block: Use bdrv_refresh_filename() to pull

Before this patch, bdrv_refresh_filename() is used in a pushing manner:
Whenever the BDS graph is modified, the parents of the modified edges
are supposed to be updated (recursively upwards).  However, that is
nonviable, considering that we want child changes not to concern
parents.

Also, in the long run we want a pull model anyway: Here, we would have a
bdrv_filename() function which returns a BDS's filename, freshly
constructed.

This patch is an intermediate step.  It adds bdrv_refresh_filename()
calls before every place a BDS.filename value is used.  The only
exceptions are protocol drivers that use their own filename, which
clearly would not profit from refreshing that filename before.

Also, bdrv_get_encrypted_filename() is removed along the way (as a user
of BDS.filename), since it is completely unused.

In turn, all of the calls to bdrv_refresh_filename() before this patch
are removed, because we no longer have to call this function on graph
changes.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

5 files changed, 12 insertions, 2 deletions

diff --git a/block/qapi.c b/block/qapi.c
index 00291f9..4623de1 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -51,6 +51,8 @@ BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
         return NULL;
     }
 
+    bdrv_refresh_filename(bs);
+
     info = g_malloc0(sizeof(*info));
     info->file                   = g_strdup(bs->filename);
     info->ro                     = bs->read_only;
@@ -264,6 +266,8 @@ void bdrv_query_image_info(BlockDriverState *bs,
         goto out;
     }
 
+    bdrv_refresh_filename(bs);
+
     info = g_new0(ImageInfo, 1);
     info->filename        = g_strdup(bs->filename);
     info->format          = g_strdup(bdrv_get_format_name(bs));
diff --git a/block/raw-format.c b/block/raw-format.c
index 6f6dc99..d07bcda 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -436,6 +436,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
             bs->file->bs->supported_zero_flags);
 
     if (bs->probed && !bdrv_is_read_only(bs)) {
+        bdrv_refresh_filename(bs->file->bs);
         fprintf(stderr,
                 "WARNING: Image format was not specified for '%s' and probing "
                 "guessed raw.\n"
diff --git a/block/replication.c b/block/replication.c
index e70dd95..9b33200 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -616,8 +616,6 @@ static void replication_done(void *opaque, int ret)
     if (ret == 0) {
         s->stage = BLOCK_REPLICATION_DONE;
 
-        /* refresh top bs's filename */
-        bdrv_refresh_filename(bs);
         s->active_disk = NULL;
         s->secondary_disk = NULL;
         s->hidden_disk = NULL;
diff --git a/block/vhdx-log.c b/block/vhdx-log.c
index ecd6426..3149ff0 100644
--- a/block/vhdx-log.c
+++ b/block/vhdx-log.c
@@ -803,6 +803,7 @@ int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed,
 
     if (logs.valid) {
         if (bs->read_only) {
+            bdrv_refresh_filename(bs);
             ret = -EPERM;
             error_setg(errp,
                        "VHDX image file '%s' opened read-only, but "
diff --git a/block/vmdk.c b/block/vmdk.c
index 096e8eb..117dc6a 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -479,6 +479,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                      extent->l1_table,
                      l1_size);
     if (ret < 0) {
+        bdrv_refresh_filename(extent->file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read l1 table from extent '%s'",
                          extent->file->bs->filename);
@@ -499,6 +500,7 @@ static int vmdk_init_tables(BlockDriverState *bs, VmdkExtent *extent,
                          extent->l1_backup_table,
                          l1_size);
         if (ret < 0) {
+            bdrv_refresh_filename(extent->file->bs);
             error_setg_errno(errp, -ret,
                              "Could not read l1 backup table from extent '%s'",
                              extent->file->bs->filename);
@@ -530,6 +532,7 @@ static int vmdk_open_vmfs_sparse(BlockDriverState *bs,
 
     ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
+        bdrv_refresh_filename(file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read header from file '%s'",
                          file->bs->filename);
@@ -607,6 +610,7 @@ static int vmdk_open_vmdk4(BlockDriverState *bs,
 
     ret = bdrv_pread(file, sizeof(magic), &header, sizeof(header));
     if (ret < 0) {
+        bdrv_refresh_filename(file->bs);
         error_setg_errno(errp, -ret,
                          "Could not read header from file '%s'",
                          file->bs->filename);
@@ -861,6 +865,7 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
         if (!path_is_absolute(fname) && !path_has_protocol(fname) &&
             !desc_file_path[0])
         {
+            bdrv_refresh_filename(bs->file->bs);
             error_setg(errp, "Cannot use relative extent paths with VMDK "
                        "descriptor file '%s'", bs->file->bs->filename);
             return -EINVAL;
@@ -2470,6 +2475,7 @@ static ImageInfo *vmdk_get_extent_info(VmdkExtent *extent)
 {
     ImageInfo *info = g_new0(ImageInfo, 1);
 
+    bdrv_refresh_filename(extent->file->bs);
     *info = (ImageInfo){
         .filename         = g_strdup(extent->file->bs->filename),
         .format           = g_strdup(extent->type),