From 24c0078a846c0e8dd7cc65f0a4a90ba05864434b Mon Sep 17 00:00:00 2001
From: Mike Yuan <me@yhndnzj.com>
Date: Sat, 29 Jul 2023 20:00:55 +0800
Subject: [PATCH 1/2] fstab-util: add fstab_has_node

---
 src/shared/fstab-util.c | 19 ++++++++++---------
 src/shared/fstab-util.h |  3 +++
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/shared/fstab-util.c b/src/shared/fstab-util.c
index 4ffec25c75..67e718b6ea 100644
--- a/src/shared/fstab-util.c
+++ b/src/shared/fstab-util.c
@@ -63,7 +63,7 @@ bool fstab_is_extrinsic(const char *mount, const char *opts) {
         return false;
 }
 
-static int fstab_is_mount_point_of(const char *what_fstab, const char *path) {
+static int fstab_is_same_node(const char *what_fstab, const char *path) {
         _cleanup_free_ char *node = NULL;
 
         assert(what_fstab);
@@ -86,7 +86,7 @@ int fstab_is_mount_point_full(const char *where, const char *path) {
         _cleanup_endmntent_ FILE *f = NULL;
         int r;
 
-        assert(where);
+        assert(where || path);
 
         f = setmntent(fstab_path(), "re");
         if (!f)
@@ -100,14 +100,15 @@ int fstab_is_mount_point_full(const char *where, const char *path) {
                 if (!me)
                         return errno != 0 ? -errno : false;
 
-                if (path_equal(where, me->mnt_dir)) {
-                        if (!path)
-                                return true;
+                if (where && !path_equal(where, me->mnt_dir))
+                        continue;
 
-                        r = fstab_is_mount_point_of(me->mnt_fsname, path);
-                        if (r > 0 || (r < 0 && !ERRNO_IS_DEVICE_ABSENT(r)))
-                                return r;
-                }
+                if (!path)
+                        return true;
+
+                r = fstab_is_same_node(me->mnt_fsname, path);
+                if (r > 0 || (r < 0 && !ERRNO_IS_DEVICE_ABSENT(r)))
+                        return r;
         }
 
         return false;
diff --git a/src/shared/fstab-util.h b/src/shared/fstab-util.h
index cb3686bee3..a1c079fd41 100644
--- a/src/shared/fstab-util.h
+++ b/src/shared/fstab-util.h
@@ -13,6 +13,9 @@ int fstab_is_mount_point_full(const char *where, const char *path);
 static inline int fstab_is_mount_point(const char *where) {
         return fstab_is_mount_point_full(where, NULL);
 }
+static inline int fstab_has_node(const char *path) {
+        return fstab_is_mount_point_full(NULL, path);
+}
 
 int fstab_filter_options(
                 const char *opts,

From 7893a547ebcee007dbc6119373d3e5d809f221fe Mon Sep 17 00:00:00 2001
From: Mike Yuan <me@yhndnzj.com>
Date: Sat, 29 Jul 2023 20:05:58 +0800
Subject: [PATCH 2/2] gpt-auto: don't mount ESP if there's an fstab entry for
 it

Follow-up for #28511

Fixes #28550
---
 src/gpt-auto-generator/gpt-auto-generator.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c
index 4465038198..585aaae2ed 100644
--- a/src/gpt-auto-generator/gpt-auto-generator.c
+++ b/src/gpt-auto-generator/gpt-auto-generator.c
@@ -574,10 +574,17 @@ static int add_partition_esp(DissectedPartition *p, bool has_xbootldr) {
                 return 0;
         }
 
+        /* Check if there's an existing fstab entry for ESP. If so, we just skip the gpt-auto logic. */
+        r = fstab_has_node(p->node);
+        if (r < 0)
+                return log_error_errno(r,
+                                       "Failed to check if fstab entry for device '%s' exists: %m", p->node);
+        if (r > 0)
+                return 0;
+
         /* If /boot/ is present, unused, and empty, we'll take that.
          * Otherwise, if /efi/ is unused and empty (or missing), we'll take that.
-         * Otherwise, we do nothing.
-         */
+         * Otherwise, we do nothing. */
         if (!has_xbootldr && slash_boot_exists()) {
                 r = slash_boot_in_fstab();
                 if (r < 0)
@@ -590,16 +597,6 @@ static int add_partition_esp(DissectedPartition *p, bool has_xbootldr) {
                                 esp_path = "/boot";
                                 id = "boot";
                         }
-                } else {
-                        /* Check if the fstab entry for /boot/ is already the ESP. If so, we don't need to
-                         * check /efi/ or duplicate the mount there. */
-                        r = fstab_is_mount_point_full("/boot", p->node);
-                        if (r < 0)
-                                return log_error_errno(r,
-                                                       "Failed to check if fstab entry for /boot uses the same device as '%s': %m",
-                                                       p->node);
-                        if (r > 0)
-                                return 0;
                 }
         }