X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fudev%2Fudevd.c;h=81e3f69a3a7cc3e9e59c47cd3efe87662af04f99;hb=e9fc29f4ecc9509ccc02eb8a014341e26c0d7831;hp=6100d7d57a3d7e0409eb3eb4a64958ed9b33f863;hpb=f3a740a5dae792fb6b2d411022ce8c29ced1c3f1;p=elogind.git

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 6100d7d57..81e3f69a3 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -38,6 +38,7 @@
 #include <sys/un.h>
 #include <sys/signalfd.h>
 #include <sys/epoll.h>
+#include <sys/mount.h>
 #include <sys/poll.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
@@ -738,17 +739,31 @@ static int synthesize_change(struct udev_device *dev) {
         char filename[UTIL_PATH_SIZE];
         int r;
 
-        log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
-        strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
-        write_string_file(filename, "change");
-
-        /* for disks devices, re-trigger all partitions too */
         if (streq_ptr("block", udev_device_get_subsystem(dev)) &&
-            streq_ptr("disk", udev_device_get_devtype(dev))) {
+            streq_ptr("disk", udev_device_get_devtype(dev)) &&
+            !startswith("dm-", udev_device_get_sysname(dev))) {
+                bool part_table_read = false;
+                bool has_partitions = false;
+                int fd;
                 struct udev *udev = udev_device_get_udev(dev);
                 _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
                 struct udev_list_entry *item;
 
+                /*
+                 * Try to re-read the partition table. This only succeeds if
+                 * none of the devices is busy. The kernel returns 0 if no
+                 * partition table is found, and we will not get an event for
+                 * the disk.
+                 */
+                fd = open(udev_device_get_devnode(dev), O_RDONLY|O_EXCL|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
+                if (fd >= 0) {
+                        r = ioctl(fd, BLKRRPART, 0);
+                        close(fd);
+                        if (r >= 0)
+                                part_table_read = true;
+                }
+
+                /* search for partitions */
                 e = udev_enumerate_new(udev);
                 if (!e)
                         return -ENOMEM;
@@ -762,6 +777,37 @@ static int synthesize_change(struct udev_device *dev) {
                         return r;
 
                 r = udev_enumerate_scan_devices(e);
+
+                udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
+                        _cleanup_udev_device_unref_ struct udev_device *d = NULL;
+
+                        d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+                        if (!d)
+                                continue;
+
+                        if (!streq_ptr("partition", udev_device_get_devtype(d)))
+                                continue;
+
+                        has_partitions = true;
+                        break;
+                }
+
+                /*
+                 * We have partitions and re-read the table, the kernel already sent
+                 * out a "change" event for the disk, and "remove/add" for all
+                 * partitions.
+                 */
+                if (part_table_read && has_partitions)
+                        return 0;
+
+                /*
+                 * We have partitions but re-reading the partition table did not
+                 * work, synthesize "change" for the disk and all partitions.
+                 */
+                log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
+                strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
+                write_string_file(filename, "change");
+
                 udev_list_entry_foreach(item, udev_enumerate_get_list_entry(e)) {
                         _cleanup_udev_device_unref_ struct udev_device *d = NULL;
 
@@ -777,8 +823,14 @@ static int synthesize_change(struct udev_device *dev) {
                         strscpyl(filename, sizeof(filename), udev_device_get_syspath(d), "/uevent", NULL);
                         write_string_file(filename, "change");
                 }
+
+                return 0;
         }
 
+        log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev));
+        strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
+        write_string_file(filename, "change");
+
         return 0;
 }