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samba-mirror/source3/smbd/globals.c
David Disseldorp 0b188e7784 s3-printing: Initiate pcap reload from parent smbd
Since commit 7022554, smbds share a printcap cache (printer_list.tdb),
therefore ordering of events between smbd processes is important when
updating printcap cache information. Consider the following two process
example:
1) smbd1 receives HUP or printcap cache time expiry
2) smbd1 checks whether pcap needs refresh, it does
3) smbd1 marks pcap as refreshed
4) smbd1 forks child1 to obtain cups printer info
5) smbd2 receives HUP or printcap cache time expiry
6) smbd2 checks whether pcap needs refresh, it does not (due to step 3)
7) smbd2 reloads printer shares prior to child1 completion (stale pcap)
8) child1 completion, pcap cache (printer_list.tdb) is updated by smbd1
9) smbd1 reloads printer shares based on new pcap information

In this case both smbd1 and smbd2 are reliant on the pcap update
performed on child1 completion.
The prior commit "reload shares after pcap cache fill" ensures that
smbd1 only reloads printer shares following pcap update, however smbd2
continues to present shares based on stale pcap data.

This commit addresses the above problem by driving pcap cache and
printer share updates from the parent smbd process.
1) smbd0 (parent) receives a HUP or printcap cache time expiry
2) smbd0 forks child0 to obtain cups printer info
3) child0 completion, pcap cache (printer_list.tdb) is updated by smbd0
4) smbd0 reloads printer shares
5) smbd0 notifies child smbds of pcap update via message_send_all()
6) child smbds read fresh pcap data and reload printer shares

This architecture has the additional advantage that only a single
process (the parent smbd) requests printer information from the printcap
backend.

Use time_mono in housekeeping functions As suggested by Björn Jacke.
2011-01-07 15:37:39 -08:00

159 lines
4.4 KiB
C

/*
Unix SMB/Netbios implementation.
smbd globals
Copyright (C) Stefan Metzmacher 2009
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "smbd/globals.h"
#include "memcache.h"
#if defined(WITH_AIO)
struct aio_extra *aio_list_head = NULL;
struct tevent_signal *aio_signal_event = NULL;
int aio_pending_size = 0;
int outstanding_aio_calls = 0;
#endif
#ifdef USE_DMAPI
struct smbd_dmapi_context *dmapi_ctx = NULL;
#endif
bool dfree_broken = false;
/* how many write cache buffers have been allocated */
unsigned int allocated_write_caches = 0;
const struct mangle_fns *mangle_fns = NULL;
unsigned char *chartest = NULL;
TDB_CONTEXT *tdb_mangled_cache = NULL;
/*
this determines how many characters are used from the original filename
in the 8.3 mangled name. A larger value leads to a weaker hash and more collisions.
The largest possible value is 6.
*/
unsigned mangle_prefix = 0;
struct msg_state *smbd_msg_state = NULL;
bool logged_ioctl_message = false;
time_t last_smb_conf_reload_time = 0;
time_t last_printer_reload_time = 0;
/****************************************************************************
structure to hold a linked list of queued messages.
for processing.
****************************************************************************/
struct pending_message_list *deferred_open_queue = NULL;
uint32_t common_flags2 = FLAGS2_LONG_PATH_COMPONENTS|FLAGS2_32_BIT_ERROR_CODES|FLAGS2_EXTENDED_ATTRIBUTES;
struct smb_srv_trans_enc_ctx *partial_srv_trans_enc_ctx = NULL;
struct smb_srv_trans_enc_ctx *srv_trans_enc_ctx = NULL;
/* A stack of security contexts. We include the current context as being
the first one, so there is room for another MAX_SEC_CTX_DEPTH more. */
struct sec_ctx sec_ctx_stack[MAX_SEC_CTX_DEPTH + 1];
int sec_ctx_stack_ndx = 0;
bool become_uid_done = false;
bool become_gid_done = false;
connection_struct *last_conn = NULL;
uint16_t last_flags = 0;
uint32_t global_client_caps = 0;
uint16_t fnf_handle = 257;
/* A stack of current_user connection contexts. */
struct conn_ctx conn_ctx_stack[MAX_SEC_CTX_DEPTH];
int conn_ctx_stack_ndx = 0;
struct vfs_init_function_entry *backends = NULL;
char *sparse_buf = NULL;
char *LastDir = NULL;
/* Current number of oplocks we have outstanding. */
int32_t exclusive_oplocks_open = 0;
int32_t level_II_oplocks_open = 0;
struct kernel_oplocks *koplocks = NULL;
int am_parent = 1;
struct memcache *smbd_memcache_ctx = NULL;
bool exit_firsttime = true;
struct child_pid *children = 0;
int num_children = 0;
struct smbd_server_connection *smbd_server_conn = NULL;
struct smbd_server_connection *msg_ctx_to_sconn(struct messaging_context *msg_ctx)
{
struct server_id my_id, msg_id;
my_id = messaging_server_id(smbd_server_conn->msg_ctx);
msg_id = messaging_server_id(msg_ctx);
if (!procid_equal(&my_id, &msg_id)) {
return NULL;
}
return smbd_server_conn;
}
struct messaging_context *smbd_messaging_context(void)
{
struct messaging_context *msg_ctx = server_messaging_context();
if (likely(msg_ctx != NULL)) {
return msg_ctx;
}
smb_panic("Could not init smbd's messaging context.\n");
}
struct memcache *smbd_memcache(void)
{
if (!smbd_memcache_ctx) {
/*
* Note we MUST use the NULL context here, not the
* autofree context, to avoid side effects in forked
* children exiting.
*/
smbd_memcache_ctx = memcache_init(NULL,
lp_max_stat_cache_size()*1024);
}
if (!smbd_memcache_ctx) {
smb_panic("Could not init smbd memcache");
}
return smbd_memcache_ctx;
}
void smbd_init_globals(void)
{
ZERO_STRUCT(conn_ctx_stack);
ZERO_STRUCT(sec_ctx_stack);
smbd_server_conn = talloc_zero(smbd_event_context(), struct smbd_server_connection);
if (!smbd_server_conn) {
exit_server("failed to create smbd_server_connection");
}
smbd_server_conn->smb1.echo_handler.trusted_fd = -1;
smbd_server_conn->smb1.echo_handler.socket_lock_fd = -1;
}