[Qemu-devel] [PATCH v4 1/6] block: Change bdrv_get_encrypted_filename()

[Max Reitz <mreitz@redhat.com>]

Instead of returning a pointer to the filename, copy it into a buffer
specified by the caller.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c               | 25 ++++++++++++++++++-------
 include/block/block.h |  2 +-
 monitor.c             |  6 +++++-
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/block.c b/block.c
index d088ee0..41b0f85 100644
--- a/block.c
+++ b/block.c
@@ -2760,10 +2760,13 @@ void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp)
         }
     } else {
         if (bdrv_key_required(bs)) {
+            char *enc_filename = g_malloc(PATH_MAX);
+            bdrv_get_encrypted_filename(bs, enc_filename, PATH_MAX);
             error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED,
                       "'%s' (%s) is encrypted",
                       bdrv_get_device_or_node_name(bs),
-                      bdrv_get_encrypted_filename(bs));
+                      enc_filename);
+            g_free(enc_filename);
         }
     }
 }
@@ -2980,14 +2983,22 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
     return false;
 }
 
-const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
+char *bdrv_get_encrypted_filename(BlockDriverState *bs, char *dest, size_t sz)
 {
-    if (bs->backing_hd && bs->backing_hd->encrypted)
-        return bs->backing_file;
-    else if (bs->encrypted)
-        return bs->filename;
-    else
+    if (sz > INT_MAX) {
+        sz = INT_MAX;
+    }
+
+    if (bs->backing_hd && bs->backing_hd->encrypted) {
+        pstrcpy(dest, sz, bs->backing_file);
+        return dest;
+    } else if (bs->encrypted) {
+        pstrcpy(dest, sz, bs->filename);
+        return dest;
+    } else {
+        dest[0] = '\0';
         return NULL;
+    }
 }
 
 void bdrv_get_backing_filename(BlockDriverState *bs,
diff --git a/include/block/block.h b/include/block/block.h
index 37916f7..a78e4f1 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -430,7 +430,7 @@ void bdrv_round_to_clusters(BlockDriverState *bs,
                             int64_t *cluster_sector_num,
                             int *cluster_nb_sectors);
 
-const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
+char *bdrv_get_encrypted_filename(BlockDriverState *bs, char *dest, size_t sz);
 void bdrv_get_backing_filename(BlockDriverState *bs,
                                char *filename, int filename_size);
 void bdrv_get_full_backing_filename(BlockDriverState *bs,
diff --git a/monitor.c b/monitor.c
index aeea2b5..a7d1650 100644
--- a/monitor.c
+++ b/monitor.c
@@ -5292,10 +5292,14 @@ int monitor_read_bdrv_key_start(Monitor *mon, BlockDriverState *bs,
                                 BlockCompletionFunc *completion_cb,
                                 void *opaque)
 {
+    char *enc_filename;
     int err;
 
+    enc_filename = g_malloc(PATH_MAX);
+    bdrv_get_encrypted_filename(bs, enc_filename, PATH_MAX);
     monitor_printf(mon, "%s (%s) is encrypted.\n", bdrv_get_device_name(bs),
-                   bdrv_get_encrypted_filename(bs));
+                   enc_filename);
+    g_free(enc_filename);
 
     mon->password_completion_cb = completion_cb;
     mon->password_opaque = opaque;
-- 
2.4.3