9pfs: deprecate handle backend
[qemu/ar7.git] / hw / 9pfs / 9p-handle.c
blobc1681d3c8ac0507de5e0bb1d772354cf68b96e77
1 /*
2 * 9p handle callback
4 * Copyright IBM, Corp. 2011
6 * Authors:
7 * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "9p.h"
16 #include "9p-xattr.h"
17 #include <arpa/inet.h>
18 #include <pwd.h>
19 #include <grp.h>
20 #include <sys/socket.h>
21 #include <sys/un.h>
22 #include "qemu/xattr.h"
23 #include "qemu/cutils.h"
24 #include "qemu/error-report.h"
25 #include <linux/fs.h>
26 #ifdef CONFIG_LINUX_MAGIC_H
27 #include <linux/magic.h>
28 #endif
29 #include <sys/ioctl.h>
31 #ifndef XFS_SUPER_MAGIC
32 #define XFS_SUPER_MAGIC 0x58465342
33 #endif
34 #ifndef EXT2_SUPER_MAGIC
35 #define EXT2_SUPER_MAGIC 0xEF53
36 #endif
37 #ifndef REISERFS_SUPER_MAGIC
38 #define REISERFS_SUPER_MAGIC 0x52654973
39 #endif
40 #ifndef BTRFS_SUPER_MAGIC
41 #define BTRFS_SUPER_MAGIC 0x9123683E
42 #endif
44 typedef struct HandleData {
45 int mountfd;
46 int handle_bytes;
47 } HandleData;
49 static inline int name_to_handle(int dirfd, const char *name,
50 struct file_handle *fh, int *mnt_id, int flags)
52 return name_to_handle_at(dirfd, name, fh, mnt_id, flags);
55 static inline int open_by_handle(int mountfd, const char *fh, int flags)
57 return open_by_handle_at(mountfd, (struct file_handle *)fh, flags);
60 static int handle_update_file_cred(int dirfd, const char *name, FsCred *credp)
62 int fd, ret;
63 fd = openat(dirfd, name, O_NONBLOCK | O_NOFOLLOW);
64 if (fd < 0) {
65 return fd;
67 ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
68 if (ret < 0) {
69 goto err_out;
71 ret = fchmod(fd, credp->fc_mode & 07777);
72 err_out:
73 close(fd);
74 return ret;
78 static int handle_lstat(FsContext *fs_ctx, V9fsPath *fs_path,
79 struct stat *stbuf)
81 int fd, ret;
82 HandleData *data = (HandleData *) fs_ctx->private;
84 fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
85 if (fd < 0) {
86 return fd;
88 ret = fstatat(fd, "", stbuf, AT_EMPTY_PATH);
89 close(fd);
90 return ret;
93 static ssize_t handle_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
94 char *buf, size_t bufsz)
96 int fd, ret;
97 HandleData *data = (HandleData *) fs_ctx->private;
99 fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
100 if (fd < 0) {
101 return fd;
103 ret = readlinkat(fd, "", buf, bufsz);
104 close(fd);
105 return ret;
108 static int handle_close(FsContext *ctx, V9fsFidOpenState *fs)
110 return close(fs->fd);
113 static int handle_closedir(FsContext *ctx, V9fsFidOpenState *fs)
115 return closedir(fs->dir.stream);
118 static int handle_open(FsContext *ctx, V9fsPath *fs_path,
119 int flags, V9fsFidOpenState *fs)
121 HandleData *data = (HandleData *) ctx->private;
123 fs->fd = open_by_handle(data->mountfd, fs_path->data, flags);
124 return fs->fd;
127 static int handle_opendir(FsContext *ctx,
128 V9fsPath *fs_path, V9fsFidOpenState *fs)
130 int ret;
131 ret = handle_open(ctx, fs_path, O_DIRECTORY, fs);
132 if (ret < 0) {
133 return -1;
135 fs->dir.stream = fdopendir(ret);
136 if (!fs->dir.stream) {
137 return -1;
139 return 0;
142 static void handle_rewinddir(FsContext *ctx, V9fsFidOpenState *fs)
144 rewinddir(fs->dir.stream);
147 static off_t handle_telldir(FsContext *ctx, V9fsFidOpenState *fs)
149 return telldir(fs->dir.stream);
152 static struct dirent *handle_readdir(FsContext *ctx, V9fsFidOpenState *fs)
154 return readdir(fs->dir.stream);
157 static void handle_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off)
159 seekdir(fs->dir.stream, off);
162 static ssize_t handle_preadv(FsContext *ctx, V9fsFidOpenState *fs,
163 const struct iovec *iov,
164 int iovcnt, off_t offset)
166 #ifdef CONFIG_PREADV
167 return preadv(fs->fd, iov, iovcnt, offset);
168 #else
169 int err = lseek(fs->fd, offset, SEEK_SET);
170 if (err == -1) {
171 return err;
172 } else {
173 return readv(fs->fd, iov, iovcnt);
175 #endif
178 static ssize_t handle_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
179 const struct iovec *iov,
180 int iovcnt, off_t offset)
182 ssize_t ret;
183 #ifdef CONFIG_PREADV
184 ret = pwritev(fs->fd, iov, iovcnt, offset);
185 #else
186 int err = lseek(fs->fd, offset, SEEK_SET);
187 if (err == -1) {
188 return err;
189 } else {
190 ret = writev(fs->fd, iov, iovcnt);
192 #endif
193 #ifdef CONFIG_SYNC_FILE_RANGE
194 if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) {
196 * Initiate a writeback. This is not a data integrity sync.
197 * We want to ensure that we don't leave dirty pages in the cache
198 * after write when writeout=immediate is sepcified.
200 sync_file_range(fs->fd, offset, ret,
201 SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE);
203 #endif
204 return ret;
207 static int handle_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
209 int fd, ret;
210 HandleData *data = (HandleData *) fs_ctx->private;
212 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
213 if (fd < 0) {
214 return fd;
216 ret = fchmod(fd, credp->fc_mode);
217 close(fd);
218 return ret;
221 static int handle_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
222 const char *name, FsCred *credp)
224 int dirfd, ret;
225 HandleData *data = (HandleData *) fs_ctx->private;
227 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
228 if (dirfd < 0) {
229 return dirfd;
231 ret = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev);
232 if (!ret) {
233 ret = handle_update_file_cred(dirfd, name, credp);
235 close(dirfd);
236 return ret;
239 static int handle_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
240 const char *name, FsCred *credp)
242 int dirfd, ret;
243 HandleData *data = (HandleData *) fs_ctx->private;
245 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
246 if (dirfd < 0) {
247 return dirfd;
249 ret = mkdirat(dirfd, name, credp->fc_mode);
250 if (!ret) {
251 ret = handle_update_file_cred(dirfd, name, credp);
253 close(dirfd);
254 return ret;
257 static int handle_fstat(FsContext *fs_ctx, int fid_type,
258 V9fsFidOpenState *fs, struct stat *stbuf)
260 int fd;
262 if (fid_type == P9_FID_DIR) {
263 fd = dirfd(fs->dir.stream);
264 } else {
265 fd = fs->fd;
267 return fstat(fd, stbuf);
270 static int handle_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
271 int flags, FsCred *credp, V9fsFidOpenState *fs)
273 int ret;
274 int dirfd, fd;
275 HandleData *data = (HandleData *) fs_ctx->private;
277 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
278 if (dirfd < 0) {
279 return dirfd;
281 fd = openat(dirfd, name, flags | O_NOFOLLOW, credp->fc_mode);
282 if (fd >= 0) {
283 ret = handle_update_file_cred(dirfd, name, credp);
284 if (ret < 0) {
285 close(fd);
286 fd = ret;
287 } else {
288 fs->fd = fd;
291 close(dirfd);
292 return fd;
296 static int handle_symlink(FsContext *fs_ctx, const char *oldpath,
297 V9fsPath *dir_path, const char *name, FsCred *credp)
299 int fd, dirfd, ret;
300 HandleData *data = (HandleData *) fs_ctx->private;
302 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
303 if (dirfd < 0) {
304 return dirfd;
306 ret = symlinkat(oldpath, dirfd, name);
307 if (!ret) {
308 fd = openat(dirfd, name, O_PATH | O_NOFOLLOW);
309 if (fd < 0) {
310 ret = fd;
311 goto err_out;
313 ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
314 close(fd);
316 err_out:
317 close(dirfd);
318 return ret;
321 static int handle_link(FsContext *ctx, V9fsPath *oldpath,
322 V9fsPath *dirpath, const char *name)
324 int oldfd, newdirfd, ret;
325 HandleData *data = (HandleData *) ctx->private;
327 oldfd = open_by_handle(data->mountfd, oldpath->data, O_PATH);
328 if (oldfd < 0) {
329 return oldfd;
331 newdirfd = open_by_handle(data->mountfd, dirpath->data, O_PATH);
332 if (newdirfd < 0) {
333 close(oldfd);
334 return newdirfd;
336 ret = linkat(oldfd, "", newdirfd, name, AT_EMPTY_PATH);
337 close(newdirfd);
338 close(oldfd);
339 return ret;
342 static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
344 int fd, ret;
345 HandleData *data = (HandleData *) ctx->private;
347 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK | O_WRONLY);
348 if (fd < 0) {
349 return fd;
351 ret = ftruncate(fd, size);
352 close(fd);
353 return ret;
356 static int handle_rename(FsContext *ctx, const char *oldpath,
357 const char *newpath)
359 errno = EOPNOTSUPP;
360 return -1;
363 static int handle_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
365 int fd, ret;
366 HandleData *data = (HandleData *) fs_ctx->private;
368 fd = open_by_handle(data->mountfd, fs_path->data, O_PATH);
369 if (fd < 0) {
370 return fd;
372 ret = fchownat(fd, "", credp->fc_uid, credp->fc_gid, AT_EMPTY_PATH);
373 close(fd);
374 return ret;
377 static int handle_utimensat(FsContext *ctx, V9fsPath *fs_path,
378 const struct timespec *buf)
380 int ret;
381 int fd;
382 HandleData *data = (HandleData *) ctx->private;
384 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
385 if (fd < 0) {
386 return fd;
388 ret = futimens(fd, buf);
389 close(fd);
390 return ret;
393 static int handle_remove(FsContext *ctx, const char *path)
395 errno = EOPNOTSUPP;
396 return -1;
399 static int handle_fsync(FsContext *ctx, int fid_type,
400 V9fsFidOpenState *fs, int datasync)
402 int fd;
404 if (fid_type == P9_FID_DIR) {
405 fd = dirfd(fs->dir.stream);
406 } else {
407 fd = fs->fd;
410 if (datasync) {
411 return qemu_fdatasync(fd);
412 } else {
413 return fsync(fd);
417 static int handle_statfs(FsContext *ctx, V9fsPath *fs_path,
418 struct statfs *stbuf)
420 int fd, ret;
421 HandleData *data = (HandleData *) ctx->private;
423 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
424 if (fd < 0) {
425 return fd;
427 ret = fstatfs(fd, stbuf);
428 close(fd);
429 return ret;
432 static ssize_t handle_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
433 const char *name, void *value, size_t size)
435 int fd, ret;
436 HandleData *data = (HandleData *) ctx->private;
438 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
439 if (fd < 0) {
440 return fd;
442 ret = fgetxattr(fd, name, value, size);
443 close(fd);
444 return ret;
447 static ssize_t handle_llistxattr(FsContext *ctx, V9fsPath *fs_path,
448 void *value, size_t size)
450 int fd, ret;
451 HandleData *data = (HandleData *) ctx->private;
453 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
454 if (fd < 0) {
455 return fd;
457 ret = flistxattr(fd, value, size);
458 close(fd);
459 return ret;
462 static int handle_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
463 void *value, size_t size, int flags)
465 int fd, ret;
466 HandleData *data = (HandleData *) ctx->private;
468 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
469 if (fd < 0) {
470 return fd;
472 ret = fsetxattr(fd, name, value, size, flags);
473 close(fd);
474 return ret;
477 static int handle_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
478 const char *name)
480 int fd, ret;
481 HandleData *data = (HandleData *) ctx->private;
483 fd = open_by_handle(data->mountfd, fs_path->data, O_NONBLOCK);
484 if (fd < 0) {
485 return fd;
487 ret = fremovexattr(fd, name);
488 close(fd);
489 return ret;
492 static int handle_name_to_path(FsContext *ctx, V9fsPath *dir_path,
493 const char *name, V9fsPath *target)
495 char *buffer;
496 struct file_handle *fh;
497 int dirfd, ret, mnt_id;
498 HandleData *data = (HandleData *) ctx->private;
500 /* "." and ".." are not allowed */
501 if (!strcmp(name, ".") || !strcmp(name, "..")) {
502 errno = EINVAL;
503 return -1;
506 if (dir_path) {
507 dirfd = open_by_handle(data->mountfd, dir_path->data, O_PATH);
508 } else {
509 /* relative to export root */
510 buffer = rpath(ctx, ".");
511 dirfd = open(buffer, O_DIRECTORY);
512 g_free(buffer);
514 if (dirfd < 0) {
515 return dirfd;
517 fh = g_malloc(sizeof(struct file_handle) + data->handle_bytes);
518 fh->handle_bytes = data->handle_bytes;
519 /* add a "./" at the beginning of the path */
520 buffer = g_strdup_printf("./%s", name);
521 /* flag = 0 imply don't follow symlink */
522 ret = name_to_handle(dirfd, buffer, fh, &mnt_id, 0);
523 if (!ret) {
524 target->data = (char *)fh;
525 target->size = sizeof(struct file_handle) + data->handle_bytes;
526 } else {
527 g_free(fh);
529 close(dirfd);
530 g_free(buffer);
531 return ret;
534 static int handle_renameat(FsContext *ctx, V9fsPath *olddir,
535 const char *old_name, V9fsPath *newdir,
536 const char *new_name)
538 int olddirfd, newdirfd, ret;
539 HandleData *data = (HandleData *) ctx->private;
541 olddirfd = open_by_handle(data->mountfd, olddir->data, O_PATH);
542 if (olddirfd < 0) {
543 return olddirfd;
545 newdirfd = open_by_handle(data->mountfd, newdir->data, O_PATH);
546 if (newdirfd < 0) {
547 close(olddirfd);
548 return newdirfd;
550 ret = renameat(olddirfd, old_name, newdirfd, new_name);
551 close(newdirfd);
552 close(olddirfd);
553 return ret;
556 static int handle_unlinkat(FsContext *ctx, V9fsPath *dir,
557 const char *name, int flags)
559 int dirfd, ret;
560 HandleData *data = (HandleData *) ctx->private;
561 int rflags;
563 dirfd = open_by_handle(data->mountfd, dir->data, O_PATH);
564 if (dirfd < 0) {
565 return dirfd;
568 rflags = 0;
569 if (flags & P9_DOTL_AT_REMOVEDIR) {
570 rflags |= AT_REMOVEDIR;
573 ret = unlinkat(dirfd, name, rflags);
575 close(dirfd);
576 return ret;
579 static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path,
580 mode_t st_mode, uint64_t *st_gen)
582 #ifdef FS_IOC_GETVERSION
583 int err;
584 V9fsFidOpenState fid_open;
587 * Do not try to open special files like device nodes, fifos etc
588 * We can get fd for regular files and directories only
590 if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
591 errno = ENOTTY;
592 return -1;
594 err = handle_open(ctx, path, O_RDONLY, &fid_open);
595 if (err < 0) {
596 return err;
598 err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen);
599 handle_close(ctx, &fid_open);
600 return err;
601 #else
602 errno = ENOTTY;
603 return -1;
604 #endif
607 static int handle_init(FsContext *ctx, Error **errp)
609 int ret, mnt_id;
610 struct statfs stbuf;
611 struct file_handle fh;
612 HandleData *data = g_malloc(sizeof(HandleData));
614 data->mountfd = open(ctx->fs_root, O_DIRECTORY);
615 if (data->mountfd < 0) {
616 ret = data->mountfd;
617 goto err_out;
619 ret = statfs(ctx->fs_root, &stbuf);
620 if (!ret) {
621 switch (stbuf.f_type) {
622 case EXT2_SUPER_MAGIC:
623 case BTRFS_SUPER_MAGIC:
624 case REISERFS_SUPER_MAGIC:
625 case XFS_SUPER_MAGIC:
626 ctx->exops.get_st_gen = handle_ioc_getversion;
627 break;
630 memset(&fh, 0, sizeof(struct file_handle));
631 ret = name_to_handle(data->mountfd, ".", &fh, &mnt_id, 0);
632 if (ret && errno == EOVERFLOW) {
633 data->handle_bytes = fh.handle_bytes;
634 ctx->private = data;
635 ret = 0;
636 goto out;
638 /* we got 0 byte handle ? */
639 ret = -1;
640 close(data->mountfd);
641 err_out:
642 g_free(data);
643 out:
644 return ret;
647 static void handle_cleanup(FsContext *ctx)
649 HandleData *data = ctx->private;
651 close(data->mountfd);
652 g_free(data);
655 static int handle_parse_opts(QemuOpts *opts, FsDriverEntry *fse, Error **errp)
657 const char *sec_model = qemu_opt_get(opts, "security_model");
658 const char *path = qemu_opt_get(opts, "path");
660 warn_report("handle backend is deprecated");
662 if (sec_model) {
663 error_report("Invalid argument security_model specified with handle fsdriver");
664 return -1;
667 if (!path) {
668 error_report("fsdev: No path specified");
669 return -1;
671 fse->path = g_strdup(path);
672 return 0;
676 FileOperations handle_ops = {
677 .parse_opts = handle_parse_opts,
678 .init = handle_init,
679 .cleanup = handle_cleanup,
680 .lstat = handle_lstat,
681 .readlink = handle_readlink,
682 .close = handle_close,
683 .closedir = handle_closedir,
684 .open = handle_open,
685 .opendir = handle_opendir,
686 .rewinddir = handle_rewinddir,
687 .telldir = handle_telldir,
688 .readdir = handle_readdir,
689 .seekdir = handle_seekdir,
690 .preadv = handle_preadv,
691 .pwritev = handle_pwritev,
692 .chmod = handle_chmod,
693 .mknod = handle_mknod,
694 .mkdir = handle_mkdir,
695 .fstat = handle_fstat,
696 .open2 = handle_open2,
697 .symlink = handle_symlink,
698 .link = handle_link,
699 .truncate = handle_truncate,
700 .rename = handle_rename,
701 .chown = handle_chown,
702 .utimensat = handle_utimensat,
703 .remove = handle_remove,
704 .fsync = handle_fsync,
705 .statfs = handle_statfs,
706 .lgetxattr = handle_lgetxattr,
707 .llistxattr = handle_llistxattr,
708 .lsetxattr = handle_lsetxattr,
709 .lremovexattr = handle_lremovexattr,
710 .name_to_path = handle_name_to_path,
711 .renameat = handle_renameat,
712 .unlinkat = handle_unlinkat,