From 4b27025223206c392c259e6c7cb98c40781801fd Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 15 Jul 2025 17:21:03 +0200
Subject: [PATCH] discover-image: pick up subvol ctime, too

The btrfs subvol ctime is conceptually what we call the images "mtime",
hence expose it like that, since we get it anyway these days.
---
 src/shared/btrfs-util.c     | 1 +
 src/shared/btrfs-util.h     | 3 ++-
 src/shared/discover-image.c | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/shared/btrfs-util.c b/src/shared/btrfs-util.c
index 869eb490f8e..349a1691071 100644
--- a/src/shared/btrfs-util.c
+++ b/src/shared/btrfs-util.c
@@ -323,6 +323,7 @@ int btrfs_subvol_get_info_fd(int fd, uint64_t subvol_id, BtrfsSubvolInfo *ret) {
         *ret = (BtrfsSubvolInfo) {
                 .subvol_id = info.treeid,
                 .otime = info.otime.sec * USEC_PER_SEC + (info.otime.nsec / NSEC_PER_USEC),
+                .ctime = info.ctime.sec * USEC_PER_SEC + (info.ctime.nsec / NSEC_PER_USEC),
                 .read_only = FLAGS_SET(info.flags, BTRFS_SUBVOL_RDONLY),
         };
 
diff --git a/src/shared/btrfs-util.h b/src/shared/btrfs-util.h
index 63fc1d0b32d..d002618bd80 100644
--- a/src/shared/btrfs-util.h
+++ b/src/shared/btrfs-util.h
@@ -8,7 +8,8 @@
 
 typedef struct BtrfsSubvolInfo {
         uint64_t subvol_id;
-        usec_t otime;
+        usec_t otime; /* creation time */
+        usec_t ctime; /* change time */
 
         sd_id128_t uuid;
         sd_id128_t parent_uuid;
diff --git a/src/shared/discover-image.c b/src/shared/discover-image.c
index d39c3a13563..58777c683b2 100644
--- a/src/shared/discover-image.c
+++ b/src/shared/discover-image.c
@@ -430,7 +430,7 @@ static int image_make(
                                               filename,
                                               info.read_only || read_only,
                                               info.otime,
-                                              0,
+                                              info.ctime,
                                               ret);
                                 if (r < 0)
                                         return r;
-- 
2.47.3