Publish attachment output once and preserve ownership through cancellation

src/chat/chat_attachment.c

@@ -23,11 +23,13 @@ enum { AK_REQUEST = 1, AK_REQUEST_ACK, AK_GRANT, AK_DENY, AK_RESULT_ACK };
 
 struct ak_file {
     struct UTUN_INSTANCE* inst;
-    char channel[32], source[1024], cipher[1024], plain[1024], temporary[1040], type[32];
+    char channel[32], source[1024], cipher[1024], plain[1024], type[32];
+    struct file_io_temp output; // Единственный собственный temp; стабильный адрес до completion.
     uint8_t id[16], key[32], message[32], hash[32], reply[32];
     struct attachment_info info;
     uint64_t author, request;
     int encrypt, error;
+    int plain_prepared, published; // Только реально подготовленный snapshot и выполненный rename дают право очистки.
 };
 
 /* Все ошибки SQLite содержат конкретную операцию. */
@@ -121,12 +123,18 @@ static int ak_parent(const char* path) {
 static void ak_file_work(void* arg) {
     struct ak_file* job = arg; job->error = -1;
     if (ak_parent(job->plain) || ak_parent(job->cipher)) return;
-    snprintf(job->temporary, sizeof(job->temporary), "%s.part", job->encrypt ? job->cipher : job->plain);
     if (job->encrypt) {
-        if (ma_copy_file(job->source, job->plain) || encrypted_file_sync(job->plain) || encrypted_file_sync_directory(job->plain) ||
-            encrypted_file_write(job->plain, job->temporary, job->key, job->author, job->id, &job->info, job->type)) return;
-    } else if (encrypted_file_read(job->cipher, job->temporary, job->key, job->author, job->id, job->hash, &job->info, job->type)) return;
-    if (encrypted_file_publish(job->temporary, job->encrypt ? job->cipher : job->plain)) return;
+        if (ma_copy_file(job->source, job->plain)) return;
+        job->plain_prepared = 1;
+        if (file_io_sync_file(job->plain) || file_io_sync_directory(job->plain) ||
+            encrypted_file_write(job->plain, job->cipher, &job->output, job->key, job->author, job->id, &job->info, job->type)) return;
+    } else if (encrypted_file_read(job->cipher, job->plain, &job->output, job->key, job->author, job->id,
+                                    job->hash, &job->info, job->type)) return;
+    int error = file_io_temp_publish(&job->output, job->encrypt ? job->plain : job->cipher, job->encrypt ? job->cipher : job->plain);
+    job->published = !job->output.temporary[0]; // Rename уже выполнен и при последующем отказе directory sync.
+    DEBUG_DEBUG(DEBUG_CATEGORY_MEDIA, "attachment keys: output publication encrypt=%d installed=%d error=%d",
+                job->encrypt, job->published, error);
+    if (error) return;
     job->error = 0;
 }
 
@@ -174,11 +182,12 @@ static void ak_file_done(void* arg, int error) {
         if (job->encrypt) chat_event_submitted(inst, job->request, 0);
     }
     if (job->encrypt && remove(job->source) && errno != ENOENT) DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "attachment keys: prepared source cleanup failed");
-    if ((!success || !valid) && job->temporary[0] && remove(job->temporary) && errno != ENOENT)
-        DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "attachment keys: temporary cleanup failed");
+    file_io_temp_discard(&job->output);
     if (!valid) {
-        if (remove(job->plain) && errno != ENOENT) DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "attachment keys: deleted channel plaintext cleanup failed");
-        if (job->encrypt && remove(job->cipher) && errno != ENOENT) DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "attachment keys: deleted channel ciphertext cleanup failed");
+        if (((job->encrypt && job->plain_prepared) || (!job->encrypt && job->published)) && remove(job->plain) && errno != ENOENT)
+            DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "attachment keys: deleted channel plaintext cleanup failed");
+        if (job->encrypt && job->published && remove(job->cipher) && errno != ENOENT)
+            DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "attachment keys: deleted channel ciphertext cleanup failed");
     }
     if (valid) {
         if (success && !job->encrypt) chat_media_cache_enforce(inst);

src/dm/dm_media.c

@@ -154,7 +154,7 @@ static void dm_cleanup_pump(struct dm_media_state* media);
 static void dm_cleanup_work(void* arg) {
     struct dm_cleanup_job* job = arg;
     job->error = dm_file_remove(job->path);
-    if (!job->error) job->error = encrypted_file_sync_directory(job->path);
+    if (!job->error) job->error = file_io_sync_directory(job->path);
 }
 
 static void dm_cleanup_done(void* arg, int error) {
@@ -488,7 +488,7 @@ static void dm_file_work(void* arg) {
     struct dm_file_job* job = arg;
     job->error = -1;
     if (job->work == DM_FILE_DELETE) {
-        if (!dm_file_remove(job->cipher) && !dm_file_remove(job->temp)) job->error = encrypted_file_sync_directory(job->cipher);
+        if (!dm_file_remove(job->cipher) && !dm_file_remove(job->temp)) job->error = file_io_sync_directory(job->cipher);
         return;
     }
     if (job->work == DM_FILE_PREPARE) {
@@ -530,9 +530,9 @@ done:
     if (out && fclose(out)) { DEBUG_ERROR(DEBUG_CATEGORY_DM, "dm_media: worker output close failed"); job->error = -1; }
     if (!job->error) {
         if (job->work == DM_FILE_PREPARE) {
-            job->error = encrypted_file_publish(job->temp, job->cipher);
-            if (!job->error) job->error = encrypted_file_sync_directory(job->plain);
-        } else job->error = encrypted_file_publish(job->work == DM_FILE_CUSTODY ? job->cipher : job->temp, job->output);
+            job->error = file_io_publish(job->temp, job->cipher);
+            if (!job->error) job->error = file_io_sync_directory(job->plain);
+        } else job->error = file_io_publish(job->work == DM_FILE_CUSTODY ? job->cipher : job->temp, job->output);
     }
 }