2 * VFS module to alter the algorithm to calculate
3 * the struct file_id used as key for the share mode
4 * and byte range locking db's.
6 * Copyright (C) 2007, Stefan Metzmacher
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see <http://www.gnu.org/licenses/>.
24 static int vfs_fileid_debug_level
= DBGC_VFS
;
27 #define DBGC_CLASS vfs_fileid_debug_level
29 struct fileid_mount_entry
{
31 const char *mnt_fsname
;
36 struct fileid_handle_data
{
37 uint64_t (*device_mapping_fn
)(struct fileid_handle_data
*data
,
39 unsigned num_mount_entries
;
40 struct fileid_mount_entry
*mount_entries
;
43 /* load all the mount entries from the mtab */
44 static void fileid_load_mount_entries(struct fileid_handle_data
*data
)
49 data
->num_mount_entries
= 0;
50 TALLOC_FREE(data
->mount_entries
);
52 f
= setmntent("/etc/mtab", "r");
55 while ((m
= getmntent(f
))) {
58 struct fileid_mount_entry
*cur
;
60 if (stat(m
->mnt_dir
, &st
) != 0) continue;
61 if (statfs(m
->mnt_dir
, &sfs
) != 0) continue;
63 if (strncmp(m
->mnt_fsname
, "/dev/", 5) == 0) {
67 data
->mount_entries
= TALLOC_REALLOC_ARRAY(data
,
69 struct fileid_mount_entry
,
70 data
->num_mount_entries
+1);
71 if (data
->mount_entries
== NULL
) {
75 cur
= &data
->mount_entries
[data
->num_mount_entries
];
76 cur
->device
= st
.st_dev
;
77 cur
->mnt_fsname
= talloc_strdup(data
->mount_entries
,
79 if (!cur
->mnt_fsname
) goto nomem
;
80 cur
->fsid
= sfs
.f_fsid
;
81 cur
->devid
= (uint64_t)-1;
83 data
->num_mount_entries
++;
91 data
->num_mount_entries
= 0;
92 TALLOC_FREE(data
->mount_entries
);
97 /* find a mount entry given a dev_t */
98 static struct fileid_mount_entry
*fileid_find_mount_entry(struct fileid_handle_data
*data
,
103 if (data
->num_mount_entries
== 0) {
104 fileid_load_mount_entries(data
);
106 for (i
=0;i
<data
->num_mount_entries
;i
++) {
107 if (data
->mount_entries
[i
].device
== dev
) {
108 return &data
->mount_entries
[i
];
111 /* 2nd pass after reloading */
112 fileid_load_mount_entries(data
);
113 for (i
=0;i
<data
->num_mount_entries
;i
++) {
114 if (data
->mount_entries
[i
].device
== dev
) {
115 return &data
->mount_entries
[i
];
122 /* a 64 bit hash, based on the one in tdb */
123 static uint64_t fileid_uint64_hash(const uint8_t *s
, size_t len
)
125 uint64_t value
; /* Used to compute the hash value. */
126 uint32_t i
; /* Used to cycle through random values. */
128 /* Set the initial value from the key size. */
129 for (value
= 0x238F13AFLL
* len
, i
=0; i
< len
; i
++)
130 value
= (value
+ (s
[i
] << (i
*5 % 24)));
132 return (1103515243LL * value
+ 12345LL);
135 /* a device mapping using a fsname */
136 static uint64_t fileid_device_mapping_fsname(struct fileid_handle_data
*data
,
139 struct fileid_mount_entry
*m
;
141 m
= fileid_find_mount_entry(data
, dev
);
144 if (m
->devid
== (uint64_t)-1) {
145 m
->devid
= fileid_uint64_hash((uint8_t *)m
->mnt_fsname
,
146 strlen(m
->mnt_fsname
));
152 /* device mapping functions using a fsid */
153 static uint64_t fileid_device_mapping_fsid(struct fileid_handle_data
*data
,
156 struct fileid_mount_entry
*m
;
158 m
= fileid_find_mount_entry(data
, dev
);
161 if (m
->devid
== (uint64_t)-1) {
162 if (sizeof(fsid_t
) > sizeof(uint64_t)) {
163 m
->devid
= fileid_uint64_hash((uint8_t *)&m
->fsid
,
179 static int fileid_connect(struct vfs_handle_struct
*handle
,
180 const char *service
, const char *user
)
182 struct fileid_handle_data
*data
;
183 const char *algorithm
;
185 data
= talloc_zero(handle
->conn
, struct fileid_handle_data
);
187 DEBUG(0, ("talloc_zero() failed\n"));
192 * "fileid:mapping" is only here as fallback for old setups
193 * "fileid:algorithm" is the option new setups should use
195 algorithm
= lp_parm_const_string(SNUM(handle
->conn
),
198 algorithm
= lp_parm_const_string(SNUM(handle
->conn
),
199 "fileid", "algorithm",
201 if (strcmp("fsname", algorithm
) == 0) {
202 data
->device_mapping_fn
= fileid_device_mapping_fsname
;
203 } else if (strcmp("fsid", algorithm
) == 0) {
204 data
->device_mapping_fn
= fileid_device_mapping_fsid
;
206 DEBUG(0,("fileid_connect(): unknown algorithm[%s]\n", algorithm
));
210 SMB_VFS_HANDLE_SET_DATA(handle
, data
, NULL
,
211 struct fileid_handle_data
,
214 DEBUG(10, ("fileid_connect(): connect to service[%s] with algorithm[%s]\n",
215 service
, algorithm
));
217 return SMB_VFS_NEXT_CONNECT(handle
, service
, user
);
220 static void fileid_disconnect(struct vfs_handle_struct
*handle
)
222 DEBUG(10,("fileid_disconnect() connect to service[%s].\n",
223 lp_servicename(SNUM(handle
->conn
))));
225 SMB_VFS_NEXT_DISCONNECT(handle
);
228 static struct file_id
fileid_file_id_create(struct vfs_handle_struct
*handle
,
229 const SMB_STRUCT_STAT
*sbuf
)
231 struct fileid_handle_data
*data
;
236 SMB_VFS_HANDLE_GET_DATA(handle
, data
,
237 struct fileid_handle_data
,
240 id
.devid
= data
->device_mapping_fn(data
, sbuf
->st_ex_dev
);
241 id
.inode
= sbuf
->st_ex_ino
;
246 static vfs_op_tuple fileid_ops
[] = {
248 /* Disk operations */
250 SMB_VFS_OP(fileid_connect
),
252 SMB_VFS_LAYER_TRANSPARENT
255 SMB_VFS_OP(fileid_disconnect
),
256 SMB_VFS_OP_DISCONNECT
,
257 SMB_VFS_LAYER_TRANSPARENT
260 /* File operations */
262 SMB_VFS_OP(fileid_file_id_create
),
263 SMB_VFS_OP_FILE_ID_CREATE
,
275 NTSTATUS
vfs_fileid_init(void);
276 NTSTATUS
vfs_fileid_init(void)
280 ret
= smb_register_vfs(SMB_VFS_INTERFACE_VERSION
, "fileid", fileid_ops
);
281 if (!NT_STATUS_IS_OK(ret
)) {
285 vfs_fileid_debug_level
= debug_add_class("fileid");
286 if (vfs_fileid_debug_level
== -1) {
287 vfs_fileid_debug_level
= DBGC_VFS
;
288 DEBUG(0, ("vfs_fileid: Couldn't register custom debugging class!\n"));
290 DEBUG(10, ("vfs_fileid: Debug class number of 'fileid': %d\n", vfs_fileid_debug_level
));