diff options
Diffstat (limited to 'source3/smbd')
| -rw-r--r-- | source3/smbd/dmapi.c | 205 | ||||
| -rw-r--r-- | source3/smbd/server.c | 6 |
2 files changed, 78 insertions, 133 deletions
diff --git a/source3/smbd/dmapi.c b/source3/smbd/dmapi.c index 620baf199e..a410748ccf 100644 --- a/source3/smbd/dmapi.c +++ b/source3/smbd/dmapi.c @@ -25,9 +25,9 @@ #ifndef USE_DMAPI -int dmapi_init_session(void) { return -1; } uint32 dmapi_file_flags(const char * const path) { return 0; } bool dmapi_have_session(void) { return False; } +const void * dmapi_get_current_session(void) { return NULL; } #else /* USE_DMAPI */ @@ -48,90 +48,48 @@ bool dmapi_have_session(void) { return False; } static dm_sessid_t samba_dmapi_session = DM_NO_SESSION; -/* Initialise the DMAPI interface. Make sure that we only end up initialising - * once per process to avoid resource leaks across different DMAPI - * implementations. - */ -static int init_dmapi_service(void) -{ - static pid_t lastpid; - - pid_t mypid; - - mypid = sys_getpid(); - if (mypid != lastpid) { - char *version; - - lastpid = mypid; - if (dm_init_service(&version) < 0) { - return -1; - } - - DEBUG(0, ("Initializing DMAPI: %s\n", version)); - } - - return 0; -} - -bool dmapi_have_session(void) -{ - return samba_dmapi_session != DM_NO_SESSION; -} - -static dm_sessid_t *realloc_session_list(dm_sessid_t * sessions, int count) -{ - dm_sessid_t *nsessions; - - nsessions = TALLOC_REALLOC_ARRAY(NULL, sessions, dm_sessid_t, count); - if (nsessions == NULL) { - TALLOC_FREE(sessions); - return NULL; - } - return nsessions; -} - -/* Initialise DMAPI session. The session is persistant kernel state, so it - * might already exist, in which case we merely want to reconnect to it. This - * function should be called as root. - */ -int dmapi_init_session(void) +/* + Initialise DMAPI session. The session is persistant kernel state, + so it might already exist, in which case we merely want to + reconnect to it. This function should be called as root. +*/ +static int dmapi_init_session(void) { char buf[DM_SESSION_INFO_LEN]; size_t buflen; - - uint nsessions = 10; + uint nsessions = 5; dm_sessid_t *sessions = NULL; + char *version; int i, err; - /* If we aren't root, something in the following will fail due to lack - * of privileges. Aborting seems a little extreme. - */ - SMB_WARN(getuid() == 0, "dmapi_init_session must be called as root"); - - samba_dmapi_session = DM_NO_SESSION; - if (init_dmapi_service() < 0) { + if (dm_init_service(&version) < 0) { + DEBUG(0, ("dm_init_service failed - disabling DMAPI\n")); return -1; } -retry: + ZERO_STRUCT(buf); - if ((sessions = realloc_session_list(sessions, nsessions)) == NULL) { - return -1; - } - - err = dm_getall_sessions(nsessions, sessions, &nsessions); - if (err < 0) { - if (errno == E2BIG) { - nsessions *= 2; - goto retry; + do { + dm_sessid_t *new_sessions; + nsessions *= 2; + new_sessions = TALLOC_REALLOC_ARRAY(NULL, sessions, + dm_sessid_t, nsessions); + if (new_sessions == NULL) { + talloc_free(sessions); + return -1; } + sessions = new_sessions; + err = dm_getall_sessions(nsessions, sessions, &nsessions); + } while (err == -1 && errno == E2BIG); + + if (err == -1) { DEBUGADD(DMAPI_TRACE, ("failed to retrieve DMAPI sessions: %s\n", strerror(errno))); - TALLOC_FREE(sessions); + talloc_free(sessions); return -1; } @@ -147,7 +105,7 @@ retry: } } - TALLOC_FREE(sessions); + talloc_free(sessions); /* No session already defined. */ if (samba_dmapi_session == DM_NO_SESSION) { @@ -162,91 +120,84 @@ retry: return -1; } - DEBUGADD(DMAPI_TRACE, - ("created new DMAPI session named '%s'\n", - DMAPI_SESSION_NAME)); + DEBUG(0, ("created new DMAPI session named '%s' for %s\n", + DMAPI_SESSION_NAME, version)); + } + + if (samba_dmapi_session != DM_NO_SESSION) { + set_effective_capability(DMAPI_ACCESS_CAPABILITY); } - /* Note that we never end the DMAPI session. This enables child - * processes to continue to use the session after we exit. It also lets - * you run a second Samba server on different ports without any - * conflict. + /* + 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. */ return 0; } -/* Reattach to an existing dmapi session. Called from service processes that - * might not be running as root. - */ -static int reattach_dmapi_session(void) +/* + Return a pointer to our DMAPI session, if available. + This assumes that you have called dmapi_have_session() first. +*/ +const void *dmapi_get_current_session(void) { - char buf[DM_SESSION_INFO_LEN]; - size_t buflen; - - if (samba_dmapi_session != DM_NO_SESSION ) { - become_root(); - - /* NOTE: On Linux, this call opens /dev/dmapi, costing us a - * file descriptor. Ideally, we would close this when we fork. - */ - if (init_dmapi_service() < 0) { - samba_dmapi_session = DM_NO_SESSION; - unbecome_root(); - return -1; - } - - if (dm_query_session(samba_dmapi_session, sizeof(buf), - buf, &buflen) < 0) { - /* Session is stale. Disable DMAPI. */ - samba_dmapi_session = DM_NO_SESSION; - unbecome_root(); - return -1; - } - - set_effective_capability(DMAPI_ACCESS_CAPABILITY); - - DEBUG(DMAPI_TRACE, ("reattached DMAPI session\n")); - unbecome_root(); + if (samba_dmapi_session == DM_NO_SESSION) { + return NULL; } - return 0; + return (void *)&samba_dmapi_session; } + +/* + dmapi_have_session() must be the first DMAPI call you make in Samba. It will + initialize DMAPI, if available, and tell you if you can get a DMAPI session. + This should be called in the client-specific child process. +*/ -/* If a DMAPI session has been initialised, then we need to make sure - * we are attached to it and have the correct privileges. This is - * necessary to be able to do DMAPI operations across a fork(2). If - * it fails, there is no likelihood of that failure being transient. - * - * Note that this use of the static attached flag relies on the fact - * that dmapi_file_flags() is never called prior to forking the - * per-client server process. - */ -const void * dmapi_get_current_session(void) +bool dmapi_have_session(void) { - static int attached = 0; - if (dmapi_have_session() && !attached) { - attached++; - if (reattach_dmapi_session() < 0) { - return DM_NO_SESSION; - } + static bool initialized; + if (!initialized) { + initialized = true; + + become_root(); + dmapi_init_session(); + unbecome_root(); + } - return &samba_dmapi_session; + + 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. + For GPFS-specific version see modules/vfs_tsmsm.c. It might be + that approach on quering existence of a specific attribute that + is used in vfs_tsmsm.c will work with other DMAPI-based HSM + implementations as well. +*/ uint32 dmapi_file_flags(const char * const path) { - dm_sessid_t dmapi_session; int err; 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; uint32 flags = 0; - dmapi_session = *(dm_sessid_t*) dmapi_get_current_session(); + dmapi_session_ptr = dmapi_get_current_session(); + if (dmapi_session_ptr == NULL) { + return 0; + } + + dmapi_session = *(dm_sessid_t *)dmapi_session_ptr; if (dmapi_session == DM_NO_SESSION) { return 0; } diff --git a/source3/smbd/server.c b/source3/smbd/server.c index db241103ed..7116027adf 100644 --- a/source3/smbd/server.c +++ b/source3/smbd/server.c @@ -1313,12 +1313,6 @@ extern void build_options(bool screen); if ( is_daemon && !interactive ) start_background_queue(); - /* Always attempt to initialize DMAPI. We will only use it later if - * lp_dmapi_support is set on the share, but we need a single global - * session to work with. - */ - dmapi_init_session(); - if (!open_sockets_smbd(is_daemon, interactive, ports)) exit(1); |