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