[PATCH v6 1/3] libqos/fw_cfg: refactor file directory iteraton to make it more reusable

[Ani Sinha <anisinha@redhat.com>]

fw-cfg file directory iteration code can be used by other functions that may
want to implement fw-cfg file operations. Refactor it into a smaller helper
so that it can be reused.

No functional change.

Signed-off-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by:  Fabiano Rosas <farosas@suse.de>
---
 tests/qtest/libqos/fw_cfg.c | 63 +++++++++++++++++++++++--------------
 1 file changed, 40 insertions(+), 23 deletions(-)

diff --git a/tests/qtest/libqos/fw_cfg.c b/tests/qtest/libqos/fw_cfg.c
index 89f053ccac..22435873d9 100644
--- a/tests/qtest/libqos/fw_cfg.c
+++ b/tests/qtest/libqos/fw_cfg.c
@@ -60,6 +60,37 @@ static void mm_fw_cfg_select(QFWCFG *fw_cfg, uint16_t key)
     qtest_writew(fw_cfg->qts, fw_cfg->base, key);
 }
 
+static bool find_pdir_entry(QFWCFG *fw_cfg, const char *filename,
+                            uint16_t *sel, uint32_t *size)
+{
+    g_autofree unsigned char *filesbuf = NULL;
+    uint32_t count;
+    size_t dsize;
+    FWCfgFile *pdir_entry;
+    uint32_t i;
+    bool found = false;
+
+    *size = 0;
+    *sel = 0;
+
+    qfw_cfg_get(fw_cfg, FW_CFG_FILE_DIR, &count, sizeof(count));
+    count = be32_to_cpu(count);
+    dsize = sizeof(uint32_t) + count * sizeof(struct fw_cfg_file);
+    filesbuf = g_malloc(dsize);
+    qfw_cfg_get(fw_cfg, FW_CFG_FILE_DIR, filesbuf, dsize);
+    pdir_entry = (FWCfgFile *)(filesbuf + sizeof(uint32_t));
+    for (i = 0; i < count; ++i, ++pdir_entry) {
+        if (!strcmp(pdir_entry->name, filename)) {
+            *size = be32_to_cpu(pdir_entry->size);
+            *sel = be16_to_cpu(pdir_entry->select);
+            found = true;
+            break;
+        }
+    }
+
+    return found;
+}
+
 /*
  * The caller need check the return value. When the return value is
  * nonzero, it means that some bytes have been transferred.
@@ -73,34 +104,20 @@ static void mm_fw_cfg_select(QFWCFG *fw_cfg, uint16_t key)
  * populated, it has received only a starting slice of the fw_cfg file.
  */
 size_t qfw_cfg_get_file(QFWCFG *fw_cfg, const char *filename,
-                      void *data, size_t buflen)
+                        void *data, size_t buflen)
 {
-    uint32_t count;
-    uint32_t i;
-    unsigned char *filesbuf = NULL;
-    size_t dsize;
-    FWCfgFile *pdir_entry;
     size_t filesize = 0;
+    uint32_t len;
+    uint16_t sel;
 
-    qfw_cfg_get(fw_cfg, FW_CFG_FILE_DIR, &count, sizeof(count));
-    count = be32_to_cpu(count);
-    dsize = sizeof(uint32_t) + count * sizeof(struct fw_cfg_file);
-    filesbuf = g_malloc(dsize);
-    qfw_cfg_get(fw_cfg, FW_CFG_FILE_DIR, filesbuf, dsize);
-    pdir_entry = (FWCfgFile *)(filesbuf + sizeof(uint32_t));
-    for (i = 0; i < count; ++i, ++pdir_entry) {
-        if (!strcmp(pdir_entry->name, filename)) {
-            uint32_t len = be32_to_cpu(pdir_entry->size);
-            uint16_t sel = be16_to_cpu(pdir_entry->select);
-            filesize = len;
-            if (len > buflen) {
-                len = buflen;
-            }
-            qfw_cfg_get(fw_cfg, sel, data, len);
-            break;
+    if (find_pdir_entry(fw_cfg, filename, &sel, &len)) {
+        filesize = len;
+        if (len > buflen) {
+            len = buflen;
         }
+        qfw_cfg_get(fw_cfg, sel, data, len);
     }
-    g_free(filesbuf);
+
     return filesize;
 }
 
-- 
2.45.2