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.stream);
 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.stream = opendir(buffer);
 374     g_free(buffer);
 375     if (!fs->dir.stream) {
 376         return -1;
 377     }
 378     return 0;
 379 }
 380
 381 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
 382 {
 383     rewinddir(fs->dir.stream);
 384 }
 385
 386 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
 387 {
 388     return telldir(fs->dir.stream);
 389 }
 390
 391 static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs)
 392 {
 393     struct dirent *entry;
 394
 395 again:
 396     entry = readdir(fs->dir.stream);
 397     if (!entry) {
 398         return NULL;
 399     }
 400
 401     if (ctx->export_flags & V9FS_SM_MAPPED) {
 402         entry->d_type = DT_UNKNOWN;
 403     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 404         if (!strcmp(entry->d_name, VIRTFS_META_DIR)) {
 405             /* skp the meta data directory */
 406             goto again;
 407         }
 408         entry->d_type = DT_UNKNOWN;
 409     }
 410
 411     return entry;
 412 }
 413
 414 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
 415 {
 416     seekdir(fs->dir.stream, off);
 417 }
 418
 419 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
 420                             const struct iovec *iov,
 421                             int iovcnt, off_t offset)
 422 {
 423 #ifdef CONFIG_PREADV
 424     return preadv(fs->fd, iov, iovcnt, offset);
 425 #else
 426     int err = lseek(fs->fd, offset, SEEK_SET);
 427     if (err == -1) {
 428         return err;
 429     } else {
 430         return readv(fs->fd, iov, iovcnt);
 431     }
 432 #endif
 433 }
 434
 435 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 436                              const struct iovec *iov,
 437                              int iovcnt, off_t offset)
 438 {
 439     ssize_t ret;
 440 #ifdef CONFIG_PREADV
 441     ret = pwritev(fs->fd, iov, iovcnt, offset);
 442 #else
 443     int err = lseek(fs->fd, offset, SEEK_SET);
 444     if (err == -1) {
 445         return err;
 446     } else {
 447         ret = writev(fs->fd, iov, iovcnt);
 448     }
 449 #endif
 450 #ifdef CONFIG_SYNC_FILE_RANGE
 451     if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
 452         /*
 453          * Initiate a writeback. This is not a data integrity sync.
 454          * We want to ensure that we don't leave dirty pages in the cache
 455          * after write when writeout=immediate is sepcified.
 456          */
 457         sync_file_range(fs->fd, offset, ret,
 458                         SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
 459     }
 460 #endif
 461     return ret;
 462 }
 463
 464 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 465 {
 466     char *buffer;
 467     int ret = -1;
 468     char *path = fs_path->data;
 469
 470     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 471         buffer = rpath(fs_ctx, path);
 472         ret = local_set_xattr(buffer, credp);
 473         g_free(buffer);
 474     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 475         return local_set_mapped_file_attr(fs_ctx, path, credp);
 476     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 477                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 478         buffer = rpath(fs_ctx, path);
 479         ret = chmod(buffer, credp->fc_mode);
 480         g_free(buffer);
 481     }
 482     return ret;
 483 }
 484
 485 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
 486                        const char *name, FsCred *credp)
 487 {
 488     char *path;
 489     int err = -1;
 490     int serrno = 0;
 491     V9fsString fullname;
 492     char *buffer = NULL;
 493
 494     v9fs_string_init(&fullname);
 495     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 496     path = fullname.data;
 497
 498     /* Determine the security model */
 499     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 500         buffer = rpath(fs_ctx, path);
 501         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
 502         if (err == -1) {
 503             goto out;
 504         }
 505         err = local_set_xattr(buffer, credp);
 506         if (err == -1) {
 507             serrno = errno;
 508             goto err_end;
 509         }
 510     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 511
 512         buffer = rpath(fs_ctx, path);
 513         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
 514         if (err == -1) {
 515             goto out;
 516         }
 517         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 518         if (err == -1) {
 519             serrno = errno;
 520             goto err_end;
 521         }
 522     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 523                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 524         buffer = rpath(fs_ctx, path);
 525         err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
 526         if (err == -1) {
 527             goto out;
 528         }
 529         err = local_post_create_passthrough(fs_ctx, path, credp);
 530         if (err == -1) {
 531             serrno = errno;
 532             goto err_end;
 533         }
 534     }
 535     goto out;
 536
 537 err_end:
 538     remove(buffer);
 539     errno = serrno;
 540 out:
 541     g_free(buffer);
 542     v9fs_string_free(&fullname);
 543     return err;
 544 }
 545
 546 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 547                        const char *name, FsCred *credp)
 548 {
 549     char *path;
 550     int err = -1;
 551     int serrno = 0;
 552     V9fsString fullname;
 553     char *buffer = NULL;
 554
 555     v9fs_string_init(&fullname);
 556     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 557     path = fullname.data;
 558
 559     /* Determine the security model */
 560     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 561         buffer = rpath(fs_ctx, path);
 562         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 563         if (err == -1) {
 564             goto out;
 565         }
 566         credp->fc_mode = credp->fc_mode|S_IFDIR;
 567         err = local_set_xattr(buffer, credp);
 568         if (err == -1) {
 569             serrno = errno;
 570             goto err_end;
 571         }
 572     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 573         buffer = rpath(fs_ctx, path);
 574         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
 575         if (err == -1) {
 576             goto out;
 577         }
 578         credp->fc_mode = credp->fc_mode|S_IFDIR;
 579         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 580         if (err == -1) {
 581             serrno = errno;
 582             goto err_end;
 583         }
 584     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 585                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 586         buffer = rpath(fs_ctx, path);
 587         err = mkdir(buffer, credp->fc_mode);
 588         if (err == -1) {
 589             goto out;
 590         }
 591         err = local_post_create_passthrough(fs_ctx, path, credp);
 592         if (err == -1) {
 593             serrno = errno;
 594             goto err_end;
 595         }
 596     }
 597     goto out;
 598
 599 err_end:
 600     remove(buffer);
 601     errno = serrno;
 602 out:
 603     g_free(buffer);
 604     v9fs_string_free(&fullname);
 605     return err;
 606 }
 607
 608 static int local_fstat(FsContext *fs_ctx, int fid_type,
 609                        V9fsFidOpenState *fs, struct stat *stbuf)
 610 {
 611     int err, fd;
 612
 613     if (fid_type == P9_FID_DIR) {
 614         fd = dirfd(fs->dir.stream);
 615     } else {
 616         fd = fs->fd;
 617     }
 618
 619     err = fstat(fd, stbuf);
 620     if (err) {
 621         return err;
 622     }
 623     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 624         /* Actual credentials are part of extended attrs */
 625         uid_t tmp_uid;
 626         gid_t tmp_gid;
 627         mode_t tmp_mode;
 628         dev_t tmp_dev;
 629
 630         if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
 631             stbuf->st_uid = le32_to_cpu(tmp_uid);
 632         }
 633         if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
 634             stbuf->st_gid = le32_to_cpu(tmp_gid);
 635         }
 636         if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
 637             stbuf->st_mode = le32_to_cpu(tmp_mode);
 638         }
 639         if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
 640             stbuf->st_rdev = le64_to_cpu(tmp_dev);
 641         }
 642     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 643         errno = EOPNOTSUPP;
 644         return -1;
 645     }
 646     return err;
 647 }
 648
 649 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
 650                        int flags, FsCred *credp, V9fsFidOpenState *fs)
 651 {
 652     char *path;
 653     int fd = -1;
 654     int err = -1;
 655     int serrno = 0;
 656     V9fsString fullname;
 657     char *buffer = NULL;
 658
 659     /*
 660      * Mark all the open to not follow symlinks
 661      */
 662     flags |= O_NOFOLLOW;
 663
 664     v9fs_string_init(&fullname);
 665     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 666     path = fullname.data;
 667
 668     /* Determine the security model */
 669     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 670         buffer = rpath(fs_ctx, path);
 671         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 672         if (fd == -1) {
 673             err = fd;
 674             goto out;
 675         }
 676         credp->fc_mode = credp->fc_mode|S_IFREG;
 677         /* Set cleint credentials in xattr */
 678         err = local_set_xattr(buffer, credp);
 679         if (err == -1) {
 680             serrno = errno;
 681             goto err_end;
 682         }
 683     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 684         buffer = rpath(fs_ctx, path);
 685         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
 686         if (fd == -1) {
 687             err = fd;
 688             goto out;
 689         }
 690         credp->fc_mode = credp->fc_mode|S_IFREG;
 691         /* Set client credentials in .virtfs_metadata directory files */
 692         err = local_set_mapped_file_attr(fs_ctx, path, credp);
 693         if (err == -1) {
 694             serrno = errno;
 695             goto err_end;
 696         }
 697     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 698                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 699         buffer = rpath(fs_ctx, path);
 700         fd = open(buffer, flags, credp->fc_mode);
 701         if (fd == -1) {
 702             err = fd;
 703             goto out;
 704         }
 705         err = local_post_create_passthrough(fs_ctx, path, credp);
 706         if (err == -1) {
 707             serrno = errno;
 708             goto err_end;
 709         }
 710     }
 711     err = fd;
 712     fs->fd = fd;
 713     goto out;
 714
 715 err_end:
 716     close(fd);
 717     remove(buffer);
 718     errno = serrno;
 719 out:
 720     g_free(buffer);
 721     v9fs_string_free(&fullname);
 722     return err;
 723 }
 724
 725
 726 static int local_symlink(FsContext *fs_ctx, const char *oldpath,
 727                          V9fsPath *dir_path, const char *name, FsCred *credp)
 728 {
 729     int err = -1;
 730     int serrno = 0;
 731     char *newpath;
 732     V9fsString fullname;
 733     char *buffer = NULL;
 734
 735     v9fs_string_init(&fullname);
 736     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 737     newpath = fullname.data;
 738
 739     /* Determine the security model */
 740     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 741         int fd;
 742         ssize_t oldpath_size, write_size;
 743         buffer = rpath(fs_ctx, newpath);
 744         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 745         if (fd == -1) {
 746             err = fd;
 747             goto out;
 748         }
 749         /* Write the oldpath (target) to the file. */
 750         oldpath_size = strlen(oldpath);
 751         do {
 752             write_size = write(fd, (void *)oldpath, oldpath_size);
 753         } while (write_size == -1 && errno == EINTR);
 754
 755         if (write_size != oldpath_size) {
 756             serrno = errno;
 757             close(fd);
 758             err = -1;
 759             goto err_end;
 760         }
 761         close(fd);
 762         /* Set cleint credentials in symlink's xattr */
 763         credp->fc_mode = credp->fc_mode|S_IFLNK;
 764         err = local_set_xattr(buffer, credp);
 765         if (err == -1) {
 766             serrno = errno;
 767             goto err_end;
 768         }
 769     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 770         int fd;
 771         ssize_t oldpath_size, write_size;
 772         buffer = rpath(fs_ctx, newpath);
 773         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
 774         if (fd == -1) {
 775             err = fd;
 776             goto out;
 777         }
 778         /* Write the oldpath (target) to the file. */
 779         oldpath_size = strlen(oldpath);
 780         do {
 781             write_size = write(fd, (void *)oldpath, oldpath_size);
 782         } while (write_size == -1 && errno == EINTR);
 783
 784         if (write_size != oldpath_size) {
 785             serrno = errno;
 786             close(fd);
 787             err = -1;
 788             goto err_end;
 789         }
 790         close(fd);
 791         /* Set cleint credentials in symlink's xattr */
 792         credp->fc_mode = credp->fc_mode|S_IFLNK;
 793         err = local_set_mapped_file_attr(fs_ctx, newpath, credp);
 794         if (err == -1) {
 795             serrno = errno;
 796             goto err_end;
 797         }
 798     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 799                (fs_ctx->export_flags & V9FS_SM_NONE)) {
 800         buffer = rpath(fs_ctx, newpath);
 801         err = symlink(oldpath, buffer);
 802         if (err) {
 803             goto out;
 804         }
 805         err = lchown(buffer, credp->fc_uid, credp->fc_gid);
 806         if (err == -1) {
 807             /*
 808              * If we fail to change ownership and if we are
 809              * using security model none. Ignore the error
 810              */
 811             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
 812                 serrno = errno;
 813                 goto err_end;
 814             } else
 815                 err = 0;
 816         }
 817     }
 818     goto out;
 819
 820 err_end:
 821     remove(buffer);
 822     errno = serrno;
 823 out:
 824     g_free(buffer);
 825     v9fs_string_free(&fullname);
 826     return err;
 827 }
 828
 829 static int local_link(FsContext *ctx, V9fsPath *oldpath,
 830                       V9fsPath *dirpath, const char *name)
 831 {
 832     int ret;
 833     V9fsString newpath;
 834     char *buffer, *buffer1;
 835
 836     v9fs_string_init(&newpath);
 837     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 838
 839     buffer = rpath(ctx, oldpath->data);
 840     buffer1 = rpath(ctx, newpath.data);
 841     ret = link(buffer, buffer1);
 842     g_free(buffer);
 843     g_free(buffer1);
 844
 845     /* now link the virtfs_metadata files */
 846     if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
 847         /* Link the .virtfs_metadata files. Create the metada directory */
 848         ret = local_create_mapped_attr_dir(ctx, newpath.data);
 849         if (ret < 0) {
 850             goto err_out;
 851         }
 852         buffer = local_mapped_attr_path(ctx, oldpath->data);
 853         buffer1 = local_mapped_attr_path(ctx, newpath.data);
 854         ret = link(buffer, buffer1);
 855         g_free(buffer);
 856         g_free(buffer1);
 857         if (ret < 0 && errno != ENOENT) {
 858             goto err_out;
 859         }
 860     }
 861 err_out:
 862     v9fs_string_free(&newpath);
 863     return ret;
 864 }
 865
 866 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 867 {
 868     char *buffer;
 869     int ret;
 870     char *path = fs_path->data;
 871
 872     buffer = rpath(ctx, path);
 873     ret = truncate(buffer, size);
 874     g_free(buffer);
 875     return ret;
 876 }
 877
 878 static int local_rename(FsContext *ctx, const char *oldpath,
 879                         const char *newpath)
 880 {
 881     int err;
 882     char *buffer, *buffer1;
 883
 884     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 885         err = local_create_mapped_attr_dir(ctx, newpath);
 886         if (err < 0) {
 887             return err;
 888         }
 889         /* rename the .virtfs_metadata files */
 890         buffer = local_mapped_attr_path(ctx, oldpath);
 891         buffer1 = local_mapped_attr_path(ctx, newpath);
 892         err = rename(buffer, buffer1);
 893         g_free(buffer);
 894         g_free(buffer1);
 895         if (err < 0 && errno != ENOENT) {
 896             return err;
 897         }
 898     }
 899
 900     buffer = rpath(ctx, oldpath);
 901     buffer1 = rpath(ctx, newpath);
 902     err = rename(buffer, buffer1);
 903     g_free(buffer);
 904     g_free(buffer1);
 905     return err;
 906 }
 907
 908 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 909 {
 910     char *buffer;
 911     int ret = -1;
 912     char *path = fs_path->data;
 913
 914     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
 915         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
 916         (fs_ctx->export_flags & V9FS_SM_NONE)) {
 917         buffer = rpath(fs_ctx, path);
 918         ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
 919         g_free(buffer);
 920     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
 921         buffer = rpath(fs_ctx, path);
 922         ret = local_set_xattr(buffer, credp);
 923         g_free(buffer);
 924     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 925         return local_set_mapped_file_attr(fs_ctx, path, credp);
 926     }
 927     return ret;
 928 }
 929
 930 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
 931                            const struct timespec *buf)
 932 {
 933     char *buffer;
 934     int ret;
 935     char *path = fs_path->data;
 936
 937     buffer = rpath(s, path);
 938     ret = qemu_utimens(buffer, buf);
 939     g_free(buffer);
 940     return ret;
 941 }
 942
 943 static int local_remove(FsContext *ctx, const char *path)
 944 {
 945     int err;
 946     struct stat stbuf;
 947     char *buffer;
 948
 949     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
 950         buffer = rpath(ctx, path);
 951         err =  lstat(buffer, &stbuf);
 952         g_free(buffer);
 953         if (err) {
 954             goto err_out;
 955         }
 956         /*
 957          * If directory remove .virtfs_metadata contained in the
 958          * directory
 959          */
 960         if (S_ISDIR(stbuf.st_mode)) {
 961             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
 962                                      path, VIRTFS_META_DIR);
 963             err = remove(buffer);
 964             g_free(buffer);
 965             if (err < 0 && errno != ENOENT) {
 966                 /*
 967                  * We didn't had the .virtfs_metadata file. May be file created
 968                  * in non-mapped mode ?. Ignore ENOENT.
 969                  */
 970                 goto err_out;
 971             }
 972         }
 973         /*
 974          * Now remove the name from parent directory
 975          * .virtfs_metadata directory
 976          */
 977         buffer = local_mapped_attr_path(ctx, path);
 978         err = remove(buffer);
 979         g_free(buffer);
 980         if (err < 0 && errno != ENOENT) {
 981             /*
 982              * We didn't had the .virtfs_metadata file. May be file created
 983              * in non-mapped mode ?. Ignore ENOENT.
 984              */
 985             goto err_out;
 986         }
 987     }
 988
 989     buffer = rpath(ctx, path);
 990     err = remove(buffer);
 991     g_free(buffer);
 992 err_out:
 993     return err;
 994 }
 995
 996 static int local_fsync(FsContext *ctx, int fid_type,
 997                        V9fsFidOpenState *fs, int datasync)
 998 {
 999     int fd;
1000
1001     if (fid_type == P9_FID_DIR) {
1002         fd = dirfd(fs->dir.stream);
1003     } else {
1004         fd = fs->fd;
1005     }
1006
1007     if (datasync) {
1008         return qemu_fdatasync(fd);
1009     } else {
1010         return fsync(fd);
1011     }
1012 }
1013
1014 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
1015 {
1016     char *buffer;
1017     int ret;
1018     char *path = fs_path->data;
1019
1020     buffer = rpath(s, path);
1021     ret = statfs(buffer, stbuf);
1022     g_free(buffer);
1023     return ret;
1024 }
1025
1026 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
1027                                const char *name, void *value, size_t size)
1028 {
1029     char *path = fs_path->data;
1030
1031     return v9fs_get_xattr(ctx, path, name, value, size);
1032 }
1033
1034 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
1035                                 void *value, size_t size)
1036 {
1037     char *path = fs_path->data;
1038
1039     return v9fs_list_xattr(ctx, path, value, size);
1040 }
1041
1042 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
1043                            void *value, size_t size, int flags)
1044 {
1045     char *path = fs_path->data;
1046
1047     return v9fs_set_xattr(ctx, path, name, value, size, flags);
1048 }
1049
1050 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
1051                               const char *name)
1052 {
1053     char *path = fs_path->data;
1054
1055     return v9fs_remove_xattr(ctx, path, name);
1056 }
1057
1058 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
1059                               const char *name, V9fsPath *target)
1060 {
1061     if (dir_path) {
1062         v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
1063     } else {
1064         v9fs_path_sprintf(target, "%s", name);
1065     }
1066     return 0;
1067 }
1068
1069 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
1070                           const char *old_name, V9fsPath *newdir,
1071                           const char *new_name)
1072 {
1073     int ret;
1074     V9fsString old_full_name, new_full_name;
1075
1076     v9fs_string_init(&old_full_name);
1077     v9fs_string_init(&new_full_name);
1078
1079     v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name);
1080     v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name);
1081
1082     ret = local_rename(ctx, old_full_name.data, new_full_name.data);
1083     v9fs_string_free(&old_full_name);
1084     v9fs_string_free(&new_full_name);
1085     return ret;
1086 }
1087
1088 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
1089                           const char *name, int flags)
1090 {
1091     int ret;
1092     V9fsString fullname;
1093     char *buffer;
1094
1095     v9fs_string_init(&fullname);
1096
1097     v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name);
1098     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1099         if (flags == AT_REMOVEDIR) {
1100             /*
1101              * If directory remove .virtfs_metadata contained in the
1102              * directory
1103              */
1104             buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root,
1105                                      fullname.data, VIRTFS_META_DIR);
1106             ret = remove(buffer);
1107             g_free(buffer);
1108             if (ret < 0 && errno != ENOENT) {
1109                 /*
1110                  * We didn't had the .virtfs_metadata file. May be file created
1111                  * in non-mapped mode ?. Ignore ENOENT.
1112                  */
1113                 goto err_out;
1114             }
1115         }
1116         /*
1117          * Now remove the name from parent directory
1118          * .virtfs_metadata directory.
1119          */
1120         buffer = local_mapped_attr_path(ctx, fullname.data);
1121         ret = remove(buffer);
1122         g_free(buffer);
1123         if (ret < 0 && errno != ENOENT) {
1124             /*
1125              * We didn't had the .virtfs_metadata file. May be file created
1126              * in non-mapped mode ?. Ignore ENOENT.
1127              */
1128             goto err_out;
1129         }
1130     }
1131     /* Remove the name finally */
1132     buffer = rpath(ctx, fullname.data);
1133     ret = remove(buffer);
1134     g_free(buffer);
1135
1136 err_out:
1137     v9fs_string_free(&fullname);
1138     return ret;
1139 }
1140
1141 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1142                                 mode_t st_mode, uint64_t *st_gen)
1143 {
1144 #ifdef FS_IOC_GETVERSION
1145     int err;
1146     V9fsFidOpenState fid_open;
1147
1148     /*
1149      * Do not try to open special files like device nodes, fifos etc
1150      * We can get fd for regular files and directories only
1151      */
1152     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1153         errno = ENOTTY;
1154         return -1;
1155     }
1156     err = local_open(ctx, path, O_RDONLY, &fid_open);
1157     if (err < 0) {
1158         return err;
1159     }
1160     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1161     local_close(ctx, &fid_open);
1162     return err;
1163 #else
1164     errno = ENOTTY;
1165     return -1;
1166 #endif
1167 }
1168
1169 static int local_init(FsContext *ctx)
1170 {
1171     int err = 0;
1172     struct statfs stbuf;
1173
1174     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1175         ctx->xops = passthrough_xattr_ops;
1176     } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1177         ctx->xops = mapped_xattr_ops;
1178     } else if (ctx->export_flags & V9FS_SM_NONE) {
1179         ctx->xops = none_xattr_ops;
1180     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1181         /*
1182          * xattr operation for mapped-file and passthrough
1183          * remain same.
1184          */
1185         ctx->xops = passthrough_xattr_ops;
1186     }
1187     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1188 #ifdef FS_IOC_GETVERSION
1189     /*
1190      * use ioc_getversion only if the iocl is definied
1191      */
1192     err = statfs(ctx->fs_root, &stbuf);
1193     if (!err) {
1194         switch (stbuf.f_type) {
1195         case EXT2_SUPER_MAGIC:
1196         case BTRFS_SUPER_MAGIC:
1197         case REISERFS_SUPER_MAGIC:
1198         case XFS_SUPER_MAGIC:
1199             ctx->exops.get_st_gen = local_ioc_getversion;
1200             break;
1201         }
1202     }
1203 #endif
1204     return err;
1205 }
1206
1207 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
1208 {
1209     const char *sec_model = qemu_opt_get(opts, "security_model");
1210     const char *path = qemu_opt_get(opts, "path");
1211     Error *err = NULL;
1212
1213     if (!sec_model) {
1214         error_report("Security model not specified, local fs needs security model");
1215         error_printf("valid options are:"
1216                      "\tsecurity_model=[passthrough|mapped-xattr|mapped-file|none]\n");
1217         return -1;
1218     }
1219
1220     if (!strcmp(sec_model, "passthrough")) {
1221         fse->export_flags |= V9FS_SM_PASSTHROUGH;
1222     } else if (!strcmp(sec_model, "mapped") ||
1223                !strcmp(sec_model, "mapped-xattr")) {
1224         fse->export_flags |= V9FS_SM_MAPPED;
1225     } else if (!strcmp(sec_model, "none")) {
1226         fse->export_flags |= V9FS_SM_NONE;
1227     } else if (!strcmp(sec_model, "mapped-file")) {
1228         fse->export_flags |= V9FS_SM_MAPPED_FILE;
1229     } else {
1230         error_report("Invalid security model %s specified", sec_model);
1231         error_printf("valid options are:"
1232                      "\t[passthrough|mapped-xattr|mapped-file|none]\n");
1233         return -1;
1234     }
1235
1236     if (!path) {
1237         error_report("fsdev: No path specified");
1238         return -1;
1239     }
1240
1241     fsdev_throttle_parse_opts(opts, &fse->fst, &err);
1242     if (err) {
1243         error_reportf_err(err, "Throttle configuration is not valid: ");
1244         return -1;
1245     }
1246
1247     fse->path = g_strdup(path);
1248
1249     return 0;
1250 }
1251
1252 FileOperations local_ops = {
1253     .parse_opts = local_parse_opts,
1254     .init  = local_init,
1255     .lstat = local_lstat,
1256     .readlink = local_readlink,
1257     .close = local_close,
1258     .closedir = local_closedir,
1259     .open = local_open,
1260     .opendir = local_opendir,
1261     .rewinddir = local_rewinddir,
1262     .telldir = local_telldir,
1263     .readdir = local_readdir,
1264     .seekdir = local_seekdir,
1265     .preadv = local_preadv,
1266     .pwritev = local_pwritev,
1267     .chmod = local_chmod,
1268     .mknod = local_mknod,
1269     .mkdir = local_mkdir,
1270     .fstat = local_fstat,
1271     .open2 = local_open2,
1272     .symlink = local_symlink,
1273     .link = local_link,
1274     .truncate = local_truncate,
1275     .rename = local_rename,
1276     .chown = local_chown,
1277     .utimensat = local_utimensat,
1278     .remove = local_remove,
1279     .fsync = local_fsync,
1280     .statfs = local_statfs,
1281     .lgetxattr = local_lgetxattr,
1282     .llistxattr = local_llistxattr,
1283     .lsetxattr = local_lsetxattr,
1284     .lremovexattr = local_lremovexattr,
1285     .name_to_path = local_name_to_path,
1286     .renameat  = local_renameat,
1287     .unlinkat = local_unlinkat,
1288 };