minix/servers/mfs/main.c
Cristiano Giuffrida d1fd04e72a Initialization protocol for system services.
SYSLIB CHANGES:
- SEF framework now supports a new SEF Init request type from RS. 3 different
callbacks are available (init_fresh, init_lu, init_restart) to specify
initialization code when a service starts fresh, starts after a live update,
or restarts.

SYSTEM SERVICE CHANGES:
- Initialization code for system services is now enclosed in a callback SEF will
automatically call at init time. The return code of the callback will
tell RS whether the initialization completed successfully.
- Each init callback can access information passed by RS to initialize. As of
now, each system service has access to the public entries of RS's system process
table to gather all the information required to initialize. This design
eliminates many existing or potential races at boot time and provides a uniform
initialization interface to system services. The same interface will be reused
for the upcoming publish/subscribe model to handle dynamic 
registration / deregistration of system services.

VM CHANGES:
- Uniform privilege management for all system services. Every service uses the
same call mask format. For boot services, VM copies the call mask from init
data. For dynamic services, VM still receives the call mask via rs_set_priv
call that will be soon replaced by the upcoming publish/subscribe model.

RS CHANGES:
- The system process table has been reorganized and split into private entries
and public entries. Only the latter ones are exposed to system services.
- VM call masks are now entirely configured in rs/table.c
- RS has now its own slot in the system process table. Only kernel tasks and
user processes not included in the boot image are now left out from the system
process table.
- RS implements the initialization protocol for system services.
- For services in the boot image, RS blocks till initialization is complete and
panics when failure is reported back. Services are initialized in their order of
appearance in the boot image priv table and RS blocks to implements synchronous
initialization for every system service having the flag SF_SYNCH_BOOT set.
- For services started dynamically, the initialization protocol is implemented
as though it were the first ping for the service. In this case, if the
system service fails to report back (or reports failure), RS brings the service
down rather than trying to restart it.
2010-01-08 01:20:42 +00:00

201 lines
5.1 KiB
C

#include "inc.h"
#include <assert.h>
#include <minix/dmap.h>
#include <minix/endpoint.h>
#include <minix/vfsif.h>
#include "fs.h"
#include "buf.h"
#include "inode.h"
#include "drivers.h"
/* Declare some local functions. */
FORWARD _PROTOTYPE(void get_work, (message *m_in) );
FORWARD _PROTOTYPE(void cch_check, (void) );
/* SEF functions and variables. */
FORWARD _PROTOTYPE( void sef_local_startup, (void) );
FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC int main(int argc, char *argv[])
{
/* This is the main routine of this service. The main loop consists of
* three major activities: getting new work, processing the work, and
* sending the reply. The loop never terminates, unless a panic occurs.
*/
int error, ind;
message m;
/* SEF local startup. */
env_setargs(argc, argv);
sef_local_startup();
while(!unmountdone || !exitsignaled) {
endpoint_t src;
/* Wait for request message. */
get_work(&fs_m_in);
src = fs_m_in.m_source;
error = OK;
caller_uid = -1; /* To trap errors */
caller_gid = -1;
/* Exit request? */
if(src == PM_PROC_NR) {
exitsignaled = 1;
fs_sync();
continue;
}
/* This must be a regular VFS request. */
assert(src == VFS_PROC_NR && !unmountdone);
req_nr = fs_m_in.m_type;
if (req_nr < VFS_BASE) {
fs_m_in.m_type += VFS_BASE;
req_nr = fs_m_in.m_type;
}
ind = req_nr - VFS_BASE;
if (ind < 0 || ind >= NREQS) {
printf("mfs: bad request %d\n", req_nr);
printf("ind = %d\n", ind);
error = EINVAL;
} else {
error = (*fs_call_vec[ind])();
/*cch_check();*/
}
fs_m_out.m_type = error;
reply(src, &fs_m_out);
if (error == OK && rdahed_inode != NIL_INODE)
read_ahead(); /* do block read ahead */
}
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
PRIVATE void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_restart_fail);
/* No live update support for now. */
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the Minix file server. */
int i, r;
/* Init inode table */
for (i = 0; i < NR_INODES; ++i) {
inode[i].i_count = 0;
cch[i] = 0;
}
init_inode_cache();
/* Init driver mapping */
for (i = 0; i < NR_DEVICES; ++i)
driver_endpoints[i].driver_e = NONE;
SELF_E = getprocnr();
buf_pool();
fs_block_size = _MIN_BLOCK_SIZE;
fs_m_in.m_type = FS_READY;
if ((r = send(FS_PROC_NR, &fs_m_in)) != OK) {
panic("MFS", "Error sending login to VFS", r);
}
return(OK);
}
/*===========================================================================*
* get_work *
*===========================================================================*/
PRIVATE void get_work(m_in)
message *m_in; /* pointer to message */
{
int r, srcok = 0;
endpoint_t src;
do {
if ((r = sef_receive(ANY, m_in)) != OK) /* wait for message */
panic("MFS","sef_receive failed", r);
src = fs_m_in.m_source;
if (src != FS_PROC_NR) {
if(src == PM_PROC_NR) {
if(is_notify(fs_m_in.m_type))
srcok = 1; /* Normal exit request. */
else
printf("MFS: unexpected message from PM\n");
} else
printf("MFS: unexpected source %d\n", src);
} else if(src == FS_PROC_NR) {
if(unmountdone)
printf("MFS: unmounted: unexpected message from FS\n");
else
srcok = 1; /* Normal FS request. */
} else
printf("MFS: unexpected source %d\n", src);
} while(!srcok);
assert((src == FS_PROC_NR && !unmountdone) ||
(src == PM_PROC_NR && is_notify(fs_m_in.m_type)));
}
/*===========================================================================*
* reply *
*===========================================================================*/
PUBLIC void reply(who, m_out)
int who;
message *m_out; /* report result */
{
if (OK != send(who, m_out)) /* send the message */
printf("MFS(%d) was unable to send reply\n", SELF_E);
}
/*===========================================================================*
* cch_check *
*===========================================================================*/
PRIVATE void cch_check(void)
{
int i;
for (i = 0; i < NR_INODES; ++i) {
if (inode[i].i_count != cch[i] &&
req_nr != REQ_GETNODE &&
req_nr != REQ_PUTNODE &&
req_nr != REQ_READSUPER &&
req_nr != REQ_MOUNTPOINT && req_nr != REQ_UNMOUNT &&
req_nr != REQ_SYNC && req_nr != REQ_LOOKUP)
printf("MFS(%d) inode(%d) cc: %d req_nr: %d\n",
SELF_E, inode[i].i_num, inode[i].i_count - cch[i], req_nr);
cch[i] = inode[i].i_count;
}
}