xref: /openbmc/qemu/hw/9pfs/9p-local.c (revision d8e39b70)
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-local.h"
17 #include "9p-xattr.h"
18 #include "9p-util.h"
19 #include "fsdev/qemu-fsdev.h"   /* local_ops */
20 #include <arpa/inet.h>
21 #include <pwd.h>
22 #include <grp.h>
23 #include <sys/socket.h>
24 #include <sys/un.h>
25 #include "qemu/xattr.h"
26 #include "qemu/cutils.h"
27 #include "qemu/error-report.h"
28 #include <libgen.h>
29 #include <linux/fs.h>
30 #ifdef CONFIG_LINUX_MAGIC_H
31 #include <linux/magic.h>
32 #endif
33 #include <sys/ioctl.h>
34 
35 #ifndef XFS_SUPER_MAGIC
36 #define XFS_SUPER_MAGIC  0x58465342
37 #endif
38 #ifndef EXT2_SUPER_MAGIC
39 #define EXT2_SUPER_MAGIC 0xEF53
40 #endif
41 #ifndef REISERFS_SUPER_MAGIC
42 #define REISERFS_SUPER_MAGIC 0x52654973
43 #endif
44 #ifndef BTRFS_SUPER_MAGIC
45 #define BTRFS_SUPER_MAGIC 0x9123683E
46 #endif
47 
48 typedef struct {
49     int mountfd;
50 } LocalData;
51 
52 int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags,
53                         mode_t mode)
54 {
55     LocalData *data = fs_ctx->private;
56     int fd = data->mountfd;
57 
58     while (*path && fd != -1) {
59         const char *c;
60         int next_fd;
61         char *head;
62 
63         /* Only relative paths without consecutive slashes */
64         assert(*path != '/');
65 
66         head = g_strdup(path);
67         c = strchrnul(path, '/');
68         if (*c) {
69             /* Intermediate path element */
70             head[c - path] = 0;
71             path = c + 1;
72             next_fd = openat_dir(fd, head);
73         } else {
74             /* Rightmost path element */
75             next_fd = openat_file(fd, head, flags, mode);
76             path = c;
77         }
78         g_free(head);
79         if (fd != data->mountfd) {
80             close_preserve_errno(fd);
81         }
82         fd = next_fd;
83     }
84 
85     assert(fd != data->mountfd);
86     return fd;
87 }
88 
89 int local_opendir_nofollow(FsContext *fs_ctx, const char *path)
90 {
91     return local_open_nofollow(fs_ctx, path, O_DIRECTORY | O_RDONLY, 0);
92 }
93 
94 static void renameat_preserve_errno(int odirfd, const char *opath, int ndirfd,
95                                     const char *npath)
96 {
97     int serrno = errno;
98     renameat(odirfd, opath, ndirfd, npath);
99     errno = serrno;
100 }
101 
102 static void unlinkat_preserve_errno(int dirfd, const char *path, int flags)
103 {
104     int serrno = errno;
105     unlinkat(dirfd, path, flags);
106     errno = serrno;
107 }
108 
109 #define VIRTFS_META_DIR ".virtfs_metadata"
110 #define VIRTFS_META_ROOT_FILE VIRTFS_META_DIR "_root"
111 
112 static FILE *local_fopenat(int dirfd, const char *name, const char *mode)
113 {
114     int fd, o_mode = 0;
115     FILE *fp;
116     int flags;
117     /*
118      * only supports two modes
119      */
120     if (mode[0] == 'r') {
121         flags = O_RDONLY;
122     } else if (mode[0] == 'w') {
123         flags = O_WRONLY | O_TRUNC | O_CREAT;
124         o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
125     } else {
126         return NULL;
127     }
128     fd = openat_file(dirfd, name, flags, o_mode);
129     if (fd == -1) {
130         return NULL;
131     }
132     fp = fdopen(fd, mode);
133     if (!fp) {
134         close(fd);
135     }
136     return fp;
137 }
138 
139 #define ATTR_MAX 100
140 static void local_mapped_file_attr(int dirfd, const char *name,
141                                    struct stat *stbuf)
142 {
143     FILE *fp;
144     char buf[ATTR_MAX];
145     int map_dirfd;
146 
147     if (strcmp(name, ".")) {
148         map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
149         if (map_dirfd == -1) {
150             return;
151         }
152 
153         fp = local_fopenat(map_dirfd, name, "r");
154         close_preserve_errno(map_dirfd);
155     } else {
156         fp = local_fopenat(dirfd, VIRTFS_META_ROOT_FILE, "r");
157     }
158     if (!fp) {
159         return;
160     }
161     memset(buf, 0, ATTR_MAX);
162     while (fgets(buf, ATTR_MAX, fp)) {
163         if (!strncmp(buf, "virtfs.uid", 10)) {
164             stbuf->st_uid = atoi(buf+11);
165         } else if (!strncmp(buf, "virtfs.gid", 10)) {
166             stbuf->st_gid = atoi(buf+11);
167         } else if (!strncmp(buf, "virtfs.mode", 11)) {
168             stbuf->st_mode = atoi(buf+12);
169         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
170             stbuf->st_rdev = atoi(buf+12);
171         }
172         memset(buf, 0, ATTR_MAX);
173     }
174     fclose(fp);
175 }
176 
177 static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
178 {
179     int err = -1;
180     char *dirpath = g_path_get_dirname(fs_path->data);
181     char *name = g_path_get_basename(fs_path->data);
182     int dirfd;
183 
184     dirfd = local_opendir_nofollow(fs_ctx, dirpath);
185     if (dirfd == -1) {
186         goto out;
187     }
188 
189     err = fstatat(dirfd, name, stbuf, AT_SYMLINK_NOFOLLOW);
190     if (err) {
191         goto err_out;
192     }
193     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
194         /* Actual credentials are part of extended attrs */
195         uid_t tmp_uid;
196         gid_t tmp_gid;
197         mode_t tmp_mode;
198         dev_t tmp_dev;
199 
200         if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.uid", &tmp_uid,
201                                  sizeof(uid_t)) > 0) {
202             stbuf->st_uid = le32_to_cpu(tmp_uid);
203         }
204         if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.gid", &tmp_gid,
205                                  sizeof(gid_t)) > 0) {
206             stbuf->st_gid = le32_to_cpu(tmp_gid);
207         }
208         if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.mode", &tmp_mode,
209                                  sizeof(mode_t)) > 0) {
210             stbuf->st_mode = le32_to_cpu(tmp_mode);
211         }
212         if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.rdev", &tmp_dev,
213                                  sizeof(dev_t)) > 0) {
214             stbuf->st_rdev = le64_to_cpu(tmp_dev);
215         }
216     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
217         local_mapped_file_attr(dirfd, name, stbuf);
218     }
219 
220 err_out:
221     close_preserve_errno(dirfd);
222 out:
223     g_free(name);
224     g_free(dirpath);
225     return err;
226 }
227 
228 static int local_set_mapped_file_attrat(int dirfd, const char *name,
229                                         FsCred *credp)
230 {
231     FILE *fp;
232     int ret;
233     char buf[ATTR_MAX];
234     int uid = -1, gid = -1, mode = -1, rdev = -1;
235     int map_dirfd = -1, map_fd;
236     bool is_root = !strcmp(name, ".");
237 
238     if (is_root) {
239         fp = local_fopenat(dirfd, VIRTFS_META_ROOT_FILE, "r");
240         if (!fp) {
241             if (errno == ENOENT) {
242                 goto update_map_file;
243             } else {
244                 return -1;
245             }
246         }
247     } else {
248         ret = mkdirat(dirfd, VIRTFS_META_DIR, 0700);
249         if (ret < 0 && errno != EEXIST) {
250             return -1;
251         }
252 
253         map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
254         if (map_dirfd == -1) {
255             return -1;
256         }
257 
258         fp = local_fopenat(map_dirfd, name, "r");
259         if (!fp) {
260             if (errno == ENOENT) {
261                 goto update_map_file;
262             } else {
263                 close_preserve_errno(map_dirfd);
264                 return -1;
265             }
266         }
267     }
268     memset(buf, 0, ATTR_MAX);
269     while (fgets(buf, ATTR_MAX, fp)) {
270         if (!strncmp(buf, "virtfs.uid", 10)) {
271             uid = atoi(buf + 11);
272         } else if (!strncmp(buf, "virtfs.gid", 10)) {
273             gid = atoi(buf + 11);
274         } else if (!strncmp(buf, "virtfs.mode", 11)) {
275             mode = atoi(buf + 12);
276         } else if (!strncmp(buf, "virtfs.rdev", 11)) {
277             rdev = atoi(buf + 12);
278         }
279         memset(buf, 0, ATTR_MAX);
280     }
281     fclose(fp);
282 
283 update_map_file:
284     if (is_root) {
285         fp = local_fopenat(dirfd, VIRTFS_META_ROOT_FILE, "w");
286     } else {
287         fp = local_fopenat(map_dirfd, name, "w");
288         /* We can't go this far with map_dirfd not being a valid file descriptor
289          * but some versions of gcc aren't smart enough to see it.
290          */
291         if (map_dirfd != -1) {
292             close_preserve_errno(map_dirfd);
293         }
294     }
295     if (!fp) {
296         return -1;
297     }
298 
299     map_fd = fileno(fp);
300     assert(map_fd != -1);
301     ret = fchmod(map_fd, 0600);
302     assert(ret == 0);
303 
304     if (credp->fc_uid != -1) {
305         uid = credp->fc_uid;
306     }
307     if (credp->fc_gid != -1) {
308         gid = credp->fc_gid;
309     }
310     if (credp->fc_mode != -1) {
311         mode = credp->fc_mode;
312     }
313     if (credp->fc_rdev != -1) {
314         rdev = credp->fc_rdev;
315     }
316 
317     if (uid != -1) {
318         fprintf(fp, "virtfs.uid=%d\n", uid);
319     }
320     if (gid != -1) {
321         fprintf(fp, "virtfs.gid=%d\n", gid);
322     }
323     if (mode != -1) {
324         fprintf(fp, "virtfs.mode=%d\n", mode);
325     }
326     if (rdev != -1) {
327         fprintf(fp, "virtfs.rdev=%d\n", rdev);
328     }
329     fclose(fp);
330 
331     return 0;
332 }
333 
334 static int fchmodat_nofollow(int dirfd, const char *name, mode_t mode)
335 {
336     struct stat stbuf;
337     int fd, ret;
338 
339     /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW).
340      * Unfortunately, the linux kernel doesn't implement it yet.
341      */
342 
343      /* First, we clear non-racing symlinks out of the way. */
344     if (fstatat(dirfd, name, &stbuf, AT_SYMLINK_NOFOLLOW)) {
345         return -1;
346     }
347     if (S_ISLNK(stbuf.st_mode)) {
348         errno = ELOOP;
349         return -1;
350     }
351 
352     fd = openat_file(dirfd, name, O_RDONLY | O_PATH_9P_UTIL | O_NOFOLLOW, 0);
353 #if O_PATH_9P_UTIL == 0
354     /* Fallback for systems that don't support O_PATH: we depend on the file
355      * being readable or writable.
356      */
357     if (fd == -1) {
358         /* In case the file is writable-only and isn't a directory. */
359         if (errno == EACCES) {
360             fd = openat_file(dirfd, name, O_WRONLY, 0);
361         }
362         if (fd == -1 && errno == EISDIR) {
363             errno = EACCES;
364         }
365     }
366     if (fd == -1) {
367         return -1;
368     }
369     ret = fchmod(fd, mode);
370 #else
371     /* Access modes are ignored when O_PATH is supported. If name is a symbolic
372      * link, O_PATH | O_NOFOLLOW causes openat(2) to return a file descriptor
373      * referring to the symbolic link.
374      */
375     if (fd == -1) {
376         return -1;
377     }
378 
379     /* Now we handle racing symlinks. */
380     ret = fstat(fd, &stbuf);
381     if (!ret) {
382         if (S_ISLNK(stbuf.st_mode)) {
383             errno = ELOOP;
384             ret = -1;
385         } else {
386             char *proc_path = g_strdup_printf("/proc/self/fd/%d", fd);
387             ret = chmod(proc_path, mode);
388             g_free(proc_path);
389         }
390     }
391 #endif
392     close_preserve_errno(fd);
393     return ret;
394 }
395 
396 static int local_set_xattrat(int dirfd, const char *path, FsCred *credp)
397 {
398     int err;
399 
400     if (credp->fc_uid != -1) {
401         uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);
402         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.uid", &tmp_uid,
403                                    sizeof(uid_t), 0);
404         if (err) {
405             return err;
406         }
407     }
408     if (credp->fc_gid != -1) {
409         uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);
410         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.gid", &tmp_gid,
411                                    sizeof(gid_t), 0);
412         if (err) {
413             return err;
414         }
415     }
416     if (credp->fc_mode != -1) {
417         uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);
418         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.mode", &tmp_mode,
419                                    sizeof(mode_t), 0);
420         if (err) {
421             return err;
422         }
423     }
424     if (credp->fc_rdev != -1) {
425         uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);
426         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.rdev", &tmp_rdev,
427                                    sizeof(dev_t), 0);
428         if (err) {
429             return err;
430         }
431     }
432     return 0;
433 }
434 
435 static int local_set_cred_passthrough(FsContext *fs_ctx, int dirfd,
436                                       const char *name, FsCred *credp)
437 {
438     if (fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
439                  AT_SYMLINK_NOFOLLOW) < 0) {
440         /*
441          * If we fail to change ownership and if we are
442          * using security model none. Ignore the error
443          */
444         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
445             return -1;
446         }
447     }
448 
449     return fchmodat_nofollow(dirfd, name, credp->fc_mode & 07777);
450 }
451 
452 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
453                               char *buf, size_t bufsz)
454 {
455     ssize_t tsize = -1;
456 
457     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
458         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
459         int fd;
460 
461         fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0);
462         if (fd == -1) {
463             return -1;
464         }
465         do {
466             tsize = read(fd, (void *)buf, bufsz);
467         } while (tsize == -1 && errno == EINTR);
468         close_preserve_errno(fd);
469     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
470                (fs_ctx->export_flags & V9FS_SM_NONE)) {
471         char *dirpath = g_path_get_dirname(fs_path->data);
472         char *name = g_path_get_basename(fs_path->data);
473         int dirfd;
474 
475         dirfd = local_opendir_nofollow(fs_ctx, dirpath);
476         if (dirfd == -1) {
477             goto out;
478         }
479 
480         tsize = readlinkat(dirfd, name, buf, bufsz);
481         close_preserve_errno(dirfd);
482     out:
483         g_free(name);
484         g_free(dirpath);
485     }
486     return tsize;
487 }
488 
489 static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
490 {
491     return close(fs->fd);
492 }
493 
494 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
495 {
496     return closedir(fs->dir.stream);
497 }
498 
499 static int local_open(FsContext *ctx, V9fsPath *fs_path,
500                       int flags, V9fsFidOpenState *fs)
501 {
502     int fd;
503 
504     fd = local_open_nofollow(ctx, fs_path->data, flags, 0);
505     if (fd == -1) {
506         return -1;
507     }
508     fs->fd = fd;
509     return fs->fd;
510 }
511 
512 static int local_opendir(FsContext *ctx,
513                          V9fsPath *fs_path, V9fsFidOpenState *fs)
514 {
515     int dirfd;
516     DIR *stream;
517 
518     dirfd = local_opendir_nofollow(ctx, fs_path->data);
519     if (dirfd == -1) {
520         return -1;
521     }
522 
523     stream = fdopendir(dirfd);
524     if (!stream) {
525         close(dirfd);
526         return -1;
527     }
528     fs->dir.stream = stream;
529     return 0;
530 }
531 
532 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
533 {
534     rewinddir(fs->dir.stream);
535 }
536 
537 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
538 {
539     return telldir(fs->dir.stream);
540 }
541 
542 static bool local_is_mapped_file_metadata(FsContext *fs_ctx, const char *name)
543 {
544     return
545         !strcmp(name, VIRTFS_META_DIR) || !strcmp(name, VIRTFS_META_ROOT_FILE);
546 }
547 
548 static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs)
549 {
550     struct dirent *entry;
551 
552 again:
553     entry = readdir(fs->dir.stream);
554     if (!entry) {
555         return NULL;
556     }
557 
558     if (ctx->export_flags & V9FS_SM_MAPPED) {
559         entry->d_type = DT_UNKNOWN;
560     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
561         if (local_is_mapped_file_metadata(ctx, entry->d_name)) {
562             /* skip the meta data */
563             goto again;
564         }
565         entry->d_type = DT_UNKNOWN;
566     }
567 
568     return entry;
569 }
570 
571 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
572 {
573     seekdir(fs->dir.stream, off);
574 }
575 
576 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
577                             const struct iovec *iov,
578                             int iovcnt, off_t offset)
579 {
580 #ifdef CONFIG_PREADV
581     return preadv(fs->fd, iov, iovcnt, offset);
582 #else
583     int err = lseek(fs->fd, offset, SEEK_SET);
584     if (err == -1) {
585         return err;
586     } else {
587         return readv(fs->fd, iov, iovcnt);
588     }
589 #endif
590 }
591 
592 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
593                              const struct iovec *iov,
594                              int iovcnt, off_t offset)
595 {
596     ssize_t ret;
597 #ifdef CONFIG_PREADV
598     ret = pwritev(fs->fd, iov, iovcnt, offset);
599 #else
600     int err = lseek(fs->fd, offset, SEEK_SET);
601     if (err == -1) {
602         return err;
603     } else {
604         ret = writev(fs->fd, iov, iovcnt);
605     }
606 #endif
607 #ifdef CONFIG_SYNC_FILE_RANGE
608     if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
609         /*
610          * Initiate a writeback. This is not a data integrity sync.
611          * We want to ensure that we don't leave dirty pages in the cache
612          * after write when writeout=immediate is sepcified.
613          */
614         sync_file_range(fs->fd, offset, ret,
615                         SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
616     }
617 #endif
618     return ret;
619 }
620 
621 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
622 {
623     char *dirpath = g_path_get_dirname(fs_path->data);
624     char *name = g_path_get_basename(fs_path->data);
625     int ret = -1;
626     int dirfd;
627 
628     dirfd = local_opendir_nofollow(fs_ctx, dirpath);
629     if (dirfd == -1) {
630         goto out;
631     }
632 
633     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
634         ret = local_set_xattrat(dirfd, name, credp);
635     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
636         ret = local_set_mapped_file_attrat(dirfd, name, credp);
637     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
638                fs_ctx->export_flags & V9FS_SM_NONE) {
639         ret = fchmodat_nofollow(dirfd, name, credp->fc_mode);
640     }
641     close_preserve_errno(dirfd);
642 
643 out:
644     g_free(dirpath);
645     g_free(name);
646     return ret;
647 }
648 
649 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
650                        const char *name, FsCred *credp)
651 {
652     int err = -1;
653     int dirfd;
654 
655     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
656         local_is_mapped_file_metadata(fs_ctx, name)) {
657         errno = EINVAL;
658         return -1;
659     }
660 
661     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
662     if (dirfd == -1) {
663         return -1;
664     }
665 
666     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
667         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
668         err = mknodat(dirfd, name, fs_ctx->fmode | S_IFREG, 0);
669         if (err == -1) {
670             goto out;
671         }
672 
673         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
674             err = local_set_xattrat(dirfd, name, credp);
675         } else {
676             err = local_set_mapped_file_attrat(dirfd, name, credp);
677         }
678         if (err == -1) {
679             goto err_end;
680         }
681     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
682                fs_ctx->export_flags & V9FS_SM_NONE) {
683         err = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
684         if (err == -1) {
685             goto out;
686         }
687         err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
688         if (err == -1) {
689             goto err_end;
690         }
691     }
692     goto out;
693 
694 err_end:
695     unlinkat_preserve_errno(dirfd, name, 0);
696 out:
697     close_preserve_errno(dirfd);
698     return err;
699 }
700 
701 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
702                        const char *name, FsCred *credp)
703 {
704     int err = -1;
705     int dirfd;
706 
707     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
708         local_is_mapped_file_metadata(fs_ctx, name)) {
709         errno = EINVAL;
710         return -1;
711     }
712 
713     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
714     if (dirfd == -1) {
715         return -1;
716     }
717 
718     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
719         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
720         err = mkdirat(dirfd, name, fs_ctx->dmode);
721         if (err == -1) {
722             goto out;
723         }
724         credp->fc_mode = credp->fc_mode | S_IFDIR;
725 
726         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
727             err = local_set_xattrat(dirfd, name, credp);
728         } else {
729             err = local_set_mapped_file_attrat(dirfd, name, credp);
730         }
731         if (err == -1) {
732             goto err_end;
733         }
734     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
735                fs_ctx->export_flags & V9FS_SM_NONE) {
736         err = mkdirat(dirfd, name, credp->fc_mode);
737         if (err == -1) {
738             goto out;
739         }
740         err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
741         if (err == -1) {
742             goto err_end;
743         }
744     }
745     goto out;
746 
747 err_end:
748     unlinkat_preserve_errno(dirfd, name, AT_REMOVEDIR);
749 out:
750     close_preserve_errno(dirfd);
751     return err;
752 }
753 
754 static int local_fstat(FsContext *fs_ctx, int fid_type,
755                        V9fsFidOpenState *fs, struct stat *stbuf)
756 {
757     int err, fd;
758 
759     if (fid_type == P9_FID_DIR) {
760         fd = dirfd(fs->dir.stream);
761     } else {
762         fd = fs->fd;
763     }
764 
765     err = fstat(fd, stbuf);
766     if (err) {
767         return err;
768     }
769     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
770         /* Actual credentials are part of extended attrs */
771         uid_t tmp_uid;
772         gid_t tmp_gid;
773         mode_t tmp_mode;
774         dev_t tmp_dev;
775 
776         if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
777             stbuf->st_uid = le32_to_cpu(tmp_uid);
778         }
779         if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
780             stbuf->st_gid = le32_to_cpu(tmp_gid);
781         }
782         if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
783             stbuf->st_mode = le32_to_cpu(tmp_mode);
784         }
785         if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
786             stbuf->st_rdev = le64_to_cpu(tmp_dev);
787         }
788     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
789         errno = EOPNOTSUPP;
790         return -1;
791     }
792     return err;
793 }
794 
795 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
796                        int flags, FsCred *credp, V9fsFidOpenState *fs)
797 {
798     int fd = -1;
799     int err = -1;
800     int dirfd;
801 
802     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
803         local_is_mapped_file_metadata(fs_ctx, name)) {
804         errno = EINVAL;
805         return -1;
806     }
807 
808     /*
809      * Mark all the open to not follow symlinks
810      */
811     flags |= O_NOFOLLOW;
812 
813     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
814     if (dirfd == -1) {
815         return -1;
816     }
817 
818     /* Determine the security model */
819     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
820         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
821         fd = openat_file(dirfd, name, flags, fs_ctx->fmode);
822         if (fd == -1) {
823             goto out;
824         }
825         credp->fc_mode = credp->fc_mode|S_IFREG;
826         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
827             /* Set cleint credentials in xattr */
828             err = local_set_xattrat(dirfd, name, credp);
829         } else {
830             err = local_set_mapped_file_attrat(dirfd, name, credp);
831         }
832         if (err == -1) {
833             goto err_end;
834         }
835     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
836                (fs_ctx->export_flags & V9FS_SM_NONE)) {
837         fd = openat_file(dirfd, name, flags, credp->fc_mode);
838         if (fd == -1) {
839             goto out;
840         }
841         err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
842         if (err == -1) {
843             goto err_end;
844         }
845     }
846     err = fd;
847     fs->fd = fd;
848     goto out;
849 
850 err_end:
851     unlinkat_preserve_errno(dirfd, name,
852                             flags & O_DIRECTORY ? AT_REMOVEDIR : 0);
853     close_preserve_errno(fd);
854 out:
855     close_preserve_errno(dirfd);
856     return err;
857 }
858 
859 
860 static int local_symlink(FsContext *fs_ctx, const char *oldpath,
861                          V9fsPath *dir_path, const char *name, FsCred *credp)
862 {
863     int err = -1;
864     int dirfd;
865 
866     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
867         local_is_mapped_file_metadata(fs_ctx, name)) {
868         errno = EINVAL;
869         return -1;
870     }
871 
872     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
873     if (dirfd == -1) {
874         return -1;
875     }
876 
877     /* Determine the security model */
878     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
879         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
880         int fd;
881         ssize_t oldpath_size, write_size;
882 
883         fd = openat_file(dirfd, name, O_CREAT | O_EXCL | O_RDWR,
884                          fs_ctx->fmode);
885         if (fd == -1) {
886             goto out;
887         }
888         /* Write the oldpath (target) to the file. */
889         oldpath_size = strlen(oldpath);
890         do {
891             write_size = write(fd, (void *)oldpath, oldpath_size);
892         } while (write_size == -1 && errno == EINTR);
893         close_preserve_errno(fd);
894 
895         if (write_size != oldpath_size) {
896             goto err_end;
897         }
898         /* Set cleint credentials in symlink's xattr */
899         credp->fc_mode = credp->fc_mode | S_IFLNK;
900 
901         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
902             err = local_set_xattrat(dirfd, name, credp);
903         } else {
904             err = local_set_mapped_file_attrat(dirfd, name, credp);
905         }
906         if (err == -1) {
907             goto err_end;
908         }
909     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
910                fs_ctx->export_flags & V9FS_SM_NONE) {
911         err = symlinkat(oldpath, dirfd, name);
912         if (err) {
913             goto out;
914         }
915         err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
916                        AT_SYMLINK_NOFOLLOW);
917         if (err == -1) {
918             /*
919              * If we fail to change ownership and if we are
920              * using security model none. Ignore the error
921              */
922             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
923                 goto err_end;
924             } else {
925                 err = 0;
926             }
927         }
928     }
929     goto out;
930 
931 err_end:
932     unlinkat_preserve_errno(dirfd, name, 0);
933 out:
934     close_preserve_errno(dirfd);
935     return err;
936 }
937 
938 static int local_link(FsContext *ctx, V9fsPath *oldpath,
939                       V9fsPath *dirpath, const char *name)
940 {
941     char *odirpath = g_path_get_dirname(oldpath->data);
942     char *oname = g_path_get_basename(oldpath->data);
943     int ret = -1;
944     int odirfd, ndirfd;
945 
946     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
947         local_is_mapped_file_metadata(ctx, name)) {
948         errno = EINVAL;
949         return -1;
950     }
951 
952     odirfd = local_opendir_nofollow(ctx, odirpath);
953     if (odirfd == -1) {
954         goto out;
955     }
956 
957     ndirfd = local_opendir_nofollow(ctx, dirpath->data);
958     if (ndirfd == -1) {
959         close_preserve_errno(odirfd);
960         goto out;
961     }
962 
963     ret = linkat(odirfd, oname, ndirfd, name, 0);
964     if (ret < 0) {
965         goto out_close;
966     }
967 
968     /* now link the virtfs_metadata files */
969     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
970         int omap_dirfd, nmap_dirfd;
971 
972         ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
973         if (ret < 0 && errno != EEXIST) {
974             goto err_undo_link;
975         }
976 
977         omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
978         if (omap_dirfd == -1) {
979             goto err;
980         }
981 
982         nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
983         if (nmap_dirfd == -1) {
984             close_preserve_errno(omap_dirfd);
985             goto err;
986         }
987 
988         ret = linkat(omap_dirfd, oname, nmap_dirfd, name, 0);
989         close_preserve_errno(nmap_dirfd);
990         close_preserve_errno(omap_dirfd);
991         if (ret < 0 && errno != ENOENT) {
992             goto err_undo_link;
993         }
994 
995         ret = 0;
996     }
997     goto out_close;
998 
999 err:
1000     ret = -1;
1001 err_undo_link:
1002     unlinkat_preserve_errno(ndirfd, name, 0);
1003 out_close:
1004     close_preserve_errno(ndirfd);
1005     close_preserve_errno(odirfd);
1006 out:
1007     g_free(oname);
1008     g_free(odirpath);
1009     return ret;
1010 }
1011 
1012 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
1013 {
1014     int fd, ret;
1015 
1016     fd = local_open_nofollow(ctx, fs_path->data, O_WRONLY, 0);
1017     if (fd == -1) {
1018         return -1;
1019     }
1020     ret = ftruncate(fd, size);
1021     close_preserve_errno(fd);
1022     return ret;
1023 }
1024 
1025 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
1026 {
1027     char *dirpath = g_path_get_dirname(fs_path->data);
1028     char *name = g_path_get_basename(fs_path->data);
1029     int ret = -1;
1030     int dirfd;
1031 
1032     dirfd = local_opendir_nofollow(fs_ctx, dirpath);
1033     if (dirfd == -1) {
1034         goto out;
1035     }
1036 
1037     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
1038         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
1039         (fs_ctx->export_flags & V9FS_SM_NONE)) {
1040         ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
1041                        AT_SYMLINK_NOFOLLOW);
1042     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
1043         ret = local_set_xattrat(dirfd, name, credp);
1044     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1045         ret = local_set_mapped_file_attrat(dirfd, name, credp);
1046     }
1047 
1048     close_preserve_errno(dirfd);
1049 out:
1050     g_free(name);
1051     g_free(dirpath);
1052     return ret;
1053 }
1054 
1055 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
1056                            const struct timespec *buf)
1057 {
1058     char *dirpath = g_path_get_dirname(fs_path->data);
1059     char *name = g_path_get_basename(fs_path->data);
1060     int dirfd, ret = -1;
1061 
1062     dirfd = local_opendir_nofollow(s, dirpath);
1063     if (dirfd == -1) {
1064         goto out;
1065     }
1066 
1067     ret = utimensat(dirfd, name, buf, AT_SYMLINK_NOFOLLOW);
1068     close_preserve_errno(dirfd);
1069 out:
1070     g_free(dirpath);
1071     g_free(name);
1072     return ret;
1073 }
1074 
1075 static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name,
1076                                  int flags)
1077 {
1078     int ret = -1;
1079 
1080     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1081         int map_dirfd;
1082 
1083         /* We need to remove the metadata as well:
1084          * - the metadata directory if we're removing a directory
1085          * - the metadata file in the parent's metadata directory
1086          *
1087          * If any of these are missing (ie, ENOENT) then we're probably
1088          * trying to remove something that wasn't created in mapped-file
1089          * mode. We just ignore the error.
1090          */
1091         if (flags == AT_REMOVEDIR) {
1092             int fd;
1093 
1094             fd = openat_dir(dirfd, name);
1095             if (fd == -1) {
1096                 goto err_out;
1097             }
1098             ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR);
1099             close_preserve_errno(fd);
1100             if (ret < 0 && errno != ENOENT) {
1101                 goto err_out;
1102             }
1103         }
1104         map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
1105         if (map_dirfd != -1) {
1106             ret = unlinkat(map_dirfd, name, 0);
1107             close_preserve_errno(map_dirfd);
1108             if (ret < 0 && errno != ENOENT) {
1109                 goto err_out;
1110             }
1111         } else if (errno != ENOENT) {
1112             goto err_out;
1113         }
1114     }
1115 
1116     ret = unlinkat(dirfd, name, flags);
1117 err_out:
1118     return ret;
1119 }
1120 
1121 static int local_remove(FsContext *ctx, const char *path)
1122 {
1123     struct stat stbuf;
1124     char *dirpath = g_path_get_dirname(path);
1125     char *name = g_path_get_basename(path);
1126     int flags = 0;
1127     int dirfd;
1128     int err = -1;
1129 
1130     dirfd = local_opendir_nofollow(ctx, dirpath);
1131     if (dirfd == -1) {
1132         goto out;
1133     }
1134 
1135     if (fstatat(dirfd, name, &stbuf, AT_SYMLINK_NOFOLLOW) < 0) {
1136         goto err_out;
1137     }
1138 
1139     if (S_ISDIR(stbuf.st_mode)) {
1140         flags |= AT_REMOVEDIR;
1141     }
1142 
1143     err = local_unlinkat_common(ctx, dirfd, name, flags);
1144 err_out:
1145     close_preserve_errno(dirfd);
1146 out:
1147     g_free(name);
1148     g_free(dirpath);
1149     return err;
1150 }
1151 
1152 static int local_fsync(FsContext *ctx, int fid_type,
1153                        V9fsFidOpenState *fs, int datasync)
1154 {
1155     int fd;
1156 
1157     if (fid_type == P9_FID_DIR) {
1158         fd = dirfd(fs->dir.stream);
1159     } else {
1160         fd = fs->fd;
1161     }
1162 
1163     if (datasync) {
1164         return qemu_fdatasync(fd);
1165     } else {
1166         return fsync(fd);
1167     }
1168 }
1169 
1170 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
1171 {
1172     int fd, ret;
1173 
1174     fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0);
1175     if (fd == -1) {
1176         return -1;
1177     }
1178     ret = fstatfs(fd, stbuf);
1179     close_preserve_errno(fd);
1180     return ret;
1181 }
1182 
1183 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
1184                                const char *name, void *value, size_t size)
1185 {
1186     char *path = fs_path->data;
1187 
1188     return v9fs_get_xattr(ctx, path, name, value, size);
1189 }
1190 
1191 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
1192                                 void *value, size_t size)
1193 {
1194     char *path = fs_path->data;
1195 
1196     return v9fs_list_xattr(ctx, path, value, size);
1197 }
1198 
1199 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
1200                            void *value, size_t size, int flags)
1201 {
1202     char *path = fs_path->data;
1203 
1204     return v9fs_set_xattr(ctx, path, name, value, size, flags);
1205 }
1206 
1207 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
1208                               const char *name)
1209 {
1210     char *path = fs_path->data;
1211 
1212     return v9fs_remove_xattr(ctx, path, name);
1213 }
1214 
1215 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
1216                               const char *name, V9fsPath *target)
1217 {
1218     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
1219         local_is_mapped_file_metadata(ctx, name)) {
1220         errno = EINVAL;
1221         return -1;
1222     }
1223 
1224     if (dir_path) {
1225         if (!strcmp(name, ".")) {
1226             /* "." relative to "foo/bar" is "foo/bar" */
1227             v9fs_path_copy(target, dir_path);
1228         } else if (!strcmp(name, "..")) {
1229             if (!strcmp(dir_path->data, ".")) {
1230                 /* ".." relative to the root is "." */
1231                 v9fs_path_sprintf(target, ".");
1232             } else {
1233                 char *tmp = g_path_get_dirname(dir_path->data);
1234                 /* Symbolic links are resolved by the client. We can assume
1235                  * that ".." relative to "foo/bar" is equivalent to "foo"
1236                  */
1237                 v9fs_path_sprintf(target, "%s", tmp);
1238                 g_free(tmp);
1239             }
1240         } else {
1241             assert(!strchr(name, '/'));
1242             v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
1243         }
1244     } else if (!strcmp(name, "/") || !strcmp(name, ".") ||
1245                !strcmp(name, "..")) {
1246             /* This is the root fid */
1247         v9fs_path_sprintf(target, ".");
1248     } else {
1249         assert(!strchr(name, '/'));
1250         v9fs_path_sprintf(target, "./%s", name);
1251     }
1252     return 0;
1253 }
1254 
1255 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
1256                           const char *old_name, V9fsPath *newdir,
1257                           const char *new_name)
1258 {
1259     int ret;
1260     int odirfd, ndirfd;
1261 
1262     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
1263         (local_is_mapped_file_metadata(ctx, old_name) ||
1264          local_is_mapped_file_metadata(ctx, new_name))) {
1265         errno = EINVAL;
1266         return -1;
1267     }
1268 
1269     odirfd = local_opendir_nofollow(ctx, olddir->data);
1270     if (odirfd == -1) {
1271         return -1;
1272     }
1273 
1274     ndirfd = local_opendir_nofollow(ctx, newdir->data);
1275     if (ndirfd == -1) {
1276         close_preserve_errno(odirfd);
1277         return -1;
1278     }
1279 
1280     ret = renameat(odirfd, old_name, ndirfd, new_name);
1281     if (ret < 0) {
1282         goto out;
1283     }
1284 
1285     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1286         int omap_dirfd, nmap_dirfd;
1287 
1288         ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
1289         if (ret < 0 && errno != EEXIST) {
1290             goto err_undo_rename;
1291         }
1292 
1293         omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
1294         if (omap_dirfd == -1) {
1295             goto err;
1296         }
1297 
1298         nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
1299         if (nmap_dirfd == -1) {
1300             close_preserve_errno(omap_dirfd);
1301             goto err;
1302         }
1303 
1304         /* rename the .virtfs_metadata files */
1305         ret = renameat(omap_dirfd, old_name, nmap_dirfd, new_name);
1306         close_preserve_errno(nmap_dirfd);
1307         close_preserve_errno(omap_dirfd);
1308         if (ret < 0 && errno != ENOENT) {
1309             goto err_undo_rename;
1310         }
1311 
1312         ret = 0;
1313     }
1314     goto out;
1315 
1316 err:
1317     ret = -1;
1318 err_undo_rename:
1319     renameat_preserve_errno(ndirfd, new_name, odirfd, old_name);
1320 out:
1321     close_preserve_errno(ndirfd);
1322     close_preserve_errno(odirfd);
1323     return ret;
1324 }
1325 
1326 static void v9fs_path_init_dirname(V9fsPath *path, const char *str)
1327 {
1328     path->data = g_path_get_dirname(str);
1329     path->size = strlen(path->data) + 1;
1330 }
1331 
1332 static int local_rename(FsContext *ctx, const char *oldpath,
1333                         const char *newpath)
1334 {
1335     int err;
1336     char *oname = g_path_get_basename(oldpath);
1337     char *nname = g_path_get_basename(newpath);
1338     V9fsPath olddir, newdir;
1339 
1340     v9fs_path_init_dirname(&olddir, oldpath);
1341     v9fs_path_init_dirname(&newdir, newpath);
1342 
1343     err = local_renameat(ctx, &olddir, oname, &newdir, nname);
1344 
1345     v9fs_path_free(&newdir);
1346     v9fs_path_free(&olddir);
1347     g_free(nname);
1348     g_free(oname);
1349 
1350     return err;
1351 }
1352 
1353 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
1354                           const char *name, int flags)
1355 {
1356     int ret;
1357     int dirfd;
1358 
1359     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
1360         local_is_mapped_file_metadata(ctx, name)) {
1361         errno = EINVAL;
1362         return -1;
1363     }
1364 
1365     dirfd = local_opendir_nofollow(ctx, dir->data);
1366     if (dirfd == -1) {
1367         return -1;
1368     }
1369 
1370     ret = local_unlinkat_common(ctx, dirfd, name, flags);
1371     close_preserve_errno(dirfd);
1372     return ret;
1373 }
1374 
1375 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1376                                 mode_t st_mode, uint64_t *st_gen)
1377 {
1378 #ifdef FS_IOC_GETVERSION
1379     int err;
1380     V9fsFidOpenState fid_open;
1381 
1382     /*
1383      * Do not try to open special files like device nodes, fifos etc
1384      * We can get fd for regular files and directories only
1385      */
1386     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1387         errno = ENOTTY;
1388         return -1;
1389     }
1390     err = local_open(ctx, path, O_RDONLY, &fid_open);
1391     if (err < 0) {
1392         return err;
1393     }
1394     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1395     local_close(ctx, &fid_open);
1396     return err;
1397 #else
1398     errno = ENOTTY;
1399     return -1;
1400 #endif
1401 }
1402 
1403 static int local_init(FsContext *ctx, Error **errp)
1404 {
1405     struct statfs stbuf;
1406     LocalData *data = g_malloc(sizeof(*data));
1407 
1408     data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY);
1409     if (data->mountfd == -1) {
1410         error_setg_errno(errp, errno, "failed to open '%s'", ctx->fs_root);
1411         goto err;
1412     }
1413 
1414 #ifdef FS_IOC_GETVERSION
1415     /*
1416      * use ioc_getversion only if the ioctl is definied
1417      */
1418     if (fstatfs(data->mountfd, &stbuf) < 0) {
1419         close_preserve_errno(data->mountfd);
1420         goto err;
1421     }
1422     switch (stbuf.f_type) {
1423     case EXT2_SUPER_MAGIC:
1424     case BTRFS_SUPER_MAGIC:
1425     case REISERFS_SUPER_MAGIC:
1426     case XFS_SUPER_MAGIC:
1427         ctx->exops.get_st_gen = local_ioc_getversion;
1428         break;
1429     }
1430 #endif
1431 
1432     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1433         ctx->xops = passthrough_xattr_ops;
1434     } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1435         ctx->xops = mapped_xattr_ops;
1436     } else if (ctx->export_flags & V9FS_SM_NONE) {
1437         ctx->xops = none_xattr_ops;
1438     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1439         /*
1440          * xattr operation for mapped-file and passthrough
1441          * remain same.
1442          */
1443         ctx->xops = passthrough_xattr_ops;
1444     }
1445     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1446 
1447     ctx->private = data;
1448     return 0;
1449 
1450 err:
1451     g_free(data);
1452     return -1;
1453 }
1454 
1455 static void local_cleanup(FsContext *ctx)
1456 {
1457     LocalData *data = ctx->private;
1458 
1459     close(data->mountfd);
1460     g_free(data);
1461 }
1462 
1463 static void error_append_security_model_hint(Error **errp)
1464 {
1465     error_append_hint(errp, "Valid options are: security_model="
1466                       "[passthrough|mapped-xattr|mapped-file|none]\n");
1467 }
1468 
1469 static int local_parse_opts(QemuOpts *opts, FsDriverEntry *fse, Error **errp)
1470 {
1471     const char *sec_model = qemu_opt_get(opts, "security_model");
1472     const char *path = qemu_opt_get(opts, "path");
1473     Error *local_err = NULL;
1474 
1475     if (!sec_model) {
1476         error_setg(errp, "security_model property not set");
1477         error_append_security_model_hint(errp);
1478         return -1;
1479     }
1480 
1481     if (!strcmp(sec_model, "passthrough")) {
1482         fse->export_flags |= V9FS_SM_PASSTHROUGH;
1483     } else if (!strcmp(sec_model, "mapped") ||
1484                !strcmp(sec_model, "mapped-xattr")) {
1485         fse->export_flags |= V9FS_SM_MAPPED;
1486     } else if (!strcmp(sec_model, "none")) {
1487         fse->export_flags |= V9FS_SM_NONE;
1488     } else if (!strcmp(sec_model, "mapped-file")) {
1489         fse->export_flags |= V9FS_SM_MAPPED_FILE;
1490     } else {
1491         error_setg(errp, "invalid security_model property '%s'", sec_model);
1492         error_append_security_model_hint(errp);
1493         return -1;
1494     }
1495 
1496     if (!path) {
1497         error_setg(errp, "path property not set");
1498         return -1;
1499     }
1500 
1501     fsdev_throttle_parse_opts(opts, &fse->fst, &local_err);
1502     if (local_err) {
1503         error_propagate(errp, local_err);
1504         error_prepend(errp, "invalid throttle configuration: ");
1505         return -1;
1506     }
1507 
1508     if (fse->export_flags & V9FS_SM_MAPPED ||
1509         fse->export_flags & V9FS_SM_MAPPED_FILE) {
1510         fse->fmode =
1511             qemu_opt_get_number(opts, "fmode", SM_LOCAL_MODE_BITS) & 0777;
1512         fse->dmode =
1513             qemu_opt_get_number(opts, "dmode", SM_LOCAL_DIR_MODE_BITS) & 0777;
1514     } else {
1515         if (qemu_opt_find(opts, "fmode")) {
1516             error_setg(errp, "fmode is only valid for mapped security modes");
1517             return -1;
1518         }
1519         if (qemu_opt_find(opts, "dmode")) {
1520             error_setg(errp, "dmode is only valid for mapped security modes");
1521             return -1;
1522         }
1523     }
1524 
1525     fse->path = g_strdup(path);
1526 
1527     return 0;
1528 }
1529 
1530 FileOperations local_ops = {
1531     .parse_opts = local_parse_opts,
1532     .init  = local_init,
1533     .cleanup = local_cleanup,
1534     .lstat = local_lstat,
1535     .readlink = local_readlink,
1536     .close = local_close,
1537     .closedir = local_closedir,
1538     .open = local_open,
1539     .opendir = local_opendir,
1540     .rewinddir = local_rewinddir,
1541     .telldir = local_telldir,
1542     .readdir = local_readdir,
1543     .seekdir = local_seekdir,
1544     .preadv = local_preadv,
1545     .pwritev = local_pwritev,
1546     .chmod = local_chmod,
1547     .mknod = local_mknod,
1548     .mkdir = local_mkdir,
1549     .fstat = local_fstat,
1550     .open2 = local_open2,
1551     .symlink = local_symlink,
1552     .link = local_link,
1553     .truncate = local_truncate,
1554     .rename = local_rename,
1555     .chown = local_chown,
1556     .utimensat = local_utimensat,
1557     .remove = local_remove,
1558     .fsync = local_fsync,
1559     .statfs = local_statfs,
1560     .lgetxattr = local_lgetxattr,
1561     .llistxattr = local_llistxattr,
1562     .lsetxattr = local_lsetxattr,
1563     .lremovexattr = local_lremovexattr,
1564     .name_to_path = local_name_to_path,
1565     .renameat  = local_renameat,
1566     .unlinkat = local_unlinkat,
1567 };
1568