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.
219 lines
6.1 KiB
C
219 lines
6.1 KiB
C
#include "fs.h"
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#include <assert.h>
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#include <minix/callnr.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <minix/dmap.h>
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#include <minix/endpoint.h>
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#include <minix/vfsif.h>
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#include <minix/optset.h>
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#include "buf.h"
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#include "inode.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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FORWARD _PROTOTYPE( void reply, (endpoint_t who, message *m_out) );
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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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EXTERN int env_argc;
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EXTERN char **env_argv;
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PRIVATE struct optset optset_table[] = {
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{ "sb", OPT_INT, &opt.block_with_super, 0 },
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{ "orlov", OPT_BOOL, &opt.use_orlov, TRUE },
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{ "oldalloc", OPT_BOOL, &opt.use_orlov, FALSE },
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{ "mfsalloc", OPT_BOOL, &opt.mfsalloc, TRUE },
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{ "reserved", OPT_BOOL, &opt.use_reserved_blocks, TRUE },
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{ "prealloc", OPT_BOOL, &opt.use_prealloc, TRUE },
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{ "noprealloc", OPT_BOOL, &opt.use_prealloc, FALSE },
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{ NULL }
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};
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC int main(int argc, char *argv[])
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{
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/* This is the main routine of this service. The main loop consists of
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* three major activities: getting new work, processing the work, and
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* sending the reply. The loop never terminates, unless a panic occurs.
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*/
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int error = OK, ind, transid;
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unsigned short test_endian = 1;
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/* SEF local startup. */
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env_setargs(argc, argv);
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sef_local_startup();
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le_CPU = (*(unsigned char *) &test_endian == 0 ? 0 : 1);
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/* Server isn't tested on big endian CPU */
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ASSERT(le_CPU == 1);
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while(!unmountdone || !exitsignaled) {
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endpoint_t src;
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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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src = fs_m_in.m_source;
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caller_uid = INVAL_UID; /* To trap errors */
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caller_gid = INVAL_GID;
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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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printf("mfs: bad request %d\n", req_nr);
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printf("ind = %d\n", ind);
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error = EINVAL;
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} else {
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error = (*fs_call_vec[ind])();
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}
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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(src, &fs_m_out);
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if (error == OK)
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read_ahead(); /* do block read ahead */
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}
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return 0;
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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 Minix file server. */
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int i;
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/* Defaults */
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opt.use_orlov = TRUE;
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opt.mfsalloc = FALSE;
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opt.use_reserved_blocks = FALSE;
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opt.block_with_super = 0;
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opt.use_prealloc = FALSE;
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/* If we have been given an options string, parse options from there. */
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for (i = 1; i < env_argc - 1; i++)
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if (!strcmp(env_argv[i], "-o"))
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optset_parse(optset_table, env_argv[++i]);
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may_use_vmcache = 1;
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/* Init inode table */
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for (i = 0; i < NR_INODES; ++i) {
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inode[i].i_count = 0;
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cch[i] = 0;
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}
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init_inode_cache();
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SELF_E = getprocnr();
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/* just a small number before we find out the block size at mount time */
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buf_pool(10);
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fs_block_size = _MIN_BLOCK_SIZE;
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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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exitsignaled = 1;
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(void) fs_sync();
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/* If unmounting has already been performed, 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 r, srcok = 0;
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endpoint_t src;
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do {
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if ((r = sef_receive(ANY, m_in)) != OK) /* wait for message */
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panic("sef_receive failed: %d", r);
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src = m_in->m_source;
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if(src == VFS_PROC_NR) {
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if(unmountdone)
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printf("ext2: unmounted: unexpected message from FS\n");
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else
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srcok = 1; /* Normal FS request. */
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} else
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printf("ext2: unexpected source %d\n", src);
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} while(!srcok);
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assert((src == VFS_PROC_NR && !unmountdone));
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}
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/*===========================================================================*
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* reply *
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*===========================================================================*/
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PRIVATE void reply(
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endpoint_t who,
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message *m_out /* report result */
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)
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{
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if (OK != send(who, m_out)) /* send the message */
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printf("ext2(%d) was unable to send reply\n", SELF_E);
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}
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