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;
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;
67 if (dm_init_service(&version) < 0) {
68 DEBUG(0, ("dm_init_service failed - disabling DMAPI\n"));
75 dm_sessid_t *new_sessions;
77 new_sessions = TALLOC_REALLOC_ARRAY(NULL, sessions,
78 dm_sessid_t, nsessions);
79 if (new_sessions == NULL) {
80 talloc_free(sessions);
84 sessions = new_sessions;
85 err = dm_getall_sessions(nsessions, sessions, &nsessions);
86 } while (err == -1 && errno == E2BIG);
90 ("failed to retrieve DMAPI sessions: %s\n",
92 talloc_free(sessions);
96 for (i = 0; i < nsessions; ++i) {
97 err = dm_query_session(sessions[i], sizeof(buf), buf, &buflen);
98 buf[sizeof(buf) - 1] = '\0';
99 if (err == 0 && strcmp(DMAPI_SESSION_NAME, buf) == 0) {
100 samba_dmapi_session = sessions[i];
101 DEBUGADD(DMAPI_TRACE,
102 ("attached to existing DMAPI session "
103 "named '%s'\n", buf));
108 talloc_free(sessions);
110 /* No session already defined. */
111 if (samba_dmapi_session == DM_NO_SESSION) {
112 err = dm_create_session(DM_NO_SESSION,
113 CONST_DISCARD(char *, DMAPI_SESSION_NAME),
114 &samba_dmapi_session);
116 DEBUGADD(DMAPI_TRACE,
117 ("failed to create new DMAPI session: %s\n",
119 samba_dmapi_session = DM_NO_SESSION;
123 DEBUG(0, ("created new DMAPI session named '%s' for %s\n",
124 DMAPI_SESSION_NAME, version));
127 if (samba_dmapi_session != DM_NO_SESSION) {
128 set_effective_capability(DMAPI_ACCESS_CAPABILITY);
132 Note that we never end the DMAPI session. It gets re-used if possiblie.
133 DMAPI session is a kernel resource that is usually lives until server reboot
134 and doesn't get destroed when an application finishes.
141 Return a pointer to our DMAPI session, if available.
142 This assumes that you have called dmapi_have_session() first.
144 const void *dmapi_get_current_session(void)
146 if (samba_dmapi_session == DM_NO_SESSION) {
150 return (void *)&samba_dmapi_session;
154 dmapi_have_session() must be the first DMAPI call you make in Samba. It will
155 initialize DMAPI, if available, and tell you if you can get a DMAPI session.
156 This should be called in the client-specific child process.
159 bool dmapi_have_session(void)
161 static bool initialized;
166 dmapi_init_session();
171 return samba_dmapi_session != DM_NO_SESSION;
175 This is default implementation of dmapi_file_flags() that is
176 called from VFS is_offline() call to know whether file is offline.
177 For GPFS-specific version see modules/vfs_tsmsm.c. It might be
178 that approach on quering existence of a specific attribute that
179 is used in vfs_tsmsm.c will work with other DMAPI-based HSM
180 implementations as well.
182 uint32 dmapi_file_flags(const char * const path)
185 dm_eventset_t events = {0};
188 dm_sessid_t dmapi_session;
189 void *dmapi_session_ptr;
190 void *dm_handle = NULL;
191 size_t dm_handle_len = 0;
195 dmapi_session_ptr = dmapi_get_current_session();
196 if (dmapi_session_ptr == NULL) {
200 dmapi_session = *(dm_sessid_t *)dmapi_session_ptr;
201 if (dmapi_session == DM_NO_SESSION) {
205 /* AIX has DMAPI but no POSIX capablities support. In this case,
206 * we need to be root to do DMAPI manipulations.
208 #ifndef HAVE_POSIX_CAPABILITIES
212 err = dm_path_to_handle(CONST_DISCARD(char *, path),
213 &dm_handle, &dm_handle_len);
215 DEBUG(DMAPI_TRACE, ("dm_path_to_handle(%s): %s\n",
216 path, strerror(errno)));
218 if (errno != EPERM) {
222 /* Linux capabilities are broken in that changing our
223 * user ID will clobber out effective capabilities irrespective
224 * of whether we have set PR_SET_KEEPCAPS. Fortunately, the
225 * capabilities are not removed from our permitted set, so we
226 * can re-acquire them if necessary.
229 set_effective_capability(DMAPI_ACCESS_CAPABILITY);
231 err = dm_path_to_handle(CONST_DISCARD(char *, path),
232 &dm_handle, &dm_handle_len);
235 ("retrying dm_path_to_handle(%s): %s\n",
236 path, strerror(errno)));
241 err = dm_get_eventlist(dmapi_session, dm_handle, dm_handle_len,
242 DM_NO_TOKEN, DM_EVENT_MAX, &events, &nevents);
244 DEBUG(DMAPI_TRACE, ("dm_get_eventlist(%s): %s\n",
245 path, strerror(errno)));
246 dm_handle_free(dm_handle, dm_handle_len);
250 /* We figure that the only reason a DMAPI application would be
251 * interested in trapping read events is that part of the file is
254 DEBUG(DMAPI_TRACE, ("DMAPI event list for %s is %#llx\n",
256 if (DMEV_ISSET(DM_EVENT_READ, events)) {
257 flags = FILE_ATTRIBUTE_OFFLINE;
260 dm_handle_free(dm_handle, dm_handle_len);
262 if (flags & FILE_ATTRIBUTE_OFFLINE) {
263 DEBUG(DMAPI_TRACE, ("%s is OFFLINE\n", path));
268 #ifndef HAVE_POSIX_CAPABILITIES
276 #endif /* USE_DMAPI */