hw/9pfs/9p-local.c

   1 /*
   2  * 9p Posix callback
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.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 "fsdev/qemu-fsdev.h"   /* local_ops */
  17 #include <arpa/inet.h>
  18 #include <pwd.h>
  19 #include <grp.h>
  20 #include <sys/socket.h>
  21 #include <sys/un.h>
  22 #include "qemu/xattr.h"
  23 #include <libgen.h>
  24 #include <linux/fs.h>
  25 #ifdef CONFIG_LINUX_MAGIC_H
  26 #include <linux/magic.h>
  27 #endif
  28 #include <sys/ioctl.h>
  29
  30 #ifndef XFS_SUPER_MAGIC
  31 #define XFS_SUPER_MAGIC  0x58465342
  32 #endif
  33 #ifndef EXT2_SUPER_MAGIC
  34 #define EXT2_SUPER_MAGIC 0xEF53
  35 #endif
  36 #ifndef REISERFS_SUPER_MAGIC
  37 #define REISERFS_SUPER_MAGIC 0x52654973
  38 #endif
  39 #ifndef BTRFS_SUPER_MAGIC
  40 #define BTRFS_SUPER_MAGIC 0x9123683E
  41 #endif
  42
  43 #define VIRTFS_META_DIR ".virtfs_metadata"
  44
  45 static char *local_mapped_attr_path(FsContext *ctx, const char *path)
  46 {
  47     int dirlen;
  48     const char *name = strrchr(path, '/');
  49     if (name) {
  50         dirlen = name - path;
  51         ++name;
  52     } else {
  53         name = path;
  54         dirlen = 0;
  55     }
  56     return g_strdup_printf("%s/%.*s/%s/%s", ctx->fs_root,
  57                            dirlen, path, VIRTFS_META_DIR, name);
  58 }
  59
  60 static FILE *local_fopen(const char *path, const char *mode)
  61 {
  62     int fd, o_mode = 0;
  63     FILE *fp;
  64     int flags = O_NOFOLLOW;
  65     /*
  66      * only supports two modes
  67      */
  68     if (mode[0] == 'r') {
  69         flags |= O_RDONLY;
  70     } else if (mode[0] == 'w') {
  71         flags |= O_WRONLY | O_TRUNC | O_CREAT;
  72         o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
  73     } else {
  74         return NULL;
  75     }
  76     fd = open(path, flags, o_mode);
  77     if (fd == -1) {
  78         return NULL;
  79     }
  80     fp = fdopen(fd, mode);
  81     if (!fp) {
  82         close(fd);
  83     }
  84     return fp;
  85 }
  86
  87 #define ATTR_MAX 100
  88 static void local_mapped_file_attr(FsContext *ctx, const char *path,
  89                                    struct stat *stbuf)
  90 {
  91     FILE *fp;
  92     char buf[ATTR_MAX];
  93     char *attr_path;
  94
  95     attr_path = local_mapped_attr_path(ctx, path);
  96     fp = local_fopen(attr_path, "r");
  97     g_free(attr_path);
  98     if (!fp) {
  99         return;
 100     }
 101     memset(buf, 0, ATTR_MAX);
 102     while (fgets(buf, ATTR_MAX, fp)) {
 103         if (!strncmp(buf, "virtfs.uid", 10)) {
 104             stbuf->st_uid = atoi(buf+11);
 105         } else if (!strncmp(buf, "virtfs.gid", 10)) {
 106             stbuf->st_gid = atoi(buf+11);
 107         } else if (!strncmp(buf, "virtfs.mode", 11)) {
 108             stbuf->st_mode = atoi(buf+12);
 109         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
 110             stbuf->st_rdev = atoi(buf+12);
 111         }
 112         memset(buf, 0, ATTR_MAX);
 113     }
 114     fclose(fp);
 115 }
 116
 117 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 118 {
 119     int err;
 120     char *buffer;
 121     char *path = fs_path->data;
 122
 123     buffer = rpath(fs_ctx, path);
 124     err =  lstat(buffer, stbuf);
 125     if (err) {
 126         goto err_out;
 127     }
 128     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 129         /* Actual credentials are part of extended attrs */
 130         uid_t tmp_uid;
 131         gid_t tmp_gid;
 132         mode_t tmp_mode;
 133         dev_t tmp_dev;
 134         if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
 135             stbuf->st_uid = le32_to_cpu(tmp_uid);
 136         }
 137         if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
 138             stbuf->st_gid = le32_to_cpu(tmp_gid);
 139         }
 140         if (getxattr(buffer, "user.virtfs.mode",
 141                     &tmp_mode, sizeof(mode_t)) > 0) {
 142             stbuf->st_mode = le32_to_cpu(tmp_mode);
 143         }
 144         if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
 145             stbuf->st_rdev = le64_to_cpu(tmp_dev);
 146         }
 147     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 148         local_mapped_file_attr(fs_ctx, path, stbuf);
 149     }
 150
 151 err_out:
 152     g_free(buffer);
 153     return err;
 154 }
 155
 156 static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
 157 {
 158     int err;
 159     char *attr_dir;
 160     char *tmp_path = g_strdup(path);
 161
 162     attr_dir = g_strdup_printf("%s/%s/%s",
 163              ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
 164
 165     err = mkdir(attr_dir, 0700);
 166     if (err < 0 && errno == EEXIST) {
 167         err = 0;
 168     }
 169     g_free(attr_dir);
 170     g_free(tmp_path);
 171     return err;
 172 }
 173
 174 static int local_set_mapped_file_attr(FsContext *ctx,
 175                                       const char *path, FsCred *credp)
 176 {
 177     FILE *fp;
 178     int ret = 0;
 179     char buf[ATTR_MAX];
 180     char *attr_path;
 181     int uid = -1, gid = -1, mode = -1, rdev = -1;
 182
 183     attr_path = local_mapped_attr_path(ctx, path);
 184     fp = local_fopen(attr_path, "r");
 185     if (!fp) {
 186         goto create_map_file;
 187     }
 188     memset(buf, 0, ATTR_MAX);
 189     while (fgets(buf, ATTR_MAX, fp)) {
 190         if (!strncmp(buf, "virtfs.uid", 10)) {
 191             uid = atoi(buf+11);
 192         } else if (!strncmp(buf, "virtfs.gid", 10)) {
 193             gid = atoi(buf+11);
 194         } else if (!strncmp(buf, "virtfs.mode", 11)) {
 195             mode = atoi(buf+12);
 196         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
 197             rdev = atoi(buf+12);
 198         }
 199         memset(buf, 0, ATTR_MAX);
 200     }
 201     fclose(fp);
 202     goto update_map_file;
 203
 204 create_map_file:
 205     ret = local_create_mapped_attr_dir(ctx, path);
 206     if (ret < 0) {
 207         goto err_out;
 208     }
 209
 210 update_map_file:
 211     fp = local_fopen(attr_path, "w");
 212     if (!fp) {
 213         ret = -1;
 214         goto err_out;
 215     }
 216
 217     if (credp->fc_uid != -1) {
 218         uid = credp->fc_uid;
 219     }
 220     if (credp->fc_gid != -1) {
 221         gid = credp->fc_gid;
 222     }
 223     if (credp->fc_mode != -1) {
 224         mode = credp->fc_mode;
 225     }
 226     if (credp->fc_rdev != -1) {
 227         rdev = credp->fc_rdev;
 228     }
 229
 230
 231     if (uid != -1) {
 232         fprintf(fp, "virtfs.uid=%d\n", uid);
 233     }
 234     if (gid != -1) {
 235         fprintf(fp, "virtfs.gid=%d\n", gid);
 236     }
 237     if (mode != -1) {
 238         fprintf(fp, "virtfs.mode=%d\n", mode);
 239     }
 240     if (rdev != -1) {
 241         fprintf(fp, "virtfs.rdev=%d\n", rdev);
 242     }
 243     fclose(fp);
 244
 245 err_out:
 246     g_free(attr_path);
 247     return ret;
 248 }
 249
 250 static int local_set_xattr(const char *path, FsCred *credp)
 251 {
 252     int err;
 253
 254     if (credp->fc_uid != -1) {
 255         uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);
 256         err = setxattr(path, "user.virtfs.uid", &tmp_uid, sizeof(uid_t), 0);
 257         if (err) {
 258             return err;
 259         }
 260     }
 261     if (credp->fc_gid != -1) {
 262         uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);
 263         err = setxattr(path, "user.virtfs.gid", &tmp_gid, sizeof(gid_t), 0);
 264         if (err) {
 265             return err;
 266         }
 267     }
 268     if (credp->fc_mode != -1) {
 269         uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);
 270         err = setxattr(path, "user.virtfs.mode", &tmp_mode, sizeof(mode_t), 0);
 271         if (err) {
 272             return err;
 273         }
 274     }
 275     if (credp->fc_rdev != -1) {
 276         uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);
 277         err = setxattr(path, "user.virtfs.rdev", &tmp_rdev, sizeof(dev_t), 0);
 278         if (err) {
 279             return err;
 280         }
 281     }
 282     return 0;
 283 }
 284
 285 static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
 286                                          FsCred *credp)
 287 {
 288     char *buffer;
 289
 290     buffer = rpath(fs_ctx, path);
 291     if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) {
 292         /*
 293          * If we fail to change ownership and if we are
 294          * using security model none. Ignore the error
 295          */
 296         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
 297             goto err;
 298         }
 299     }
 300
 301     if (chmod(buffer, credp->fc_mode & 07777) < 0) {
 302         goto err;
 303     }
 304
 305     g_free(buffer);
 306     return 0;
 307 err:
 308     g_free(buffer);
 309     return -1;
 310 }
 311
 312 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
 313                               char *buf, size_t bufsz)
 314 {
 315     ssize_t tsize = -1;
 316     char *buffer;
 317     char *path = fs_path->data;
 318
 319     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
 320         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
 321         int fd;
 322         buffer = rpath(fs_ctx, path);
 323         fd = open(buffer, O_RDONLY | O_NOFOLLOW);
 324         g_free(buffer);
 325         if (fd == -1) {
 326             return -1;
 327         }
 328         do {
 329             tsize = read(fd, (void *)buf, bufsz);
 330         } while (tsize == -1 && errno == EINTR);
 331         close(fd);
 332     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 333                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 334         buffer = rpath(fs_ctx, path);
 335         tsize = readlink(buffer, buf, bufsz);
 336         g_free(buffer);
 337     }
 338     return tsize;
 339 }
 340
 341 static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
 342 {
 343     return close(fs->fd);
 344 }
 345
 346 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 347 {
 348     return closedir(fs->dir);
 349 }
 350
 351 static int local_open(FsContext *ctx, V9fsPath *fs_path,
 352                       int flags, V9fsFidOpenState *fs)
 353 {
 354     char *buffer;
 355     char *path = fs_path->data;
 356
 357     buffer = rpath(ctx, path);
 358     fs->fd = open(buffer, flags | O_NOFOLLOW);
 359     g_free(buffer);
 360     return fs->fd;
 361 }
 362
 363 static int local_opendir(FsContext *ctx,
 364                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 365 {
 366     char *buffer;
 367     char *path = fs_path->data;
 368
 369     buffer = rpath(ctx, path);
 370     fs->dir = opendir(buffer);
 371     g_free(buffer);
 372     if (!fs->dir) {
 373         return -1;
 374     }
 375     return 0;
 376 }
 377
 378 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
 379 {
 380     rewinddir(fs->dir);
 381 }
 382
 383 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
 384 {
 385     return telldir(fs->dir);
 386 }
 387
 388 static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
 389                            struct dirent *entry,
 390                            struct dirent **result)
 391 {
 392     int ret;
 393
 394 again:
 395     ret = readdir_r(fs->dir, entry, result);
 396     if (ctx->export_flags & V9FS_SM_MAPPED) {
 397         entry->d_type = DT_UNKNOWN;
 398     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 399         if (!ret && *result != NULL &&
 400             !strcmp(entry->d_name, VIRTFS_META_DIR)) {
 401             /* skp the meta data directory */
 402             goto again;
 403         }
 404         entry->d_type = DT_UNKNOWN;
 405     }
 406     return ret;
 407 }
 408
 409 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
 410 {
 411     seekdir(fs->dir, off);
 412 }
 413
 414 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
 415                             const struct iovec *iov,
 416                             int iovcnt, off_t offset)
 417 {
 418 #ifdef CONFIG_PREADV
 419     return preadv(fs->fd, iov, iovcnt, offset);
 420 #else
 421     int err = lseek(fs->fd, offset, SEEK_SET);
 422     if (err == -1) {
 423         return err;
 424     } else {
 425         return readv(fs->fd, iov, iovcnt);
 426     }
 427 #endif
 428 }
 429
 430 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 431                              const struct iovec *iov,
 432                              int iovcnt, off_t offset)
 433 {
 434     ssize_t ret
 435 ;
 436 #ifdef CONFIG_PREADV
 437     ret = pwritev(fs->fd, iov, iovcnt, offset);
 438 #else
 439     int err = lseek(fs->fd, offset, SEEK_SET);
 440     if (err == -1) {
 441         return err;
 442     } else {
 443         ret = writev(fs->fd, iov, iovcnt);
 444     }
 445 #endif
 446 #ifdef CONFIG_SYNC_FILE_RANGE
 447     if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
 448         /*
 449          * Initiate a writeback. This is not a data integrity sync.
 450          * We want to ensure that we don't leave dirty pages in the cache
 451          * after write when writeout=immediate is sepcified.
 452          */
 453         sync_file_range(fs->fd, offset, ret,
 454                         SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
 455     }
 456 #endif
 457     return ret;
 458 }
 459
 460 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 461 {
 462     char *buffer;
 463     int ret = -1;
 464     char *path = fs_path->data;
 465
 466     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 467         buffer = rpath(fs_ctx, path);
 468         ret = local_set_xattr(buffer, credp);
 469         g_free(buffer);
 470     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 471         return local_set_mapped_file_attr(fs_ctx, path, credp);
 472     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 473                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 474         buffer = rpath(fs_ctx, path);
 475         ret = chmod(buffer, credp->fc_mode);
 476         g_free(buffer);
 477     }
 478     return ret;
 479 }
 480
 481 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
 482                        const char *name, FsCred *credp)
 483 {
 484     char *path;
 485     int err = -1;
 486     int serrno = 0;
 487     V9fsString fullname;
 488     char *buffer = NULL;
 489
 490     v9fs_string_init(&fullname);
 491     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 492     path = fullname.data;
 493
 494     /* Determine the security model */
 495     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 496         buffer = rpath(fs_ctx, path);
 497         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
 498         if (err == -1) {
 499             goto out;
 500         }
 501         err = local_set_xattr(buffer, credp);
 502         if (err == -1) {
 503             serrno = errno;
 504             goto err_end;
 505         }
 506     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 507
 508         buffer = rpath(fs_ctx, path);
 509         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
 510         if (err == -1) {
 511             goto out;
 512         }
 513         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 514         if (err == -1) {
 515             serrno = errno;
 516             goto err_end;
 517         }
 518     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 519                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 520         buffer = rpath(fs_ctx, path);
 521         err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
 522         if (err == -1) {
 523             goto out;
 524         }
 525         err = local_post_create_passthrough(fs_ctx, path, credp);
 526         if (err == -1) {
 527             serrno = errno;
 528             goto err_end;
 529         }
 530     }
 531     goto out;
 532
 533 err_end:
 534     remove(buffer);
 535     errno = serrno;
 536 out:
 537     g_free(buffer);
 538     v9fs_string_free(&fullname);
 539     return err;
 540 }
 541
 542 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 543                        const char *name, FsCred *credp)
 544 {
 545     char *path;
 546     int err = -1;
 547     int serrno = 0;
 548     V9fsString fullname;
 549     char *buffer = NULL;
 550
 551     v9fs_string_init(&fullname);
 552     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 553     path = fullname.data;
 554
 555     /* Determine the security model */
 556     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 557         buffer = rpath(fs_ctx, path);
 558         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 559         if (err == -1) {
 560             goto out;
 561         }
 562         credp->fc_mode = credp->fc_mode|S_IFDIR;
 563         err = local_set_xattr(buffer, credp);
 564         if (err == -1) {
 565             serrno = errno;
 566             goto err_end;
 567         }
 568     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 569         buffer = rpath(fs_ctx, path);
 570         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 571         if (err == -1) {
 572             goto out;
 573         }
 574         credp->fc_mode = credp->fc_mode|S_IFDIR;
 575         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 576         if (err == -1) {
 577             serrno = errno;
 578             goto err_end;
 579         }
 580     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 581                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 582         buffer = rpath(fs_ctx, path);
 583         err = mkdir(buffer, credp->fc_mode);
 584         if (err == -1) {
 585             goto out;
 586         }
 587         err = local_post_create_passthrough(fs_ctx, path, credp);
 588         if (err == -1) {
 589             serrno = errno;
 590             goto err_end;
 591         }
 592     }
 593     goto out;
 594
 595 err_end:
 596     remove(buffer);
 597     errno = serrno;
 598 out:
 599     g_free(buffer);
 600     v9fs_string_free(&fullname);
 601     return err;
 602 }
 603
 604 static int local_fstat(FsContext *fs_ctx, int fid_type,
 605                        V9fsFidOpenState *fs, struct stat *stbuf)
 606 {
 607     int err, fd;
 608
 609     if (fid_type == P9_FID_DIR) {
 610         fd = dirfd(fs->dir);
 611     } else {
 612         fd = fs->fd;
 613     }
 614
 615     err = fstat(fd, stbuf);
 616     if (err) {
 617         return err;
 618     }
 619     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 620         /* Actual credentials are part of extended attrs */
 621         uid_t tmp_uid;
 622         gid_t tmp_gid;
 623         mode_t tmp_mode;
 624         dev_t tmp_dev;
 625
 626         if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
 627             stbuf->st_uid = le32_to_cpu(tmp_uid);
 628         }
 629         if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
 630             stbuf->st_gid = le32_to_cpu(tmp_gid);
 631         }
 632         if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
 633             stbuf->st_mode = le32_to_cpu(tmp_mode);
 634         }
 635         if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
 636             stbuf->st_rdev = le64_to_cpu(tmp_dev);
 637         }
 638     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 639         errno = EOPNOTSUPP;
 640         return -1;
 641     }
 642     return err;
 643 }
 644
 645 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 646                        int flags, FsCred *credp, V9fsFidOpenState *fs)
 647 {
 648     char *path;
 649     int fd = -1;
 650     int err = -1;
 651     int serrno = 0;
 652     V9fsString fullname;
 653     char *buffer = NULL;
 654
 655     /*
 656      * Mark all the open to not follow symlinks
 657      */
 658     flags |= O_NOFOLLOW;
 659
 660     v9fs_string_init(&fullname);
 661     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 662     path = fullname.data;
 663
 664     /* Determine the security model */
 665     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 666         buffer = rpath(fs_ctx, path);
 667         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 668         if (fd == -1) {
 669             err = fd;
 670             goto out;
 671         }
 672         credp->fc_mode = credp->fc_mode|S_IFREG;
 673         /* Set cleint credentials in xattr */
 674         err = local_set_xattr(buffer, credp);
 675         if (err == -1) {
 676             serrno = errno;
 677             goto err_end;
 678         }
 679     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 680         buffer = rpath(fs_ctx, path);
 681         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 682         if (fd == -1) {
 683             err = fd;
 684             goto out;
 685         }
 686         credp->fc_mode = credp->fc_mode|S_IFREG;
 687         /* Set client credentials in .virtfs_metadata directory files */
 688         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 689         if (err == -1) {
 690             serrno = errno;
 691             goto err_end;
 692         }
 693     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 694                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 695         buffer = rpath(fs_ctx, path);
 696         fd = open(buffer, flags, credp->fc_mode);
 697         if (fd == -1) {
 698             err = fd;
 699             goto out;
 700         }
 701         err = local_post_create_passthrough(fs_ctx, path, credp);
 702         if (err == -1) {
 703             serrno = errno;
 704             goto err_end;
 705         }
 706     }
 707     err = fd;
 708     fs->fd = fd;
 709     goto out;
 710
 711 err_end:
 712     close(fd);
 713     remove(buffer);
 714     errno = serrno;
 715 out:
 716     g_free(buffer);
 717     v9fs_string_free(&fullname);
 718     return err;
 719 }
 720
 721
 722 static int local_symlink(FsContext *fs_ctx, const char *oldpath,
 723                          V9fsPath *dir_path, const char *name, FsCred *credp)
 724 {
 725     int err = -1;
 726     int serrno = 0;
 727     char *newpath;
 728     V9fsString fullname;
 729     char *buffer = NULL;
 730
 731     v9fs_string_init(&fullname);
 732     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 733     newpath = fullname.data;
 734
 735     /* Determine the security model */
 736     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 737         int fd;
 738         ssize_t oldpath_size, write_size;
 739         buffer = rpath(fs_ctx, newpath);
 740         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 741         if (fd == -1) {
 742             err = fd;
 743             goto out;
 744         }
 745         /* Write the oldpath (target) to the file. */
 746         oldpath_size = strlen(oldpath);
 747         do {
 748             write_size = write(fd, (void *)oldpath, oldpath_size);
 749         } while (write_size == -1 && errno == EINTR);
 750
 751         if (write_size != oldpath_size) {
 752             serrno = errno;
 753             close(fd);
 754             err = -1;
 755             goto err_end;
 756         }
 757         close(fd);
 758         /* Set cleint credentials in symlink's xattr */
 759         credp->fc_mode = credp->fc_mode|S_IFLNK;
 760         err = local_set_xattr(buffer, credp);
 761         if (err == -1) {
 762             serrno = errno;
 763             goto err_end;
 764         }
 765     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 766         int fd;
 767         ssize_t oldpath_size, write_size;
 768         buffer = rpath(fs_ctx, newpath);
 769         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 770         if (fd == -1) {
 771             err = fd;
 772             goto out;
 773         }
 774         /* Write the oldpath (target) to the file. */
 775         oldpath_size = strlen(oldpath);
 776         do {
 777             write_size = write(fd, (void *)oldpath, oldpath_size);
 778         } while (write_size == -1 && errno == EINTR);
 779
 780         if (write_size != oldpath_size) {
 781             serrno = errno;
 782             close(fd);
 783             err = -1;
 784             goto err_end;
 785         }
 786         close(fd);
 787         /* Set cleint credentials in symlink's xattr */
 788         credp->fc_mode = credp->fc_mode|S_IFLNK;
 789         err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
 790         if (err == -1) {
 791             serrno = errno;
 792             goto err_end;
 793         }
 794     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 795                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 796         buffer = rpath(fs_ctx, newpath);
 797         err = symlink(oldpath, buffer);
 798         if (err) {
 799             goto out;
 800         }
 801         err = lchown(buffer, credp->fc_uid, credp->fc_gid);
 802         if (err == -1) {
 803             /*
 804              * If we fail to change ownership and if we are
 805              * using security model none. Ignore the error
 806              */
 807             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
 808                 serrno = errno;
 809                 goto err_end;
 810             } else
 811                 err = 0;
 812         }
 813     }
 814     goto out;
 815
 816 err_end:
 817     remove(buffer);
 818     errno = serrno;
 819 out:
 820     g_free(buffer);
 821     v9fs_string_free(&fullname);
 822     return err;
 823 }
 824
 825 static int local_link(FsContext *ctx, V9fsPath *oldpath,
 826                       V9fsPath *dirpath, const char *name)
 827 {
 828     int ret;
 829     V9fsString newpath;
 830     char *buffer, *buffer1;
 831
 832     v9fs_string_init(&newpath);
 833     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 834
 835     buffer = rpath(ctx, oldpath->data);
 836     buffer1 = rpath(ctx, newpath.data);
 837     ret = link(buffer, buffer1);
 838     g_free(buffer);
 839     g_free(buffer1);
 840
 841     /* now link the virtfs_metadata files */
 842     if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
 843         /* Link the .virtfs_metadata files. Create the metada directory */
 844         ret = local_create_mapped_attr_dir(ctx, newpath.data);
 845         if (ret < 0) {
 846             goto err_out;
 847         }
 848         buffer = local_mapped_attr_path(ctx, oldpath->data);
 849         buffer1 = local_mapped_attr_path(ctx, newpath.data);
 850         ret = link(buffer, buffer1);
 851         g_free(buffer);
 852         g_free(buffer1);
 853         if (ret < 0 && errno != ENOENT) {
 854             goto err_out;
 855         }
 856     }
 857 err_out:
 858     v9fs_string_free(&newpath);
 859     return ret;
 860 }
 861
 862 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 863 {
 864     char *buffer;
 865     int ret;
 866     char *path = fs_path->data;
 867
 868     buffer = rpath(ctx, path);
 869     ret = truncate(buffer, size);
 870     g_free(buffer);
 871     return ret;
 872 }
 873
 874 static int local_rename(FsContext *ctx, const char *oldpath,
 875                         const char *newpath)
 876 {
 877     int err;
 878     char *buffer, *buffer1;
 879
 880     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 881         err = local_create_mapped_attr_dir(ctx, newpath);
 882         if (err < 0) {
 883             return err;
 884         }
 885         /* rename the .virtfs_metadata files */
 886         buffer = local_mapped_attr_path(ctx, oldpath);
 887         buffer1 = local_mapped_attr_path(ctx, newpath);
 888         err = rename(buffer, buffer1);
 889         g_free(buffer);
 890         g_free(buffer1);
 891         if (err < 0 && errno != ENOENT) {
 892             return err;
 893         }
 894     }
 895
 896     buffer = rpath(ctx, oldpath);
 897     buffer1 = rpath(ctx, newpath);
 898     err = rename(buffer, buffer1);
 899     g_free(buffer);
 900     g_free(buffer1);
 901     return err;
 902 }
 903
 904 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 905 {
 906     char *buffer;
 907     int ret = -1;
 908     char *path = fs_path->data;
 909
 910     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
 911         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 912         (fs_ctx->export_flags & V9FS_SM_NONE)) {
 913         buffer = rpath(fs_ctx, path);
 914         ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
 915         g_free(buffer);
 916     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 917         buffer = rpath(fs_ctx, path);
 918         ret = local_set_xattr(buffer, credp);
 919         g_free(buffer);
 920     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 921         return local_set_mapped_file_attr(fs_ctx, path, credp);
 922     }
 923     return ret;
 924 }
 925
 926 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
 927                            const struct timespec *buf)
 928 {
 929     char *buffer;
 930     int ret;
 931     char *path = fs_path->data;
 932
 933     buffer = rpath(s, path);
 934     ret = qemu_utimens(buffer, buf);
 935     g_free(buffer);
 936     return ret;
 937 }
 938
 939 static int local_remove(FsContext *ctx, const char *path)
 940 {
 941     int err;
 942     struct stat stbuf;
 943     char *buffer;
 944
 945     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 946         buffer = rpath(ctx, path);
 947         err =  lstat(buffer, &stbuf);
 948         g_free(buffer);
 949         if (err) {
 950             goto err_out;
 951         }
 952         /*
 953          * If directory remove .virtfs_metadata contained in the
 954          * directory
 955          */
 956         if (S_ISDIR(stbuf.st_mode)) {
 957             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
 958                                      path, VIRTFS_META_DIR);
 959             err = remove(buffer);
 960             g_free(buffer);
 961             if (err < 0 && errno != ENOENT) {
 962                 /*
 963                  * We didn't had the .virtfs_metadata file. May be file created
 964                  * in non-mapped mode ?. Ignore ENOENT.
 965                  */
 966                 goto err_out;
 967             }
 968         }
 969         /*
 970          * Now remove the name from parent directory
 971          * .virtfs_metadata directory
 972          */
 973         buffer = local_mapped_attr_path(ctx, path);
 974         err = remove(buffer);
 975         g_free(buffer);
 976         if (err < 0 && errno != ENOENT) {
 977             /*
 978              * We didn't had the .virtfs_metadata file. May be file created
 979              * in non-mapped mode ?. Ignore ENOENT.
 980              */
 981             goto err_out;
 982         }
 983     }
 984
 985     buffer = rpath(ctx, path);
 986     err = remove(buffer);
 987     g_free(buffer);
 988 err_out:
 989     return err;
 990 }
 991
 992 static int local_fsync(FsContext *ctx, int fid_type,
 993                        V9fsFidOpenState *fs, int datasync)
 994 {
 995     int fd;
 996
 997     if (fid_type == P9_FID_DIR) {
 998         fd = dirfd(fs->dir);
 999     } else {
1000         fd = fs->fd;
1001     }
1002
1003     if (datasync) {
1004         return qemu_fdatasync(fd);
1005     } else {
1006         return fsync(fd);
1007     }
1008 }
1009
1010 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
1011 {
1012     char *buffer;
1013     int ret;
1014     char *path = fs_path->data;
1015
1016     buffer = rpath(s, path);
1017     ret = statfs(buffer, stbuf);
1018     g_free(buffer);
1019     return ret;
1020 }
1021
1022 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
1023                                const char *name, void *value, size_t size)
1024 {
1025     char *path = fs_path->data;
1026
1027     return v9fs_get_xattr(ctx, path, name, value, size);
1028 }
1029
1030 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
1031                                 void *value, size_t size)
1032 {
1033     char *path = fs_path->data;
1034
1035     return v9fs_list_xattr(ctx, path, value, size);
1036 }
1037
1038 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
1039                            void *value, size_t size, int flags)
1040 {
1041     char *path = fs_path->data;
1042
1043     return v9fs_set_xattr(ctx, path, name, value, size, flags);
1044 }
1045
1046 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
1047                               const char *name)
1048 {
1049     char *path = fs_path->data;
1050
1051     return v9fs_remove_xattr(ctx, path, name);
1052 }
1053
1054 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
1055                               const char *name, V9fsPath *target)
1056 {
1057     if (dir_path) {
1058         v9fs_string_sprintf((V9fsString *)target, "%s/%s",
1059                             dir_path->data, name);
1060     } else {
1061         v9fs_string_sprintf((V9fsString *)target, "%s", name);
1062     }
1063     /* Bump the size for including terminating NULL */
1064     target->size++;
1065     return 0;
1066 }
1067
1068 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
1069                           const char *old_name, V9fsPath *newdir,
1070                           const char *new_name)
1071 {
1072     int ret;
1073     V9fsString old_full_name, new_full_name;
1074
1075     v9fs_string_init(&old_full_name);
1076     v9fs_string_init(&new_full_name);
1077
1078     v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
1079     v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
1080
1081     ret = local_rename(ctx, old_full_name.data, new_full_name.data);
1082     v9fs_string_free(&old_full_name);
1083     v9fs_string_free(&new_full_name);
1084     return ret;
1085 }
1086
1087 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
1088                           const char *name, int flags)
1089 {
1090     int ret;
1091     V9fsString fullname;
1092     char *buffer;
1093
1094     v9fs_string_init(&fullname);
1095
1096     v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
1097     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1098         if (flags == AT_REMOVEDIR) {
1099             /*
1100              * If directory remove .virtfs_metadata contained in the
1101              * directory
1102              */
1103             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
1104                                      fullname.data, VIRTFS_META_DIR);
1105             ret = remove(buffer);
1106             g_free(buffer);
1107             if (ret < 0 && errno != ENOENT) {
1108                 /*
1109                  * We didn't had the .virtfs_metadata file. May be file created
1110                  * in non-mapped mode ?. Ignore ENOENT.
1111                  */
1112                 goto err_out;
1113             }
1114         }
1115         /*
1116          * Now remove the name from parent directory
1117          * .virtfs_metadata directory.
1118          */
1119         buffer = local_mapped_attr_path(ctx, fullname.data);
1120         ret = remove(buffer);
1121         g_free(buffer);
1122         if (ret < 0 && errno != ENOENT) {
1123             /*
1124              * We didn't had the .virtfs_metadata file. May be file created
1125              * in non-mapped mode ?. Ignore ENOENT.
1126              */
1127             goto err_out;
1128         }
1129     }
1130     /* Remove the name finally */
1131     buffer = rpath(ctx, fullname.data);
1132     ret = remove(buffer);
1133     g_free(buffer);
1134
1135 err_out:
1136     v9fs_string_free(&fullname);
1137     return ret;
1138 }
1139
1140 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1141                                 mode_t st_mode, uint64_t *st_gen)
1142 {
1143 #ifdef FS_IOC_GETVERSION
1144     int err;
1145     V9fsFidOpenState fid_open;
1146
1147     /*
1148      * Do not try to open special files like device nodes, fifos etc
1149      * We can get fd for regular files and directories only
1150      */
1151     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1152         errno = ENOTTY;
1153         return -1;
1154     }
1155     err = local_open(ctx, path, O_RDONLY, &fid_open);
1156     if (err < 0) {
1157         return err;
1158     }
1159     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1160     local_close(ctx, &fid_open);
1161     return err;
1162 #else
1163     errno = ENOTTY;
1164     return -1;
1165 #endif
1166 }
1167
1168 static int local_init(FsContext *ctx)
1169 {
1170     int err = 0;
1171     struct statfs stbuf;
1172
1173     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1174         ctx->xops = passthrough_xattr_ops;
1175     } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1176         ctx->xops = mapped_xattr_ops;
1177     } else if (ctx->export_flags & V9FS_SM_NONE) {
1178         ctx->xops = none_xattr_ops;
1179     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1180         /*
1181          * xattr operation for mapped-file and passthrough
1182          * remain same.
1183          */
1184         ctx->xops = passthrough_xattr_ops;
1185     }
1186     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1187 #ifdef FS_IOC_GETVERSION
1188     /*
1189      * use ioc_getversion only if the iocl is definied
1190      */
1191     err = statfs(ctx->fs_root, &stbuf);
1192     if (!err) {
1193         switch (stbuf.f_type) {
1194         case EXT2_SUPER_MAGIC:
1195         case BTRFS_SUPER_MAGIC:
1196         case REISERFS_SUPER_MAGIC:
1197         case XFS_SUPER_MAGIC:
1198             ctx->exops.get_st_gen = local_ioc_getversion;
1199             break;
1200         }
1201     }
1202 #endif
1203     return err;
1204 }
1205
1206 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
1207 {
1208     const char *sec_model = qemu_opt_get(opts, "security_model");
1209     const char *path = qemu_opt_get(opts, "path");
1210
1211     if (!sec_model) {
1212         fprintf(stderr, "security model not specified, "
1213                 "local fs needs security model\nvalid options are:"
1214                 "\tsecurity_model=[passthrough|mapped|none]\n");
1215         return -1;
1216     }
1217
1218     if (!strcmp(sec_model, "passthrough")) {
1219         fse->export_flags |= V9FS_SM_PASSTHROUGH;
1220     } else if (!strcmp(sec_model, "mapped") ||
1221                !strcmp(sec_model, "mapped-xattr")) {
1222         fse->export_flags |= V9FS_SM_MAPPED;
1223     } else if (!strcmp(sec_model, "none")) {
1224         fse->export_flags |= V9FS_SM_NONE;
1225     } else if (!strcmp(sec_model, "mapped-file")) {
1226         fse->export_flags |= V9FS_SM_MAPPED_FILE;
1227     } else {
1228         fprintf(stderr, "Invalid security model %s specified, valid options are"
1229                 "\n\t [passthrough|mapped-xattr|mapped-file|none]\n",
1230                 sec_model);
1231         return -1;
1232     }
1233
1234     if (!path) {
1235         fprintf(stderr, "fsdev: No path specified.\n");
1236         return -1;
1237     }
1238     fse->path = g_strdup(path);
1239
1240     return 0;
1241 }
1242
1243 FileOperations local_ops = {
1244     .parse_opts = local_parse_opts,
1245     .init  = local_init,
1246     .lstat = local_lstat,
1247     .readlink = local_readlink,
1248     .close = local_close,
1249     .closedir = local_closedir,
1250     .open = local_open,
1251     .opendir = local_opendir,
1252     .rewinddir = local_rewinddir,
1253     .telldir = local_telldir,
1254     .readdir_r = local_readdir_r,
1255     .seekdir = local_seekdir,
1256     .preadv = local_preadv,
1257     .pwritev = local_pwritev,
1258     .chmod = local_chmod,
1259     .mknod = local_mknod,
1260     .mkdir = local_mkdir,
1261     .fstat = local_fstat,
1262     .open2 = local_open2,
1263     .symlink = local_symlink,
1264     .link = local_link,
1265     .truncate = local_truncate,
1266     .rename = local_rename,
1267     .chown = local_chown,
1268     .utimensat = local_utimensat,
1269     .remove = local_remove,
1270     .fsync = local_fsync,
1271     .statfs = local_statfs,
1272     .lgetxattr = local_lgetxattr,
1273     .llistxattr = local_llistxattr,
1274     .lsetxattr = local_lsetxattr,
1275     .lremovexattr = local_lremovexattr,
1276     .name_to_path = local_name_to_path,
1277     .renameat  = local_renameat,
1278     .unlinkat = local_unlinkat,
1279 };