dissect: reenable automatic removal before trying again

The device node may be different from we want to activate, and we may
try to activate different device in the subsequent loop. In such case,
we should enable the automatic removal for the unexpected device.
Otherwise, it will not be removed even when not necessary anymore.

diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c
index 3fb5b1b74501d3ffcd3b71455e8c813749faaff8..58a87431a9b4826f01a226f3301383031cdac146 100644 (file)
--- a/src/shared/dissect-image.c
+++ b/src/shared/dissect-image.c
@@ -2703,7 +2703,6 @@ static int verity_partition(
                 DecryptedImage *d) {
 
         _cleanup_(sym_crypt_freep) struct crypt_device *cd = NULL;
-        _cleanup_(dm_deferred_remove_cleanp) char *restore_deferred_remove = NULL;
         _cleanup_free_ char *node = NULL, *name = NULL;
         _cleanup_close_ int mount_node_fd = -EBADF;
         int r;
@@ -2766,6 +2765,7 @@ static int verity_partition(
          * In case of ENODEV/ENOENT, which can happen if another process is activating at the exact same time,
          * retry a few times before giving up. */
         for (unsigned i = 0; i < N_DEVICE_NODE_LIST_ATTEMPTS; i++) {
+                _cleanup_(dm_deferred_remove_cleanp) char *restore_deferred_remove = NULL;
                 _cleanup_(sym_crypt_freep) struct crypt_device *existing_cd = NULL;
                 _cleanup_close_ int fd = -EBADF;
 
@@ -2795,21 +2795,19 @@ static int verity_partition(
                         return log_debug_errno(r, "Failed to activate verity device %s: %m", node);
 
         check:
-                if (!restore_deferred_remove) {
-                        /* To avoid races, disable automatic removal on umount while setting up the new device. Restore it on failure. */
-                        r = dm_deferred_remove_cancel(name);
-                        /* -EBUSY and -ENXIO: the device has already been removed or being removed. We cannot
-                         * use the device, try to open again. See target_message() in drivers/md/dm-ioctl.c
-                         * and dm_cancel_deferred_remove() in drivers/md/dm.c */
-                        if (IN_SET(r, -EBUSY, -ENXIO))
-                                goto try_again;
-                        if (r < 0)
-                                return log_debug_errno(r, "Failed to disable automated deferred removal for verity device %s: %m", node);
+                /* To avoid races, disable automatic removal on umount while setting up the new device. Restore it on failure. */
+                r = dm_deferred_remove_cancel(name);
+                /* -EBUSY and -ENXIO: the device has already been removed or being removed. We cannot
+                 * use the device, try to open again. See target_message() in drivers/md/dm-ioctl.c
+                 * and dm_cancel_deferred_remove() in drivers/md/dm.c */
+                if (IN_SET(r, -EBUSY, -ENXIO))
+                        goto try_again;
+                if (r < 0)
+                        return log_debug_errno(r, "Failed to disable automated deferred removal for verity device %s: %m", node);
 
-                        restore_deferred_remove = strdup(name);
-                        if (!restore_deferred_remove)
-                                return log_oom_debug();
-                }
+                restore_deferred_remove = strdup(name);
+                if (!restore_deferred_remove)
+                        return log_oom_debug();
 
                 r = verity_can_reuse(verity, name, &existing_cd);
                 /* Same as above, -EINVAL can randomly happen when it actually means -EEXIST */
@@ -2847,6 +2845,9 @@ static int verity_partition(
                         }
                 }
 
+                /* Everything looks good and we'll be able to mount the device, so deferred remove will be re-enabled at that point. */
+                restore_deferred_remove = mfree(restore_deferred_remove);
+
                 mount_node_fd = TAKE_FD(fd);
                 if (existing_cd)
                         crypt_free_and_replace(cd, existing_cd);
@@ -2874,9 +2875,6 @@ static int verity_partition(
         return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), "All attempts to activate verity device %s failed.", name);
 
 success:
-        /* Everything looks good and we'll be able to mount the device, so deferred remove will be re-enabled at that point. */
-        restore_deferred_remove = mfree(restore_deferred_remove);
-
         d->decrypted[d->n_decrypted++] = (DecryptedPartition) {
                 .name = TAKE_PTR(name),
                 .device = TAKE_PTR(cd),