUPPORT:
 340                 case -EPROTONOSUPPORT:
 341                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 342                                         "(will not retry)\n");
 343                         server->caps &= ~NFS_CAP_ACLS;
 344                 case -ENOTSUPP:
 345                         status = -EOPNOTSUPP;
 346         }
 347 out:
 348         return status;
 349 }
 350
 351 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
 352 {
 353         struct posix_acl *alloc = NULL, *dfacl = NULL;
 354         int status;
 355
 356         if (S_ISDIR(inode->i_mode)) {
 357                 switch(type) {
 358                         case ACL_TYPE_ACCESS:
 359                                 alloc = dfacl = nfs3_proc_getacl(inode,
 360                                                 ACL_TYPE_DEFAULT);
 361                                 if (IS_ERR(alloc))
 362                                         goto fail;
 363                                 break;
 364
 365                         case ACL_TYPE_DEFAULT:
 366                                 dfacl = acl;
 367                                 alloc = acl = nfs3_proc_getacl(inode,
 368                                                 ACL_TYPE_ACCESS);
 369                                 if (IS_ERR(alloc))
 370                                         goto fail;
 371                                 break;
 372
 373                         default:
 374                                 return -EINVAL;
 375                 }
 376         } else if (type != ACL_TYPE_ACCESS)
 377                         return -EINVAL;
 378
 379         if (acl == NULL) {
 380                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 381                 if (IS_ERR(alloc))
 382                         goto fail;
 383         }
 384         status = nfs3_proc_setacls(inode, acl, dfacl);
 385         posix_acl_release(alloc);
 386         return status;
 387
 388 fail:
 389         return PTR_ERR(alloc);
 390 }
 391
 392 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 393                 mode_t mode)
 394 {
 395         struct posix_acl *dfacl, *acl;
 396         int error = 0;
 397
 398         dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
 399         if (IS_ERR(dfacl)) {
 400                 error = PTR_ERR(dfacl);
 401                 return (error == -EOPNOTSUPP) ? 0 : error;
 402         }
 403         if (!dfacl)
 404                 return 0;
 405         acl = posix_acl_clone(dfacl, GFP_KERNEL);
 406         error = -ENOMEM;
 407         if (!acl)
 408                 goto out_release_dfacl;
 409         error = posix_acl_create_masq(acl, &mode);
 410         if (error < 0)
 411                 goto out_release_acl;
 412         error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
 413                                                       dfacl : NULL);
 414 out_release_acl:
 415         posix_acl_release(acl);
 416 out_release_dfacl:
 417         posix_acl_release(dfacl);
 418         return error;
 419 }