af01bda509
The "bdev" library provides basic primitives for file systems to talk to block device drivers, hiding the details of the underlying protocol and interaction model. This version of libbdev is rather basic. It is planned to support the following features in the long run: - asynchronous requests and replies; - recovery support for underlying block drivers; - retrying of failed I/O requests. The commit also changes our block-based file systems (mfs, ext2, isofs) to make use of libbdev.
147 lines
4.3 KiB
C
147 lines
4.3 KiB
C
/* This file contains the main directory for the server. It waits for a
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* request and then send a response. */
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#include "inc.h"
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#include <minix/vfsif.h>
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#include <assert.h>
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#include "const.h"
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#include "glo.h"
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/* Declare some local functions. */
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FORWARD _PROTOTYPE(void get_work, (message *m_in) );
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/* SEF functions and variables. */
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FORWARD _PROTOTYPE( void sef_local_startup, (void) );
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FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
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FORWARD _PROTOTYPE( void sef_cb_signal_handler, (int signo) );
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC int main(void) {
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endpoint_t who_e;
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int ind, error, transid;
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/* SEF local startup. */
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sef_local_startup();
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for (;;) {
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/* Wait for request message. */
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get_work(&fs_m_in);
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transid = TRNS_GET_ID(fs_m_in.m_type);
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fs_m_in.m_type = TRNS_DEL_ID(fs_m_in.m_type);
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if (fs_m_in.m_type == 0) {
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assert(!IS_VFS_FS_TRANSID(transid));
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fs_m_in.m_type = transid; /* Backwards compat. */
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transid = 0;
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} else
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assert(IS_VFS_FS_TRANSID(transid));
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error = OK;
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caller_uid = -1; /* To trap errors */
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caller_gid = -1;
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who_e = fs_m_in.m_source; /* source of the request */
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if (who_e != VFS_PROC_NR) { /* If the message is not for us just
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* continue */
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continue;
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}
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req_nr = fs_m_in.m_type;
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if (req_nr < VFS_BASE) {
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fs_m_in.m_type += VFS_BASE;
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req_nr = fs_m_in.m_type;
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}
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ind = req_nr-VFS_BASE;
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if (ind < 0 || ind >= NREQS) {
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error = EINVAL;
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} else
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error = (*fs_call_vec[ind])(); /* Process the request calling
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* the appropriate function. */
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fs_m_out.m_type = error;
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if (IS_VFS_FS_TRANSID(transid)) {
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/* If a transaction ID was set, reset it */
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fs_m_out.m_type = TRNS_ADD_ID(fs_m_out.m_type, transid);
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}
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reply(who_e, &fs_m_out); /* returns the response to VFS */
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}
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}
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/*===========================================================================*
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* sef_local_startup *
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*===========================================================================*/
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PRIVATE void sef_local_startup()
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{
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/* Register init callbacks. */
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sef_setcb_init_fresh(sef_cb_init_fresh);
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sef_setcb_init_restart(sef_cb_init_fail);
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/* No live update support for now. */
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/* Register signal callbacks. */
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sef_setcb_signal_handler(sef_cb_signal_handler);
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/* Let SEF perform startup. */
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sef_startup();
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}
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/*===========================================================================*
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* sef_cb_init_fresh *
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*===========================================================================*/
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PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
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{
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/* Initialize the iso9660fs server. */
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/* SELF_E will contain the id of this process */
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SELF_E = getprocnr();
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/* hash_init(); */ /* Init the table with the ids */
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setenv("TZ","",1); /* Used to calculate the time */
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return(OK);
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}
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/*===========================================================================*
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* sef_cb_signal_handler *
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*===========================================================================*/
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PRIVATE void sef_cb_signal_handler(int signo)
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{
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/* Only check for termination signal, ignore anything else. */
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if (signo != SIGTERM) return;
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/* No need to do a sync, as this is a read-only file system. */
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/* If the file system has already been unmounted, exit immediately.
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* We might not get another message.
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*/
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if (unmountdone) exit(0);
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}
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/*===========================================================================*
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* get_work *
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*===========================================================================*/
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PRIVATE void get_work(m_in)
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message *m_in; /* pointer to message */
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{
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int s; /* receive status */
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if (OK != (s = sef_receive(ANY, m_in))) /* wait for message */
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panic("sef_receive failed: %d", s);
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}
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/*===========================================================================*
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* reply *
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*===========================================================================*/
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PUBLIC void reply(who, m_out)
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int who;
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message *m_out; /* report result */
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{
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if (OK != send(who, m_out)) /* send the message */
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printf("ISOFS(%d) was unable to send reply\n", SELF_E);
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}
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