hw/9pfs/9p-handle.c

   1 /*
   2  * 9p handle callback
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *    Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "9p.h"
  15 #include "9p-xattr.h"
  16 #include <arpa/inet.h>
  17 #include <pwd.h>
  18 #include <grp.h>
  19 #include <sys/socket.h>
  20 #include <sys/un.h>
  21 #include "qemu/xattr.h"
  22 #include <unistd.h>
  23 #include <linux/fs.h>
  24 #ifdef CONFIG_LINUX_MAGIC_H
  25 #include <linux/magic.h>
  26 #endif
  27 #include <sys/ioctl.h>
  28
  29 #ifndef XFS_SUPER_MAGIC
  30 #define XFS_SUPER_MAGIC  0x58465342
  31 #endif
  32 #ifndef EXT2_SUPER_MAGIC
  33 #define EXT2_SUPER_MAGIC 0xEF53
  34 #endif
  35 #ifndef REISERFS_SUPER_MAGIC
  36 #define REISERFS_SUPER_MAGIC 0x52654973
  37 #endif
  38 #ifndef BTRFS_SUPER_MAGIC
  39 #define BTRFS_SUPER_MAGIC 0x9123683E
  40 #endif
  41
  42 struct handle_data {
  43     int mountfd;
  44     int handle_bytes;
  45 };
  46
  47 static inline int name_to_handle(int dirfd, const char *name,
  48                                  struct file_handle *fh, int *mnt_id, int flags)
  49 {
  50     return name_to_handle_at(dirfd, name, fh, mnt_id, flags);
  51 }
  52
  53 static inline int open_by_handle(int mountfd, const char *fh, int flags)
  54 {
  55     return open_by_handle_at(mountfd, (struct file_handle *)fh, flags);
  56 }
  57
  58 static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp)
  59 {
  60     int fd, ret;
  61     fd = openat(dirfd, name, O_NONBLOCK | O_NOFOLLOW);
  62     if (fd < 0) {
  63         return fd;
  64     }
  65     ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
  66     if (ret < 0) {
  67         goto err_out;
  68     }
  69     ret = fchmod(fd, credp->fc_mode & 07777);
  70 err_out:
  71     close(fd);
  72     return ret;
  73 }
  74
  75
  76 static int handle_lstat(FsContext *fs_ctx, V9fsPath *fs_path,
  77                         struct stat *stbuf)
  78 {
  79     int fd, ret;
  80     struct handle_data *data = (struct handle_data *)fs_ctx->private;
  81
  82     fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
  83     if (fd < 0) {
  84         return fd;
  85     }
  86     ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH);
  87     close(fd);
  88     return ret;
  89 }
  90
  91 static ssize_t handle_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
  92                                char *buf, size_t bufsz)
  93 {
  94     int fd, ret;
  95     struct handle_data *data = (struct handle_data *)fs_ctx->private;
  96
  97     fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
  98     if (fd < 0) {
  99         return fd;
 100     }
 101     ret = readlinkat(fd, "", buf, bufsz);
 102     close(fd);
 103     return ret;
 104 }
 105
 106 static int handle_close(FsContext *ctx, V9fsFidOpenState *fs)
 107 {
 108     return close(fs->fd);
 109 }
 110
 111 static int handle_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 112 {
 113     return closedir(fs->dir);
 114 }
 115
 116 static int handle_open(FsContext *ctx, V9fsPath *fs_path,
 117                        int flags, V9fsFidOpenState *fs)
 118 {
 119     struct handle_data *data = (struct handle_data *)ctx->private;
 120
 121     fs->fd = open_by_handle(data->mountfd, fs_path->data, flags);
 122     return fs->fd;
 123 }
 124
 125 static int handle_opendir(FsContext *ctx,
 126                           V9fsPath *fs_path, V9fsFidOpenState *fs)
 127 {
 128     int ret;
 129     ret = handle_open(ctx, fs_path, O_DIRECTORY, fs);
 130     if (ret < 0) {
 131         return -1;
 132     }
 133     fs->dir = fdopendir(ret);
 134     if (!fs->dir) {
 135         return -1;
 136     }
 137     return 0;
 138 }
 139
 140 static void handle_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
 141 {
 142     rewinddir(fs->dir);
 143 }
 144
 145 static off_t handle_telldir(FsContext *ctx, V9fsFidOpenState *fs)
 146 {
 147     return telldir(fs->dir);
 148 }
 149
 150 static int handle_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
 151                             struct dirent *entry,
 152                             struct dirent **result)
 153 {
 154     return readdir_r(fs->dir, entry, result);
 155 }
 156
 157 static void handle_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
 158 {
 159     seekdir(fs->dir, off);
 160 }
 161
 162 static ssize_t handle_preadv(FsContext *ctx, V9fsFidOpenState *fs,
 163                              const struct iovec *iov,
 164                              int iovcnt, off_t offset)
 165 {
 166 #ifdef CONFIG_PREADV
 167     return preadv(fs->fd, iov, iovcnt, offset);
 168 #else
 169     int err = lseek(fs->fd, offset, SEEK_SET);
 170     if (err == -1) {
 171         return err;
 172     } else {
 173         return readv(fs->fd, iov, iovcnt);
 174     }
 175 #endif
 176 }
 177
 178 static ssize_t handle_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 179                               const struct iovec *iov,
 180                               int iovcnt, off_t offset)
 181 {
 182     ssize_t ret;
 183 #ifdef CONFIG_PREADV
 184     ret = pwritev(fs->fd, iov, iovcnt, offset);
 185 #else
 186     int err = lseek(fs->fd, offset, SEEK_SET);
 187     if (err == -1) {
 188         return err;
 189     } else {
 190         ret = writev(fs->fd, iov, iovcnt);
 191     }
 192 #endif
 193 #ifdef CONFIG_SYNC_FILE_RANGE
 194     if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
 195         /*
 196          * Initiate a writeback. This is not a data integrity sync.
 197          * We want to ensure that we don't leave dirty pages in the cache
 198          * after write when writeout=immediate is sepcified.
 199          */
 200         sync_file_range(fs->fd, offset, ret,
 201                         SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
 202     }
 203 #endif
 204     return ret;
 205 }
 206
 207 static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 208 {
 209     int fd, ret;
 210     struct handle_data *data = (struct handle_data *)fs_ctx->private;
 211
 212     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 213     if (fd < 0) {
 214         return fd;
 215     }
 216     ret = fchmod(fd, credp->fc_mode);
 217     close(fd);
 218     return ret;
 219 }
 220
 221 static int handle_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
 222                        const char *name, FsCred *credp)
 223 {
 224     int dirfd, ret;
 225     struct handle_data *data = (struct handle_data *)fs_ctx->private;
 226
 227     dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
 228     if (dirfd < 0) {
 229         return dirfd;
 230     }
 231     ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
 232     if (!ret) {
 233         ret = handle_update_file_cred(dirfd, name, credp);
 234     }
 235     close(dirfd);
 236     return ret;
 237 }
 238
 239 static int handle_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 240                        const char *name, FsCred *credp)
 241 {
 242     int dirfd, ret;
 243     struct handle_data *data = (struct handle_data *)fs_ctx->private;
 244
 245     dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
 246     if (dirfd < 0) {
 247         return dirfd;
 248     }
 249     ret = mkdirat(dirfd, name, credp->fc_mode);
 250     if (!ret) {
 251         ret = handle_update_file_cred(dirfd, name, credp);
 252     }
 253     close(dirfd);
 254     return ret;
 255 }
 256
 257 static int handle_fstat(FsContext *fs_ctx, int fid_type,
 258                         V9fsFidOpenState *fs, struct stat *stbuf)
 259 {
 260     int fd;
 261
 262     if (fid_type == P9_FID_DIR) {
 263         fd = dirfd(fs->dir);
 264     } else {
 265         fd = fs->fd;
 266     }
 267     return fstat(fd, stbuf);
 268 }
 269
 270 static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 271                         int flags, FsCred *credp, V9fsFidOpenState *fs)
 272 {
 273     int ret;
 274     int dirfd, fd;
 275     struct handle_data *data = (struct handle_data *)fs_ctx->private;
 276
 277     dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
 278     if (dirfd < 0) {
 279         return dirfd;
 280     }
 281     fd = openat(dirfd, name, flags | O_NOFOLLOW, credp->fc_mode);
 282     if (fd >= 0) {
 283         ret = handle_update_file_cred(dirfd, name, credp);
 284         if (ret < 0) {
 285             close(fd);
 286             fd = ret;
 287         } else {
 288             fs->fd = fd;
 289         }
 290     }
 291     close(dirfd);
 292     return fd;
 293 }
 294
 295
 296 static int handle_symlink(FsContext *fs_ctx, const char *oldpath,
 297                           V9fsPath *dir_path, const char *name, FsCred *credp)
 298 {
 299     int fd, dirfd, ret;
 300     struct handle_data *data = (struct handle_data *)fs_ctx->private;
 301
 302     dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
 303     if (dirfd < 0) {
 304         return dirfd;
 305     }
 306     ret = symlinkat(oldpath, dirfd, name);
 307     if (!ret) {
 308         fd = openat(dirfd, name, O_PATH | O_NOFOLLOW);
 309         if (fd < 0) {
 310             ret = fd;
 311             goto err_out;
 312         }
 313         ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
 314         close(fd);
 315     }
 316 err_out:
 317     close(dirfd);
 318     return ret;
 319 }
 320
 321 static int handle_link(FsContext *ctx, V9fsPath *oldpath,
 322                        V9fsPath *dirpath, const char *name)
 323 {
 324     int oldfd, newdirfd, ret;
 325     struct handle_data *data = (struct handle_data *)ctx->private;
 326
 327     oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH);
 328     if (oldfd < 0) {
 329         return oldfd;
 330     }
 331     newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH);
 332     if (newdirfd < 0) {
 333         close(oldfd);
 334         return newdirfd;
 335     }
 336     ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH);
 337     close(newdirfd);
 338     close(oldfd);
 339     return ret;
 340 }
 341
 342 static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 343 {
 344     int fd, ret;
 345     struct handle_data *data = (struct handle_data *)ctx->private;
 346
 347     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK | O_WRONLY);
 348     if (fd < 0) {
 349         return fd;
 350     }
 351     ret = ftruncate(fd, size);
 352     close(fd);
 353     return ret;
 354 }
 355
 356 static int handle_rename(FsContext *ctx, const char *oldpath,
 357                          const char *newpath)
 358 {
 359     errno = EOPNOTSUPP;
 360     return -1;
 361 }
 362
 363 static int handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 364 {
 365     int fd, ret;
 366     struct handle_data *data = (struct handle_data *)fs_ctx->private;
 367
 368     fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
 369     if (fd < 0) {
 370         return fd;
 371     }
 372     ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
 373     close(fd);
 374     return ret;
 375 }
 376
 377 static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
 378                             const struct timespec *buf)
 379 {
 380     int ret;
 381 #ifdef CONFIG_UTIMENSAT
 382     int fd;
 383     struct handle_data *data = (struct handle_data *)ctx->private;
 384
 385     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 386     if (fd < 0) {
 387         return fd;
 388     }
 389     ret = futimens(fd, buf);
 390     close(fd);
 391 #else
 392     ret = -1;
 393     errno = ENOSYS;
 394 #endif
 395     return ret;
 396 }
 397
 398 static int handle_remove(FsContext *ctx, const char *path)
 399 {
 400     errno = EOPNOTSUPP;
 401     return -1;
 402 }
 403
 404 static int handle_fsync(FsContext *ctx, int fid_type,
 405                         V9fsFidOpenState *fs, int datasync)
 406 {
 407     int fd;
 408
 409     if (fid_type == P9_FID_DIR) {
 410         fd = dirfd(fs->dir);
 411     } else {
 412         fd = fs->fd;
 413     }
 414
 415     if (datasync) {
 416         return qemu_fdatasync(fd);
 417     } else {
 418         return fsync(fd);
 419     }
 420 }
 421
 422 static int handle_statfs(FsContext *ctx, V9fsPath *fs_path,
 423                          struct statfs *stbuf)
 424 {
 425     int fd, ret;
 426     struct handle_data *data = (struct handle_data *)ctx->private;
 427
 428     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 429     if (fd < 0) {
 430         return fd;
 431     }
 432     ret = fstatfs(fd, stbuf);
 433     close(fd);
 434     return ret;
 435 }
 436
 437 static ssize_t handle_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
 438                                 const char *name, void *value, size_t size)
 439 {
 440     int fd, ret;
 441     struct handle_data *data = (struct handle_data *)ctx->private;
 442
 443     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 444     if (fd < 0) {
 445         return fd;
 446     }
 447     ret = fgetxattr(fd, name, value, size);
 448     close(fd);
 449     return ret;
 450 }
 451
 452 static ssize_t handle_llistxattr(FsContext *ctx, V9fsPath *fs_path,
 453                                  void *value, size_t size)
 454 {
 455     int fd, ret;
 456     struct handle_data *data = (struct handle_data *)ctx->private;
 457
 458     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 459     if (fd < 0) {
 460         return fd;
 461     }
 462     ret = flistxattr(fd, value, size);
 463     close(fd);
 464     return ret;
 465 }
 466
 467 static int handle_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
 468                             void *value, size_t size, int flags)
 469 {
 470     int fd, ret;
 471     struct handle_data *data = (struct handle_data *)ctx->private;
 472
 473     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 474     if (fd < 0) {
 475         return fd;
 476     }
 477     ret = fsetxattr(fd, name, value, size, flags);
 478     close(fd);
 479     return ret;
 480 }
 481
 482 static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
 483                                const char *name)
 484 {
 485     int fd, ret;
 486     struct handle_data *data = (struct handle_data *)ctx->private;
 487
 488     fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
 489     if (fd < 0) {
 490         return fd;
 491     }
 492     ret = fremovexattr(fd, name);
 493     close(fd);
 494     return ret;
 495 }
 496
 497 static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
 498                               const char *name, V9fsPath *target)
 499 {
 500     char *buffer;
 501     struct file_handle *fh;
 502     int dirfd, ret, mnt_id;
 503     struct handle_data *data = (struct handle_data *)ctx->private;
 504
 505     /* "." and ".." are not allowed */
 506     if (!strcmp(name, ".") || !strcmp(name, "..")) {
 507         errno = EINVAL;
 508         return -1;
 509
 510     }
 511     if (dir_path) {
 512         dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
 513     } else {
 514         /* relative to export root */
 515         buffer = rpath(ctx, ".");
 516         dirfd = open(buffer, O_DIRECTORY);
 517         g_free(buffer);
 518     }
 519     if (dirfd < 0) {
 520         return dirfd;
 521     }
 522     fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
 523     fh->handle_bytes = data->handle_bytes;
 524     /* add a "./" at the beginning of the path */
 525     buffer = g_strdup_printf("./%s", name);
 526     /* flag = 0 imply don't follow symlink */
 527     ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
 528     if (!ret) {
 529         target->data = (char *)fh;
 530         target->size = sizeof(struct file_handle) + data->handle_bytes;
 531     } else {
 532         g_free(fh);
 533     }
 534     close(dirfd);
 535     g_free(buffer);
 536     return ret;
 537 }
 538
 539 static int handle_renameat(FsContext *ctx, V9fsPath *olddir,
 540                            const char *old_name, V9fsPath *newdir,
 541                            const char *new_name)
 542 {
 543     int olddirfd, newdirfd, ret;
 544     struct handle_data *data = (struct handle_data *)ctx->private;
 545
 546     olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH);
 547     if (olddirfd < 0) {
 548         return olddirfd;
 549     }
 550     newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH);
 551     if (newdirfd < 0) {
 552         close(olddirfd);
 553         return newdirfd;
 554     }
 555     ret = renameat(olddirfd, old_name, newdirfd, new_name);
 556     close(newdirfd);
 557     close(olddirfd);
 558     return ret;
 559 }
 560
 561 static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
 562                            const char *name, int flags)
 563 {
 564     int dirfd, ret;
 565     struct handle_data *data = (struct handle_data *)ctx->private;
 566     int rflags;
 567
 568     dirfd = open_by_handle(data->mountfd, dir->data, O_PATH);
 569     if (dirfd < 0) {
 570         return dirfd;
 571     }
 572
 573     rflags = 0;
 574     if (flags & P9_DOTL_AT_REMOVEDIR) {
 575         rflags |= AT_REMOVEDIR;
 576     }
 577
 578     ret = unlinkat(dirfd, name, rflags);
 579
 580     close(dirfd);
 581     return ret;
 582 }
 583
 584 static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
 585                                  mode_t st_mode, uint64_t *st_gen)
 586 {
 587 #ifdef FS_IOC_GETVERSION
 588     int err;
 589     V9fsFidOpenState fid_open;
 590
 591     /*
 592      * Do not try to open special files like device nodes, fifos etc
 593      * We can get fd for regular files and directories only
 594      */
 595     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
 596         errno = ENOTTY;
 597         return -1;
 598     }
 599     err = handle_open(ctx, path, O_RDONLY, &fid_open);
 600     if (err < 0) {
 601         return err;
 602     }
 603     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
 604     handle_close(ctx, &fid_open);
 605     return err;
 606 #else
 607     errno = ENOTTY;
 608     return -1;
 609 #endif
 610 }
 611
 612 static int handle_init(FsContext *ctx)
 613 {
 614     int ret, mnt_id;
 615     struct statfs stbuf;
 616     struct file_handle fh;
 617     struct handle_data *data = g_malloc(sizeof(struct handle_data));
 618
 619     data->mountfd = open(ctx->fs_root, O_DIRECTORY);
 620     if (data->mountfd < 0) {
 621         ret = data->mountfd;
 622         goto err_out;
 623     }
 624     ret = statfs(ctx->fs_root, &stbuf);
 625     if (!ret) {
 626         switch (stbuf.f_type) {
 627         case EXT2_SUPER_MAGIC:
 628         case BTRFS_SUPER_MAGIC:
 629         case REISERFS_SUPER_MAGIC:
 630         case XFS_SUPER_MAGIC:
 631             ctx->exops.get_st_gen = handle_ioc_getversion;
 632             break;
 633         }
 634     }
 635     memset(&fh, 0, sizeof(struct file_handle));
 636     ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0);
 637     if (ret && errno == EOVERFLOW) {
 638         data->handle_bytes = fh.handle_bytes;
 639         ctx->private = data;
 640         ret = 0;
 641         goto out;
 642     }
 643     /* we got 0 byte handle ? */
 644     ret = -1;
 645     close(data->mountfd);
 646 err_out:
 647     g_free(data);
 648 out:
 649     return ret;
 650 }
 651
 652 static int handle_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
 653 {
 654     const char *sec_model = qemu_opt_get(opts, "security_model");
 655     const char *path = qemu_opt_get(opts, "path");
 656
 657     if (sec_model) {
 658         fprintf(stderr, "Invalid argument security_model specified with handle fsdriver\n");
 659         return -1;
 660     }
 661
 662     if (!path) {
 663         fprintf(stderr, "fsdev: No path specified.\n");
 664         return -1;
 665     }
 666     fse->path = g_strdup(path);
 667     return 0;
 668
 669 }
 670
 671 FileOperations handle_ops = {
 672     .parse_opts   = handle_parse_opts,
 673     .init         = handle_init,
 674     .lstat        = handle_lstat,
 675     .readlink     = handle_readlink,
 676     .close        = handle_close,
 677     .closedir     = handle_closedir,
 678     .open         = handle_open,
 679     .opendir      = handle_opendir,
 680     .rewinddir    = handle_rewinddir,
 681     .telldir      = handle_telldir,
 682     .readdir_r    = handle_readdir_r,
 683     .seekdir      = handle_seekdir,
 684     .preadv       = handle_preadv,
 685     .pwritev      = handle_pwritev,
 686     .chmod        = handle_chmod,
 687     .mknod        = handle_mknod,
 688     .mkdir        = handle_mkdir,
 689     .fstat        = handle_fstat,
 690     .open2        = handle_open2,
 691     .symlink      = handle_symlink,
 692     .link         = handle_link,
 693     .truncate     = handle_truncate,
 694     .rename       = handle_rename,
 695     .chown        = handle_chown,
 696     .utimensat    = handle_utimensat,
 697     .remove       = handle_remove,
 698     .fsync        = handle_fsync,
 699     .statfs       = handle_statfs,
 700     .lgetxattr    = handle_lgetxattr,
 701     .llistxattr   = handle_llistxattr,
 702     .lsetxattr    = handle_lsetxattr,
 703     .lremovexattr = handle_lremovexattr,
 704     .name_to_path = handle_name_to_path,
 705     .renameat     = handle_renameat,
 706     .unlinkat     = handle_unlinkat,
 707 };