diff options
Diffstat (limited to 'source3/smbd/dmapi.c')
| -rw-r--r-- | source3/smbd/dmapi.c | 72 |
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; } |