block: Introduce bs->explicit_options

bs->options doesn't only contain options that the user explicitly
requested, but also option that were derived from flags, the filename or
inherited from the parent node.

For reopen, it is important to know the difference because reopening the
parent can change inherited values in child nodes, but it shouldn't
change any options that were explicitly specified for the child.

Signed-off-by: Kevin Wolf <[email protected]>
Reviewed-by: Max Reitz <[email protected]>

diff --git a/block.c b/block.c
index 5bf3e2211594814f48c044fb0ffaa468aea1b088..a22c47cdb67cf83a4e9c7170c3bb2c3b27d4e7d8 100644 (file)
--- a/block.c
+++ b/block.c
@@ -1495,12 +1495,15 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
         options = qdict_new();
     }
 
+    /* json: syntax counts as explicit options, as if in the QDict */
     parse_json_protocol(options, &filename, &local_err);
     if (local_err) {
         ret = -EINVAL;
         goto fail;
     }
 
+    bs->explicit_options = qdict_clone_shallow(options);
+
     if (child_role) {
         bs->inherits_from = parent;
         child_role->inherit_options(&flags, options,
@@ -1655,6 +1658,7 @@ fail:
     if (file != NULL) {
         bdrv_unref_child(bs, file);
     }
+    QDECREF(bs->explicit_options);
     QDECREF(bs->options);
     QDECREF(options);
     bs->options = NULL;
@@ -1729,7 +1733,7 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
 
     BlockReopenQueueEntry *bs_entry;
     BdrvChild *child;
-    QDict *old_options;
+    QDict *old_options, *explicit_options;
 
     if (bs_queue == NULL) {
         bs_queue = g_new0(BlockReopenQueue, 1);
@@ -1744,11 +1748,18 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
      * Precedence of options:
      * 1. Explicitly passed in options (highest)
      * 2. TODO Set in flags (only for top level)
-     * 3. TODO Retained from explicitly set options of bs
+     * 3. Retained from explicitly set options of bs
      * 4. Inherited from parent node
      * 5. Retained from effective options of bs
      */
 
+    /* Old explicitly set values (don't overwrite by inherited value) */
+    old_options = qdict_clone_shallow(bs->explicit_options);
+    bdrv_join_options(bs, options, old_options);
+    QDECREF(old_options);
+
+    explicit_options = qdict_clone_shallow(options);
+
     /* Inherit from parent node */
     if (parent_options) {
         assert(!flags);
@@ -1787,6 +1798,7 @@ static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
 
     bs_entry->state.bs = bs;
     bs_entry->state.options = options;
+    bs_entry->state.explicit_options = explicit_options;
     bs_entry->state.flags = flags;
 
     return bs_queue;
@@ -1846,6 +1858,8 @@ cleanup:
     QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
         if (ret && bs_entry->prepared) {
             bdrv_reopen_abort(&bs_entry->state);
+        } else if (ret) {
+            QDECREF(bs_entry->state.explicit_options);
         }
         QDECREF(bs_entry->state.options);
         g_free(bs_entry);
@@ -1980,6 +1994,9 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state)
     }
 
     /* set BDS specific flags now */
+    QDECREF(reopen_state->bs->explicit_options);
+
+    reopen_state->bs->explicit_options   = reopen_state->explicit_options;
     reopen_state->bs->open_flags         = reopen_state->flags;
     reopen_state->bs->enable_write_cache = !!(reopen_state->flags &
                                               BDRV_O_CACHE_WB);
@@ -2003,6 +2020,8 @@ void bdrv_reopen_abort(BDRVReopenState *reopen_state)
     if (drv->bdrv_reopen_abort) {
         drv->bdrv_reopen_abort(reopen_state);
     }
+
+    QDECREF(reopen_state->explicit_options);
 }
 
 
@@ -2061,6 +2080,7 @@ void bdrv_close(BlockDriverState *bs)
         bs->sg = 0;
         bs->zero_beyond_eof = false;
         QDECREF(bs->options);
+        QDECREF(bs->explicit_options);
         bs->options = NULL;
         QDECREF(bs->full_open_options);
         bs->full_open_options = NULL;

diff --git a/include/block/block.h b/include/block/block.h
index 2e77288d82ccfc718180beffbb077ab85c652f21..121544b3c38d42cedbe79aa0d145ca394e281b6e 100644 (file)
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -150,6 +150,7 @@ typedef struct BDRVReopenState {
     BlockDriverState *bs;
     int flags;
     QDict *options;
+    QDict *explicit_options;
     void *opaque;
 } BDRVReopenState;
 

diff --git a/include/block/block_int.h b/include/block/block_int.h
index abb6224439f47a1066b9726351e31ec5da194178..edfe376ecc2d0fc86369b3db812928a770889153 100644 (file)
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -459,6 +459,7 @@ struct BlockDriverState {
     QLIST_HEAD(, BdrvChild) parents;
 
     QDict *options;
+    QDict *explicit_options;
     BlockdevDetectZeroesOptions detect_zeroes;
 
     /* The error object in use for blocking operations on backing_hd */