Primitive support for polling removable devices
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>
Mon, 2 Apr 2007 06:34:21 +0000 (16:34 +1000)
committerJeremy Kerr <jk@ozlabs.org>
Tue, 3 Apr 2007 04:15:43 +0000 (14:15 +1000)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
devices/udev-helper.c

index a3f47a56c1229775b6b63a2a6f64193287f45817..f54ca238fd03178d165a169c520c36efa2f6b5e0 100644 (file)
 #include <errno.h>
 #include <string.h>
 #include <asm/byteorder.h>
+#include <linux/cdrom.h>
+#include <sys/ioctl.h>
 
 #include "udev-helper.h"
+#define REMOVABLE_SLEEP_DELAY  2
+
 #include "petitboot-paths.h"
 
 extern struct parser native_parser;
@@ -358,7 +362,10 @@ static const struct boot_option fake_boot_options[] =
 
 enum generic_icon_type guess_device_type(void)
 {
+       const char *type = getenv("ID_TYPE");
        const char *bus = getenv("ID_BUS");
+       if (type && streq(type, "cd"))
+               return ICON_TYPE_OPTICAL;
        if (streq(bus, "usb"))
                return ICON_TYPE_USB;
        if (streq(bus, "ata") || streq(bus, "scsi"))
@@ -366,9 +373,138 @@ enum generic_icon_type guess_device_type(void)
        return ICON_TYPE_UNKNOWN;
 }
 
-int main(int argc, char **argv)
+
+static int is_removable_device(const char *sysfs_path) 
+{
+       char full_path[PATH_MAX];
+       char buf[80];
+       int fd, buf_len;
+
+       sprintf(full_path, "/sys/%s/removable", sysfs_path);    
+       fd = open(full_path, O_RDONLY);
+       printf(" -> removable check on %s, fd=%d\n", full_path, fd);
+       if (fd < 0)
+               return 0;
+       buf_len = read(fd, buf, 79);
+       close(fd);
+       if (buf_len < 0)
+               return 0;
+       buf[buf_len] = 0;
+       return strtol(buf, NULL, 10);
+}
+
+static int found_new_device(const char *dev_path)
 {
        char mountpoint[PATH_MAX];
+
+       if (mount_device(dev_path, mountpoint)) {
+               log("failed to mount %s\n", dev_path);
+               return EXIT_FAILURE;
+       }
+
+       log("mounted %s at %s\n", dev_path, mountpoint);
+
+       iterate_parsers(dev_path, mountpoint);
+
+       return EXIT_SUCCESS;
+}
+
+static int poll_device_plug(const char *dev_path,
+                           int *optical)
+{
+       int rc, fd;
+
+       /* Polling loop for optical drive */
+       for (; (*optical) != 0; ) {
+               printf("poll for optical drive insertion ...\n");
+               fd = open(dev_path, O_RDONLY|O_NONBLOCK);
+               if (fd < 0)
+                       return EXIT_FAILURE;
+               rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
+               close(fd);
+               if (rc == -1) {
+                       printf("not an optical drive, fallback...\n");
+                       break;
+               }
+               *optical = 1;
+               if (rc == CDS_DISC_OK)
+                       return EXIT_SUCCESS;
+
+               printf("no... waiting\n");
+               sleep(REMOVABLE_SLEEP_DELAY);
+       }
+
+       /* Fall back to bare open() */
+       *optical = 0;
+       for (;;) {
+               printf("poll for non-optical drive insertion ...\n");
+               fd = open(dev_path, O_RDONLY);
+               if (fd < 0 && errno != ENOMEDIUM)
+                       return EXIT_FAILURE;
+               close(fd);
+               if (fd >= 0)
+                       return EXIT_SUCCESS;
+               printf("no... waiting\n");
+               sleep(REMOVABLE_SLEEP_DELAY);
+       }
+}
+
+static int poll_device_unplug(const char *dev_path, int optical)
+{
+       int rc, fd;
+
+       for (;optical;) {
+               printf("poll for optical drive removal ...\n");
+               fd = open(dev_path, O_RDONLY|O_NONBLOCK);
+               if (fd < 0)
+                       return EXIT_FAILURE;
+               rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
+               close(fd);
+               if (rc != CDS_DISC_OK)
+                       return EXIT_SUCCESS;
+               printf("no... waiting\n");
+               sleep(REMOVABLE_SLEEP_DELAY);
+       }
+
+       /* Fall back to bare open() */
+       for (;;) {
+               printf("poll for non-optical drive removal ...\n");
+               fd = open(dev_path, O_RDONLY);
+               if (fd < 0 && errno != ENOMEDIUM)
+                       return EXIT_FAILURE;
+               close(fd);
+               if (fd < 0)
+                       return EXIT_SUCCESS;
+               printf("no... waiting\n");
+               sleep(REMOVABLE_SLEEP_DELAY);
+       }
+}
+
+static int poll_removable_device(const char *sysfs_path,
+                                const char *dev_path)
+{
+       int rc, mounted, optical = -1;
+       
+       for (;;) {
+               rc = poll_device_plug(dev_path, &optical);
+               if (rc == EXIT_FAILURE)
+                       return rc;
+               rc = found_new_device(dev_path);
+               mounted = (rc == EXIT_SUCCESS);
+
+               poll_device_unplug(dev_path, optical);
+
+               remove_device(dev_path);
+
+               /* Unmount it repeatedly, if needs be */
+               while (mounted && !unmount_device(dev_path))
+                       ;
+               sleep(1);
+       }
+}
+
+int main(int argc, char **argv)
+{
        char *dev_path, *action;
        int rc;
 
@@ -408,15 +544,11 @@ int main(int argc, char **argv)
        }
 
        if (streq(action, "add")) {
-               if (mount_device(dev_path, mountpoint)) {
-                       log("failed to mount %s\n", dev_path);
-                       return EXIT_FAILURE;
-               }
-
-               log("mounted %s at %s\n", dev_path, mountpoint);
-
-               iterate_parsers(dev_path, mountpoint);
-
+               char *sysfs_path = getenv("DEVPATH");
+               if (sysfs_path && is_removable_device(sysfs_path))
+                       rc = poll_removable_device(sysfs_path, dev_path);
+               else
+                       rc = found_new_device(dev_path);
        } else if (streq(action, "remove")) {
                log("%s removed\n", dev_path);