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Sourcecode: bacula version File versions

acquire.c

/*
 *  Routines to acquire and release a device for read/write
 *
 *   Kern Sibbald, August MMII
 *                      
 *   Version $Id: acquire.c,v 1.77.2.2 2005/02/27 21:53:29 kerns Exp $
 */
/*
   Copyright (C) 2002-2004 Kern Sibbald and John Walker

   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 2 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, write to the Free
   Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.

 */

#include "bacula.h"                   /* pull in global headers */
#include "stored.h"                   /* pull in Storage Deamon headers */

static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

DCR *new_dcr(JCR *jcr, DEVICE *dev)
{
   if (jcr && jcr->dcr) {
      return jcr->dcr;
   }
   DCR *dcr = (DCR *)malloc(sizeof(DCR));
   memset(dcr, 0, sizeof(DCR));
   if (jcr) {
      jcr->dcr = dcr;
   }
   dcr->jcr = jcr;
   dcr->dev = dev;
   if (dev) {
      dcr->device = dev->device;
   }
   dcr->block = new_block(dev);
   dcr->rec = new_record();
   dcr->spool_fd = -1;
   dcr->max_spool_size = dev->device->max_spool_size;
   /* Attach this dcr only if dev is initialized */
   if (dev->fd != 0 && jcr && jcr->JobType != JT_SYSTEM) {
      dev->attached_dcrs->append(dcr);
   }
   return dcr;
}

void free_dcr(DCR *dcr)
{
   JCR *jcr = dcr->jcr;
   DEVICE *dev = dcr->dev;

   /* Detach this dcr only if the dev is initialized */
   if (dev->fd != 0 && jcr && jcr->JobType != JT_SYSTEM) {
      dcr->dev->attached_dcrs->remove(dcr);
   }
   if (dcr->block) {
      free_block(dcr->block);
   }
   if (dcr->rec) {
      free_record(dcr->rec);
   }
   if (dcr->jcr) {
      dcr->jcr->dcr = NULL;
   }
   free(dcr);
}


/********************************************************************* 
 * Acquire device for reading.      We permit (for the moment)
 *  only one reader.  We read the Volume label from the block and
 *  leave the block pointers just after the label.
 *
 *  Returns: NULL if failed for any reason
 *         dcr  if successful
 */
DCR *acquire_device_for_read(JCR *jcr)
{
   bool vol_ok = false;
   bool tape_previously_mounted;
   bool tape_initially_mounted;
   VOL_LIST *vol;
   bool try_autochanger = true;
   int i;
   DCR *dcr = jcr->dcr;
   DEVICE *dev;
   
   /* Called for each volume */
   if (!dcr) {
      dcr = new_dcr(jcr, jcr->device->dev);
   }
   dev = dcr->dev;
   if (device_is_unmounted(dev)) {
      Jmsg(jcr, M_WARNING, 0, _("device %s is BLOCKED due to user unmount.\n"),
       dev_name(dev));
   }
   lock_device(dev);
   block_device(dev, BST_DOING_ACQUIRE);
   unlock_device(dev);

   init_dev_wait_timers(dev);
   if (dev_state(dev, ST_READ) || dev->num_writers > 0) {
      Jmsg2(jcr, M_FATAL, 0, _("Device %s is busy. Job %d canceled.\n"), 
          dev_name(dev), jcr->JobId);
      goto get_out;
   }

   tape_previously_mounted = dev_state(dev, ST_READ) || 
                       dev_state(dev, ST_APPEND) ||
                       dev_state(dev, ST_LABEL);
   tape_initially_mounted = tape_previously_mounted;

   /* Find next Volume, if any */
   vol = jcr->VolList;
   if (!vol) {
      Jmsg(jcr, M_FATAL, 0, _("No volumes specified. Job %d canceled.\n"), jcr->JobId);
      goto get_out;
   }
   jcr->CurVolume++;
   for (i=1; i<jcr->CurVolume; i++) {
      vol = vol->next;
   }
   bstrncpy(dcr->VolumeName, vol->VolumeName, sizeof(dcr->VolumeName));

   for (i=0; i<5; i++) {
      dcr->dev->state &= ~ST_LABEL;       /* force reread of label */
      if (job_canceled(jcr)) {
         Mmsg1(dev->errmsg, _("Job %d canceled.\n"), jcr->JobId);
       goto get_out;                /* error return */
      }
      /*
       * This code ensures that the device is ready for
       * reading. If it is a file, it opens it.
       * If it is a tape, it checks the volume name 
       */
      for ( ; !(dev->state & ST_OPENED); ) {
         Dmsg1(120, "bstored: open vol=%s\n", dcr->VolumeName);
       if (open_dev(dev, dcr->VolumeName, OPEN_READ_ONLY) < 0) {
          if (dev->dev_errno == EIO) {   /* no tape loaded */
             goto default_path;
          }
            Jmsg(jcr, M_FATAL, 0, _("Open device %s volume %s failed, ERR=%s\n"), 
            dev_name(dev), dcr->VolumeName, strerror_dev(dev));
          goto get_out;
       }
         Dmsg1(129, "open_dev %s OK\n", dev_name(dev));
      }
      /****FIXME***** do not reread label if ioctl() says we are
       *  correctly possitioned.  Possibly have way user can turn
       *  this optimization (to be implemented) off.
       */
      Dmsg0(200, "calling read-vol-label\n");
      switch (read_dev_volume_label(dcr)) {
      case VOL_OK:
       vol_ok = true;
       memcpy(&dev->VolCatInfo, &dcr->VolCatInfo, sizeof(dev->VolCatInfo));
       break;              /* got it */
      case VOL_IO_ERROR:
       /*
        * Send error message generated by read_dev_volume_label()
        *  only we really had a tape mounted. This supresses superfluous
        *  error messages when nothing is mounted.
        */
       if (tape_previously_mounted) {
            Jmsg(jcr, M_WARNING, 0, "%s", jcr->errmsg);                         
       }
       goto default_path;
      case VOL_NAME_ERROR:
       if (tape_initially_mounted) {
          tape_initially_mounted = false;
          goto default_path;
       }
       /* Fall through */
      default:
         Jmsg(jcr, M_WARNING, 0, "%s", jcr->errmsg);
default_path:
       tape_previously_mounted = true;
         Dmsg0(200, "dir_get_volume_info\n");
       if (!dir_get_volume_info(dcr, GET_VOL_INFO_FOR_READ)) { 
            Jmsg1(jcr, M_WARNING, 0, "%s", jcr->errmsg);
       }
       /* Call autochanger only once unless ask_sysop called */
       if (try_autochanger) {
          int stat;
            Dmsg2(200, "calling autoload Vol=%s Slot=%d\n",
             dcr->VolumeName, dcr->VolCatInfo.Slot);                     
          stat = autoload_device(dcr, 0, NULL);
          if (stat > 0) {
             try_autochanger = false;
             continue;
          }
       }
       /* Mount a specific volume and no other */
         Dmsg0(200, "calling dir_ask_sysop\n");
       if (!dir_ask_sysop_to_mount_volume(dcr)) {
          goto get_out;       /* error return */
       }
       try_autochanger = true;      /* permit using autochanger again */
       continue;              /* try reading again */
      } /* end switch */
      break;
   } /* end for loop */
   if (!vol_ok) {
      Jmsg1(jcr, M_FATAL, 0, _("Too many errors trying to mount device \"%s\".\n"),
          dev_name(dev));
      goto get_out;
   }

   dev->state &= ~ST_APPEND;        /* clear any previous append mode */
   dev->state |= ST_READ;           /* set read mode */
   set_jcr_job_status(jcr, JS_Running);
   dir_send_job_status(jcr);
   Jmsg(jcr, M_INFO, 0, _("Ready to read from volume \"%s\" on device %s.\n"),
      dcr->VolumeName, dev_name(dev));

get_out:
   P(dev->mutex); 
   unblock_device(dev);
   V(dev->mutex);
   if (!vol_ok) {
      free_dcr(dcr);
      dcr = NULL;
   }
   return dcr;
}

/*
 * Acquire device for writing. We permit multiple writers.
 *  If this is the first one, we read the label.
 *
 *  Returns: NULL if failed for any reason
 *         dev if successful (may change if new dev opened)
 *  This routine must be single threaded because we may create
 *   multiple devices (for files), thus we have our own mutex 
 *   on top of the device mutex.
 */
DCR *acquire_device_for_append(JCR *jcr)
{
   bool release = false;
   bool recycle = false;
   bool do_mount = false;
   DCR *dcr;
   DEVICE *dev = jcr->device->dev;

   dcr = new_dcr(jcr, dev);
   if (device_is_unmounted(dev)) {
      Jmsg(jcr, M_WARNING, 0, _("device %s is BLOCKED due to user unmount.\n"),
       dev_name(dev));
   }
   lock_device(dev);
   block_device(dev, BST_DOING_ACQUIRE);
   unlock_device(dev);
   P(mutex);                       /* lock all devices */
   Dmsg1(190, "acquire_append device is %s\n", dev_is_tape(dev)?"tape":"disk");
           
   if (dev_state(dev, ST_APPEND)) {
      Dmsg0(190, "device already in append.\n");
      /* 
       * Device already in append mode     
       *
       * Check if we have the right Volume mounted   
       *   OK if current volume info OK
       *   OK if next volume matches current volume
       *   otherwise mount desired volume obtained from
       *    dir_find_next_appendable_volume
       */
      bstrncpy(dcr->VolumeName, dev->VolHdr.VolName, sizeof(dcr->VolumeName));
      if (!dir_get_volume_info(dcr, GET_VOL_INFO_FOR_WRITE) &&
        !(dir_find_next_appendable_volume(dcr) &&
          strcmp(dev->VolHdr.VolName, dcr->VolumeName) == 0)) { /* wrong tape mounted */
         Dmsg0(190, "Wrong tape mounted.\n");
       if (dev->num_writers != 0) {
          DEVICE *d = ((DEVRES *)dev->device)->dev;
          uint32_t open_vols = 0;
          for ( ; d; d=d->next) {
             open_vols++;
          }
          if (dev_state(dev, ST_FILE) && dev->max_open_vols > open_vols) {
             d = init_dev(NULL, (DEVRES *)dev->device); /* init new device */
             d->prev = dev;               /* chain in new device */
             d->next = dev->next;
             dev->next = d;
             /* Release old device */
             P(dev->mutex); 
             unblock_device(dev);
             V(dev->mutex);
             free_dcr(dcr);         /* release dcr pointing to old dev */
             /* Make new device current device and lock it */
             dev = d;
             dcr = new_dcr(jcr, dev); /* get new dcr for new device */
             lock_device(dev);
             block_device(dev, BST_DOING_ACQUIRE);
             unlock_device(dev);
          } else {
               Jmsg(jcr, M_FATAL, 0, _("Device %s is busy writing on another Volume.\n"), dev_name(dev));
             goto get_out;
          }
       }
       /* Wrong tape mounted, release it, then fall through to get correct one */
         Dmsg0(190, "Wrong tape mounted, release and try mount.\n");
       release = true;
       do_mount = true;
      } else {
       /*     
        * At this point, the correct tape is already mounted, so 
        *   we do not need to do mount_next_write_volume(), unless
        *   we need to recycle the tape.
        */
          recycle = strcmp(dcr->VolCatInfo.VolCatStatus, "Recycle") == 0;
          Dmsg1(190, "Correct tape mounted. recycle=%d\n", recycle);
        if (recycle && dev->num_writers != 0) {
             Jmsg(jcr, M_FATAL, 0, _("Cannot recycle volume \"%s\""
                  " because it is in use by another job.\n"));
           goto get_out;
        }
        if (dev->num_writers == 0) {
           memcpy(&dev->VolCatInfo, &dcr->VolCatInfo, sizeof(dev->VolCatInfo));
        }
       }
   } else { 
      /* Not already in append mode, so mount the device */
      Dmsg0(190, "Not in append mode, try mount.\n");
      if (dev_state(dev, ST_READ)) {
         Jmsg(jcr, M_FATAL, 0, _("Device %s is busy reading.\n"), dev_name(dev));
       goto get_out;
      } 
      ASSERT(dev->num_writers == 0);
      do_mount = true;
   }

   if (do_mount || recycle) {
      Dmsg0(190, "Do mount_next_write_vol\n");
      V(mutex);                       /* don't lock everything during mount */
      bool mounted = mount_next_write_volume(dcr, release);
      P(mutex);               /* re-lock */
      if (!mounted) {
       if (!job_canceled(jcr)) {
            /* Reduce "noise" -- don't print if job canceled */
            Jmsg(jcr, M_FATAL, 0, _("Could not ready device \"%s\" for append.\n"),
             dev_name(dev));
       }
       goto get_out;
      }
   }

   dev->num_writers++;
   if (jcr->NumVolumes == 0) {
      jcr->NumVolumes = 1;
   }
   set_jcr_job_status(jcr, JS_Running);
   dir_send_job_status(jcr);
   goto ok_out;

/*
 * If we jump here, it is an error return because
 *  rtn_dev will still be NULL
 */
get_out:
   free_dcr(dcr);
   dcr = NULL;
ok_out:
   P(dev->mutex); 
   unblock_device(dev);
   V(dev->mutex);
   V(mutex);                        /* unlock other threads */
   return dcr;
}

/*
 * This job is done, so release the device. From a Unix standpoint,
 *  the device remains open.
 *
 */
bool release_device(JCR *jcr)
{
   DCR *dcr = jcr->dcr;
   DEVICE *dev = dcr->dev;   
   lock_device(dev);
   Dmsg1(100, "release_device device is %s\n", dev_is_tape(dev)?"tape":"disk");
   if (dev->can_read()) {
      dev->clear_read();            /* clear read bit */
      if (!dev_is_tape(dev) || !dev_cap(dev, CAP_ALWAYSOPEN)) {
       offline_or_rewind_dev(dev);
       close_dev(dev);
      }
      /******FIXME**** send read volume usage statistics to director */

   } else if (dev->num_writers > 0) {
      dev->num_writers--;
      Dmsg1(100, "There are %d writers in release_device\n", dev->num_writers);
      if (dev->is_labeled()) {
         Dmsg0(100, "dir_create_jobmedia_record. Release\n");
       if (!dir_create_jobmedia_record(dcr)) {
            Jmsg(jcr, M_FATAL, 0, _("Could not create JobMedia record for Volume=\"%s\" Job=%s\n"),
             dcr->VolCatInfo.VolCatName, jcr->Job);
       }
       /* If no more writers, write an EOF */
       if (!dev->num_writers && dev_can_write(dev)) {
          weof_dev(dev, 1);
       }
       dev->VolCatInfo.VolCatFiles = dev->file;   /* set number of files */
       dev->VolCatInfo.VolCatJobs++;                /* increment number of jobs */
       /* Note! do volume update before close, which zaps VolCatInfo */
         Dmsg0(100, "dir_update_vol_info. Release0\n");
       dir_update_volume_info(dcr, false); /* send Volume info to Director */
      }

      if (!dev->num_writers && (!dev_is_tape(dev) || !dev_cap(dev, CAP_ALWAYSOPEN))) {
       offline_or_rewind_dev(dev);
       close_dev(dev);
      }
   } else {
      Jmsg2(jcr, M_FATAL, 0, _("BAD ERROR: release_device %s, Volume \"%s\" not in use.\n"), 
          dev_name(dev), NPRT(dcr->VolumeName));
      Jmsg2(jcr, M_ERROR, 0, _("num_writers=%d state=%x\n"), dev->num_writers, dev->state);
   }

   /* Fire off Alert command and include any output */
   if (!job_canceled(jcr) && jcr->device->alert_command) {
      POOLMEM *alert;
      int status = 1;
      BPIPE *bpipe;
      char line[MAXSTRING];
      alert = get_pool_memory(PM_FNAME);
      alert = edit_device_codes(jcr, alert, jcr->device->alert_command, "");
      bpipe = open_bpipe(alert, 0, "r");
      if (bpipe) {
       while (fgets(line, sizeof(line), bpipe->rfd)) {
            Jmsg(jcr, M_ALERT, 0, _("Alert: %s"), line);
       }
       status = close_bpipe(bpipe);
      } else {
       status = errno;
      }
      if (status != 0) {
       berrno be;
         Jmsg(jcr, M_ALERT, 0, _("3997 Bad alert command: %s: ERR=%s.\n"),
            alert, be.strerror(status));
      }

      Dmsg1(400, "alert status=%d\n", status);
      free_pool_memory(alert);
   }
   if (dev->prev && !dev_state(dev, ST_READ) && !dev->num_writers) {
      P(mutex);
      unlock_device(dev);
      dev->prev->next = dev->next;    /* dechain */
      term_dev(dev);
      V(mutex);
   } else {
      unlock_device(dev);
   }
   free_dcr(jcr->dcr);
   jcr->dcr = NULL;
   return true;
}

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