linux/fs/nfs/nfs3acl.c
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   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
  13ssize_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
  52ssize_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(&init_user_ns, acl, buffer, size);
  74                posix_acl_release(acl);
  75        } else
  76                error = -ENODATA;
  77
  78        return error;
  79}
  80
  81int 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(&init_user_ns, 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
 104int 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
 119static 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
 131void 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
 140static 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);
 162out:
 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
 169static 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
 185struct 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                NULL,
 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
 280getout:
 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
 292static 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 does not
 315         * return any results, it BUGs. */
 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);
 367out_freepages:
 368        while (args.npages != 0) {
 369                args.npages--;
 370                __free_page(args.pages[args.npages]);
 371        }
 372out:
 373        return status;
 374}
 375
 376int 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
 413fail:
 414        return PTR_ERR(alloc);
 415}
 416
 417int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
 418                umode_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_dup(dfacl);
 431        error = posix_acl_create(&acl, GFP_KERNEL, &mode);
 432        if (error < 0)
 433                goto out_release_dfacl;
 434        error = nfs3_proc_setacls(inode, acl, S_ISDIR(inode->i_mode) ?
 435                                                      dfacl : NULL);
 436        posix_acl_release(acl);
 437out_release_dfacl:
 438        posix_acl_release(dfacl);
 439        return error;
 440}
 441
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