Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Block pull request

# gpg: Signature made Thu 13 Mar 2014 13:50:49 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request: (24 commits)
  block/raw-win32: bdrv_parse_filename() for hdev
  block/raw-posix: Strip protocol prefix on creation
  block/raw-posix: bdrv_parse_filename() for cdrom
  block/raw-posix: bdrv_parse_filename() for floppy
  block/raw-posix: bdrv_parse_filename() for hdev
  qemu-io: Fix warnings from static code analysis
  block: Unlink temporary file
  qcow2: Don't write with BDRV_O_INCOMING
  qcow2: Keep option in qcow2_invalidate_cache()
  qmp: add query-iothreads command
  iothread: stash thread ID away
  dataplane: replace internal thread with IOThread
  iothread: add "iothread" qdev property type
  qdev: make get_pointer() handle temporary strings
  iothread: add I/O thread object
  aio: add aio_context_acquire() and aio_context_release()
  rfifolock: add recursive FIFO lock
  object: add object_get_canonical_path_component()
  block: Rewrite the snapshot authorization mechanism for block filters.
  iotests: Test corruption during COW request
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 32 insertions, 29 deletions

diff --git a/block.c b/block.c
index f1ef4b0109..fae50c95b5 100644
--- a/block.c
+++ b/block.c
@@ -1321,7 +1321,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename,
                           bdrv_open_flags(bs, flags | BDRV_O_UNMAP) |
                           BDRV_O_PROTOCOL, true, &local_err);
     if (ret < 0) {
-        goto fail;
+        goto unlink_and_fail;
     }
 
     /* Find the right image format driver */
@@ -4055,7 +4055,7 @@ int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
 
 int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
 {
-    while (bs && bs->drv && !bs->drv->bdrv_debug_resume) {
+    while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
         bs = bs->file;
     }
 
@@ -4776,9 +4776,17 @@ flush_parent:
 
 void bdrv_invalidate_cache(BlockDriverState *bs)
 {
-    if (bs->drv && bs->drv->bdrv_invalidate_cache) {
+    if (!bs->drv)  {
+        return;
+    }
+
+    if (bs->drv->bdrv_invalidate_cache) {
         bs->drv->bdrv_invalidate_cache(bs);
+    } else if (bs->file) {
+        bdrv_invalidate_cache(bs->file);
     }
+
+    refresh_total_sectors(bs, bs->total_sectors);
 }
 
 void bdrv_invalidate_cache_all(void)
@@ -5390,43 +5398,37 @@ int bdrv_amend_options(BlockDriverState *bs, QEMUOptionParameter *options)
     return bs->drv->bdrv_amend_options(bs, options);
 }
 
-/* Used to recurse on single child block filters.
- * Single child block filter will store their child in bs->file.
+/* This function will be called by the bdrv_recurse_is_first_non_filter method
+ * of block filter and by bdrv_is_first_non_filter.
+ * It is used to test if the given bs is the candidate or recurse more in the
+ * node graph.
  */
-bool bdrv_generic_is_first_non_filter(BlockDriverState *bs,
+bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
                                       BlockDriverState *candidate)
 {
-    if (!bs->drv) {
-        return false;
-    }
-
-    if (!bs->drv->authorizations[BS_IS_A_FILTER]) {
-        if (bs == candidate) {
-            return true;
-        } else {
-            return false;
-        }
-    }
-
-    if (!bs->drv->authorizations[BS_FILTER_PASS_DOWN]) {
+    /* return false if basic checks fails */
+    if (!bs || !bs->drv) {
         return false;
     }
 
-    if (!bs->file) {
-        return false;
+    /* the code reached a non block filter driver -> check if the bs is
+     * the same as the candidate. It's the recursion termination condition.
+     */
+    if (!bs->drv->is_filter) {
+        return bs == candidate;
     }
+    /* Down this path the driver is a block filter driver */
 
-    return bdrv_recurse_is_first_non_filter(bs->file, candidate);
-}
-
-bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
-                                      BlockDriverState *candidate)
-{
-    if (bs->drv && bs->drv->bdrv_recurse_is_first_non_filter) {
+    /* If the block filter recursion method is defined use it to recurse down
+     * the node graph.
+     */
+    if (bs->drv->bdrv_recurse_is_first_non_filter) {
         return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
     }
 
-    return bdrv_generic_is_first_non_filter(bs, candidate);
+    /* the driver is a block filter but don't allow to recurse -> return false
+     */
+    return false;
 }
 
 /* This function checks if the candidate is the first non filter bs down it's
@@ -5441,6 +5443,7 @@ bool bdrv_is_first_non_filter(BlockDriverState *candidate)
     QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
         bool perm;
 
+        /* try to recurse in this top level bs */
         perm = bdrv_recurse_is_first_non_filter(bs, candidate);
 
         /* candidate is the first non filter */