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 nfs_fattr fattr;
 189         struct page *pages[NFSACL_MAXPAGES] = { };
 190         struct nfs3_getaclargs args = {
 191                 .fh = NFS_FH(inode),
 192                 /* The xdr layer may allocate pages here. */
 193                 .pages = pages,
 194         };
 195         struct nfs3_getaclres res = {
 196                 .fattr =        &fattr,
 197         };
 198         struct rpc_message msg = {
 199                 .rpc_argp       = &args,
 200                 .rpc_resp       = &res,
 201         };
 202         struct posix_acl *acl;
 203         int status, count;
 204
 205         if (!nfs_server_capable(inode, NFS_CAP_ACLS))
 206                 return ERR_PTR(-EOPNOTSUPP);
 207
 208         status = nfs_revalidate_inode(server, inode);
 209         if (status < 0)
 210                 return ERR_PTR(status);
 211         acl = nfs3_get_cached_acl(inode, type);
 212         if (acl != ERR_PTR(-EAGAIN))
 213                 return acl;
 214         acl = NULL;
 215
 216         /*
 217          * Only get the access acl when explicitly requested: We don't
 218          * need it for access decisions, and only some applications use
 219          * it. Applications which request the access acl first are not
 220          * penalized from this optimization.
 221          */
 222         if (type == ACL_TYPE_ACCESS)
 223                 args.mask |= NFS_ACLCNT|NFS_ACL;
 224         if (S_ISDIR(inode->i_mode))
 225                 args.mask |= NFS_DFACLCNT|NFS_DFACL;
 226         if (args.mask == 0)
 227                 return NULL;
 228
 229         dprintk("NFS call getacl\n");
 230         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
 231         nfs_fattr_init(&fattr);
 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;
 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                 args.len = nfsacl_size(acl, dfacl);
 322         } else
 323                 args.len = nfsacl_size(acl, NULL);
 324
 325         if (args.len > NFS_ACL_INLINE_BUFSIZE) {
 326                 unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
 327
 328                 status = -ENOMEM;
 329                 do {
 330                         args.pages[args.npages] = alloc_page(GFP_KERNEL);
 331                         if (args.pages[args.npages] == NULL)
 332                                 goto out_freepages;
 333                         args.npages++;
 334                 } while (args.npages < npages);
 335         }
 336
 337         dprintk("NFS call setacl\n");
 338         msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
 339         nfs_fattr_init(&fattr);
 340         status = rpc_call_sync(server->client_acl, &msg, 0);
 341         nfs_access_zap_cache(inode);
 342         nfs_zap_acl_cache(inode);
 343         dprintk("NFS reply setacl: %d\n", status);
 344
 345         switch (status) {
 346                 case 0:
 347                         status = nfs_refresh_inode(inode, &fattr);
 348                         nfs3_cache_acls(inode, acl, dfacl);
 349                         break;
 350                 case -EPFNOSUPPORT:
 351                 case -EPROTONOSUPPORT:
 352                         dprintk("NFS_V3_ACL SETACL RPC not supported"
 353                                         "(will not retry)\n");
 354                         server->caps &= ~NFS_CAP_ACLS;
 355                 case -ENOTSUPP:
 356                         status = -EOPNOTSUPP;
 357         }
 358 out_freepages:
 359         while (args.npages != 0) {
 360                 args.npages--;
 361                 __free_page(args.pages[args.npages]);
 362         }
 363 out:
 364         return status;
 365 }
 366
 367 int nfs3_proc_setacl(struct inode *inode, int type, struct posix_acl *acl)
 368 {
 369         struct posix_acl *alloc = NULL, *dfacl = NULL;
 370         int status;
 371
 372         if (S_ISDIR(inode->i_mode)) {
 373                 switch(type) {
 374                         case ACL_TYPE_ACCESS:
 375                                 alloc = dfacl = nfs3_proc_getacl(inode,
 376                                                 ACL_TYPE_DEFAULT);
 377                                 if (IS_ERR(alloc))
 378                                         goto fail;
 379                                 break;
 380
 381                         case ACL_TYPE_DEFAULT:
 382                                 dfacl = acl;
 383                                 alloc = acl = nfs3_proc_getacl(inode,
 384                                                 ACL_TYPE_ACCESS);
 385                                 if (IS_ERR(alloc))
 386                                         goto fail;
 387                                 break;
 388
 389                         default:
 390                                 return -EINVAL;
 391                 }
 392         } else if (type != ACL_TYPE_ACCESS)
 393                         return -EINVAL;
 394
 395         if (acl == NULL) {
 396                 alloc = acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
 397                 if (IS_ERR(alloc))
 398                         goto fail;
 399         }
 400         status = nfs3_proc_setacls(inode, acl, dfacl);
 401         posix_acl_release(alloc);
 402         return status;
 403
 404 fail:
 405         return PTR_ERR(alloc);
 406 }
 407
 408 int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 409                 mode_t mode)
 410 {
 411         struct posix_acl *dfacl, *acl;
 412         int error = 0;
 413
 414         dfacl = nfs3_proc_getacl(dir, ACL_TYPE_DEFAULT);
 415         if (IS_ERR(dfacl)) {
 416                 error = PTR_ERR(dfacl);
 417                 return (error == -EOPNOTSUPP) ? 0 : error;
 418         }
 419         if (!dfacl)
 420                 return 0;
 421         acl = posix_acl_clone(dfacl, GFP_KERNEL);
 422         error = -ENOMEM;
 423         if (!acl)
 424                 goto out_release_dfacl;
 425         error = posix_acl_create_masq(acl, &mode);
 426         if (error < 0)
 427                 goto out_release_acl;
 428         error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
 429                                                       dfacl : NULL);
 430 out_release_acl:
 431         posix_acl_release(acl);
 432 out_release_dfacl:
 433         posix_acl_release(dfacl);
 434         return error;
 435 }