2 * Store streams in a separate subdirectory
4 * Copyright (C) Volker Lendecke, 2007
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/>.
23 #define DBGC_CLASS DBGC_VFS
26 * Excerpt from a mail from tridge:
28 * Volker, what I'm thinking of is this:
29 * /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream1
30 * /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream2
32 * where XX/YY is a 2 level hash based on the fsid/inode. "aaaa.bbbb"
33 * is the fsid/inode. "namedstreamX" is a file named after the stream
37 static uint32_t hash_fn(DATA_BLOB key)
39 uint32_t value; /* Used to compute the hash value. */
40 uint32_t i; /* Used to cycle through random values. */
42 /* Set the initial value from the key size. */
43 for (value = 0x238F13AF * key.length, i=0; i < key.length; i++)
44 value = (value + (key.data[i] << (i*5 % 24)));
46 return (1103515243 * value + 12345);
50 * With the hashing scheme based on the inode we need to protect against
51 * streams showing up on files with re-used inodes. This can happen if we
52 * create a stream directory from within Samba, and a local process or NFS
53 * client deletes the file without deleting the streams directory. When the
54 * inode is re-used and the stream directory is still around, the streams in
55 * there would be show up as belonging to the new file.
57 * There are several workarounds for this, probably the easiest one is on
58 * systems which have a true birthtime stat element: When the file has a later
59 * birthtime than the streams directory, then we have to recreate the
62 * The other workaround is to somehow mark the file as generated by Samba with
63 * something that a NFS client would not do. The closest one is a special
64 * xattr value being set. On systems which do not support xattrs, it might be
65 * an option to put in a special ACL entry for a non-existing group.
68 #define SAMBA_XATTR_MARKER "user.SAMBA_STREAMS"
70 static bool file_is_valid(vfs_handle_struct *handle, const char *path)
74 DEBUG(10, ("file_is_valid (%s) called\n", path));
76 if (SMB_VFS_NEXT_GETXATTR(handle, path, SAMBA_XATTR_MARKER,
77 &buf, sizeof(buf)) != sizeof(buf)) {
78 DEBUG(10, ("GETXATTR failed: %s\n", strerror(errno)));
83 DEBUG(10, ("got wrong buffer content: '%c'\n", buf));
90 static bool mark_file_valid(vfs_handle_struct *handle, const char *path)
95 DEBUG(10, ("marking file %s as valid\n", path));
97 ret = SMB_VFS_NEXT_SETXATTR(handle, path, SAMBA_XATTR_MARKER,
98 &buf, sizeof(buf), 0);
101 DEBUG(10, ("SETXATTR failed: %s\n", strerror(errno)));
108 static char *stream_dir(vfs_handle_struct *handle, const char *base_path,
109 const SMB_STRUCT_STAT *base_sbuf, bool create_it)
113 SMB_STRUCT_STAT sbuf;
114 uint8_t first, second;
121 tmp = talloc_asprintf(talloc_tos(), "%s/.streams", handle->conn->connectpath);
128 rootdir = lp_parm_const_string(
129 SNUM(handle->conn), "streams_depot", "directory",
133 if (base_sbuf == NULL) {
134 if (SMB_VFS_NEXT_STAT(handle, base_path, &sbuf) == -1) {
136 * base file is not there
143 id = SMB_VFS_FILE_ID_CREATE(handle->conn, base_sbuf->st_dev,
146 push_file_id_16((char *)id_buf, &id);
148 hash = hash_fn(data_blob_const(id_buf, sizeof(id_buf)));
151 second = (hash >> 8) & 0xff;
153 id_hex = hex_encode_talloc(talloc_tos(), id_buf, sizeof(id_buf));
155 if (id_hex == NULL) {
160 result = talloc_asprintf(talloc_tos(), "%s/%2.2X/%2.2X/%s", rootdir,
161 first, second, id_hex);
165 if (result == NULL) {
170 if (SMB_VFS_NEXT_STAT(handle, result, &sbuf) == 0) {
173 if (!S_ISDIR(sbuf.st_mode)) {
178 if (file_is_valid(handle, base_path)) {
183 * Someone has recreated a file under an existing inode
184 * without deleting the streams directory. For now, just move
189 newname = talloc_asprintf(talloc_tos(), "lost-%lu", random());
190 if (newname == NULL) {
195 if (SMB_VFS_NEXT_RENAME(handle, result, newname) == -1) {
196 if ((errno == EEXIST) || (errno == ENOTEMPTY)) {
197 TALLOC_FREE(newname);
203 TALLOC_FREE(newname);
211 if ((SMB_VFS_NEXT_MKDIR(handle, rootdir, 0755) != 0)
212 && (errno != EEXIST)) {
216 tmp = talloc_asprintf(result, "%s/%2.2X", rootdir, first);
222 if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
223 && (errno != EEXIST)) {
229 tmp = talloc_asprintf(result, "%s/%2.2X/%2.2X", rootdir, first,
236 if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
237 && (errno != EEXIST)) {
243 if ((SMB_VFS_NEXT_MKDIR(handle, result, 0755) != 0)
244 && (errno != EEXIST)) {
248 if (!mark_file_valid(handle, base_path)) {
259 static char *stream_name(vfs_handle_struct *handle, const char *fname,
265 char *dirname, *stream_fname;
267 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
269 DEBUG(10, ("split_ntfs_stream_name failed\n"));
274 /* if it's the ::$DATA stream just return the base file name */
279 dirname = stream_dir(handle, base, NULL, create_dir);
281 if (dirname == NULL) {
285 stream_fname = talloc_asprintf(talloc_tos(), "%s/:%s", dirname, sname);
287 if (stream_fname == NULL) {
292 DEBUG(10, ("stream filename = %s\n", stream_fname));
301 DEBUG(5, ("stream_name failed: %s\n", strerror(errno)));
308 static NTSTATUS walk_streams(vfs_handle_struct *handle,
310 const SMB_STRUCT_STAT *sbuf,
312 bool (*fn)(const char *dirname,
318 SMB_STRUCT_DIR *dirhandle = NULL;
321 dirname = stream_dir(handle, fname, sbuf, false);
323 if (dirname == NULL) {
324 if (errno == ENOENT) {
330 return map_nt_error_from_unix(errno);
333 DEBUG(10, ("walk_streams: dirname=%s\n", dirname));
335 dirhandle = SMB_VFS_NEXT_OPENDIR(handle, dirname, NULL, 0);
337 if (dirhandle == NULL) {
338 TALLOC_FREE(dirname);
339 return map_nt_error_from_unix(errno);
342 while ((dirent = vfs_readdirname(handle->conn, dirhandle)) != NULL) {
344 if (ISDOT(dirent) || ISDOTDOT(dirent)) {
348 DEBUG(10, ("walk_streams: dirent=%s\n", dirent));
350 if (!fn(dirname, dirent, private_data)) {
355 SMB_VFS_NEXT_CLOSEDIR(handle, dirhandle);
357 if (pdirname != NULL) {
361 TALLOC_FREE(dirname);
367 static int streams_depot_stat(vfs_handle_struct *handle, const char *fname,
368 SMB_STRUCT_STAT *sbuf)
373 DEBUG(10, ("streams_depot_stat called for [%s]\n", fname));
375 if (!is_ntfs_stream_name(fname)) {
376 return SMB_VFS_NEXT_STAT(handle, fname, sbuf);
379 stream_fname = stream_name(handle, fname, false);
380 if (stream_fname == NULL) {
384 ret = SMB_VFS_NEXT_STAT(handle, stream_fname, sbuf);
387 TALLOC_FREE(stream_fname);
391 static int streams_depot_lstat(vfs_handle_struct *handle, const char *fname,
392 SMB_STRUCT_STAT *sbuf)
397 if (!is_ntfs_stream_name(fname)) {
398 return SMB_VFS_NEXT_LSTAT(handle, fname, sbuf);
401 stream_fname = stream_name(handle, fname, false);
402 if (stream_fname == NULL) {
406 ret = SMB_VFS_NEXT_LSTAT(handle, stream_fname, sbuf);
409 TALLOC_FREE(stream_fname);
413 static int streams_depot_open(vfs_handle_struct *handle, const char *fname,
414 files_struct *fsp, int flags, mode_t mode)
419 SMB_STRUCT_STAT base_sbuf;
423 if (!is_ntfs_stream_name(fname)) {
424 return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
427 frame = talloc_stackframe();
429 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
436 ret = SMB_VFS_NEXT_OPEN(handle, base, fsp, flags, mode);
440 ret = SMB_VFS_NEXT_STAT(handle, base, &base_sbuf);
448 stream_fname = stream_name(handle, fname, true);
449 if (stream_fname == NULL) {
453 ret = SMB_VFS_NEXT_OPEN(handle, stream_fname, fsp, flags, mode);
460 static int streams_depot_unlink(vfs_handle_struct *handle, const char *fname)
463 SMB_STRUCT_STAT sbuf;
465 DEBUG(10, ("streams_depot_unlink called for %s\n", fname));
467 if (is_ntfs_stream_name(fname)) {
470 stream_fname = stream_name(handle, fname, false);
471 if (stream_fname == NULL) {
475 ret = SMB_VFS_NEXT_UNLINK(handle, stream_fname);
477 TALLOC_FREE(stream_fname);
482 * We potentially need to delete the per-inode streams directory
485 if (SMB_VFS_NEXT_STAT(handle, fname, &sbuf) == -1) {
489 if (sbuf.st_nlink == 1) {
490 char *dirname = stream_dir(handle, fname, &sbuf, false);
492 if (dirname != NULL) {
493 SMB_VFS_NEXT_RMDIR(handle, dirname);
495 TALLOC_FREE(dirname);
498 return SMB_VFS_NEXT_UNLINK(handle, fname);
501 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
502 struct stream_struct **streams,
503 const char *name, SMB_OFF_T size,
504 SMB_OFF_T alloc_size)
506 struct stream_struct *tmp;
508 tmp = TALLOC_REALLOC_ARRAY(mem_ctx, *streams, struct stream_struct,
514 tmp[*num_streams].name = talloc_strdup(tmp, name);
515 if (tmp[*num_streams].name == NULL) {
519 tmp[*num_streams].size = size;
520 tmp[*num_streams].alloc_size = alloc_size;
527 struct streaminfo_state {
529 vfs_handle_struct *handle;
530 unsigned int num_streams;
531 struct stream_struct *streams;
535 static bool collect_one_stream(const char *dirname,
539 struct streaminfo_state *state =
540 (struct streaminfo_state *)private_data;
542 SMB_STRUCT_STAT sbuf;
544 if (asprintf(&full_sname, "%s/%s", dirname, dirent) == -1) {
545 state->status = NT_STATUS_NO_MEMORY;
548 if (SMB_VFS_NEXT_STAT(state->handle, full_sname, &sbuf) == -1) {
549 DEBUG(10, ("Could not stat %s: %s\n", full_sname,
551 SAFE_FREE(full_sname);
555 SAFE_FREE(full_sname);
557 if (!add_one_stream(state->mem_ctx,
558 &state->num_streams, &state->streams,
559 dirent, sbuf.st_size,
561 state->handle->conn, NULL, &sbuf))) {
562 state->status = NT_STATUS_NO_MEMORY;
569 static NTSTATUS streams_depot_streaminfo(vfs_handle_struct *handle,
570 struct files_struct *fsp,
573 unsigned int *pnum_streams,
574 struct stream_struct **pstreams)
576 SMB_STRUCT_STAT sbuf;
579 struct streaminfo_state state;
581 if ((fsp != NULL) && (fsp->fh->fd != -1)) {
582 if (is_ntfs_stream_name(fsp->fsp_name)) {
583 return NT_STATUS_INVALID_PARAMETER;
585 ret = SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf);
588 if (is_ntfs_stream_name(fname)) {
589 return NT_STATUS_INVALID_PARAMETER;
591 ret = SMB_VFS_NEXT_STAT(handle, fname, &sbuf);
595 return map_nt_error_from_unix(errno);
598 state.streams = NULL;
599 state.num_streams = 0;
601 if (!S_ISDIR(sbuf.st_mode)) {
602 if (!add_one_stream(mem_ctx,
603 &state.num_streams, &state.streams,
604 "::$DATA", sbuf.st_size,
605 get_allocation_size(handle->conn, fsp,
607 return NT_STATUS_NO_MEMORY;
611 state.mem_ctx = mem_ctx;
612 state.handle = handle;
613 state.status = NT_STATUS_OK;
615 status = walk_streams(handle, fname, &sbuf, NULL, collect_one_stream,
618 if (!NT_STATUS_IS_OK(status)) {
619 TALLOC_FREE(state.streams);
623 if (!NT_STATUS_IS_OK(state.status)) {
624 TALLOC_FREE(state.streams);
628 *pnum_streams = state.num_streams;
629 *pstreams = state.streams;
633 static uint32_t streams_depot_fs_capabilities(struct vfs_handle_struct *handle)
635 return SMB_VFS_NEXT_FS_CAPABILITIES(handle) | FILE_NAMED_STREAMS;
638 /* VFS operations structure */
640 static vfs_op_tuple streams_depot_ops[] = {
641 {SMB_VFS_OP(streams_depot_fs_capabilities), SMB_VFS_OP_FS_CAPABILITIES,
642 SMB_VFS_LAYER_TRANSPARENT},
643 {SMB_VFS_OP(streams_depot_open), SMB_VFS_OP_OPEN,
644 SMB_VFS_LAYER_TRANSPARENT},
645 {SMB_VFS_OP(streams_depot_stat), SMB_VFS_OP_STAT,
646 SMB_VFS_LAYER_TRANSPARENT},
647 {SMB_VFS_OP(streams_depot_lstat), SMB_VFS_OP_LSTAT,
648 SMB_VFS_LAYER_TRANSPARENT},
649 {SMB_VFS_OP(streams_depot_unlink), SMB_VFS_OP_UNLINK,
650 SMB_VFS_LAYER_TRANSPARENT},
651 {SMB_VFS_OP(streams_depot_streaminfo), SMB_VFS_OP_STREAMINFO,
652 SMB_VFS_LAYER_OPAQUE},
653 {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
656 NTSTATUS vfs_streams_depot_init(void);
657 NTSTATUS vfs_streams_depot_init(void)
659 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_depot",