Merge pull request #24618 from yuwata/udev-split-synthesizing

udev: shorten synthesize_change() a bit

src/shared/blockdev-util.c

@@ -3,6 +3,7 @@
 #include <linux/blkpg.h>
 #include <sys/file.h>
 #include <sys/ioctl.h>
+#include <sys/mount.h>
 #include <unistd.h>
 
 #include "sd-device.h"
@@ -509,7 +510,7 @@ int block_device_resize_partition(
         return RET_NERRNO(ioctl(fd, BLKPG, &ba));
 }
 
-static int partition_enumerator_new(sd_device *dev, sd_device_enumerator **ret) {
+int partition_enumerator_new(sd_device *dev, sd_device_enumerator **ret) {
         _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
         const char *s;
         int r;
@@ -649,3 +650,23 @@ int block_device_has_partitions(sd_device *dev) {
 
         return !!sd_device_enumerator_get_device_first(e);
 }
+
+int blockdev_reread_partition_table(sd_device *dev) {
+        _cleanup_close_ int fd = -1;
+
+        assert(dev);
+
+        /* Try to re-read the partition table. This only succeeds if none of the devices is busy. */
+
+        fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+        if (fd < 0)
+                return fd;
+
+        if (flock(fd, LOCK_EX|LOCK_NB) < 0)
+                return -errno;
+
+        if (ioctl(fd, BLKRRPART, 0) < 0)
+                return -errno;
+
+        return 0;
+}

src/shared/blockdev-util.h

@@ -36,5 +36,7 @@ int path_get_whole_disk(const char *path, bool backing, dev_t *ret);
 int block_device_add_partition(int fd, const char *name, int nr, uint64_t start, uint64_t size);
 int block_device_remove_partition(int fd, const char *name, int nr);
 int block_device_resize_partition(int fd, int nr, uint64_t start, uint64_t size);
+int partition_enumerator_new(sd_device *dev, sd_device_enumerator **ret);
 int block_device_remove_all_partitions(sd_device *dev, int fd);
 int block_device_has_partitions(sd_device *dev);
+int blockdev_reread_partition_table(sd_device *dev);

src/udev/udevd.c

@@ -28,6 +28,7 @@
 #include "sd-event.h"
 
 #include "alloc-util.h"
+#include "blockdev-util.h"
 #include "cgroup-setup.h"
 #include "cgroup-util.h"
 #include "cpu-set-util.h"
@@ -1399,69 +1400,29 @@ static int synthesize_change(sd_device *dev) {
             streq_ptr(devtype, "disk") &&
             !startswith(sysname, "dm-")) {
                 _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
-                bool part_table_read = false, has_partitions = false;
+                bool part_table_read;
                 sd_device *d;
-                int fd;
 
-                /* 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 = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
-                if (fd >= 0) {
-                        r = flock(fd, LOCK_EX|LOCK_NB);
-                        if (r >= 0)
-                                r = ioctl(fd, BLKRRPART, 0);
-
-                        close(fd);
-                        if (r >= 0)
-                                part_table_read = true;
-                }
+                r = blockdev_reread_partition_table(dev);
+                if (r < 0)
+                        log_device_debug_errno(dev, r, "Failed to re-read partition table, ignoring: %m");
+                part_table_read = r >= 0;
 
                 /* search for partitions */
-                r = sd_device_enumerator_new(&e);
+                r = partition_enumerator_new(dev, &e);
                 if (r < 0)
                         return r;
 
-                r = sd_device_enumerator_allow_uninitialized(e);
-                if (r < 0)
-                        return r;
-
-                r = sd_device_enumerator_add_match_parent(e, dev);
-                if (r < 0)
-                        return r;
-
-                r = sd_device_enumerator_add_match_subsystem(e, "block", true);
-                if (r < 0)
-                        return r;
-
-                FOREACH_DEVICE(e, d) {
-                        const char *t;
-
-                        if (sd_device_get_devtype(d, &t) < 0 || !streq(t, "partition"))
-                                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)
+                if (part_table_read && sd_device_enumerator_get_device_first(e))
                         return 0;
 
                 /* We have partitions but re-reading the partition table did not work, synthesize
                  * "change" for the disk and all partitions. */
                 (void) synthesize_change_one(dev, dev);
-
-                FOREACH_DEVICE(e, d) {
-                        const char *t;
-
-                        if (sd_device_get_devtype(d, &t) < 0 || !streq(t, "partition"))
-                                continue;
-
+                FOREACH_DEVICE(e, d)
                         (void) synthesize_change_one(dev, d);
-                }
-
         } else
                 (void) synthesize_change_one(dev, dev);