From 9ccceb9d2b645b9f0253ff5fc81e35c6c442ae7d Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 6 Sep 2022 01:58:34 +0900
Subject: repart: make existing partition can be also 'dropped'

Previously, when an existing partition cannot grow, then entire process
fails. This makes such an existing partion handled as an foreign
partition, i.e. it is not managed by us.
---
 src/partition/repart.c | 90 +++++++++++++++++++++++++++++++++-----------------
 1 file changed, 59 insertions(+), 31 deletions(-)

(limited to 'src/partition')

diff --git a/src/partition/repart.c b/src/partition/repart.c
index ae3c0bdb26..8b1092e99a 100644
--- a/src/partition/repart.c
+++ b/src/partition/repart.c
@@ -316,6 +316,39 @@ static Partition* partition_free(Partition *p) {
         return mfree(p);
 }
 
+static void partition_foreignize(Partition *p) {
+        assert(p);
+        assert(PARTITION_EXISTS(p));
+
+        /* Reset several parameters set through definition file to make the partition foreign. */
+
+        p->new_label = mfree(p->new_label);
+        p->definition_path = mfree(p->definition_path);
+        p->drop_in_files = strv_free(p->drop_in_files);
+
+        p->copy_blocks_path = mfree(p->copy_blocks_path);
+        p->copy_blocks_fd = safe_close(p->copy_blocks_fd);
+
+        p->format = mfree(p->format);
+        p->copy_files = strv_free(p->copy_files);
+        p->make_directories = strv_free(p->make_directories);
+        p->verity_match_key = mfree(p->verity_match_key);
+
+        p->new_uuid = SD_ID128_NULL;
+        p->new_uuid_is_set = false;
+        p->priority = 0;
+        p->weight = 1000;
+        p->padding_weight = 0;
+        p->size_min = UINT64_MAX;
+        p->size_max = UINT64_MAX;
+        p->padding_min = UINT64_MAX;
+        p->padding_max = UINT64_MAX;
+        p->no_auto = -1;
+        p->read_only = -1;
+        p->growfs = -1;
+        p->verity = VERITY_OFF;
+}
+
 static Partition* partition_unlink_and_free(Context *context, Partition *p) {
         if (!p)
                 return NULL;
@@ -405,56 +438,51 @@ static int context_add_free_area(
         return 0;
 }
 
-static bool context_drop_one_priority(Context *context) {
+static void partition_drop_or_foreignize(Partition *p) {
+        if (!p || p->dropped || PARTITION_IS_FOREIGN(p))
+                return;
+
+        if (PARTITION_EXISTS(p)) {
+                log_info("Can't grow existing partition %s of priority %" PRIi32 ", ignoring.",
+                         strna(p->current_label ?: p->new_label), p->priority);
+
+                /* Handle the partition as foreign. Do not set dropped flag. */
+                partition_foreignize(p);
+        } else {
+                log_info("Can't fit partition %s of priority %" PRIi32 ", dropping.",
+                         p->definition_path, p->priority);
+
+                p->dropped = true;
+                p->allocated_to_area = NULL;
+        }
+}
+
+static bool context_drop_or_foreignize_one_priority(Context *context) {
         int32_t priority = 0;
-        bool exists = false;
 
         LIST_FOREACH(partitions, p, context->partitions) {
                 if (p->dropped)
                         continue;
-                if (p->priority < priority)
-                        continue;
-                if (p->priority == priority) {
-                        exists = exists || PARTITION_EXISTS(p);
-                        continue;
-                }
 
-                priority = p->priority;
-                exists = PARTITION_EXISTS(p);
+                priority = MAX(priority, p->priority);
         }
 
         /* Refuse to drop partitions with 0 or negative priorities or partitions of priorities that have at
          * least one existing priority */
-        if (priority <= 0 || exists)
+        if (priority <= 0)
                 return false;
 
         LIST_FOREACH(partitions, p, context->partitions) {
                 if (p->priority < priority)
                         continue;
 
-                if (p->dropped)
-                        continue;
-
-                p->dropped = true;
-                p->allocated_to_area = NULL;
-
-                log_info("Can't fit partition %s of priority %" PRIi32 ", dropping.", p->definition_path, p->priority);
+                partition_drop_or_foreignize(p);
 
                 /* We ensure that all verity sibling partitions have the same priority, so it's safe
                  * to drop all siblings here as well. */
 
-                for (VerityMode mode = VERITY_OFF + 1; mode < _VERITY_MODE_MAX; mode++) {
-                        if (!p->siblings[mode])
-                                continue;
-
-                        if (p->siblings[mode]->dropped)
-                                continue;
-
-                        p->siblings[mode]->dropped = true;
-                        p->siblings[mode]->allocated_to_area = NULL;
-                        log_info("Also dropping sibling verity %s partition %s",
-                                 verity_mode_to_string(mode), p->siblings[mode]->definition_path);
-                }
+                for (VerityMode mode = VERITY_OFF + 1; mode < _VERITY_MODE_MAX; mode++)
+                        partition_drop_or_foreignize(p->siblings[mode]);
         }
 
         return true;
@@ -5412,7 +5440,7 @@ static int run(int argc, char *argv[]) {
                 if (context_allocate_partitions(context, &largest_free_area))
                         break; /* Success! */
 
-                if (!context_drop_one_priority(context)) {
+                if (!context_drop_or_foreignize_one_priority(context)) {
                         r = log_error_errno(SYNTHETIC_ERRNO(ENOSPC),
                                             "Can't fit requested partitions into available free space (%s), refusing.",
                                             FORMAT_BYTES(largest_free_area));
-- 
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