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 "qemu/osdep.h"
  15 #include "9p.h"
  16 #include "9p-xattr.h"
  17 #include "fsdev/qemu-fsdev.h"   /* local_ops */
  18 #include <arpa/inet.h>
  19 #include <pwd.h>
  20 #include <grp.h>
  21 #include <sys/socket.h>
  22 #include <sys/un.h>
  23 #include "qemu/xattr.h"
  24 #include "qemu/cutils.h"
  25 #include "qemu/error-report.h"
  26 #include <libgen.h>
  27 #include <linux/fs.h>
  28 #ifdef CONFIG_LINUX_MAGIC_H
  29 #include <linux/magic.h>
  30 #endif
  31 #include <sys/ioctl.h>
  32
  33 #ifndef XFS_SUPER_MAGIC
  34 #define XFS_SUPER_MAGIC  0x58465342
  35 #endif
  36 #ifndef EXT2_SUPER_MAGIC
  37 #define EXT2_SUPER_MAGIC 0xEF53
  38 #endif
  39 #ifndef REISERFS_SUPER_MAGIC
  40 #define REISERFS_SUPER_MAGIC 0x52654973
  41 #endif
  42 #ifndef BTRFS_SUPER_MAGIC
  43 #define BTRFS_SUPER_MAGIC 0x9123683E
  44 #endif
  45
  46 #define VIRTFS_META_DIR ".virtfs_metadata"
  47
  48 static char *local_mapped_attr_path(FsContext *ctx, const char *path)
  49 {
  50     int dirlen;
  51     const char *name = strrchr(path, '/');
  52     if (name) {
  53         dirlen = name - path;
  54         ++name;
  55     } else {
  56         name = path;
  57         dirlen = 0;
  58     }
  59     return g_strdup_printf("%s/%.*s/%s/%s", ctx->fs_root,
  60                            dirlen, path, VIRTFS_META_DIR, name);
  61 }
  62
  63 static FILE *local_fopen(const char *path, const char *mode)
  64 {
  65     int fd, o_mode = 0;
  66     FILE *fp;
  67     int flags = O_NOFOLLOW;
  68     /*
  69      * only supports two modes
  70      */
  71     if (mode[0] == 'r') {
  72         flags |= O_RDONLY;
  73     } else if (mode[0] == 'w') {
  74         flags |= O_WRONLY | O_TRUNC | O_CREAT;
  75         o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
  76     } else {
  77         return NULL;
  78     }
  79     fd = open(path, flags, o_mode);
  80     if (fd == -1) {
  81         return NULL;
  82     }
  83     fp = fdopen(fd, mode);
  84     if (!fp) {
  85         close(fd);
  86     }
  87     return fp;
  88 }
  89
  90 #define ATTR_MAX 100
  91 static void local_mapped_file_attr(FsContext *ctx, const char *path,
  92                                    struct stat *stbuf)
  93 {
  94     FILE *fp;
  95     char buf[ATTR_MAX];
  96     char *attr_path;
  97
  98     attr_path = local_mapped_attr_path(ctx, path);
  99     fp = local_fopen(attr_path, "r");
 100     g_free(attr_path);
 101     if (!fp) {
 102         return;
 103     }
 104     memset(buf, 0, ATTR_MAX);
 105     while (fgets(buf, ATTR_MAX, fp)) {
 106         if (!strncmp(buf, "virtfs.uid", 10)) {
 107             stbuf->st_uid = atoi(buf+11);
 108         } else if (!strncmp(buf, "virtfs.gid", 10)) {
 109             stbuf->st_gid = atoi(buf+11);
 110         } else if (!strncmp(buf, "virtfs.mode", 11)) {
 111             stbuf->st_mode = atoi(buf+12);
 112         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
 113             stbuf->st_rdev = atoi(buf+12);
 114         }
 115         memset(buf, 0, ATTR_MAX);
 116     }
 117     fclose(fp);
 118 }
 119
 120 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 121 {
 122     int err;
 123     char *buffer;
 124     char *path = fs_path->data;
 125
 126     buffer = rpath(fs_ctx, path);
 127     err =  lstat(buffer, stbuf);
 128     if (err) {
 129         goto err_out;
 130     }
 131     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 132         /* Actual credentials are part of extended attrs */
 133         uid_t tmp_uid;
 134         gid_t tmp_gid;
 135         mode_t tmp_mode;
 136         dev_t tmp_dev;
 137         if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
 138             stbuf->st_uid = le32_to_cpu(tmp_uid);
 139         }
 140         if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
 141             stbuf->st_gid = le32_to_cpu(tmp_gid);
 142         }
 143         if (getxattr(buffer, "user.virtfs.mode",
 144                     &tmp_mode, sizeof(mode_t)) > 0) {
 145             stbuf->st_mode = le32_to_cpu(tmp_mode);
 146         }
 147         if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
 148             stbuf->st_rdev = le64_to_cpu(tmp_dev);
 149         }
 150     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 151         local_mapped_file_attr(fs_ctx, path, stbuf);
 152     }
 153
 154 err_out:
 155     g_free(buffer);
 156     return err;
 157 }
 158
 159 static int local_create_mapped_attr_dir(FsContext *ctx, const char *path)
 160 {
 161     int err;
 162     char *attr_dir;
 163     char *tmp_path = g_strdup(path);
 164
 165     attr_dir = g_strdup_printf("%s/%s/%s",
 166              ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR);
 167
 168     err = mkdir(attr_dir, 0700);
 169     if (err < 0 && errno == EEXIST) {
 170         err = 0;
 171     }
 172     g_free(attr_dir);
 173     g_free(tmp_path);
 174     return err;
 175 }
 176
 177 static int local_set_mapped_file_attr(FsContext *ctx,
 178                                       const char *path, FsCred *credp)
 179 {
 180     FILE *fp;
 181     int ret = 0;
 182     char buf[ATTR_MAX];
 183     char *attr_path;
 184     int uid = -1, gid = -1, mode = -1, rdev = -1;
 185
 186     attr_path = local_mapped_attr_path(ctx, path);
 187     fp = local_fopen(attr_path, "r");
 188     if (!fp) {
 189         goto create_map_file;
 190     }
 191     memset(buf, 0, ATTR_MAX);
 192     while (fgets(buf, ATTR_MAX, fp)) {
 193         if (!strncmp(buf, "virtfs.uid", 10)) {
 194             uid = atoi(buf+11);
 195         } else if (!strncmp(buf, "virtfs.gid", 10)) {
 196             gid = atoi(buf+11);
 197         } else if (!strncmp(buf, "virtfs.mode", 11)) {
 198             mode = atoi(buf+12);
 199         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
 200             rdev = atoi(buf+12);
 201         }
 202         memset(buf, 0, ATTR_MAX);
 203     }
 204     fclose(fp);
 205     goto update_map_file;
 206
 207 create_map_file:
 208     ret = local_create_mapped_attr_dir(ctx, path);
 209     if (ret < 0) {
 210         goto err_out;
 211     }
 212
 213 update_map_file:
 214     fp = local_fopen(attr_path, "w");
 215     if (!fp) {
 216         ret = -1;
 217         goto err_out;
 218     }
 219
 220     if (credp->fc_uid != -1) {
 221         uid = credp->fc_uid;
 222     }
 223     if (credp->fc_gid != -1) {
 224         gid = credp->fc_gid;
 225     }
 226     if (credp->fc_mode != -1) {
 227         mode = credp->fc_mode;
 228     }
 229     if (credp->fc_rdev != -1) {
 230         rdev = credp->fc_rdev;
 231     }
 232
 233
 234     if (uid != -1) {
 235         fprintf(fp, "virtfs.uid=%d\n", uid);
 236     }
 237     if (gid != -1) {
 238         fprintf(fp, "virtfs.gid=%d\n", gid);
 239     }
 240     if (mode != -1) {
 241         fprintf(fp, "virtfs.mode=%d\n", mode);
 242     }
 243     if (rdev != -1) {
 244         fprintf(fp, "virtfs.rdev=%d\n", rdev);
 245     }
 246     fclose(fp);
 247
 248 err_out:
 249     g_free(attr_path);
 250     return ret;
 251 }
 252
 253 static int local_set_xattr(const char *path, FsCred *credp)
 254 {
 255     int err;
 256
 257     if (credp->fc_uid != -1) {
 258         uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);
 259         err = setxattr(path, "user.virtfs.uid", &tmp_uid, sizeof(uid_t), 0);
 260         if (err) {
 261             return err;
 262         }
 263     }
 264     if (credp->fc_gid != -1) {
 265         uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);
 266         err = setxattr(path, "user.virtfs.gid", &tmp_gid, sizeof(gid_t), 0);
 267         if (err) {
 268             return err;
 269         }
 270     }
 271     if (credp->fc_mode != -1) {
 272         uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);
 273         err = setxattr(path, "user.virtfs.mode", &tmp_mode, sizeof(mode_t), 0);
 274         if (err) {
 275             return err;
 276         }
 277     }
 278     if (credp->fc_rdev != -1) {
 279         uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);
 280         err = setxattr(path, "user.virtfs.rdev", &tmp_rdev, sizeof(dev_t), 0);
 281         if (err) {
 282             return err;
 283         }
 284     }
 285     return 0;
 286 }
 287
 288 static int local_post_create_passthrough(FsContext *fs_ctx, const char *path,
 289                                          FsCred *credp)
 290 {
 291     char *buffer;
 292
 293     buffer = rpath(fs_ctx, path);
 294     if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) {
 295         /*
 296          * If we fail to change ownership and if we are
 297          * using security model none. Ignore the error
 298          */
 299         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
 300             goto err;
 301         }
 302     }
 303
 304     if (chmod(buffer, credp->fc_mode & 07777) < 0) {
 305         goto err;
 306     }
 307
 308     g_free(buffer);
 309     return 0;
 310 err:
 311     g_free(buffer);
 312     return -1;
 313 }
 314
 315 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
 316                               char *buf, size_t bufsz)
 317 {
 318     ssize_t tsize = -1;
 319     char *buffer;
 320     char *path = fs_path->data;
 321
 322     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
 323         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
 324         int fd;
 325         buffer = rpath(fs_ctx, path);
 326         fd = open(buffer, O_RDONLY | O_NOFOLLOW);
 327         g_free(buffer);
 328         if (fd == -1) {
 329             return -1;
 330         }
 331         do {
 332             tsize = read(fd, (void *)buf, bufsz);
 333         } while (tsize == -1 && errno == EINTR);
 334         close(fd);
 335     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 336                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 337         buffer = rpath(fs_ctx, path);
 338         tsize = readlink(buffer, buf, bufsz);
 339         g_free(buffer);
 340     }
 341     return tsize;
 342 }
 343
 344 static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
 345 {
 346     return close(fs->fd);
 347 }
 348
 349 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 350 {
 351     return closedir(fs->dir);
 352 }
 353
 354 static int local_open(FsContext *ctx, V9fsPath *fs_path,
 355                       int flags, V9fsFidOpenState *fs)
 356 {
 357     char *buffer;
 358     char *path = fs_path->data;
 359
 360     buffer = rpath(ctx, path);
 361     fs->fd = open(buffer, flags | O_NOFOLLOW);
 362     g_free(buffer);
 363     return fs->fd;
 364 }
 365
 366 static int local_opendir(FsContext *ctx,
 367                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 368 {
 369     char *buffer;
 370     char *path = fs_path->data;
 371
 372     buffer = rpath(ctx, path);
 373     fs->dir = opendir(buffer);
 374     g_free(buffer);
 375     if (!fs->dir) {
 376         return -1;
 377     }
 378     return 0;
 379 }
 380
 381 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
 382 {
 383     rewinddir(fs->dir);
 384 }
 385
 386 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
 387 {
 388     return telldir(fs->dir);
 389 }
 390
 391 static int local_readdir_r(FsContext *ctx, V9fsFidOpenState *fs,
 392                            struct dirent *entry,
 393                            struct dirent **result)
 394 {
 395     int ret;
 396
 397 again:
 398     ret = readdir_r(fs->dir, entry, result);
 399     if (ctx->export_flags & V9FS_SM_MAPPED) {
 400         entry->d_type = DT_UNKNOWN;
 401     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 402         if (!ret && *result != NULL &&
 403             !strcmp(entry->d_name, VIRTFS_META_DIR)) {
 404             /* skp the meta data directory */
 405             goto again;
 406         }
 407         entry->d_type = DT_UNKNOWN;
 408     }
 409     return ret;
 410 }
 411
 412 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
 413 {
 414     seekdir(fs->dir, off);
 415 }
 416
 417 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
 418                             const struct iovec *iov,
 419                             int iovcnt, off_t offset)
 420 {
 421 #ifdef CONFIG_PREADV
 422     return preadv(fs->fd, iov, iovcnt, offset);
 423 #else
 424     int err = lseek(fs->fd, offset, SEEK_SET);
 425     if (err == -1) {
 426         return err;
 427     } else {
 428         return readv(fs->fd, iov, iovcnt);
 429     }
 430 #endif
 431 }
 432
 433 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 434                              const struct iovec *iov,
 435                              int iovcnt, off_t offset)
 436 {
 437     ssize_t ret
 438 ;
 439 #ifdef CONFIG_PREADV
 440     ret = pwritev(fs->fd, iov, iovcnt, offset);
 441 #else
 442     int err = lseek(fs->fd, offset, SEEK_SET);
 443     if (err == -1) {
 444         return err;
 445     } else {
 446         ret = writev(fs->fd, iov, iovcnt);
 447     }
 448 #endif
 449 #ifdef CONFIG_SYNC_FILE_RANGE
 450     if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
 451         /*
 452          * Initiate a writeback. This is not a data integrity sync.
 453          * We want to ensure that we don't leave dirty pages in the cache
 454          * after write when writeout=immediate is sepcified.
 455          */
 456         sync_file_range(fs->fd, offset, ret,
 457                         SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
 458     }
 459 #endif
 460     return ret;
 461 }
 462
 463 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 464 {
 465     char *buffer;
 466     int ret = -1;
 467     char *path = fs_path->data;
 468
 469     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 470         buffer = rpath(fs_ctx, path);
 471         ret = local_set_xattr(buffer, credp);
 472         g_free(buffer);
 473     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 474         return local_set_mapped_file_attr(fs_ctx, path, credp);
 475     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 476                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 477         buffer = rpath(fs_ctx, path);
 478         ret = chmod(buffer, credp->fc_mode);
 479         g_free(buffer);
 480     }
 481     return ret;
 482 }
 483
 484 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
 485                        const char *name, FsCred *credp)
 486 {
 487     char *path;
 488     int err = -1;
 489     int serrno = 0;
 490     V9fsString fullname;
 491     char *buffer = NULL;
 492
 493     v9fs_string_init(&fullname);
 494     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 495     path = fullname.data;
 496
 497     /* Determine the security model */
 498     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 499         buffer = rpath(fs_ctx, path);
 500         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
 501         if (err == -1) {
 502             goto out;
 503         }
 504         err = local_set_xattr(buffer, credp);
 505         if (err == -1) {
 506             serrno = errno;
 507             goto err_end;
 508         }
 509     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 510
 511         buffer = rpath(fs_ctx, path);
 512         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
 513         if (err == -1) {
 514             goto out;
 515         }
 516         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 517         if (err == -1) {
 518             serrno = errno;
 519             goto err_end;
 520         }
 521     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 522                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 523         buffer = rpath(fs_ctx, path);
 524         err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
 525         if (err == -1) {
 526             goto out;
 527         }
 528         err = local_post_create_passthrough(fs_ctx, path, credp);
 529         if (err == -1) {
 530             serrno = errno;
 531             goto err_end;
 532         }
 533     }
 534     goto out;
 535
 536 err_end:
 537     remove(buffer);
 538     errno = serrno;
 539 out:
 540     g_free(buffer);
 541     v9fs_string_free(&fullname);
 542     return err;
 543 }
 544
 545 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 546                        const char *name, FsCred *credp)
 547 {
 548     char *path;
 549     int err = -1;
 550     int serrno = 0;
 551     V9fsString fullname;
 552     char *buffer = NULL;
 553
 554     v9fs_string_init(&fullname);
 555     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 556     path = fullname.data;
 557
 558     /* Determine the security model */
 559     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 560         buffer = rpath(fs_ctx, path);
 561         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 562         if (err == -1) {
 563             goto out;
 564         }
 565         credp->fc_mode = credp->fc_mode|S_IFDIR;
 566         err = local_set_xattr(buffer, credp);
 567         if (err == -1) {
 568             serrno = errno;
 569             goto err_end;
 570         }
 571     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 572         buffer = rpath(fs_ctx, path);
 573         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 574         if (err == -1) {
 575             goto out;
 576         }
 577         credp->fc_mode = credp->fc_mode|S_IFDIR;
 578         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 579         if (err == -1) {
 580             serrno = errno;
 581             goto err_end;
 582         }
 583     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 584                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 585         buffer = rpath(fs_ctx, path);
 586         err = mkdir(buffer, credp->fc_mode);
 587         if (err == -1) {
 588             goto out;
 589         }
 590         err = local_post_create_passthrough(fs_ctx, path, credp);
 591         if (err == -1) {
 592             serrno = errno;
 593             goto err_end;
 594         }
 595     }
 596     goto out;
 597
 598 err_end:
 599     remove(buffer);
 600     errno = serrno;
 601 out:
 602     g_free(buffer);
 603     v9fs_string_free(&fullname);
 604     return err;
 605 }
 606
 607 static int local_fstat(FsContext *fs_ctx, int fid_type,
 608                        V9fsFidOpenState *fs, struct stat *stbuf)
 609 {
 610     int err, fd;
 611
 612     if (fid_type == P9_FID_DIR) {
 613         fd = dirfd(fs->dir);
 614     } else {
 615         fd = fs->fd;
 616     }
 617
 618     err = fstat(fd, stbuf);
 619     if (err) {
 620         return err;
 621     }
 622     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 623         /* Actual credentials are part of extended attrs */
 624         uid_t tmp_uid;
 625         gid_t tmp_gid;
 626         mode_t tmp_mode;
 627         dev_t tmp_dev;
 628
 629         if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
 630             stbuf->st_uid = le32_to_cpu(tmp_uid);
 631         }
 632         if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
 633             stbuf->st_gid = le32_to_cpu(tmp_gid);
 634         }
 635         if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
 636             stbuf->st_mode = le32_to_cpu(tmp_mode);
 637         }
 638         if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
 639             stbuf->st_rdev = le64_to_cpu(tmp_dev);
 640         }
 641     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 642         errno = EOPNOTSUPP;
 643         return -1;
 644     }
 645     return err;
 646 }
 647
 648 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 649                        int flags, FsCred *credp, V9fsFidOpenState *fs)
 650 {
 651     char *path;
 652     int fd = -1;
 653     int err = -1;
 654     int serrno = 0;
 655     V9fsString fullname;
 656     char *buffer = NULL;
 657
 658     /*
 659      * Mark all the open to not follow symlinks
 660      */
 661     flags |= O_NOFOLLOW;
 662
 663     v9fs_string_init(&fullname);
 664     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 665     path = fullname.data;
 666
 667     /* Determine the security model */
 668     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 669         buffer = rpath(fs_ctx, path);
 670         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 671         if (fd == -1) {
 672             err = fd;
 673             goto out;
 674         }
 675         credp->fc_mode = credp->fc_mode|S_IFREG;
 676         /* Set cleint credentials in xattr */
 677         err = local_set_xattr(buffer, credp);
 678         if (err == -1) {
 679             serrno = errno;
 680             goto err_end;
 681         }
 682     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 683         buffer = rpath(fs_ctx, path);
 684         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 685         if (fd == -1) {
 686             err = fd;
 687             goto out;
 688         }
 689         credp->fc_mode = credp->fc_mode|S_IFREG;
 690         /* Set client credentials in .virtfs_metadata directory files */
 691         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 692         if (err == -1) {
 693             serrno = errno;
 694             goto err_end;
 695         }
 696     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 697                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 698         buffer = rpath(fs_ctx, path);
 699         fd = open(buffer, flags, credp->fc_mode);
 700         if (fd == -1) {
 701             err = fd;
 702             goto out;
 703         }
 704         err = local_post_create_passthrough(fs_ctx, path, credp);
 705         if (err == -1) {
 706             serrno = errno;
 707             goto err_end;
 708         }
 709     }
 710     err = fd;
 711     fs->fd = fd;
 712     goto out;
 713
 714 err_end:
 715     close(fd);
 716     remove(buffer);
 717     errno = serrno;
 718 out:
 719     g_free(buffer);
 720     v9fs_string_free(&fullname);
 721     return err;
 722 }
 723
 724
 725 static int local_symlink(FsContext *fs_ctx, const char *oldpath,
 726                          V9fsPath *dir_path, const char *name, FsCred *credp)
 727 {
 728     int err = -1;
 729     int serrno = 0;
 730     char *newpath;
 731     V9fsString fullname;
 732     char *buffer = NULL;
 733
 734     v9fs_string_init(&fullname);
 735     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 736     newpath = fullname.data;
 737
 738     /* Determine the security model */
 739     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 740         int fd;
 741         ssize_t oldpath_size, write_size;
 742         buffer = rpath(fs_ctx, newpath);
 743         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 744         if (fd == -1) {
 745             err = fd;
 746             goto out;
 747         }
 748         /* Write the oldpath (target) to the file. */
 749         oldpath_size = strlen(oldpath);
 750         do {
 751             write_size = write(fd, (void *)oldpath, oldpath_size);
 752         } while (write_size == -1 && errno == EINTR);
 753
 754         if (write_size != oldpath_size) {
 755             serrno = errno;
 756             close(fd);
 757             err = -1;
 758             goto err_end;
 759         }
 760         close(fd);
 761         /* Set cleint credentials in symlink's xattr */
 762         credp->fc_mode = credp->fc_mode|S_IFLNK;
 763         err = local_set_xattr(buffer, credp);
 764         if (err == -1) {
 765             serrno = errno;
 766             goto err_end;
 767         }
 768     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 769         int fd;
 770         ssize_t oldpath_size, write_size;
 771         buffer = rpath(fs_ctx, newpath);
 772         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 773         if (fd == -1) {
 774             err = fd;
 775             goto out;
 776         }
 777         /* Write the oldpath (target) to the file. */
 778         oldpath_size = strlen(oldpath);
 779         do {
 780             write_size = write(fd, (void *)oldpath, oldpath_size);
 781         } while (write_size == -1 && errno == EINTR);
 782
 783         if (write_size != oldpath_size) {
 784             serrno = errno;
 785             close(fd);
 786             err = -1;
 787             goto err_end;
 788         }
 789         close(fd);
 790         /* Set cleint credentials in symlink's xattr */
 791         credp->fc_mode = credp->fc_mode|S_IFLNK;
 792         err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
 793         if (err == -1) {
 794             serrno = errno;
 795             goto err_end;
 796         }
 797     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 798                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 799         buffer = rpath(fs_ctx, newpath);
 800         err = symlink(oldpath, buffer);
 801         if (err) {
 802             goto out;
 803         }
 804         err = lchown(buffer, credp->fc_uid, credp->fc_gid);
 805         if (err == -1) {
 806             /*
 807              * If we fail to change ownership and if we are
 808              * using security model none. Ignore the error
 809              */
 810             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
 811                 serrno = errno;
 812                 goto err_end;
 813             } else
 814                 err = 0;
 815         }
 816     }
 817     goto out;
 818
 819 err_end:
 820     remove(buffer);
 821     errno = serrno;
 822 out:
 823     g_free(buffer);
 824     v9fs_string_free(&fullname);
 825     return err;
 826 }
 827
 828 static int local_link(FsContext *ctx, V9fsPath *oldpath,
 829                       V9fsPath *dirpath, const char *name)
 830 {
 831     int ret;
 832     V9fsString newpath;
 833     char *buffer, *buffer1;
 834
 835     v9fs_string_init(&newpath);
 836     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 837
 838     buffer = rpath(ctx, oldpath->data);
 839     buffer1 = rpath(ctx, newpath.data);
 840     ret = link(buffer, buffer1);
 841     g_free(buffer);
 842     g_free(buffer1);
 843
 844     /* now link the virtfs_metadata files */
 845     if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
 846         /* Link the .virtfs_metadata files. Create the metada directory */
 847         ret = local_create_mapped_attr_dir(ctx, newpath.data);
 848         if (ret < 0) {
 849             goto err_out;
 850         }
 851         buffer = local_mapped_attr_path(ctx, oldpath->data);
 852         buffer1 = local_mapped_attr_path(ctx, newpath.data);
 853         ret = link(buffer, buffer1);
 854         g_free(buffer);
 855         g_free(buffer1);
 856         if (ret < 0 && errno != ENOENT) {
 857             goto err_out;
 858         }
 859     }
 860 err_out:
 861     v9fs_string_free(&newpath);
 862     return ret;
 863 }
 864
 865 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 866 {
 867     char *buffer;
 868     int ret;
 869     char *path = fs_path->data;
 870
 871     buffer = rpath(ctx, path);
 872     ret = truncate(buffer, size);
 873     g_free(buffer);
 874     return ret;
 875 }
 876
 877 static int local_rename(FsContext *ctx, const char *oldpath,
 878                         const char *newpath)
 879 {
 880     int err;
 881     char *buffer, *buffer1;
 882
 883     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 884         err = local_create_mapped_attr_dir(ctx, newpath);
 885         if (err < 0) {
 886             return err;
 887         }
 888         /* rename the .virtfs_metadata files */
 889         buffer = local_mapped_attr_path(ctx, oldpath);
 890         buffer1 = local_mapped_attr_path(ctx, newpath);
 891         err = rename(buffer, buffer1);
 892         g_free(buffer);
 893         g_free(buffer1);
 894         if (err < 0 && errno != ENOENT) {
 895             return err;
 896         }
 897     }
 898
 899     buffer = rpath(ctx, oldpath);
 900     buffer1 = rpath(ctx, newpath);
 901     err = rename(buffer, buffer1);
 902     g_free(buffer);
 903     g_free(buffer1);
 904     return err;
 905 }
 906
 907 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 908 {
 909     char *buffer;
 910     int ret = -1;
 911     char *path = fs_path->data;
 912
 913     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
 914         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 915         (fs_ctx->export_flags & V9FS_SM_NONE)) {
 916         buffer = rpath(fs_ctx, path);
 917         ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
 918         g_free(buffer);
 919     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 920         buffer = rpath(fs_ctx, path);
 921         ret = local_set_xattr(buffer, credp);
 922         g_free(buffer);
 923     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 924         return local_set_mapped_file_attr(fs_ctx, path, credp);
 925     }
 926     return ret;
 927 }
 928
 929 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
 930                            const struct timespec *buf)
 931 {
 932     char *buffer;
 933     int ret;
 934     char *path = fs_path->data;
 935
 936     buffer = rpath(s, path);
 937     ret = qemu_utimens(buffer, buf);
 938     g_free(buffer);
 939     return ret;
 940 }
 941
 942 static int local_remove(FsContext *ctx, const char *path)
 943 {
 944     int err;
 945     struct stat stbuf;
 946     char *buffer;
 947
 948     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 949         buffer = rpath(ctx, path);
 950         err =  lstat(buffer, &stbuf);
 951         g_free(buffer);
 952         if (err) {
 953             goto err_out;
 954         }
 955         /*
 956          * If directory remove .virtfs_metadata contained in the
 957          * directory
 958          */
 959         if (S_ISDIR(stbuf.st_mode)) {
 960             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
 961                                      path, VIRTFS_META_DIR);
 962             err = remove(buffer);
 963             g_free(buffer);
 964             if (err < 0 && errno != ENOENT) {
 965                 /*
 966                  * We didn't had the .virtfs_metadata file. May be file created
 967                  * in non-mapped mode ?. Ignore ENOENT.
 968                  */
 969                 goto err_out;
 970             }
 971         }
 972         /*
 973          * Now remove the name from parent directory
 974          * .virtfs_metadata directory
 975          */
 976         buffer = local_mapped_attr_path(ctx, path);
 977         err = remove(buffer);
 978         g_free(buffer);
 979         if (err < 0 && errno != ENOENT) {
 980             /*
 981              * We didn't had the .virtfs_metadata file. May be file created
 982              * in non-mapped mode ?. Ignore ENOENT.
 983              */
 984             goto err_out;
 985         }
 986     }
 987
 988     buffer = rpath(ctx, path);
 989     err = remove(buffer);
 990     g_free(buffer);
 991 err_out:
 992     return err;
 993 }
 994
 995 static int local_fsync(FsContext *ctx, int fid_type,
 996                        V9fsFidOpenState *fs, int datasync)
 997 {
 998     int fd;
 999
1000     if (fid_type == P9_FID_DIR) {
1001         fd = dirfd(fs->dir);
1002     } else {
1003         fd = fs->fd;
1004     }
1005
1006     if (datasync) {
1007         return qemu_fdatasync(fd);
1008     } else {
1009         return fsync(fd);
1010     }
1011 }
1012
1013 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
1014 {
1015     char *buffer;
1016     int ret;
1017     char *path = fs_path->data;
1018
1019     buffer = rpath(s, path);
1020     ret = statfs(buffer, stbuf);
1021     g_free(buffer);
1022     return ret;
1023 }
1024
1025 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
1026                                const char *name, void *value, size_t size)
1027 {
1028     char *path = fs_path->data;
1029
1030     return v9fs_get_xattr(ctx, path, name, value, size);
1031 }
1032
1033 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
1034                                 void *value, size_t size)
1035 {
1036     char *path = fs_path->data;
1037
1038     return v9fs_list_xattr(ctx, path, value, size);
1039 }
1040
1041 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
1042                            void *value, size_t size, int flags)
1043 {
1044     char *path = fs_path->data;
1045
1046     return v9fs_set_xattr(ctx, path, name, value, size, flags);
1047 }
1048
1049 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
1050                               const char *name)
1051 {
1052     char *path = fs_path->data;
1053
1054     return v9fs_remove_xattr(ctx, path, name);
1055 }
1056
1057 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
1058                               const char *name, V9fsPath *target)
1059 {
1060     if (dir_path) {
1061         v9fs_string_sprintf((V9fsString *)target, "%s/%s",
1062                             dir_path->data, name);
1063     } else {
1064         v9fs_string_sprintf((V9fsString *)target, "%s", name);
1065     }
1066     /* Bump the size for including terminating NULL */
1067     target->size++;
1068     return 0;
1069 }
1070
1071 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
1072                           const char *old_name, V9fsPath *newdir,
1073                           const char *new_name)
1074 {
1075     int ret;
1076     V9fsString old_full_name, new_full_name;
1077
1078     v9fs_string_init(&old_full_name);
1079     v9fs_string_init(&new_full_name);
1080
1081     v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
1082     v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
1083
1084     ret = local_rename(ctx, old_full_name.data, new_full_name.data);
1085     v9fs_string_free(&old_full_name);
1086     v9fs_string_free(&new_full_name);
1087     return ret;
1088 }
1089
1090 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
1091                           const char *name, int flags)
1092 {
1093     int ret;
1094     V9fsString fullname;
1095     char *buffer;
1096
1097     v9fs_string_init(&fullname);
1098
1099     v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
1100     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1101         if (flags == AT_REMOVEDIR) {
1102             /*
1103              * If directory remove .virtfs_metadata contained in the
1104              * directory
1105              */
1106             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
1107                                      fullname.data, VIRTFS_META_DIR);
1108             ret = remove(buffer);
1109             g_free(buffer);
1110             if (ret < 0 && errno != ENOENT) {
1111                 /*
1112                  * We didn't had the .virtfs_metadata file. May be file created
1113                  * in non-mapped mode ?. Ignore ENOENT.
1114                  */
1115                 goto err_out;
1116             }
1117         }
1118         /*
1119          * Now remove the name from parent directory
1120          * .virtfs_metadata directory.
1121          */
1122         buffer = local_mapped_attr_path(ctx, fullname.data);
1123         ret = remove(buffer);
1124         g_free(buffer);
1125         if (ret < 0 && errno != ENOENT) {
1126             /*
1127              * We didn't had the .virtfs_metadata file. May be file created
1128              * in non-mapped mode ?. Ignore ENOENT.
1129              */
1130             goto err_out;
1131         }
1132     }
1133     /* Remove the name finally */
1134     buffer = rpath(ctx, fullname.data);
1135     ret = remove(buffer);
1136     g_free(buffer);
1137
1138 err_out:
1139     v9fs_string_free(&fullname);
1140     return ret;
1141 }
1142
1143 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1144                                 mode_t st_mode, uint64_t *st_gen)
1145 {
1146 #ifdef FS_IOC_GETVERSION
1147     int err;
1148     V9fsFidOpenState fid_open;
1149
1150     /*
1151      * Do not try to open special files like device nodes, fifos etc
1152      * We can get fd for regular files and directories only
1153      */
1154     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1155         errno = ENOTTY;
1156         return -1;
1157     }
1158     err = local_open(ctx, path, O_RDONLY, &fid_open);
1159     if (err < 0) {
1160         return err;
1161     }
1162     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1163     local_close(ctx, &fid_open);
1164     return err;
1165 #else
1166     errno = ENOTTY;
1167     return -1;
1168 #endif
1169 }
1170
1171 static int local_init(FsContext *ctx)
1172 {
1173     int err = 0;
1174     struct statfs stbuf;
1175
1176     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1177         ctx->xops = passthrough_xattr_ops;
1178     } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1179         ctx->xops = mapped_xattr_ops;
1180     } else if (ctx->export_flags & V9FS_SM_NONE) {
1181         ctx->xops = none_xattr_ops;
1182     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1183         /*
1184          * xattr operation for mapped-file and passthrough
1185          * remain same.
1186          */
1187         ctx->xops = passthrough_xattr_ops;
1188     }
1189     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1190 #ifdef FS_IOC_GETVERSION
1191     /*
1192      * use ioc_getversion only if the iocl is definied
1193      */
1194     err = statfs(ctx->fs_root, &stbuf);
1195     if (!err) {
1196         switch (stbuf.f_type) {
1197         case EXT2_SUPER_MAGIC:
1198         case BTRFS_SUPER_MAGIC:
1199         case REISERFS_SUPER_MAGIC:
1200         case XFS_SUPER_MAGIC:
1201             ctx->exops.get_st_gen = local_ioc_getversion;
1202             break;
1203         }
1204     }
1205 #endif
1206     return err;
1207 }
1208
1209 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
1210 {
1211     const char *sec_model = qemu_opt_get(opts, "security_model");
1212     const char *path = qemu_opt_get(opts, "path");
1213
1214     if (!sec_model) {
1215         error_report("Security model not specified, local fs needs security model");
1216         error_printf("valid options are:"
1217                      "\tsecurity_model=[passthrough|mapped-xattr|mapped-file|none]\n");
1218         return -1;
1219     }
1220
1221     if (!strcmp(sec_model, "passthrough")) {
1222         fse->export_flags |= V9FS_SM_PASSTHROUGH;
1223     } else if (!strcmp(sec_model, "mapped") ||
1224                !strcmp(sec_model, "mapped-xattr")) {
1225         fse->export_flags |= V9FS_SM_MAPPED;
1226     } else if (!strcmp(sec_model, "none")) {
1227         fse->export_flags |= V9FS_SM_NONE;
1228     } else if (!strcmp(sec_model, "mapped-file")) {
1229         fse->export_flags |= V9FS_SM_MAPPED_FILE;
1230     } else {
1231         error_report("Invalid security model %s specified", sec_model);
1232         error_printf("valid options are:"
1233                      "\t[passthrough|mapped-xattr|mapped-file|none]\n");
1234         return -1;
1235     }
1236
1237     if (!path) {
1238         error_report("fsdev: No path specified");
1239         return -1;
1240     }
1241     fse->path = g_strdup(path);
1242
1243     return 0;
1244 }
1245
1246 FileOperations local_ops = {
1247     .parse_opts = local_parse_opts,
1248     .init  = local_init,
1249     .lstat = local_lstat,
1250     .readlink = local_readlink,
1251     .close = local_close,
1252     .closedir = local_closedir,
1253     .open = local_open,
1254     .opendir = local_opendir,
1255     .rewinddir = local_rewinddir,
1256     .telldir = local_telldir,
1257     .readdir_r = local_readdir_r,
1258     .seekdir = local_seekdir,
1259     .preadv = local_preadv,
1260     .pwritev = local_pwritev,
1261     .chmod = local_chmod,
1262     .mknod = local_mknod,
1263     .mkdir = local_mkdir,
1264     .fstat = local_fstat,
1265     .open2 = local_open2,
1266     .symlink = local_symlink,
1267     .link = local_link,
1268     .truncate = local_truncate,
1269     .rename = local_rename,
1270     .chown = local_chown,
1271     .utimensat = local_utimensat,
1272     .remove = local_remove,
1273     .fsync = local_fsync,
1274     .statfs = local_statfs,
1275     .lgetxattr = local_lgetxattr,
1276     .llistxattr = local_llistxattr,
1277     .lsetxattr = local_lsetxattr,
1278     .lremovexattr = local_lremovexattr,
1279     .name_to_path = local_name_to_path,
1280     .renameat  = local_renameat,
1281     .unlinkat = local_unlinkat,
1282 };