| 2013-10-24 12:38:58 |
Hao-Ran Liu |
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)
---- 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);
...
}
---- 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) |
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);
...
} |
|
