minix/fs/pfs/main.c

   1 #include "fs.h"
   2 #include <assert.h>
   3 #include <signal.h>
   4 #include <minix/dmap.h>
   5 #include <minix/driver.h>
   6 #include <minix/endpoint.h>
   7 #include <minix/rs.h>
   8 #include <minix/vfsif.h>
   9 #include <sys/types.h>
  10 #include <pwd.h>
  11 #include "buf.h"
  12 #include "inode.h"
  13
  14 static void get_work(message *m_in, int *status);
  15
  16 /* SEF functions and variables. */
  17 static void sef_local_startup(void);
  18 static int sef_cb_init_fresh(int type, sef_init_info_t *info);
  19 static void sef_cb_signal_handler(int signo);
  20
  21 /*===========================================================================*
  22  *                              main                                         *
  23  *===========================================================================*/
  24 int main(int argc, char *argv[])
  25 {
  26 /* This is the main routine of this service. The main loop consists of
  27  * three major activities: getting new work, processing the work, and
  28  * sending the reply. The loop never terminates, unless a panic occurs.
  29  */
  30   int ind, transid, req_nr, ipc_status;
  31   message pfs_m_in;
  32   message pfs_m_out;
  33   endpoint_t src;
  34
  35   /* SEF local startup. */
  36   env_setargs(argc, argv);
  37   sef_local_startup();
  38
  39   while(!unmountdone || !exitsignaled) {
  40         /* Wait for request message. */
  41         get_work(&pfs_m_in, &ipc_status);
  42
  43         transid = TRNS_GET_ID(pfs_m_in.m_type);
  44         pfs_m_in.m_type = TRNS_DEL_ID(pfs_m_in.m_type);
  45         if (pfs_m_in.m_type == 0) {
  46                 assert(!IS_VFS_FS_TRANSID(transid));
  47                 pfs_m_in.m_type = transid;
  48                 transid = 0;
  49         } else
  50                 assert(IS_VFS_FS_TRANSID(transid) || transid == 0);
  51
  52         src = pfs_m_in.m_source;
  53         req_nr = pfs_m_in.m_type;
  54
  55         if (IS_FS_RQ(req_nr)) {
  56                 ind = req_nr - FS_BASE;
  57                 if (ind < 0 || ind >= FS_CALL_VEC_SIZE) {
  58                         printf("pfs: bad FS request %d\n", req_nr);
  59                         pfs_m_out.m_type = EINVAL;
  60                 } else {
  61                         pfs_m_out.m_type =
  62                                 (*fs_call_vec[ind])(&pfs_m_in, &pfs_m_out);
  63                 }
  64         } else {
  65                 printf("pfs: bad request %d\n", req_nr);
  66                 pfs_m_out.m_type = EINVAL;
  67         }
  68
  69         if (IS_FS_RQ(req_nr) && IS_VFS_FS_TRANSID(transid)) {
  70                 pfs_m_out.m_type = TRNS_ADD_ID(pfs_m_out.m_type, transid);
  71         }
  72         reply(src, &pfs_m_out);
  73   }
  74   return(OK);
  75 }
  76
  77 /*===========================================================================*
  78  *                             sef_local_startup                             *
  79  *===========================================================================*/
  80 static void sef_local_startup()
  81 {
  82   /* Register init callbacks. */
  83   sef_setcb_init_fresh(sef_cb_init_fresh);
  84   sef_setcb_init_restart(sef_cb_init_fail);
  85
  86   /* No live update support for now. */
  87
  88   /* Register signal callbacks. */
  89   sef_setcb_signal_handler(sef_cb_signal_handler);
  90
  91   /* Let SEF perform startup. */
  92   sef_startup();
  93 }
  94
  95 /*===========================================================================*
  96  *                          sef_cb_init_fresh                                *
  97  *===========================================================================*/
  98 static int sef_cb_init_fresh(int type, sef_init_info_t *info)
  99 {
 100 /* Initialize the pipe file server. */
 101   int i;
 102   struct passwd *pw;
 103
 104   /* Initialize main loop parameters. */
 105   exitsignaled = 0;     /* No exit request seen yet. */
 106   busy = 0;             /* Server is not 'busy' (i.e., inodes in use). */
 107
 108   /* Init inode table */
 109   for (i = 0; i < PFS_NR_INODES; ++i) {
 110         inode[i].i_count = 0;
 111   }
 112
 113   init_inode_cache();
 114   buf_pool();
 115
 116   /* Drop root privileges */
 117   if ((pw = getpwnam(SERVICE_LOGIN)) == NULL) {
 118         printf("PFS: unable to retrieve uid of SERVICE_LOGIN, "
 119                 "still running as root");
 120   } else if (setuid(pw->pw_uid) != 0) {
 121         panic("unable to drop privileges");
 122   }
 123
 124   return(OK);
 125 }
 126
 127 /*===========================================================================*
 128  *                         sef_cb_signal_handler                             *
 129  *===========================================================================*/
 130 static void sef_cb_signal_handler(int signo)
 131 {
 132   /* Only check for termination signal, ignore anything else. */
 133   if (signo != SIGTERM) return;
 134
 135
 136   exitsignaled = 1;
 137 }
 138
 139 /*===========================================================================*
 140  *                              get_work                                     *
 141  *===========================================================================*/
 142 static void get_work(message * m_in, int *status)
 143 {
 144   int r, srcok = 0;
 145   endpoint_t src;
 146
 147   do {
 148         /* wait for a message */
 149         if ((r = sef_receive_status(ANY, m_in, status)) != OK)
 150                 panic("sef_receive_status failed: %d", r);
 151         src = m_in->m_source;
 152
 153         if(src == VFS_PROC_NR) {
 154                 srcok = 1;              /* Normal FS request. */
 155         } else
 156                 printf("PFS: unexpected source %d\n", src);
 157   } while(!srcok);
 158 }
 159
 160
 161 /*===========================================================================*
 162  *                              reply                                        *
 163  *===========================================================================*/
 164 void reply(who, m_out)
 165 endpoint_t who;
 166 message *m_out;                         /* report result */
 167 {
 168   int r;
 169
 170   if (OK != (r = ipc_send(who, m_out))) /* send the message */
 171         printf("PFS: unable to send reply: %d\n", r);
 172 }