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
;
120 tmp
= talloc_asprintf(talloc_tos(), "%s/.streams", handle
->conn
->connectpath
);
127 const char *rootdir
= lp_parm_const_string(
128 SNUM(handle
->conn
), "streams_depot", "directory",
132 if (base_sbuf
== NULL
) {
133 if (SMB_VFS_NEXT_STAT(handle
, base_path
, &sbuf
) == -1) {
135 * base file is not there
142 id
= SMB_VFS_FILE_ID_CREATE(handle
->conn
, base_sbuf
->st_dev
,
145 push_file_id_16((char *)id_buf
, &id
);
147 hash
= hash_fn(data_blob_const(id_buf
, sizeof(id_buf
)));
150 second
= (hash
>> 8) & 0xff;
152 id_hex
= hex_encode(talloc_tos(), id_buf
, sizeof(id_buf
));
154 if (id_hex
== NULL
) {
159 result
= talloc_asprintf(talloc_tos(), "%s/%2.2X/%2.2X/%s", rootdir
,
160 first
, second
, id_hex
);
164 if (result
== NULL
) {
169 if (SMB_VFS_NEXT_STAT(handle
, result
, &sbuf
) == 0) {
172 if (!S_ISDIR(sbuf
.st_mode
)) {
177 if (file_is_valid(handle
, base_path
)) {
182 * Someone has recreated a file under an existing inode
183 * without deleting the streams directory. For now, just move
188 newname
= talloc_asprintf(talloc_tos(), "lost-%lu", random());
189 if (newname
== NULL
) {
194 if (SMB_VFS_NEXT_RENAME(handle
, result
, newname
) == -1) {
195 if ((errno
== EEXIST
) || (errno
== ENOTEMPTY
)) {
196 TALLOC_FREE(newname
);
202 TALLOC_FREE(newname
);
210 if ((SMB_VFS_NEXT_MKDIR(handle
, rootdir
, 0755) != 0)
211 && (errno
!= EEXIST
)) {
215 tmp
= talloc_asprintf(result
, "%s/%2.2X", rootdir
, first
);
221 if ((SMB_VFS_NEXT_MKDIR(handle
, tmp
, 0755) != 0)
222 && (errno
!= EEXIST
)) {
228 tmp
= talloc_asprintf(result
, "%s/%2.2X/%2.2X", rootdir
, first
,
235 if ((SMB_VFS_NEXT_MKDIR(handle
, tmp
, 0755) != 0)
236 && (errno
!= EEXIST
)) {
242 if ((SMB_VFS_NEXT_MKDIR(handle
, result
, 0755) != 0)
243 && (errno
!= EEXIST
)) {
247 if (!mark_file_valid(handle
, base_path
)) {
258 static char *stream_name(vfs_handle_struct
*handle
, const char *fname
,
264 char *dirname
, *stream_fname
;
266 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname
,
268 DEBUG(10, ("split_ntfs_stream_name failed\n"));
273 dirname
= stream_dir(handle
, base
, NULL
, create_dir
);
275 if (dirname
== NULL
) {
279 stream_fname
= talloc_asprintf(talloc_tos(), "%s/:%s", dirname
, sname
);
281 if (stream_fname
== NULL
) {
286 DEBUG(10, ("stream filename = %s\n", stream_fname
));
295 DEBUG(5, ("stream_name failed: %s\n", strerror(errno
)));
302 static NTSTATUS
walk_streams(vfs_handle_struct
*handle
,
304 const SMB_STRUCT_STAT
*sbuf
,
306 bool (*fn
)(const char *dirname
,
312 SMB_STRUCT_DIR
*dirhandle
= NULL
;
315 dirname
= stream_dir(handle
, fname
, sbuf
, false);
317 if (dirname
== NULL
) {
318 if (errno
== ENOENT
) {
324 return map_nt_error_from_unix(errno
);
327 DEBUG(10, ("walk_streams: dirname=%s\n", dirname
));
329 dirhandle
= SMB_VFS_NEXT_OPENDIR(handle
, dirname
, NULL
, 0);
331 if (dirhandle
== NULL
) {
332 TALLOC_FREE(dirname
);
333 return map_nt_error_from_unix(errno
);
336 while ((dirent
= vfs_readdirname(handle
->conn
, dirhandle
)) != NULL
) {
338 if (ISDOT(dirent
) || ISDOTDOT(dirent
)) {
342 DEBUG(10, ("walk_streams: dirent=%s\n", dirent
));
344 if (!fn(dirname
, dirent
, private_data
)) {
349 SMB_VFS_NEXT_CLOSEDIR(handle
, dirhandle
);
351 if (pdirname
!= NULL
) {
355 TALLOC_FREE(dirname
);
361 static int streams_depot_stat(vfs_handle_struct
*handle
, const char *fname
,
362 SMB_STRUCT_STAT
*sbuf
)
367 DEBUG(10, ("streams_depot_stat called for [%s]\n", fname
));
369 if (!is_ntfs_stream_name(fname
)) {
370 return SMB_VFS_NEXT_STAT(handle
, fname
, sbuf
);
373 stream_fname
= stream_name(handle
, fname
, false);
374 if (stream_fname
== NULL
) {
378 ret
= SMB_VFS_NEXT_STAT(handle
, stream_fname
, sbuf
);
381 TALLOC_FREE(stream_fname
);
385 static int streams_depot_lstat(vfs_handle_struct
*handle
, const char *fname
,
386 SMB_STRUCT_STAT
*sbuf
)
391 if (!is_ntfs_stream_name(fname
)) {
392 return SMB_VFS_NEXT_LSTAT(handle
, fname
, sbuf
);
395 stream_fname
= stream_name(handle
, fname
, false);
396 if (stream_fname
== NULL
) {
400 ret
= SMB_VFS_NEXT_LSTAT(handle
, stream_fname
, sbuf
);
403 TALLOC_FREE(stream_fname
);
407 static int streams_depot_open(vfs_handle_struct
*handle
, const char *fname
,
408 files_struct
*fsp
, int flags
, mode_t mode
)
412 SMB_STRUCT_STAT base_sbuf
;
416 if (!is_ntfs_stream_name(fname
)) {
417 return SMB_VFS_NEXT_OPEN(handle
, fname
, fsp
, flags
, mode
);
420 frame
= talloc_stackframe();
422 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname
,
428 ret
= SMB_VFS_NEXT_STAT(handle
, base
, &base_sbuf
);
436 stream_fname
= stream_name(handle
, fname
, true);
437 if (stream_fname
== NULL
) {
441 ret
= SMB_VFS_NEXT_OPEN(handle
, stream_fname
, fsp
, flags
, mode
);
448 static int streams_depot_unlink(vfs_handle_struct
*handle
, const char *fname
)
451 SMB_STRUCT_STAT sbuf
;
453 DEBUG(10, ("streams_depot_unlink called for %s\n", fname
));
455 if (is_ntfs_stream_name(fname
)) {
458 stream_fname
= stream_name(handle
, fname
, false);
459 if (stream_fname
== NULL
) {
463 ret
= SMB_VFS_NEXT_UNLINK(handle
, stream_fname
);
465 TALLOC_FREE(stream_fname
);
470 * We potentially need to delete the per-inode streams directory
473 if (SMB_VFS_NEXT_STAT(handle
, fname
, &sbuf
) == -1) {
477 if (sbuf
.st_nlink
== 1) {
478 char *dirname
= stream_dir(handle
, fname
, &sbuf
, false);
480 if (dirname
!= NULL
) {
481 SMB_VFS_NEXT_RMDIR(handle
, dirname
);
483 TALLOC_FREE(dirname
);
486 return SMB_VFS_NEXT_UNLINK(handle
, fname
);
489 static bool add_one_stream(TALLOC_CTX
*mem_ctx
, unsigned int *num_streams
,
490 struct stream_struct
**streams
,
491 const char *name
, SMB_OFF_T size
,
492 SMB_OFF_T alloc_size
)
494 struct stream_struct
*tmp
;
496 tmp
= TALLOC_REALLOC_ARRAY(mem_ctx
, *streams
, struct stream_struct
,
502 tmp
[*num_streams
].name
= talloc_strdup(tmp
, name
);
503 if (tmp
[*num_streams
].name
== NULL
) {
507 tmp
[*num_streams
].size
= size
;
508 tmp
[*num_streams
].alloc_size
= alloc_size
;
515 struct streaminfo_state
{
517 vfs_handle_struct
*handle
;
518 unsigned int num_streams
;
519 struct stream_struct
*streams
;
523 static bool collect_one_stream(const char *dirname
,
527 struct streaminfo_state
*state
=
528 (struct streaminfo_state
*)private_data
;
530 SMB_STRUCT_STAT sbuf
;
532 if (asprintf(&full_sname
, "%s/%s", dirname
, dirent
) == -1) {
533 state
->status
= NT_STATUS_NO_MEMORY
;
536 if (SMB_VFS_NEXT_STAT(state
->handle
, full_sname
, &sbuf
) == -1) {
537 DEBUG(10, ("Could not stat %s: %s\n", full_sname
,
539 SAFE_FREE(full_sname
);
543 SAFE_FREE(full_sname
);
545 if (!add_one_stream(state
->mem_ctx
,
546 &state
->num_streams
, &state
->streams
,
547 dirent
, sbuf
.st_size
,
549 state
->handle
->conn
, NULL
, &sbuf
))) {
550 state
->status
= NT_STATUS_NO_MEMORY
;
557 static NTSTATUS
streams_depot_streaminfo(vfs_handle_struct
*handle
,
558 struct files_struct
*fsp
,
561 unsigned int *pnum_streams
,
562 struct stream_struct
**pstreams
)
564 SMB_STRUCT_STAT sbuf
;
567 struct streaminfo_state state
;
569 if ((fsp
!= NULL
) && (fsp
->fh
->fd
!= -1)) {
570 if (is_ntfs_stream_name(fsp
->fsp_name
)) {
571 return NT_STATUS_INVALID_PARAMETER
;
573 ret
= SMB_VFS_NEXT_FSTAT(handle
, fsp
, &sbuf
);
576 if (is_ntfs_stream_name(fname
)) {
577 return NT_STATUS_INVALID_PARAMETER
;
579 ret
= SMB_VFS_NEXT_STAT(handle
, fname
, &sbuf
);
583 return map_nt_error_from_unix(errno
);
586 state
.streams
= NULL
;
587 state
.num_streams
= 0;
589 if (!S_ISDIR(sbuf
.st_mode
)) {
590 if (!add_one_stream(mem_ctx
,
591 &state
.num_streams
, &state
.streams
,
592 "::$DATA", sbuf
.st_size
,
593 get_allocation_size(handle
->conn
, fsp
,
595 return NT_STATUS_NO_MEMORY
;
599 state
.mem_ctx
= mem_ctx
;
600 state
.handle
= handle
;
601 state
.status
= NT_STATUS_OK
;
603 status
= walk_streams(handle
, fname
, &sbuf
, NULL
, collect_one_stream
,
606 if (!NT_STATUS_IS_OK(status
)) {
607 TALLOC_FREE(state
.streams
);
611 if (!NT_STATUS_IS_OK(state
.status
)) {
612 TALLOC_FREE(state
.streams
);
616 *pnum_streams
= state
.num_streams
;
617 *pstreams
= state
.streams
;
621 static uint32_t streams_depot_fs_capabilities(struct vfs_handle_struct
*handle
)
623 return SMB_VFS_NEXT_FS_CAPABILITIES(handle
) | FILE_NAMED_STREAMS
;
626 /* VFS operations structure */
628 static vfs_op_tuple streams_depot_ops
[] = {
629 {SMB_VFS_OP(streams_depot_fs_capabilities
), SMB_VFS_OP_FS_CAPABILITIES
,
630 SMB_VFS_LAYER_TRANSPARENT
},
631 {SMB_VFS_OP(streams_depot_open
), SMB_VFS_OP_OPEN
,
632 SMB_VFS_LAYER_TRANSPARENT
},
633 {SMB_VFS_OP(streams_depot_stat
), SMB_VFS_OP_STAT
,
634 SMB_VFS_LAYER_TRANSPARENT
},
635 {SMB_VFS_OP(streams_depot_lstat
), SMB_VFS_OP_LSTAT
,
636 SMB_VFS_LAYER_TRANSPARENT
},
637 {SMB_VFS_OP(streams_depot_unlink
), SMB_VFS_OP_UNLINK
,
638 SMB_VFS_LAYER_TRANSPARENT
},
639 {SMB_VFS_OP(streams_depot_streaminfo
), SMB_VFS_OP_STREAMINFO
,
640 SMB_VFS_LAYER_OPAQUE
},
641 {SMB_VFS_OP(NULL
), SMB_VFS_OP_NOOP
, SMB_VFS_LAYER_NOOP
}
644 NTSTATUS
vfs_streams_depot_init(void);
645 NTSTATUS
vfs_streams_depot_init(void)
647 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION
, "streams_depot",