2 Unix SMB/CIFS implementation.
5 Copyright (C) James Peach 2006
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
24 #define DBGC_CLASS DBGC_DMAPI
28 uint32
dmapi_file_flags(const char * const path
) { return 0; }
29 bool dmapi_have_session(void) { return False
; }
30 const void * dmapi_get_current_session(void) { return NULL
; }
34 #ifdef HAVE_XFS_DMAPI_H
35 #include <xfs/dmapi.h>
36 #elif defined(HAVE_SYS_DMI_H)
38 #elif defined(HAVE_SYS_JFSDMAPI_H)
39 #include <sys/jfsdmapi.h>
40 #elif defined(HAVE_SYS_DMAPI_H)
41 #include <sys/dmapi.h>
42 #elif defined(HAVE_DMAPI_H)
46 #define DMAPI_SESSION_NAME "samba"
47 #define DMAPI_TRACE 10
49 static dm_sessid_t samba_dmapi_session
= DM_NO_SESSION
;
50 static unsigned session_num
;
53 Initialise DMAPI session. The session is persistant kernel state,
54 so it might already exist, in which case we merely want to
55 reconnect to it. This function should be called as root.
57 static int dmapi_init_session(void)
59 char buf
[DM_SESSION_INFO_LEN
];
62 dm_sessid_t
*sessions
= NULL
;
65 TALLOC_CTX
*tmp_ctx
= talloc_new(NULL
);
69 if (session_num
== 0) {
70 session_name
= DMAPI_SESSION_NAME
;
72 session_name
= talloc_asprintf(tmp_ctx
, "%s%u", DMAPI_SESSION_NAME
,
76 if (session_name
== NULL
) {
77 DEBUG(0,("Out of memory in dmapi_init_session\n"));
83 if (dm_init_service(&version
) < 0) {
84 DEBUG(0, ("dm_init_service failed - disabling DMAPI\n"));
91 /* Fetch kernel DMAPI sessions until we get any of them */
93 dm_sessid_t
*new_sessions
;
95 new_sessions
= TALLOC_REALLOC_ARRAY(tmp_ctx
, sessions
,
96 dm_sessid_t
, nsessions
);
97 if (new_sessions
== NULL
) {
102 sessions
= new_sessions
;
103 err
= dm_getall_sessions(nsessions
, sessions
, &nsessions
);
104 } while (err
== -1 && errno
== E2BIG
);
107 DEBUGADD(DMAPI_TRACE
,
108 ("failed to retrieve DMAPI sessions: %s\n",
110 talloc_free(tmp_ctx
);
114 /* Look through existing kernel DMAPI sessions to find out ours */
115 for (i
= 0; i
< nsessions
; ++i
) {
116 err
= dm_query_session(sessions
[i
], sizeof(buf
), buf
, &buflen
);
117 buf
[sizeof(buf
) - 1] = '\0';
118 if (err
== 0 && strcmp(session_name
, buf
) == 0) {
119 samba_dmapi_session
= sessions
[i
];
120 DEBUGADD(DMAPI_TRACE
,
121 ("attached to existing DMAPI session "
122 "named '%s'\n", buf
));
127 /* No session already defined. */
128 if (samba_dmapi_session
== DM_NO_SESSION
) {
129 err
= dm_create_session(DM_NO_SESSION
,
131 &samba_dmapi_session
);
133 DEBUGADD(DMAPI_TRACE
,
134 ("failed to create new DMAPI session: %s\n",
136 samba_dmapi_session
= DM_NO_SESSION
;
137 talloc_free(tmp_ctx
);
141 DEBUG(0, ("created new DMAPI session named '%s' for %s\n",
142 session_name
, version
));
145 if (samba_dmapi_session
!= DM_NO_SESSION
) {
146 set_effective_capability(DMAPI_ACCESS_CAPABILITY
);
150 Note that we never end the DMAPI session. It gets re-used if possiblie.
151 DMAPI session is a kernel resource that is usually lives until server reboot
152 and doesn't get destroed when an application finishes.
154 However, we free list of references to DMAPI sessions we've got from the kernel
155 as it is not needed anymore once we have found (or created) our session.
158 talloc_free(tmp_ctx
);
163 Return a pointer to our DMAPI session, if available.
164 This assumes that you have called dmapi_have_session() first.
166 const void *dmapi_get_current_session(void)
168 if (samba_dmapi_session
== DM_NO_SESSION
) {
172 return (void *)&samba_dmapi_session
;
176 dmapi_have_session() must be the first DMAPI call you make in Samba. It will
177 initialize DMAPI, if available, and tell you if you can get a DMAPI session.
178 This should be called in the client-specific child process.
181 bool dmapi_have_session(void)
183 static bool initialized
;
188 dmapi_init_session();
193 return samba_dmapi_session
!= DM_NO_SESSION
;
197 only call this when you get back an EINVAL error indicating that the
198 session you are using is invalid. This destroys the existing session
199 and creates a new one.
201 bool dmapi_new_session(void)
203 if (dmapi_have_session()) {
204 /* try to destroy the old one - this may not succeed */
205 dm_destroy_session(samba_dmapi_session
);
207 samba_dmapi_session
= DM_NO_SESSION
;
210 dmapi_init_session();
212 return samba_dmapi_session
!= DM_NO_SESSION
;
216 only call this when exiting from master smbd process. DMAPI sessions
217 are long-lived kernel resources we ought to share across smbd processes.
218 However, we must free them when all smbd processes are finished to
219 allow other subsystems clean up properly. Not freeing DMAPI session
220 blocks certain HSM implementations from proper shutdown.
222 bool dmapi_destroy_session(void)
224 if (samba_dmapi_session
!= DM_NO_SESSION
) {
226 if (!dm_destroy_session(samba_dmapi_session
)) {
228 samba_dmapi_session
= DM_NO_SESSION
;
230 DEBUG(0,("Couldn't destroy DMAPI session: %s\n",
235 return samba_dmapi_session
== DM_NO_SESSION
;
240 This is default implementation of dmapi_file_flags() that is
241 called from VFS is_offline() call to know whether file is offline.
242 For GPFS-specific version see modules/vfs_tsmsm.c. It might be
243 that approach on quering existence of a specific attribute that
244 is used in vfs_tsmsm.c will work with other DMAPI-based HSM
245 implementations as well.
247 uint32
dmapi_file_flags(const char * const path
)
250 dm_eventset_t events
= {0};
253 dm_sessid_t dmapi_session
;
254 const void *dmapi_session_ptr
;
255 void *dm_handle
= NULL
;
256 size_t dm_handle_len
= 0;
260 dmapi_session_ptr
= dmapi_get_current_session();
261 if (dmapi_session_ptr
== NULL
) {
265 dmapi_session
= *(dm_sessid_t
*)dmapi_session_ptr
;
266 if (dmapi_session
== DM_NO_SESSION
) {
270 /* AIX has DMAPI but no POSIX capablities support. In this case,
271 * we need to be root to do DMAPI manipulations.
273 #ifndef HAVE_POSIX_CAPABILITIES
277 err
= dm_path_to_handle(CONST_DISCARD(char *, path
),
278 &dm_handle
, &dm_handle_len
);
280 DEBUG(DMAPI_TRACE
, ("dm_path_to_handle(%s): %s\n",
281 path
, strerror(errno
)));
283 if (errno
!= EPERM
) {
287 /* Linux capabilities are broken in that changing our
288 * user ID will clobber out effective capabilities irrespective
289 * of whether we have set PR_SET_KEEPCAPS. Fortunately, the
290 * capabilities are not removed from our permitted set, so we
291 * can re-acquire them if necessary.
294 set_effective_capability(DMAPI_ACCESS_CAPABILITY
);
296 err
= dm_path_to_handle(CONST_DISCARD(char *, path
),
297 &dm_handle
, &dm_handle_len
);
300 ("retrying dm_path_to_handle(%s): %s\n",
301 path
, strerror(errno
)));
306 err
= dm_get_eventlist(dmapi_session
, dm_handle
, dm_handle_len
,
307 DM_NO_TOKEN
, DM_EVENT_MAX
, &events
, &nevents
);
309 DEBUG(DMAPI_TRACE
, ("dm_get_eventlist(%s): %s\n",
310 path
, strerror(errno
)));
311 dm_handle_free(dm_handle
, dm_handle_len
);
315 /* We figure that the only reason a DMAPI application would be
316 * interested in trapping read events is that part of the file is
319 DEBUG(DMAPI_TRACE
, ("DMAPI event list for %s\n", path
));
320 if (DMEV_ISSET(DM_EVENT_READ
, events
)) {
321 flags
= FILE_ATTRIBUTE_OFFLINE
;
324 dm_handle_free(dm_handle
, dm_handle_len
);
326 if (flags
& FILE_ATTRIBUTE_OFFLINE
) {
327 DEBUG(DMAPI_TRACE
, ("%s is OFFLINE\n", path
));
332 #ifndef HAVE_POSIX_CAPABILITIES
340 #endif /* USE_DMAPI */