The current release of CUPS does not have this problem. And unfortunately we do not have time to re-develop "fixes" for old CUPS releases that we no longer support in order to work around a design deficiency in a Linux-specific monitoring application which should not be using 15-minute lease times in the first place.


On Nov 8, 2013, at 7:14 AM, Hao-Ran Liu <email address hidden> wrote:

> I think a fix for this bug could be limited in this function:
> cupsdCloseCreatedConfFile(). Is there any concern if the logics of
> secure erase (overwrite_data() and fsync()) are removed from
> cupsdCloseCreatedConfFile()?
> 
> It's desirable to have a small diff so that we could have a SRU for
> precise.
> 
> -- 
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1244205
> 
> Title:
>  cupsd wakes up the hard disk every 14 minutes
> 
> Status in The Ubuntu Power Consumption Project:
>  New
> Status in “cups” package in Ubuntu:
>  New
> Status in “indicator-printers” package in Ubuntu:
>  New
> 
> Bug description:
>  cupsd  calls fsync() on /etc/subscriptions.conf.N every 14~15 minutes.
>  This causes the hard disk to wake up soon after it spins down.
>  Subscription renewal is from indicator-printers every 15 minutes.
> 
>  I think we don't need cupsdRemoveFile() to always overwrite data and do a fsync() for this file. Currently only Precise is confirmed to be affected. Saucy seems not having the same issue according to
>  (http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/saucy/cups/saucy/view/head:/scheduler/file.c#L149)
> 
>  ---- block_dump from the kernel ----
>  <7>[19935.646436] cupsd(1066): dirtied inode 15336755 (subscriptions.conf.N) on sda3
>  <7>[19935.646673] cupsd(1066): WRITE block 352753016 on sda3 (8 sectors)
>  <7>[19935.646755] cupsd(1066): dirtied inode 15335603 (?) on sda3
>  <7>[19935.646763] cupsd(1066): dirtied inode 15335603 (?) on sda3
>  <7>[19935.646776] cupsd(1066): WRITE block 352701128 on sda3 (8 sectors)
>  <7>[20774.607856] cupsd(1066): dirtied inode 15335603 (subscriptions.conf.N) on sda3
>  <7>[20774.608034] cupsd(1066): WRITE block 352862776 on sda3 (8 sectors)
>  <7>[20774.608113] cupsd(1066): dirtied inode 15335607 (?) on sda3
>  <7>[20774.608120] cupsd(1066): dirtied inode 15335607 (?) on sda3
>  <7>[20774.608133] cupsd(1066): WRITE block 352753008 on sda3 (8 sectors)
>  <7>[21613.569033] cupsd(1066): dirtied inode 15335607 (subscriptions.conf.N) on sda3
>  <7>[21613.569257] cupsd(1066): WRITE block 352753024 on sda3 (8 sectors)
>  <7>[21613.569345] cupsd(1066): dirtied inode 15336755 (?) on sda3
>  <7>[21613.569353] cupsd(1066): dirtied inode 15336755 (?) on sda3
>  <7>[21613.569367] cupsd(1066): WRITE block 352753016 on sda3 (8 sectors)
> 
>  ---- cups: scheduler/file.c ----
>  int					/* O - 0 on success, -1 on error */
>  cupsdCloseCreatedConfFile(
>      cups_file_t *fp,			/* I - File to close */
>      const char  *filename)		/* I - Filename */
>  {
>  ...
>    snprintf(newfile, sizeof(newfile), "%s.N", filename);
>    snprintf(oldfile, sizeof(oldfile), "%s.O", filename);
> 
>    if ((cupsdRemoveFile(oldfile) && errno != ENOENT) ||
>        (rename(filename, oldfile) && errno != ENOENT) ||
>        rename(newfile, filename))
>    {
>      cupsdLogMessage(CUPSD_LOG_ERROR, "Unable to finalize \"%s\": %s",
>                      filename, strerror(errno));
>      return (-1);
>    }
> 
>    return (0);
>  }
> 
>  int					/* O - 0 on success, -1 on error */
>  cupsdRemoveFile(const char *filename)	/* I - File to remove */
>  {
>  ...
>   /*
>    * Overwrite the file 7 times with 0xF6, 0x00, 0xFF, random, 0x00, 0xFF,
>    * and more random data.
>    */
> 
>    memset(buffer, 0xF6, sizeof(buffer));
>    if (overwrite_data(fd, buffer, sizeof(buffer), (int)info.st_size))
>    {
>      close(fd);
>      return (-1);
>    }
>  ...
>  }
> 
>  static int				/* O - 0 on success, -1 on error */
>  overwrite_data(int        fd,		/* I - File descriptor */
>                 const char *buffer,	/* I - Buffer to write */
>          int        bufsize,	/* I - Size of buffer */
>                 int        filesize)	/* I - Size of file */
>  {
>    int	bytes;				/* Bytes to write/written */
> 
>   /*
>    * Start at the beginning of the file...
>    */
> 
>    if (lseek(fd, 0, SEEK_SET) < 0)
>      return (-1);
> 
>   /*
>    * Fill the file with the provided data...
>    */
> 
>    while (filesize > 0)
>    {
>      if (filesize > bufsize)
>        bytes = bufsize;
>      else
>        bytes = filesize;
> 
>      if ((bytes = write(fd, buffer, bytes)) < 0)
>        return (-1);
> 
>      filesize -= bytes;
>    }
> 
>   /*
>    * Force the changes to disk...
>    */
> 
>    return (fsync(fd));
>  }
> 
>  ---- indicator-printers-service.c ----
>  #define NOTIFY_LEASE_DURATION (15 * 60)
> 
>  int main (int argc, char *argv[])
>  {
>  ...
>      g_timeout_add_seconds (NOTIFY_LEASE_DURATION - 60,
>                             renew_subscription_timeout,
>                             &subscription_id);
>  ...
>  }
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu-power-consumption/+bug/1244205/+subscriptions

_________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair