2 * Module to make use of awesome Btrfs features
4 * Copyright (C) David Disseldorp 2011-2013
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
20 #include <linux/ioctl.h>
22 #include <sys/ioctl.h>
27 #include "system/filesys.h"
29 #include "smbd/smbd.h"
30 #include "smbd/globals.h"
31 #include "librpc/gen_ndr/smbXsrv.h"
32 #include "librpc/gen_ndr/ioctl.h"
33 #include "lib/util/tevent_ntstatus.h"
34 #include "offload_token.h"
36 static uint32_t btrfs_fs_capabilities(struct vfs_handle_struct *handle,
37 enum timestamp_set_resolution *_ts_res)
39 uint32_t fs_capabilities;
40 enum timestamp_set_resolution ts_res;
42 /* inherit default capabilities, expose compression support */
43 fs_capabilities = SMB_VFS_NEXT_FS_CAPABILITIES(handle, &ts_res);
44 fs_capabilities |= (FILE_FILE_COMPRESSION
45 | FILE_SUPPORTS_BLOCK_REFCOUNTING);
48 return fs_capabilities;
51 #define SHADOW_COPY_PREFIX "@GMT-" /* vfs_shadow_copy format */
52 #define SHADOW_COPY_PATH_FORMAT "@GMT-%Y.%m.%d-%H.%M.%S"
54 #define BTRFS_SUBVOL_RDONLY (1ULL << 1)
55 #define BTRFS_SUBVOL_NAME_MAX 4039
56 #define BTRFS_PATH_NAME_MAX 4087
57 struct btrfs_ioctl_vol_args_v2 {
62 char name[BTRFS_SUBVOL_NAME_MAX + 1];
64 struct btrfs_ioctl_vol_args {
66 char name[BTRFS_PATH_NAME_MAX + 1];
69 struct btrfs_ioctl_clone_range_args {
76 #define BTRFS_IOCTL_MAGIC 0x94
77 #define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
78 struct btrfs_ioctl_clone_range_args)
79 #define BTRFS_IOC_SNAP_DESTROY _IOW(BTRFS_IOCTL_MAGIC, 15, \
80 struct btrfs_ioctl_vol_args)
81 #define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
82 struct btrfs_ioctl_vol_args_v2)
84 static struct vfs_offload_ctx *btrfs_offload_ctx;
86 struct btrfs_offload_read_state {
87 struct vfs_handle_struct *handle;
94 static void btrfs_offload_read_done(struct tevent_req *subreq);
96 static struct tevent_req *btrfs_offload_read_send(
98 struct tevent_context *ev,
99 struct vfs_handle_struct *handle,
106 struct tevent_req *req = NULL;
107 struct tevent_req *subreq = NULL;
108 struct btrfs_offload_read_state *state = NULL;
111 req = tevent_req_create(mem_ctx, &state,
112 struct btrfs_offload_read_state);
116 *state = (struct btrfs_offload_read_state) {
121 status = vfs_offload_token_ctx_init(fsp->conn->sconn->client,
123 if (tevent_req_nterror(req, status)) {
124 return tevent_req_post(req, ev);
127 if (fsctl == FSCTL_DUP_EXTENTS_TO_FILE) {
128 status = vfs_offload_token_create_blob(state, fsp, fsctl,
130 if (tevent_req_nterror(req, status)) {
131 return tevent_req_post(req, ev);
134 status = vfs_offload_token_db_store_fsp(btrfs_offload_ctx, fsp,
136 if (tevent_req_nterror(req, status)) {
137 return tevent_req_post(req, ev);
139 tevent_req_done(req);
140 return tevent_req_post(req, ev);
143 subreq = SMB_VFS_NEXT_OFFLOAD_READ_SEND(mem_ctx, ev, handle, fsp,
144 fsctl, ttl, offset, to_copy);
145 if (tevent_req_nomem(subreq, req)) {
146 return tevent_req_post(req, ev);
148 tevent_req_set_callback(subreq, btrfs_offload_read_done, req);
152 static void btrfs_offload_read_done(struct tevent_req *subreq)
154 struct tevent_req *req = tevent_req_callback_data(
155 subreq, struct tevent_req);
156 struct btrfs_offload_read_state *state = tevent_req_data(
157 req, struct btrfs_offload_read_state);
160 status = SMB_VFS_NEXT_OFFLOAD_READ_RECV(subreq,
167 if (tevent_req_nterror(req, status)) {
171 status = vfs_offload_token_db_store_fsp(btrfs_offload_ctx,
174 if (tevent_req_nterror(req, status)) {
178 tevent_req_done(req);
182 static NTSTATUS btrfs_offload_read_recv(struct tevent_req *req,
183 struct vfs_handle_struct *handle,
189 struct btrfs_offload_read_state *state = tevent_req_data(
190 req, struct btrfs_offload_read_state);
193 if (tevent_req_is_nterror(req, &status)) {
194 tevent_req_received(req);
198 *flags = state->flags;
199 *xferlen = state->xferlen;
200 token->length = state->token.length;
201 token->data = talloc_move(mem_ctx, &state->token.data);
203 tevent_req_received(req);
207 struct btrfs_offload_write_state {
208 struct vfs_handle_struct *handle;
210 bool need_unbecome_user;
213 static void btrfs_offload_write_cleanup(struct tevent_req *req,
214 enum tevent_req_state req_state)
216 struct btrfs_offload_write_state *state =
218 struct btrfs_offload_write_state);
221 if (!state->need_unbecome_user) {
225 ok = unbecome_user_without_service();
227 state->need_unbecome_user = false;
230 static void btrfs_offload_write_done(struct tevent_req *subreq);
232 static struct tevent_req *btrfs_offload_write_send(struct vfs_handle_struct *handle,
234 struct tevent_context *ev,
237 off_t transfer_offset,
238 struct files_struct *dest_fsp,
242 struct tevent_req *req = NULL;
243 struct btrfs_offload_write_state *state = NULL;
244 struct tevent_req *subreq = NULL;
245 struct btrfs_ioctl_clone_range_args cr_args;
246 struct lock_struct src_lck;
247 struct lock_struct dest_lck;
248 off_t src_off = transfer_offset;
249 files_struct *src_fsp = NULL;
251 bool handle_offload_write = true;
252 bool do_locking = false;
256 req = tevent_req_create(mem_ctx, &state,
257 struct btrfs_offload_write_state);
262 state->handle = handle;
264 tevent_req_set_cleanup_fn(req, btrfs_offload_write_cleanup);
266 status = vfs_offload_token_db_fetch_fsp(btrfs_offload_ctx,
268 if (tevent_req_nterror(req, status)) {
269 return tevent_req_post(req, ev);
273 case FSCTL_SRV_COPYCHUNK:
274 case FSCTL_SRV_COPYCHUNK_WRITE:
278 case FSCTL_DUP_EXTENTS_TO_FILE:
279 /* dup extents does not use locking */
283 handle_offload_write = false;
289 * With a @src_length of zero, BTRFS_IOC_CLONE_RANGE clones
290 * all data from @src_offset->EOF! This is certainly not what
291 * the caller expects, and not what vfs_default does.
293 handle_offload_write = false;
296 if (!handle_offload_write) {
297 subreq = SMB_VFS_NEXT_OFFLOAD_WRITE_SEND(handle,
306 if (tevent_req_nomem(subreq, req)) {
307 return tevent_req_post(req, ev);
309 tevent_req_set_callback(subreq,
310 btrfs_offload_write_done,
315 status = vfs_offload_token_check_handles(
316 fsctl, src_fsp, dest_fsp);
317 if (!NT_STATUS_IS_OK(status)) {
318 tevent_req_nterror(req, status);
319 return tevent_req_post(req, ev);
322 ok = become_user_without_service_by_fsp(src_fsp);
324 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
325 return tevent_req_post(req, ev);
327 state->need_unbecome_user = true;
329 status = vfs_stat_fsp(src_fsp);
330 if (tevent_req_nterror(req, status)) {
331 return tevent_req_post(req, ev);
334 if (src_fsp->fsp_name->st.st_ex_size < src_off + num) {
335 /* [MS-SMB2] Handling a Server-Side Data Copy Request */
336 tevent_req_nterror(req, NT_STATUS_INVALID_VIEW_SIZE);
337 return tevent_req_post(req, ev);
341 init_strict_lock_struct(src_fsp,
342 src_fsp->op->global->open_persistent_id,
347 if (!SMB_VFS_STRICT_LOCK_CHECK(src_fsp->conn, src_fsp, &src_lck)) {
348 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
349 return tevent_req_post(req, ev);
353 ok = unbecome_user_without_service();
355 state->need_unbecome_user = false;
358 init_strict_lock_struct(dest_fsp,
359 dest_fsp->op->global->open_persistent_id,
365 if (!SMB_VFS_STRICT_LOCK_CHECK(dest_fsp->conn, dest_fsp, &dest_lck)) {
366 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
367 return tevent_req_post(req, ev);
371 ZERO_STRUCT(cr_args);
372 cr_args.src_fd = fsp_get_io_fd(src_fsp);
373 cr_args.src_offset = (uint64_t)src_off;
374 cr_args.dest_offset = (uint64_t)dest_off;
375 cr_args.src_length = (uint64_t)num;
377 ret = ioctl(fsp_get_io_fd(dest_fsp), BTRFS_IOC_CLONE_RANGE, &cr_args);
380 * BTRFS_IOC_CLONE_RANGE only supports 'sectorsize' aligned
381 * cloning. Which is 4096 by default, therefore fall back to
382 * manual read/write on failure.
384 DEBUG(5, ("BTRFS_IOC_CLONE_RANGE failed: %s, length %llu, "
385 "src fd: %lld off: %llu, dest fd: %d off: %llu\n",
387 (unsigned long long)cr_args.src_length,
388 (long long)cr_args.src_fd,
389 (unsigned long long)cr_args.src_offset,
390 fsp_get_io_fd(dest_fsp),
391 (unsigned long long)cr_args.dest_offset));
392 subreq = SMB_VFS_NEXT_OFFLOAD_WRITE_SEND(handle,
401 if (tevent_req_nomem(subreq, req)) {
402 return tevent_req_post(req, ev);
404 /* wait for subreq completion */
405 tevent_req_set_callback(subreq,
406 btrfs_offload_write_done,
411 DEBUG(5, ("BTRFS_IOC_CLONE_RANGE returned %d\n", ret));
412 /* BTRFS_IOC_CLONE_RANGE is all or nothing */
414 tevent_req_done(req);
415 return tevent_req_post(req, ev);
418 /* only used if the request is passed through to next VFS module */
419 static void btrfs_offload_write_done(struct tevent_req *subreq)
421 struct tevent_req *req =
422 tevent_req_callback_data(subreq,
424 struct btrfs_offload_write_state *state =
426 struct btrfs_offload_write_state);
429 status = SMB_VFS_NEXT_OFFLOAD_WRITE_RECV(state->handle,
433 if (tevent_req_nterror(req, status)) {
436 tevent_req_done(req);
439 static NTSTATUS btrfs_offload_write_recv(struct vfs_handle_struct *handle,
440 struct tevent_req *req,
443 struct btrfs_offload_write_state *state =
445 struct btrfs_offload_write_state);
448 if (tevent_req_is_nterror(req, &status)) {
449 DEBUG(4, ("server side copy chunk failed: %s\n",
451 tevent_req_received(req);
455 DEBUG(10, ("server side copy chunk copied %llu\n",
456 (unsigned long long)state->copied));
457 *copied = state->copied;
458 tevent_req_received(req);
462 static NTSTATUS btrfs_fget_compression(struct vfs_handle_struct *handle,
464 struct files_struct *fsp,
465 uint16_t *_compression_fmt)
468 const char *p = NULL;
471 int fsp_fd = fsp_get_pathref_fd(fsp);
475 if (!fsp->fsp_flags.is_pathref) {
476 ret = ioctl(fsp_fd, FS_IOC_GETFLAGS, &flags);
478 DBG_WARNING("FS_IOC_GETFLAGS failed: %s, fd %lld\n",
479 strerror(errno), (long long)fd);
480 return map_nt_error_from_unix(errno);
482 if (flags & FS_COMPR_FL) {
483 *_compression_fmt = COMPRESSION_FORMAT_LZNT1;
485 *_compression_fmt = COMPRESSION_FORMAT_NONE;
490 if (!fsp->fsp_flags.have_proc_fds) {
491 return NT_STATUS_NOT_IMPLEMENTED;
494 p = sys_proc_fd_path(fsp_fd, buf, sizeof(buf));
496 return NT_STATUS_NO_MEMORY;
499 fd = open(p, O_RDONLY);
501 DBG_ERR("/proc open of %s failed: %s\n", p, strerror(errno));
502 return map_nt_error_from_unix(errno);
505 ret = ioctl(fd, FS_IOC_GETFLAGS, &flags);
507 DEBUG(1, ("FS_IOC_GETFLAGS failed: %s, fd %lld\n",
508 strerror(errno), (long long)fd));
509 status = map_nt_error_from_unix(errno);
512 if (flags & FS_COMPR_FL) {
513 *_compression_fmt = COMPRESSION_FORMAT_LZNT1;
515 *_compression_fmt = COMPRESSION_FORMAT_NONE;
517 status = NT_STATUS_OK;
527 static NTSTATUS btrfs_set_compression(struct vfs_handle_struct *handle,
529 struct files_struct *fsp,
530 uint16_t compression_fmt)
537 if ((fsp == NULL) || (fsp_get_io_fd(fsp) == -1)) {
538 status = NT_STATUS_INVALID_PARAMETER;
541 fd = fsp_get_io_fd(fsp);
543 ret = ioctl(fd, FS_IOC_GETFLAGS, &flags);
545 DEBUG(1, ("FS_IOC_GETFLAGS failed: %s, fd %d\n",
546 strerror(errno), fd));
547 status = map_nt_error_from_unix(errno);
551 if (compression_fmt == COMPRESSION_FORMAT_NONE) {
552 DEBUG(5, ("setting compression\n"));
553 flags &= (~FS_COMPR_FL);
554 } else if ((compression_fmt == COMPRESSION_FORMAT_DEFAULT)
555 || (compression_fmt == COMPRESSION_FORMAT_LZNT1)) {
556 DEBUG(5, ("clearing compression\n"));
557 flags |= FS_COMPR_FL;
559 DEBUG(1, ("invalid compression format 0x%x\n",
560 (int)compression_fmt));
561 status = NT_STATUS_INVALID_PARAMETER;
565 ret = ioctl(fd, FS_IOC_SETFLAGS, &flags);
567 DEBUG(1, ("FS_IOC_SETFLAGS failed: %s, fd %d\n",
568 strerror(errno), fd));
569 status = map_nt_error_from_unix(errno);
572 status = NT_STATUS_OK;
578 * Check whether a path can be shadow copied. Return the base volume, allowing
579 * the caller to determine if multiple paths lie on the same base volume.
581 #define BTRFS_INODE_SUBVOL 256
582 static NTSTATUS btrfs_snap_check_path(struct vfs_handle_struct *handle,
584 const char *service_path,
590 if (!lp_parm_bool(SNUM(handle->conn),
591 "btrfs", "manipulate snapshots", false)) {
592 DEBUG(2, ("Btrfs snapshot manipulation disabled, passing\n"));
593 return SMB_VFS_NEXT_SNAP_CHECK_PATH(handle, mem_ctx,
594 service_path, base_volume);
597 /* btrfs userspace uses this logic to confirm subvolume */
598 if (stat(service_path, &st) < 0) {
599 return NT_STATUS_NOT_SUPPORTED;
601 if ((st.st_ino != BTRFS_INODE_SUBVOL) || !S_ISDIR(st.st_mode)) {
602 DEBUG(0, ("%s not a btrfs subvolume, snapshots not available\n",
604 return NT_STATUS_NOT_SUPPORTED;
607 /* we "snapshot" the service path itself */
608 base = talloc_strdup(mem_ctx, service_path);
610 return NT_STATUS_NO_MEMORY;
617 static NTSTATUS btrfs_gen_snap_dest_path(TALLOC_CTX *mem_ctx,
618 const char *src_path,
620 char **dest_path, char **subvolume)
626 gmtime_r(tstamp, &t_gmt);
628 tlen = strftime(time_str, ARRAY_SIZE(time_str),
629 SHADOW_COPY_PATH_FORMAT, &t_gmt);
631 return NT_STATUS_UNSUCCESSFUL;
634 *dest_path = talloc_strdup(mem_ctx, src_path);
635 *subvolume = talloc_strdup(mem_ctx, time_str);
636 if ((*dest_path == NULL) || (*subvolume == NULL)) {
637 return NT_STATUS_NO_MEMORY;
643 static NTSTATUS btrfs_snap_create(struct vfs_handle_struct *handle,
645 const char *base_volume,
651 struct btrfs_ioctl_vol_args_v2 ioctl_arg;
656 char *dest_path = NULL;
657 char *dest_subvolume = NULL;
666 if (!lp_parm_bool(SNUM(handle->conn),
667 "btrfs", "manipulate snapshots", false)) {
668 DEBUG(2, ("Btrfs snapshot manipulation disabled, passing\n"));
669 return SMB_VFS_NEXT_SNAP_CREATE(handle, mem_ctx, base_volume,
670 tstamp, rw, _base_path,
674 tmp_ctx = talloc_new(mem_ctx);
675 if (tmp_ctx == NULL) {
676 return NT_STATUS_NO_MEMORY;
679 base_path = talloc_strdup(tmp_ctx, base_volume);
680 if (base_path == NULL) {
681 talloc_free(tmp_ctx);
682 return NT_STATUS_NO_MEMORY;
685 status = btrfs_gen_snap_dest_path(tmp_ctx, base_volume, tstamp,
686 &dest_path, &dest_subvolume);
687 if (!NT_STATUS_IS_OK(status)) {
688 talloc_free(tmp_ctx);
692 snap_path = talloc_asprintf(tmp_ctx, "%s/%s", dest_path,
694 if (snap_path == NULL) {
695 talloc_free(tmp_ctx);
696 return NT_STATUS_NO_MEMORY;
699 src_dir = opendir(base_volume);
700 if (src_dir == NULL) {
701 DEBUG(0, ("snap src %s open failed: %s\n",
702 base_volume, strerror(errno)));
703 status = map_nt_error_from_unix(errno);
704 talloc_free(tmp_ctx);
707 src_fd = dirfd(src_dir);
709 status = map_nt_error_from_unix(errno);
711 talloc_free(tmp_ctx);
715 dest_dir = opendir(dest_path);
716 if (dest_dir == NULL) {
717 DEBUG(0, ("snap dest %s open failed: %s\n",
718 dest_path, strerror(errno)));
719 status = map_nt_error_from_unix(errno);
721 talloc_free(tmp_ctx);
724 dest_fd = dirfd(dest_dir);
726 status = map_nt_error_from_unix(errno);
729 talloc_free(tmp_ctx);
733 /* avoid zeroing the entire struct here, name is 4k */
734 ioctl_arg.fd = src_fd;
735 ioctl_arg.transid = 0;
736 ioctl_arg.flags = (rw == false) ? BTRFS_SUBVOL_RDONLY : 0;
737 memset(ioctl_arg.unused, 0, sizeof(ioctl_arg.unused));
738 len = strlcpy(ioctl_arg.name, dest_subvolume,
739 ARRAY_SIZE(ioctl_arg.name));
740 if (len >= ARRAY_SIZE(ioctl_arg.name)) {
741 DEBUG(1, ("subvolume name too long for SNAP_CREATE ioctl\n"));
744 talloc_free(tmp_ctx);
745 return NT_STATUS_INVALID_PARAMETER;
749 ret = ioctl(dest_fd, BTRFS_IOC_SNAP_CREATE_V2, &ioctl_arg);
753 DEBUG(0, ("%s -> %s(%s) BTRFS_IOC_SNAP_CREATE_V2 failed: %s\n",
754 base_volume, dest_path, dest_subvolume,
755 strerror(saved_errno)));
756 status = map_nt_error_from_unix(saved_errno);
759 talloc_free(tmp_ctx);
762 DEBUG(5, ("%s -> %s(%s) BTRFS_IOC_SNAP_CREATE_V2 done\n",
763 base_volume, dest_path, dest_subvolume));
765 *_base_path = talloc_steal(mem_ctx, base_path);
766 *_snap_path = talloc_steal(mem_ctx, snap_path);
769 talloc_free(tmp_ctx);
774 static NTSTATUS btrfs_snap_delete(struct vfs_handle_struct *handle,
783 struct btrfs_ioctl_vol_args ioctl_arg;
792 if (!lp_parm_bool(SNUM(handle->conn),
793 "btrfs", "manipulate snapshots", false)) {
794 DEBUG(2, ("Btrfs snapshot manipulation disabled, passing\n"));
795 return SMB_VFS_NEXT_SNAP_DELETE(handle, mem_ctx,
796 base_path, snap_path);
799 tmp_ctx = talloc_new(mem_ctx);
800 if (tmp_ctx == NULL) {
801 return NT_STATUS_NO_MEMORY;
804 dest_path = talloc_strdup(tmp_ctx, snap_path);
805 if (dest_path == NULL) {
806 talloc_free(tmp_ctx);
807 return NT_STATUS_NO_MEMORY;
809 subvolume = talloc_strdup(tmp_ctx, snap_path);
810 if (subvolume == NULL) {
811 talloc_free(tmp_ctx);
812 return NT_STATUS_NO_MEMORY;
814 dest_path = dirname(dest_path);
815 subvolume = basename(subvolume);
817 /* confirm snap_path matches creation format */
818 tstr = strptime(subvolume, SHADOW_COPY_PATH_FORMAT, &t_gmt);
819 if ((tstr == NULL) || (*tstr != '\0')) {
820 DEBUG(0, ("snapshot path %s does not match creation format\n",
822 talloc_free(tmp_ctx);
823 return NT_STATUS_UNSUCCESSFUL;
826 dest_dir = opendir(dest_path);
827 if (dest_dir == NULL) {
828 DEBUG(0, ("snap destroy dest %s open failed: %s\n",
829 dest_path, strerror(errno)));
830 status = map_nt_error_from_unix(errno);
831 talloc_free(tmp_ctx);
834 dest_fd = dirfd(dest_dir);
836 status = map_nt_error_from_unix(errno);
838 talloc_free(tmp_ctx);
842 ioctl_arg.fd = -1; /* not needed */
843 len = strlcpy(ioctl_arg.name, subvolume, ARRAY_SIZE(ioctl_arg.name));
844 if (len >= ARRAY_SIZE(ioctl_arg.name)) {
845 DEBUG(1, ("subvolume name too long for SNAP_DESTROY ioctl\n"));
847 talloc_free(tmp_ctx);
848 return NT_STATUS_INVALID_PARAMETER;
852 ret = ioctl(dest_fd, BTRFS_IOC_SNAP_DESTROY, &ioctl_arg);
856 DEBUG(0, ("%s(%s) BTRFS_IOC_SNAP_DESTROY failed: %s\n",
857 dest_path, subvolume, strerror(saved_errno)));
858 status = map_nt_error_from_unix(saved_errno);
860 talloc_free(tmp_ctx);
863 DEBUG(5, ("%s(%s) BTRFS_IOC_SNAP_DESTROY done\n",
864 dest_path, subvolume));
867 talloc_free(tmp_ctx);
871 static struct vfs_fn_pointers btrfs_fns = {
872 .fs_capabilities_fn = btrfs_fs_capabilities,
873 .offload_read_send_fn = btrfs_offload_read_send,
874 .offload_read_recv_fn = btrfs_offload_read_recv,
875 .offload_write_send_fn = btrfs_offload_write_send,
876 .offload_write_recv_fn = btrfs_offload_write_recv,
877 .fget_compression_fn = btrfs_fget_compression,
878 .set_compression_fn = btrfs_set_compression,
879 .snap_check_path_fn = btrfs_snap_check_path,
880 .snap_create_fn = btrfs_snap_create,
881 .snap_delete_fn = btrfs_snap_delete,
885 NTSTATUS vfs_btrfs_init(TALLOC_CTX *ctx)
887 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
888 "btrfs", &btrfs_fns);