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Diffstat (limited to 'source3/smbd/dmapi.c')
-rw-r--r--source3/smbd/dmapi.c72
1 files changed, 56 insertions, 16 deletions
diff --git a/source3/smbd/dmapi.c b/source3/smbd/dmapi.c
index a410748ccf..8d43e0a9d1 100644
--- a/source3/smbd/dmapi.c
+++ b/source3/smbd/dmapi.c
@@ -47,7 +47,7 @@ const void * dmapi_get_current_session(void) { return NULL; }
#define DMAPI_TRACE 10
static dm_sessid_t samba_dmapi_session = DM_NO_SESSION;
-
+static unsigned session_num;
/*
Initialise DMAPI session. The session is persistant kernel state,
@@ -61,23 +61,41 @@ static int dmapi_init_session(void)
uint nsessions = 5;
dm_sessid_t *sessions = NULL;
char *version;
+ char *session_name;
+ TALLOC_CTX *tmp_ctx = talloc_new(NULL);
int i, err;
+ if (session_num == 0) {
+ session_name = DMAPI_SESSION_NAME;
+ } else {
+ session_name = talloc_asprintf(tmp_ctx, "%s%u", DMAPI_SESSION_NAME,
+ session_num);
+ }
+
+ if (session_name == NULL) {
+ DEBUG(0,("Out of memory in dmapi_init_session\n"));
+ talloc_free(tmp_ctx);
+ return -1;
+ }
+
+
if (dm_init_service(&version) < 0) {
DEBUG(0, ("dm_init_service failed - disabling DMAPI\n"));
+ talloc_free(tmp_ctx);
return -1;
}
ZERO_STRUCT(buf);
+ /* Fetch kernel DMAPI sessions until we get any of them */
do {
dm_sessid_t *new_sessions;
nsessions *= 2;
- new_sessions = TALLOC_REALLOC_ARRAY(NULL, sessions,
+ new_sessions = TALLOC_REALLOC_ARRAY(tmp_ctx, sessions,
dm_sessid_t, nsessions);
if (new_sessions == NULL) {
- talloc_free(sessions);
+ talloc_free(tmp_ctx);
return -1;
}
@@ -89,14 +107,15 @@ static int dmapi_init_session(void)
DEBUGADD(DMAPI_TRACE,
("failed to retrieve DMAPI sessions: %s\n",
strerror(errno)));
- talloc_free(sessions);
+ talloc_free(tmp_ctx);
return -1;
}
+ /* Look through existing kernel DMAPI sessions to find out ours */
for (i = 0; i < nsessions; ++i) {
err = dm_query_session(sessions[i], sizeof(buf), buf, &buflen);
buf[sizeof(buf) - 1] = '\0';
- if (err == 0 && strcmp(DMAPI_SESSION_NAME, buf) == 0) {
+ if (err == 0 && strcmp(session_name, buf) == 0) {
samba_dmapi_session = sessions[i];
DEBUGADD(DMAPI_TRACE,
("attached to existing DMAPI session "
@@ -105,23 +124,22 @@ static int dmapi_init_session(void)
}
}
- talloc_free(sessions);
-
/* No session already defined. */
if (samba_dmapi_session == DM_NO_SESSION) {
err = dm_create_session(DM_NO_SESSION,
- CONST_DISCARD(char *, DMAPI_SESSION_NAME),
+ session_name,
&samba_dmapi_session);
if (err < 0) {
DEBUGADD(DMAPI_TRACE,
("failed to create new DMAPI session: %s\n",
strerror(errno)));
samba_dmapi_session = DM_NO_SESSION;
+ talloc_free(tmp_ctx);
return -1;
}
DEBUG(0, ("created new DMAPI session named '%s' for %s\n",
- DMAPI_SESSION_NAME, version));
+ session_name, version));
}
if (samba_dmapi_session != DM_NO_SESSION) {
@@ -132,8 +150,12 @@ static int dmapi_init_session(void)
Note that we never end the DMAPI session. It gets re-used if possiblie.
DMAPI session is a kernel resource that is usually lives until server reboot
and doesn't get destroed when an application finishes.
+
+ However, we free list of references to DMAPI sessions we've got from the kernel
+ as it is not needed anymore once we have found (or created) our session.
*/
+ talloc_free(tmp_ctx);
return 0;
}
@@ -171,6 +193,25 @@ bool dmapi_have_session(void)
return samba_dmapi_session != DM_NO_SESSION;
}
+/*
+ only call this when you get back an EINVAL error indicating that the
+ session you are using is invalid. This destroys the existing session
+ and creates a new one.
+ */
+BOOL dmapi_new_session(void)
+{
+ if (dmapi_have_session()) {
+ /* try to destroy the old one - this may not succeed */
+ dm_destroy_session(samba_dmapi_session);
+ }
+ samba_dmapi_session = DM_NO_SESSION;
+ become_root();
+ session_num++;
+ dmapi_init_session();
+ unbecome_root();
+ return samba_dmapi_session != DM_NO_SESSION;
+}
+
/*
This is default implementation of dmapi_file_flags() that is
called from VFS is_offline() call to know whether file is offline.
@@ -185,12 +226,12 @@ uint32 dmapi_file_flags(const char * const path)
dm_eventset_t events = {0};
uint nevents;
- dm_sessid_t dmapi_session;
- void *dmapi_session_ptr;
- void *dm_handle = NULL;
- size_t dm_handle_len = 0;
+ dm_sessid_t dmapi_session;
+ const void *dmapi_session_ptr;
+ void *dm_handle = NULL;
+ size_t dm_handle_len = 0;
- uint32 flags = 0;
+ uint32 flags = 0;
dmapi_session_ptr = dmapi_get_current_session();
if (dmapi_session_ptr == NULL) {
@@ -251,8 +292,7 @@ uint32 dmapi_file_flags(const char * const path)
* interested in trapping read events is that part of the file is
* offline.
*/
- DEBUG(DMAPI_TRACE, ("DMAPI event list for %s is %#llx\n",
- path, events));
+ DEBUG(DMAPI_TRACE, ("DMAPI event list for %s\n", path));
if (DMEV_ISSET(DM_EVENT_READ, events)) {
flags = FILE_ATTRIBUTE_OFFLINE;
}