xref: /openbmc/qemu/hw/9pfs/9p-local.c (revision 0b1183e3)
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     int fd, ret;
337 
338     /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW).
339      * Unfortunately, the linux kernel doesn't implement it yet. As an
340      * alternative, let's open the file and use fchmod() instead. This
341      * may fail depending on the permissions of the file, but it is the
342      * best we can do to avoid TOCTTOU. We first try to open read-only
343      * in case name points to a directory. If that fails, we try write-only
344      * in case name doesn't point to a directory.
345      */
346     fd = openat_file(dirfd, name, O_RDONLY, 0);
347     if (fd == -1) {
348         /* In case the file is writable-only and isn't a directory. */
349         if (errno == EACCES) {
350             fd = openat_file(dirfd, name, O_WRONLY, 0);
351         }
352         if (fd == -1 && errno == EISDIR) {
353             errno = EACCES;
354         }
355     }
356     if (fd == -1) {
357         return -1;
358     }
359     ret = fchmod(fd, mode);
360     close_preserve_errno(fd);
361     return ret;
362 }
363 
364 static int local_set_xattrat(int dirfd, const char *path, FsCred *credp)
365 {
366     int err;
367 
368     if (credp->fc_uid != -1) {
369         uint32_t tmp_uid = cpu_to_le32(credp->fc_uid);
370         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.uid", &tmp_uid,
371                                    sizeof(uid_t), 0);
372         if (err) {
373             return err;
374         }
375     }
376     if (credp->fc_gid != -1) {
377         uint32_t tmp_gid = cpu_to_le32(credp->fc_gid);
378         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.gid", &tmp_gid,
379                                    sizeof(gid_t), 0);
380         if (err) {
381             return err;
382         }
383     }
384     if (credp->fc_mode != -1) {
385         uint32_t tmp_mode = cpu_to_le32(credp->fc_mode);
386         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.mode", &tmp_mode,
387                                    sizeof(mode_t), 0);
388         if (err) {
389             return err;
390         }
391     }
392     if (credp->fc_rdev != -1) {
393         uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev);
394         err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.rdev", &tmp_rdev,
395                                    sizeof(dev_t), 0);
396         if (err) {
397             return err;
398         }
399     }
400     return 0;
401 }
402 
403 static int local_set_cred_passthrough(FsContext *fs_ctx, int dirfd,
404                                       const char *name, FsCred *credp)
405 {
406     if (fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
407                  AT_SYMLINK_NOFOLLOW) < 0) {
408         /*
409          * If we fail to change ownership and if we are
410          * using security model none. Ignore the error
411          */
412         if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
413             return -1;
414         }
415     }
416 
417     return fchmodat_nofollow(dirfd, name, credp->fc_mode & 07777);
418 }
419 
420 static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
421                               char *buf, size_t bufsz)
422 {
423     ssize_t tsize = -1;
424 
425     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
426         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
427         int fd;
428 
429         fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0);
430         if (fd == -1) {
431             return -1;
432         }
433         do {
434             tsize = read(fd, (void *)buf, bufsz);
435         } while (tsize == -1 && errno == EINTR);
436         close_preserve_errno(fd);
437     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
438                (fs_ctx->export_flags & V9FS_SM_NONE)) {
439         char *dirpath = g_path_get_dirname(fs_path->data);
440         char *name = g_path_get_basename(fs_path->data);
441         int dirfd;
442 
443         dirfd = local_opendir_nofollow(fs_ctx, dirpath);
444         if (dirfd == -1) {
445             goto out;
446         }
447 
448         tsize = readlinkat(dirfd, name, buf, bufsz);
449         close_preserve_errno(dirfd);
450     out:
451         g_free(name);
452         g_free(dirpath);
453     }
454     return tsize;
455 }
456 
457 static int local_close(FsContext *ctx, V9fsFidOpenState *fs)
458 {
459     return close(fs->fd);
460 }
461 
462 static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs)
463 {
464     return closedir(fs->dir.stream);
465 }
466 
467 static int local_open(FsContext *ctx, V9fsPath *fs_path,
468                       int flags, V9fsFidOpenState *fs)
469 {
470     int fd;
471 
472     fd = local_open_nofollow(ctx, fs_path->data, flags, 0);
473     if (fd == -1) {
474         return -1;
475     }
476     fs->fd = fd;
477     return fs->fd;
478 }
479 
480 static int local_opendir(FsContext *ctx,
481                          V9fsPath *fs_path, V9fsFidOpenState *fs)
482 {
483     int dirfd;
484     DIR *stream;
485 
486     dirfd = local_opendir_nofollow(ctx, fs_path->data);
487     if (dirfd == -1) {
488         return -1;
489     }
490 
491     stream = fdopendir(dirfd);
492     if (!stream) {
493         close(dirfd);
494         return -1;
495     }
496     fs->dir.stream = stream;
497     return 0;
498 }
499 
500 static void local_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
501 {
502     rewinddir(fs->dir.stream);
503 }
504 
505 static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
506 {
507     return telldir(fs->dir.stream);
508 }
509 
510 static bool local_is_mapped_file_metadata(FsContext *fs_ctx, const char *name)
511 {
512     return
513         !strcmp(name, VIRTFS_META_DIR) || !strcmp(name, VIRTFS_META_ROOT_FILE);
514 }
515 
516 static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs)
517 {
518     struct dirent *entry;
519 
520 again:
521     entry = readdir(fs->dir.stream);
522     if (!entry) {
523         return NULL;
524     }
525 
526     if (ctx->export_flags & V9FS_SM_MAPPED) {
527         entry->d_type = DT_UNKNOWN;
528     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
529         if (local_is_mapped_file_metadata(ctx, entry->d_name)) {
530             /* skip the meta data */
531             goto again;
532         }
533         entry->d_type = DT_UNKNOWN;
534     }
535 
536     return entry;
537 }
538 
539 static void local_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
540 {
541     seekdir(fs->dir.stream, off);
542 }
543 
544 static ssize_t local_preadv(FsContext *ctx, V9fsFidOpenState *fs,
545                             const struct iovec *iov,
546                             int iovcnt, off_t offset)
547 {
548 #ifdef CONFIG_PREADV
549     return preadv(fs->fd, iov, iovcnt, offset);
550 #else
551     int err = lseek(fs->fd, offset, SEEK_SET);
552     if (err == -1) {
553         return err;
554     } else {
555         return readv(fs->fd, iov, iovcnt);
556     }
557 #endif
558 }
559 
560 static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
561                              const struct iovec *iov,
562                              int iovcnt, off_t offset)
563 {
564     ssize_t ret;
565 #ifdef CONFIG_PREADV
566     ret = pwritev(fs->fd, iov, iovcnt, offset);
567 #else
568     int err = lseek(fs->fd, offset, SEEK_SET);
569     if (err == -1) {
570         return err;
571     } else {
572         ret = writev(fs->fd, iov, iovcnt);
573     }
574 #endif
575 #ifdef CONFIG_SYNC_FILE_RANGE
576     if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
577         /*
578          * Initiate a writeback. This is not a data integrity sync.
579          * We want to ensure that we don't leave dirty pages in the cache
580          * after write when writeout=immediate is sepcified.
581          */
582         sync_file_range(fs->fd, offset, ret,
583                         SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
584     }
585 #endif
586     return ret;
587 }
588 
589 static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
590 {
591     char *dirpath = g_path_get_dirname(fs_path->data);
592     char *name = g_path_get_basename(fs_path->data);
593     int ret = -1;
594     int dirfd;
595 
596     dirfd = local_opendir_nofollow(fs_ctx, dirpath);
597     if (dirfd == -1) {
598         goto out;
599     }
600 
601     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
602         ret = local_set_xattrat(dirfd, name, credp);
603     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
604         ret = local_set_mapped_file_attrat(dirfd, name, credp);
605     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
606                fs_ctx->export_flags & V9FS_SM_NONE) {
607         ret = fchmodat_nofollow(dirfd, name, credp->fc_mode);
608     }
609     close_preserve_errno(dirfd);
610 
611 out:
612     g_free(dirpath);
613     g_free(name);
614     return ret;
615 }
616 
617 static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
618                        const char *name, FsCred *credp)
619 {
620     int err = -1;
621     int dirfd;
622 
623     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
624         local_is_mapped_file_metadata(fs_ctx, name)) {
625         errno = EINVAL;
626         return -1;
627     }
628 
629     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
630     if (dirfd == -1) {
631         return -1;
632     }
633 
634     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
635         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
636         err = mknodat(dirfd, name, fs_ctx->fmode | S_IFREG, 0);
637         if (err == -1) {
638             goto out;
639         }
640 
641         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
642             err = local_set_xattrat(dirfd, name, credp);
643         } else {
644             err = local_set_mapped_file_attrat(dirfd, name, credp);
645         }
646         if (err == -1) {
647             goto err_end;
648         }
649     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
650                fs_ctx->export_flags & V9FS_SM_NONE) {
651         err = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
652         if (err == -1) {
653             goto out;
654         }
655         err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
656         if (err == -1) {
657             goto err_end;
658         }
659     }
660     goto out;
661 
662 err_end:
663     unlinkat_preserve_errno(dirfd, name, 0);
664 out:
665     close_preserve_errno(dirfd);
666     return err;
667 }
668 
669 static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
670                        const char *name, FsCred *credp)
671 {
672     int err = -1;
673     int dirfd;
674 
675     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
676         local_is_mapped_file_metadata(fs_ctx, name)) {
677         errno = EINVAL;
678         return -1;
679     }
680 
681     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
682     if (dirfd == -1) {
683         return -1;
684     }
685 
686     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
687         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
688         err = mkdirat(dirfd, name, fs_ctx->dmode);
689         if (err == -1) {
690             goto out;
691         }
692         credp->fc_mode = credp->fc_mode | S_IFDIR;
693 
694         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
695             err = local_set_xattrat(dirfd, name, credp);
696         } else {
697             err = local_set_mapped_file_attrat(dirfd, name, credp);
698         }
699         if (err == -1) {
700             goto err_end;
701         }
702     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
703                fs_ctx->export_flags & V9FS_SM_NONE) {
704         err = mkdirat(dirfd, name, credp->fc_mode);
705         if (err == -1) {
706             goto out;
707         }
708         err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
709         if (err == -1) {
710             goto err_end;
711         }
712     }
713     goto out;
714 
715 err_end:
716     unlinkat_preserve_errno(dirfd, name, AT_REMOVEDIR);
717 out:
718     close_preserve_errno(dirfd);
719     return err;
720 }
721 
722 static int local_fstat(FsContext *fs_ctx, int fid_type,
723                        V9fsFidOpenState *fs, struct stat *stbuf)
724 {
725     int err, fd;
726 
727     if (fid_type == P9_FID_DIR) {
728         fd = dirfd(fs->dir.stream);
729     } else {
730         fd = fs->fd;
731     }
732 
733     err = fstat(fd, stbuf);
734     if (err) {
735         return err;
736     }
737     if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
738         /* Actual credentials are part of extended attrs */
739         uid_t tmp_uid;
740         gid_t tmp_gid;
741         mode_t tmp_mode;
742         dev_t tmp_dev;
743 
744         if (fgetxattr(fd, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) {
745             stbuf->st_uid = le32_to_cpu(tmp_uid);
746         }
747         if (fgetxattr(fd, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) {
748             stbuf->st_gid = le32_to_cpu(tmp_gid);
749         }
750         if (fgetxattr(fd, "user.virtfs.mode", &tmp_mode, sizeof(mode_t)) > 0) {
751             stbuf->st_mode = le32_to_cpu(tmp_mode);
752         }
753         if (fgetxattr(fd, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) {
754             stbuf->st_rdev = le64_to_cpu(tmp_dev);
755         }
756     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
757         errno = EOPNOTSUPP;
758         return -1;
759     }
760     return err;
761 }
762 
763 static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
764                        int flags, FsCred *credp, V9fsFidOpenState *fs)
765 {
766     int fd = -1;
767     int err = -1;
768     int dirfd;
769 
770     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
771         local_is_mapped_file_metadata(fs_ctx, name)) {
772         errno = EINVAL;
773         return -1;
774     }
775 
776     /*
777      * Mark all the open to not follow symlinks
778      */
779     flags |= O_NOFOLLOW;
780 
781     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
782     if (dirfd == -1) {
783         return -1;
784     }
785 
786     /* Determine the security model */
787     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
788         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
789         fd = openat_file(dirfd, name, flags, fs_ctx->fmode);
790         if (fd == -1) {
791             goto out;
792         }
793         credp->fc_mode = credp->fc_mode|S_IFREG;
794         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
795             /* Set cleint credentials in xattr */
796             err = local_set_xattrat(dirfd, name, credp);
797         } else {
798             err = local_set_mapped_file_attrat(dirfd, name, credp);
799         }
800         if (err == -1) {
801             goto err_end;
802         }
803     } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
804                (fs_ctx->export_flags & V9FS_SM_NONE)) {
805         fd = openat_file(dirfd, name, flags, credp->fc_mode);
806         if (fd == -1) {
807             goto out;
808         }
809         err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp);
810         if (err == -1) {
811             goto err_end;
812         }
813     }
814     err = fd;
815     fs->fd = fd;
816     goto out;
817 
818 err_end:
819     unlinkat_preserve_errno(dirfd, name,
820                             flags & O_DIRECTORY ? AT_REMOVEDIR : 0);
821     close_preserve_errno(fd);
822 out:
823     close_preserve_errno(dirfd);
824     return err;
825 }
826 
827 
828 static int local_symlink(FsContext *fs_ctx, const char *oldpath,
829                          V9fsPath *dir_path, const char *name, FsCred *credp)
830 {
831     int err = -1;
832     int dirfd;
833 
834     if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
835         local_is_mapped_file_metadata(fs_ctx, name)) {
836         errno = EINVAL;
837         return -1;
838     }
839 
840     dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
841     if (dirfd == -1) {
842         return -1;
843     }
844 
845     /* Determine the security model */
846     if (fs_ctx->export_flags & V9FS_SM_MAPPED ||
847         fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
848         int fd;
849         ssize_t oldpath_size, write_size;
850 
851         fd = openat_file(dirfd, name, O_CREAT | O_EXCL | O_RDWR,
852                          fs_ctx->fmode);
853         if (fd == -1) {
854             goto out;
855         }
856         /* Write the oldpath (target) to the file. */
857         oldpath_size = strlen(oldpath);
858         do {
859             write_size = write(fd, (void *)oldpath, oldpath_size);
860         } while (write_size == -1 && errno == EINTR);
861         close_preserve_errno(fd);
862 
863         if (write_size != oldpath_size) {
864             goto err_end;
865         }
866         /* Set cleint credentials in symlink's xattr */
867         credp->fc_mode = credp->fc_mode | S_IFLNK;
868 
869         if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
870             err = local_set_xattrat(dirfd, name, credp);
871         } else {
872             err = local_set_mapped_file_attrat(dirfd, name, credp);
873         }
874         if (err == -1) {
875             goto err_end;
876         }
877     } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH ||
878                fs_ctx->export_flags & V9FS_SM_NONE) {
879         err = symlinkat(oldpath, dirfd, name);
880         if (err) {
881             goto out;
882         }
883         err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
884                        AT_SYMLINK_NOFOLLOW);
885         if (err == -1) {
886             /*
887              * If we fail to change ownership and if we are
888              * using security model none. Ignore the error
889              */
890             if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) {
891                 goto err_end;
892             } else {
893                 err = 0;
894             }
895         }
896     }
897     goto out;
898 
899 err_end:
900     unlinkat_preserve_errno(dirfd, name, 0);
901 out:
902     close_preserve_errno(dirfd);
903     return err;
904 }
905 
906 static int local_link(FsContext *ctx, V9fsPath *oldpath,
907                       V9fsPath *dirpath, const char *name)
908 {
909     char *odirpath = g_path_get_dirname(oldpath->data);
910     char *oname = g_path_get_basename(oldpath->data);
911     int ret = -1;
912     int odirfd, ndirfd;
913 
914     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
915         local_is_mapped_file_metadata(ctx, name)) {
916         errno = EINVAL;
917         return -1;
918     }
919 
920     odirfd = local_opendir_nofollow(ctx, odirpath);
921     if (odirfd == -1) {
922         goto out;
923     }
924 
925     ndirfd = local_opendir_nofollow(ctx, dirpath->data);
926     if (ndirfd == -1) {
927         close_preserve_errno(odirfd);
928         goto out;
929     }
930 
931     ret = linkat(odirfd, oname, ndirfd, name, 0);
932     if (ret < 0) {
933         goto out_close;
934     }
935 
936     /* now link the virtfs_metadata files */
937     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
938         int omap_dirfd, nmap_dirfd;
939 
940         ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
941         if (ret < 0 && errno != EEXIST) {
942             goto err_undo_link;
943         }
944 
945         omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
946         if (omap_dirfd == -1) {
947             goto err;
948         }
949 
950         nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
951         if (nmap_dirfd == -1) {
952             close_preserve_errno(omap_dirfd);
953             goto err;
954         }
955 
956         ret = linkat(omap_dirfd, oname, nmap_dirfd, name, 0);
957         close_preserve_errno(nmap_dirfd);
958         close_preserve_errno(omap_dirfd);
959         if (ret < 0 && errno != ENOENT) {
960             goto err_undo_link;
961         }
962 
963         ret = 0;
964     }
965     goto out_close;
966 
967 err:
968     ret = -1;
969 err_undo_link:
970     unlinkat_preserve_errno(ndirfd, name, 0);
971 out_close:
972     close_preserve_errno(ndirfd);
973     close_preserve_errno(odirfd);
974 out:
975     g_free(oname);
976     g_free(odirpath);
977     return ret;
978 }
979 
980 static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
981 {
982     int fd, ret;
983 
984     fd = local_open_nofollow(ctx, fs_path->data, O_WRONLY, 0);
985     if (fd == -1) {
986         return -1;
987     }
988     ret = ftruncate(fd, size);
989     close_preserve_errno(fd);
990     return ret;
991 }
992 
993 static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
994 {
995     char *dirpath = g_path_get_dirname(fs_path->data);
996     char *name = g_path_get_basename(fs_path->data);
997     int ret = -1;
998     int dirfd;
999 
1000     dirfd = local_opendir_nofollow(fs_ctx, dirpath);
1001     if (dirfd == -1) {
1002         goto out;
1003     }
1004 
1005     if ((credp->fc_uid == -1 && credp->fc_gid == -1) ||
1006         (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
1007         (fs_ctx->export_flags & V9FS_SM_NONE)) {
1008         ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid,
1009                        AT_SYMLINK_NOFOLLOW);
1010     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
1011         ret = local_set_xattrat(dirfd, name, credp);
1012     } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1013         ret = local_set_mapped_file_attrat(dirfd, name, credp);
1014     }
1015 
1016     close_preserve_errno(dirfd);
1017 out:
1018     g_free(name);
1019     g_free(dirpath);
1020     return ret;
1021 }
1022 
1023 static int local_utimensat(FsContext *s, V9fsPath *fs_path,
1024                            const struct timespec *buf)
1025 {
1026     char *dirpath = g_path_get_dirname(fs_path->data);
1027     char *name = g_path_get_basename(fs_path->data);
1028     int dirfd, ret = -1;
1029 
1030     dirfd = local_opendir_nofollow(s, dirpath);
1031     if (dirfd == -1) {
1032         goto out;
1033     }
1034 
1035     ret = utimensat(dirfd, name, buf, AT_SYMLINK_NOFOLLOW);
1036     close_preserve_errno(dirfd);
1037 out:
1038     g_free(dirpath);
1039     g_free(name);
1040     return ret;
1041 }
1042 
1043 static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name,
1044                                  int flags)
1045 {
1046     int ret = -1;
1047 
1048     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1049         int map_dirfd;
1050 
1051         /* We need to remove the metadata as well:
1052          * - the metadata directory if we're removing a directory
1053          * - the metadata file in the parent's metadata directory
1054          *
1055          * If any of these are missing (ie, ENOENT) then we're probably
1056          * trying to remove something that wasn't created in mapped-file
1057          * mode. We just ignore the error.
1058          */
1059         if (flags == AT_REMOVEDIR) {
1060             int fd;
1061 
1062             fd = openat_dir(dirfd, name);
1063             if (fd == -1) {
1064                 goto err_out;
1065             }
1066             ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR);
1067             close_preserve_errno(fd);
1068             if (ret < 0 && errno != ENOENT) {
1069                 goto err_out;
1070             }
1071         }
1072         map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR);
1073         if (map_dirfd != -1) {
1074             ret = unlinkat(map_dirfd, name, 0);
1075             close_preserve_errno(map_dirfd);
1076             if (ret < 0 && errno != ENOENT) {
1077                 goto err_out;
1078             }
1079         } else if (errno != ENOENT) {
1080             goto err_out;
1081         }
1082     }
1083 
1084     ret = unlinkat(dirfd, name, flags);
1085 err_out:
1086     return ret;
1087 }
1088 
1089 static int local_remove(FsContext *ctx, const char *path)
1090 {
1091     struct stat stbuf;
1092     char *dirpath = g_path_get_dirname(path);
1093     char *name = g_path_get_basename(path);
1094     int flags = 0;
1095     int dirfd;
1096     int err = -1;
1097 
1098     dirfd = local_opendir_nofollow(ctx, dirpath);
1099     if (dirfd == -1) {
1100         goto out;
1101     }
1102 
1103     if (fstatat(dirfd, name, &stbuf, AT_SYMLINK_NOFOLLOW) < 0) {
1104         goto err_out;
1105     }
1106 
1107     if (S_ISDIR(stbuf.st_mode)) {
1108         flags |= AT_REMOVEDIR;
1109     }
1110 
1111     err = local_unlinkat_common(ctx, dirfd, name, flags);
1112 err_out:
1113     close_preserve_errno(dirfd);
1114 out:
1115     g_free(name);
1116     g_free(dirpath);
1117     return err;
1118 }
1119 
1120 static int local_fsync(FsContext *ctx, int fid_type,
1121                        V9fsFidOpenState *fs, int datasync)
1122 {
1123     int fd;
1124 
1125     if (fid_type == P9_FID_DIR) {
1126         fd = dirfd(fs->dir.stream);
1127     } else {
1128         fd = fs->fd;
1129     }
1130 
1131     if (datasync) {
1132         return qemu_fdatasync(fd);
1133     } else {
1134         return fsync(fd);
1135     }
1136 }
1137 
1138 static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
1139 {
1140     int fd, ret;
1141 
1142     fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0);
1143     if (fd == -1) {
1144         return -1;
1145     }
1146     ret = fstatfs(fd, stbuf);
1147     close_preserve_errno(fd);
1148     return ret;
1149 }
1150 
1151 static ssize_t local_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
1152                                const char *name, void *value, size_t size)
1153 {
1154     char *path = fs_path->data;
1155 
1156     return v9fs_get_xattr(ctx, path, name, value, size);
1157 }
1158 
1159 static ssize_t local_llistxattr(FsContext *ctx, V9fsPath *fs_path,
1160                                 void *value, size_t size)
1161 {
1162     char *path = fs_path->data;
1163 
1164     return v9fs_list_xattr(ctx, path, value, size);
1165 }
1166 
1167 static int local_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
1168                            void *value, size_t size, int flags)
1169 {
1170     char *path = fs_path->data;
1171 
1172     return v9fs_set_xattr(ctx, path, name, value, size, flags);
1173 }
1174 
1175 static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
1176                               const char *name)
1177 {
1178     char *path = fs_path->data;
1179 
1180     return v9fs_remove_xattr(ctx, path, name);
1181 }
1182 
1183 static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
1184                               const char *name, V9fsPath *target)
1185 {
1186     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
1187         local_is_mapped_file_metadata(ctx, name)) {
1188         errno = EINVAL;
1189         return -1;
1190     }
1191 
1192     if (dir_path) {
1193         if (!strcmp(name, ".")) {
1194             /* "." relative to "foo/bar" is "foo/bar" */
1195             v9fs_path_copy(target, dir_path);
1196         } else if (!strcmp(name, "..")) {
1197             if (!strcmp(dir_path->data, ".")) {
1198                 /* ".." relative to the root is "." */
1199                 v9fs_path_sprintf(target, ".");
1200             } else {
1201                 char *tmp = g_path_get_dirname(dir_path->data);
1202                 /* Symbolic links are resolved by the client. We can assume
1203                  * that ".." relative to "foo/bar" is equivalent to "foo"
1204                  */
1205                 v9fs_path_sprintf(target, "%s", tmp);
1206                 g_free(tmp);
1207             }
1208         } else {
1209             assert(!strchr(name, '/'));
1210             v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
1211         }
1212     } else if (!strcmp(name, "/") || !strcmp(name, ".") ||
1213                !strcmp(name, "..")) {
1214             /* This is the root fid */
1215         v9fs_path_sprintf(target, ".");
1216     } else {
1217         assert(!strchr(name, '/'));
1218         v9fs_path_sprintf(target, "./%s", name);
1219     }
1220     return 0;
1221 }
1222 
1223 static int local_renameat(FsContext *ctx, V9fsPath *olddir,
1224                           const char *old_name, V9fsPath *newdir,
1225                           const char *new_name)
1226 {
1227     int ret;
1228     int odirfd, ndirfd;
1229 
1230     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
1231         (local_is_mapped_file_metadata(ctx, old_name) ||
1232          local_is_mapped_file_metadata(ctx, new_name))) {
1233         errno = EINVAL;
1234         return -1;
1235     }
1236 
1237     odirfd = local_opendir_nofollow(ctx, olddir->data);
1238     if (odirfd == -1) {
1239         return -1;
1240     }
1241 
1242     ndirfd = local_opendir_nofollow(ctx, newdir->data);
1243     if (ndirfd == -1) {
1244         close_preserve_errno(odirfd);
1245         return -1;
1246     }
1247 
1248     ret = renameat(odirfd, old_name, ndirfd, new_name);
1249     if (ret < 0) {
1250         goto out;
1251     }
1252 
1253     if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1254         int omap_dirfd, nmap_dirfd;
1255 
1256         ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700);
1257         if (ret < 0 && errno != EEXIST) {
1258             goto err_undo_rename;
1259         }
1260 
1261         omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR);
1262         if (omap_dirfd == -1) {
1263             goto err;
1264         }
1265 
1266         nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR);
1267         if (nmap_dirfd == -1) {
1268             close_preserve_errno(omap_dirfd);
1269             goto err;
1270         }
1271 
1272         /* rename the .virtfs_metadata files */
1273         ret = renameat(omap_dirfd, old_name, nmap_dirfd, new_name);
1274         close_preserve_errno(nmap_dirfd);
1275         close_preserve_errno(omap_dirfd);
1276         if (ret < 0 && errno != ENOENT) {
1277             goto err_undo_rename;
1278         }
1279 
1280         ret = 0;
1281     }
1282     goto out;
1283 
1284 err:
1285     ret = -1;
1286 err_undo_rename:
1287     renameat_preserve_errno(ndirfd, new_name, odirfd, old_name);
1288 out:
1289     close_preserve_errno(ndirfd);
1290     close_preserve_errno(odirfd);
1291     return ret;
1292 }
1293 
1294 static void v9fs_path_init_dirname(V9fsPath *path, const char *str)
1295 {
1296     path->data = g_path_get_dirname(str);
1297     path->size = strlen(path->data) + 1;
1298 }
1299 
1300 static int local_rename(FsContext *ctx, const char *oldpath,
1301                         const char *newpath)
1302 {
1303     int err;
1304     char *oname = g_path_get_basename(oldpath);
1305     char *nname = g_path_get_basename(newpath);
1306     V9fsPath olddir, newdir;
1307 
1308     v9fs_path_init_dirname(&olddir, oldpath);
1309     v9fs_path_init_dirname(&newdir, newpath);
1310 
1311     err = local_renameat(ctx, &olddir, oname, &newdir, nname);
1312 
1313     v9fs_path_free(&newdir);
1314     v9fs_path_free(&olddir);
1315     g_free(nname);
1316     g_free(oname);
1317 
1318     return err;
1319 }
1320 
1321 static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
1322                           const char *name, int flags)
1323 {
1324     int ret;
1325     int dirfd;
1326 
1327     if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
1328         local_is_mapped_file_metadata(ctx, name)) {
1329         errno = EINVAL;
1330         return -1;
1331     }
1332 
1333     dirfd = local_opendir_nofollow(ctx, dir->data);
1334     if (dirfd == -1) {
1335         return -1;
1336     }
1337 
1338     ret = local_unlinkat_common(ctx, dirfd, name, flags);
1339     close_preserve_errno(dirfd);
1340     return ret;
1341 }
1342 
1343 static int local_ioc_getversion(FsContext *ctx, V9fsPath *path,
1344                                 mode_t st_mode, uint64_t *st_gen)
1345 {
1346 #ifdef FS_IOC_GETVERSION
1347     int err;
1348     V9fsFidOpenState fid_open;
1349 
1350     /*
1351      * Do not try to open special files like device nodes, fifos etc
1352      * We can get fd for regular files and directories only
1353      */
1354     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
1355         errno = ENOTTY;
1356         return -1;
1357     }
1358     err = local_open(ctx, path, O_RDONLY, &fid_open);
1359     if (err < 0) {
1360         return err;
1361     }
1362     err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
1363     local_close(ctx, &fid_open);
1364     return err;
1365 #else
1366     errno = ENOTTY;
1367     return -1;
1368 #endif
1369 }
1370 
1371 static int local_init(FsContext *ctx)
1372 {
1373     struct statfs stbuf;
1374     LocalData *data = g_malloc(sizeof(*data));
1375 
1376     data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY);
1377     if (data->mountfd == -1) {
1378         goto err;
1379     }
1380 
1381 #ifdef FS_IOC_GETVERSION
1382     /*
1383      * use ioc_getversion only if the ioctl is definied
1384      */
1385     if (fstatfs(data->mountfd, &stbuf) < 0) {
1386         close_preserve_errno(data->mountfd);
1387         goto err;
1388     }
1389     switch (stbuf.f_type) {
1390     case EXT2_SUPER_MAGIC:
1391     case BTRFS_SUPER_MAGIC:
1392     case REISERFS_SUPER_MAGIC:
1393     case XFS_SUPER_MAGIC:
1394         ctx->exops.get_st_gen = local_ioc_getversion;
1395         break;
1396     }
1397 #endif
1398 
1399     if (ctx->export_flags & V9FS_SM_PASSTHROUGH) {
1400         ctx->xops = passthrough_xattr_ops;
1401     } else if (ctx->export_flags & V9FS_SM_MAPPED) {
1402         ctx->xops = mapped_xattr_ops;
1403     } else if (ctx->export_flags & V9FS_SM_NONE) {
1404         ctx->xops = none_xattr_ops;
1405     } else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
1406         /*
1407          * xattr operation for mapped-file and passthrough
1408          * remain same.
1409          */
1410         ctx->xops = passthrough_xattr_ops;
1411     }
1412     ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;
1413 
1414     ctx->private = data;
1415     return 0;
1416 
1417 err:
1418     g_free(data);
1419     return -1;
1420 }
1421 
1422 static void local_cleanup(FsContext *ctx)
1423 {
1424     LocalData *data = ctx->private;
1425 
1426     close(data->mountfd);
1427     g_free(data);
1428 }
1429 
1430 static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse)
1431 {
1432     const char *sec_model = qemu_opt_get(opts, "security_model");
1433     const char *path = qemu_opt_get(opts, "path");
1434     Error *err = NULL;
1435 
1436     if (!sec_model) {
1437         error_report("Security model not specified, local fs needs security model");
1438         error_printf("valid options are:"
1439                      "\tsecurity_model=[passthrough|mapped-xattr|mapped-file|none]\n");
1440         return -1;
1441     }
1442 
1443     if (!strcmp(sec_model, "passthrough")) {
1444         fse->export_flags |= V9FS_SM_PASSTHROUGH;
1445     } else if (!strcmp(sec_model, "mapped") ||
1446                !strcmp(sec_model, "mapped-xattr")) {
1447         fse->export_flags |= V9FS_SM_MAPPED;
1448     } else if (!strcmp(sec_model, "none")) {
1449         fse->export_flags |= V9FS_SM_NONE;
1450     } else if (!strcmp(sec_model, "mapped-file")) {
1451         fse->export_flags |= V9FS_SM_MAPPED_FILE;
1452     } else {
1453         error_report("Invalid security model %s specified", sec_model);
1454         error_printf("valid options are:"
1455                      "\t[passthrough|mapped-xattr|mapped-file|none]\n");
1456         return -1;
1457     }
1458 
1459     if (!path) {
1460         error_report("fsdev: No path specified");
1461         return -1;
1462     }
1463 
1464     fsdev_throttle_parse_opts(opts, &fse->fst, &err);
1465     if (err) {
1466         error_reportf_err(err, "Throttle configuration is not valid: ");
1467         return -1;
1468     }
1469 
1470     if (fse->export_flags & V9FS_SM_MAPPED ||
1471         fse->export_flags & V9FS_SM_MAPPED_FILE) {
1472         fse->fmode =
1473             qemu_opt_get_number(opts, "fmode", SM_LOCAL_MODE_BITS) & 0777;
1474         fse->dmode =
1475             qemu_opt_get_number(opts, "dmode", SM_LOCAL_DIR_MODE_BITS) & 0777;
1476     } else {
1477         if (qemu_opt_find(opts, "fmode")) {
1478             error_report("fmode is only valid for mapped 9p modes");
1479             return -1;
1480         }
1481         if (qemu_opt_find(opts, "dmode")) {
1482             error_report("dmode is only valid for mapped 9p modes");
1483             return -1;
1484         }
1485     }
1486 
1487     fse->path = g_strdup(path);
1488 
1489     return 0;
1490 }
1491 
1492 FileOperations local_ops = {
1493     .parse_opts = local_parse_opts,
1494     .init  = local_init,
1495     .cleanup = local_cleanup,
1496     .lstat = local_lstat,
1497     .readlink = local_readlink,
1498     .close = local_close,
1499     .closedir = local_closedir,
1500     .open = local_open,
1501     .opendir = local_opendir,
1502     .rewinddir = local_rewinddir,
1503     .telldir = local_telldir,
1504     .readdir = local_readdir,
1505     .seekdir = local_seekdir,
1506     .preadv = local_preadv,
1507     .pwritev = local_pwritev,
1508     .chmod = local_chmod,
1509     .mknod = local_mknod,
1510     .mkdir = local_mkdir,
1511     .fstat = local_fstat,
1512     .open2 = local_open2,
1513     .symlink = local_symlink,
1514     .link = local_link,
1515     .truncate = local_truncate,
1516     .rename = local_rename,
1517     .chown = local_chown,
1518     .utimensat = local_utimensat,
1519     .remove = local_remove,
1520     .fsync = local_fsync,
1521     .statfs = local_statfs,
1522     .lgetxattr = local_lgetxattr,
1523     .llistxattr = local_llistxattr,
1524     .lsetxattr = local_lsetxattr,
1525     .lremovexattr = local_lremovexattr,
1526     .name_to_path = local_name_to_path,
1527     .renameat  = local_renameat,
1528     .unlinkat = local_unlinkat,
1529 };
1530