[PATCH] Fix wait_for_sysfs messages (more debugging info)

On Sat, Oct 16, 2004 at 02:48:42PM -0400, Jeff wrote:
> Kay Sievers wrote:
> >On Sat, Oct 16, 2004 at 04:40:51AM +0200, Kay Sievers wrote:
> >
> >Here is a better version. We return successful in the case, that the
> >advertised device does not appear within the timeout or goes completely
> >away while waiting for the attributes. All magic numbers should be
> >readable as a string now.
> >
> >This hopefully fixes the last vc errors.
> >
> K, first patch produced a couple of device unavailables & a slew of no
> device symlinks. Second patch-no messages at all :)
>
> Thank god, if I have to reboot again I'm going to puke.

Nice to hear that we covered all the vc errors now. I think we should
apply the same logic to the /devices device wait loops, as they may go
with a remove event too.

Here is the 3rd version of the patch :)

diff --git a/wait_for_sysfs.c b/wait_for_sysfs.c
index d775eb1c95b9bce9099db482b0cb29500223ca6a..aac42e24214e753f28084ec58da99eb9d34177c3 100644 (file)
--- a/wait_for_sysfs.c
+++ b/wait_for_sysfs.c
@@ -56,7 +56,8 @@ void log_message(int level, const char *format, ...)
 #define WAIT_LOOP_PER_SECOND           20
 
 /* wait for specific file to show up, normally the "dev"-file */
-static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev)
+static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev,
+                                           const char **error)
 {
        static struct class_file {
                char *subsystem;
@@ -77,7 +78,7 @@ static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev
                { NULL, NULL }
        };
        struct class_file *classfile;
-       const char *file = "dev";
+       char *file = "dev";
        char filename[FILENAME_MAX];
        int loop;
 
@@ -103,11 +104,11 @@ static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev
                struct stat stats;
 
                if (stat(class_dev->path, &stats) == -1) {
-                       dbg("oops, the directory '%s' just disappeared.", class_dev->path);
+                       dbg("'%s' now disappeared (probably remove has beaten us)", class_dev->path);
                        return -ENODEV;
                }
 
-               if (stat(filename, &stats) == 0) {      
+               if (stat(filename, &stats) == 0) {
                        dbg("class '%s' specific file '%s' found", class_dev->classname, file);
                        return 0;
                }
@@ -116,6 +117,7 @@ static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev
        }
 
        dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file);
+       *error = "class specific file unavailable";
        return -ENOENT;
 }
 
@@ -226,7 +228,8 @@ static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
 }
 
 /* wait for the bus and for a bus specific file to show up */
-static int wait_for_bus_device(struct sysfs_device *device_dev)
+static int wait_for_bus_device(struct sysfs_device *devices_dev,
+                              const char **error)
 {
        static struct bus_file {
                char *bus;
@@ -246,19 +249,20 @@ static int wait_for_bus_device(struct sysfs_device *device_dev)
        struct bus_file *busfile;
        int loop;
 
-       /* wait for the /bus-device link to the /device-device */
+       /* wait for the bus device link to the devices device */
        loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
        while (--loop) {
-               if (sysfs_get_device_bus(device_dev) == 0)
+               if (sysfs_get_device_bus(devices_dev) == 0)
                        break;
 
                usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
        }
        if (loop == 0) {
-               dbg("error: getting /bus-device link");
+               dbg("error: getting bus device link");
+               *error = "no bus device link";
                return -1;
        }
-       dbg("/bus-device link found for bus '%s'", device_dev->bus);
+       dbg("bus device link found for bus '%s'", devices_dev->bus);
 
        /* wait for a bus specific file to show up */
        loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
@@ -266,27 +270,115 @@ static int wait_for_bus_device(struct sysfs_device *device_dev)
                int found = 0;
 
                for (busfile = bus_files; busfile->bus != NULL; busfile++) {
-                       if (strcmp(device_dev->bus, busfile->bus) == 0) {
+                       if (strcmp(devices_dev->bus, busfile->bus) == 0) {
                                found = 1;
-                               dbg("looking at bus '%s' for specific file '%s'", device_dev->bus, busfile->file);
-                               if (sysfs_get_device_attr(device_dev, busfile->file) != NULL) {
-                                       dbg("bus '%s' specific file '%s' found", device_dev->bus, busfile->file);
+                               dbg("looking at bus '%s' for specific file '%s'", devices_dev->bus, busfile->file);
+                               if (sysfs_get_device_attr(devices_dev, busfile->file) != NULL) {
+                                       dbg("bus '%s' specific file '%s' found", devices_dev->bus, busfile->file);
                                        return 0;
                                }
                        }
                }
                if (found == 0) {
+                       *error = "unknown bus";
                        info("error: unknown bus, please report to "
-                            "<linux-hotplug-devel@lists.sourceforge.net> '%s'", device_dev->bus);
+                            "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus);
                        return -1;
                }
                usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
        }
 
-       dbg("error: getting bus '%s' specific file '%s'", device_dev->bus, busfile->file);
+       dbg("error: getting bus '%s' specific file '%s'", devices_dev->bus, busfile->file);
+       *error = "bus specific file unavailable";
        return -1;
 }
 
+
+static struct sysfs_class_device *open_class_device(const char *path)
+{
+       struct sysfs_class_device *class_dev;
+       int loop;
+
+       loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
+       while (--loop) {
+               class_dev = sysfs_open_class_device_path(path);
+               if (class_dev)
+                       break;
+
+               usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
+       }
+
+       return (class_dev);
+}
+
+static int wait_for_class_device(struct sysfs_class_device *class_dev,
+                                const char **error)
+{
+       struct sysfs_class_device *class_dev_parent;
+       struct sysfs_device *devices_dev = NULL;
+       int loop;
+
+       if (wait_for_class_device_attributes(class_dev, error) != 0)
+               return -ENOENT;
+
+       /* skip devices without devices-link */
+       if (class_device_expect_no_device_link(class_dev)) {
+               dbg("no device symlink expected for '%s', ", class_dev->name);
+               return -ENODEV;
+       }
+
+       /* the symlink may be on the parent device */
+       class_dev_parent = sysfs_get_classdev_parent(class_dev);
+       if (class_dev_parent)
+               dbg("looking at parent device for device link '%s'", class_dev_parent->path);
+
+       /* wait for the symlink to the devices device */
+       dbg("waiting for symlink to devices device");
+       loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
+       while (--loop) {
+               if (class_dev_parent)
+                       devices_dev = sysfs_get_classdev_device(class_dev_parent);
+               else
+                       devices_dev = sysfs_get_classdev_device(class_dev);
+
+               if (devices_dev)
+                       break;
+
+               usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
+       }
+       if (!devices_dev) {
+               dbg(" error: no devices device symlink found");
+               *error = "no device symlink";
+               return -ENODEV;
+       }
+       dbg("device symlink found pointing to '%s'", devices_dev->path);
+
+       /* wait for the bus value */
+       if (class_device_expect_no_bus(class_dev)) {
+               dbg("no bus device expected for '%s', ", class_dev->classname);
+               return 0;
+       } else {
+               return wait_for_bus_device(devices_dev, error);
+       }
+}
+
+static struct sysfs_device *open_devices_device(const char *path)
+{
+       struct sysfs_device *devices_dev;
+       int loop;
+
+       loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
+       while (--loop) {
+               devices_dev = sysfs_open_device_path(path);
+               if (devices_dev)
+                       break;
+
+               usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
+       }
+
+       return(devices_dev);
+}
+
 int main(int argc, char *argv[], char *envp[])
 {
        const char *devpath = "";
@@ -295,11 +387,9 @@ int main(int argc, char *argv[], char *envp[])
        char sysfs_path[SYSFS_PATH_MAX];
        char filename[SYSFS_PATH_MAX];
        struct sysfs_class_device *class_dev;
-       struct sysfs_class_device *class_dev_parent;
-       struct sysfs_device *device_dev = NULL;
-       int loop;
-       int retval;
+       struct sysfs_device *devices_dev;
        int rc = 0;
+       const char *error = NULL;
 
        init_logging("wait_for_sysfs");
 
@@ -312,133 +402,77 @@ int main(int argc, char *argv[], char *envp[])
        devpath = getenv ("DEVPATH");
        if (!devpath) {
                dbg("error: no DEVPATH");
-               return 1;
+               rc = 1;
+               goto exit;
        }
 
        action = getenv ("ACTION");
        if (!action) {
                dbg("error: no ACTION");
-               return 1;
+               rc = 1;
+               goto exit;
        }
 
        /* we only wait on an add event */
-       if (strcmp(action, "add") != 0)
-               return 0;
+       if (strcmp(action, "add") != 0) {
+               dbg("no add ACTION");
+               goto exit;
+       }
 
        if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
                dbg("error: no sysfs path");
-               return 2;
+               rc = 2;
+               goto exit;
        }
 
        if ((strncmp(devpath, "/block/", 7) == 0) || (strncmp(devpath, "/class/", 7) == 0)) {
-               /* open the class device we are called for */
                snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
                filename[SYSFS_PATH_MAX-1] = '\0';
 
-               loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
-               while (--loop) {
-                       class_dev = sysfs_open_class_device_path(filename);
-                       if (class_dev)
-                               break;
-
-                       usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
-               }
-               if (class_dev == NULL) {
-                       dbg("error: getting class_device");
-                       rc = 3;
+               /* open the class device we are called for */
+               class_dev = open_class_device(filename);
+               if (!class_dev) {
+                       dbg("error: class device unavailable (probably remove has beaten us)");
                        goto exit;
                }
-               dbg("class_device opened '%s'", filename);
-
-               retval = wait_for_class_device_attributes(class_dev);
-               if (retval == -ENODEV)
-                       goto exit_class;
-               if (retval != 0) {
-                       rc = 4;
-                       goto exit_class;
-               }
+               dbg("class device opened '%s'", filename);
 
-               /* skip devices without /device-link */
-               if (class_device_expect_no_device_link(class_dev)) {
-                       dbg("no device symlink expected for '%s', ", class_dev->name);
-                       goto exit_class;
-               }
-
-               /* the symlink may be on the parent device */
-               class_dev_parent = sysfs_get_classdev_parent(class_dev);
-               if (class_dev_parent)
-                       dbg("looking at parent device for device link '%s'", class_dev_parent->path);
-
-               /* wait for the symlink to the /device-device */
-               dbg("waiting for symlink to /device-device");
-               loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
-               while (--loop) {
-                       if (class_dev_parent)
-                               device_dev = sysfs_get_classdev_device(class_dev_parent);
-                       else
-                               device_dev = sysfs_get_classdev_device(class_dev);
-
-                       if (device_dev)
-                               break;
+               /* wait for the class device with possible physical device and bus */
+               wait_for_class_device(class_dev, &error);
 
-                       usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
-               }
-               if (device_dev == NULL) {
-                       dbg("error: getting /device-device");
-                       rc = 5;
-                       goto exit_class;
-               }
-               dbg("device symlink found pointing to '%s'", device_dev->path);
-
-               /* wait for the bus value */
-               if (class_device_expect_no_bus(class_dev)) {
-                       dbg("no bus device expected for '%s', ", class_dev->classname);
-               } else {
-                       if (wait_for_bus_device(device_dev) != 0)
-                               rc = 6;
-               }
-
-exit_class:
                sysfs_close_class_device(class_dev);
 
        } else if ((strncmp(devpath, "/devices/", 9) == 0)) {
-               /* open the path we are called for */
                snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
                filename[SYSFS_PATH_MAX-1] = '\0';
 
-               loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
-               while (--loop) {
-                       device_dev = sysfs_open_device_path(filename);
-                       if (device_dev)
-                               break;
-
-                       usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
-               }
-               if (device_dev == NULL) {
-                       dbg("error: getting /device-device");
-                       rc = 7;
+               /* open the path we are called for */
+               devices_dev = open_devices_device(filename);
+               if (!devices_dev) {
+                       dbg("error: devices device unavailable (probably remove has beaten us)");
                        goto exit;
                }
-               dbg("device_device opened '%s'", filename);
+               dbg("devices device opened '%s'", filename);
 
                /* wait for the bus value */
-               if (wait_for_bus_device(device_dev) != 0)
-                       rc = 8;
+               wait_for_bus_device(devices_dev, &error);
 
-               sysfs_close_device(device_dev);
+               sysfs_close_device(devices_dev);
 
        } else {
                dbg("unhandled sysfs path, no need to wait");
        }
 
 exit:
-       if (rc == 0)
-               dbg("result: waiting for sysfs successful '%s'", devpath);
-       else
+       if (error) {
                info("either wait_for_sysfs (udev %s) needs an update to handle the device '%s' "
-                    "properly (%d) or the sysfs-support of your device's driver needs to be fixed, "
+                    "properly (%s) or the sysfs-support of your device's driver needs to be fixed, "
                     "please report to <linux-hotplug-devel@lists.sourceforge.net>",
-                    UDEV_VERSION, devpath, rc);
+                    UDEV_VERSION, devpath, error);
+               rc =3;
+       } else {
+               dbg("result: waiting for sysfs successful '%s'", devpath);
+       }
 
-       return rc;
+       exit(rc);
 }