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[PATCH] don't sleep if 'dev' file is already present on device add. 

instead sleep for up to 10 seconds waiting for it to show up.
This commit is contained in:
greg@kroah.com 2003-10-20 21:03:15 -07:00 committed by Greg KH
parent 727d1ba5be
commit 29fd7e679b
1 changed files with 43 additions and 14 deletions
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57
udev-add.c
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@ -34,6 +34,7 @@
#include "udevdb.h"
#include "libsysfs/libsysfs.h"
static char sysfs_path[SYSFS_PATH_MAX];
/*
* Right now the major/minor of a device is stored in a file called
@ -101,19 +102,9 @@ static int create_node(char *name, char type, int major, int minor, mode_t mode)
static struct sysfs_class_device *get_class_dev(char *device_name)
{
char sysfs_path[SYSFS_PATH_MAX];
char dev_path[SYSFS_PATH_MAX];
int retval;
struct sysfs_class_device *class_dev = NULL;
retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
dbg("sysfs_path = %s", sysfs_path);
if (retval) {
dbg("sysfs_get_mnt_path failed");
goto exit;
}
strcpy(dev_path, sysfs_path);
strcat(dev_path, device_name);
@ -131,6 +122,38 @@ exit:
return class_dev;
}
/* wait for the "dev" file to show up in the directory in sysfs.
* If it doesn't happen in about 10 seconds, give up.
*/
#define SECONDS_TO_WAIT_FOR_DEV 10
int sleep_for_dev(char *device)
{
char filename[SYSFS_PATH_MAX + 6];
struct stat buf;
int loop = 0;
int retval = -ENODEV;
strcpy(filename, sysfs_path);
strcat(filename, device);
strcat(filename, "/dev");
while (loop < SECONDS_TO_WAIT_FOR_DEV) {
dbg("looking for %s", filename);
retval = stat(filename, &buf);
if (retval == 0) {
retval = 0;
goto exit;
}
/* sleep for a second or two to give the kernel a chance to
* create the dev file */
sleep(1);
}
retval = -ENODEV;
exit:
return retval;
}
int udev_add_device(char *device, char *subsystem)
{
struct sysfs_class_device *class_dev;
@ -146,10 +169,16 @@ int udev_add_device(char *device, char *subsystem)
else
type = 'c';
/* sleep for a second or two to give the kernel a chance to
* create the dev file
*/
sleep(1);
retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
dbg("sysfs_path = %s", sysfs_path);
if (retval) {
dbg("sysfs_get_mnt_path failed");
goto exit;
}
retval = sleep_for_dev(device);
if (retval)
goto exit;
class_dev = get_class_dev(device);
if (class_dev == NULL)