Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Thu 19 May 2016 16:09:27 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (31 commits)
  qemu-iotests: Fix regression in 136 on aio_read invalid
  qemu-iotests: Simplify 109 with unaligned qemu-img compare
  qemu-io: Fix recent UI updates
  block: clarify error message for qmp-eject
  qemu-iotests: Some more write_zeroes tests
  qcow2: Fix write_zeroes with partially allocated backing file cluster
  qcow2: fix condition in is_zero_cluster
  block: Propagate AioContext change to all children
  block: Remove BlockDriverState.blk
  block: Don't return throttling info in query-named-block-nodes
  block: Avoid bs->blk in bdrv_next()
  block: Add bdrv_has_blk()
  block: Remove bdrv_aio_multiwrite()
  blockjob: Don't touch BDS iostatus
  blockjob: Don't set iostatus of target
  block: User BdrvChild callback for device name
  block: Use BdrvChild callbacks for change_media/resize
  block: Don't check throttled reqs in bdrv_requests_pending()
  Revert "block: Forbid I/O throttling on nodes with multiple parents for 2.6"
  block: Remove bdrv_move_feature_fields()
  ...

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

1 files changed, 64 insertions, 117 deletions

diff --git a/block.c b/block.c
index 18a497f69d..1205ef8860 100644
--- a/block.c
+++ b/block.c
@@ -38,7 +38,6 @@
 #include "qmp-commands.h"
 #include "qemu/timer.h"
 #include "qapi-event.h"
-#include "block/throttle-groups.h"
 #include "qemu/cutils.h"
 #include "qemu/id.h"
 
@@ -237,8 +236,6 @@ BlockDriverState *bdrv_new(void)
         QLIST_INIT(&bs->op_blockers[i]);
     }
     notifier_with_return_list_init(&bs->before_write_notifiers);
-    qemu_co_queue_init(&bs->throttled_reqs[0]);
-    qemu_co_queue_init(&bs->throttled_reqs[1]);
     bs->refcnt = 1;
     bs->aio_context = qemu_get_aio_context();
 
@@ -1217,6 +1214,27 @@ void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
     bdrv_root_unref_child(child);
 }
 
+
+static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
+{
+    BdrvChild *c;
+    QLIST_FOREACH(c, &bs->parents, next_parent) {
+        if (c->role->change_media) {
+            c->role->change_media(c, load);
+        }
+    }
+}
+
+static void bdrv_parent_cb_resize(BlockDriverState *bs)
+{
+    BdrvChild *c;
+    QLIST_FOREACH(c, &bs->parents, next_parent) {
+        if (c->role->resize) {
+            c->role->resize(c);
+        }
+    }
+}
+
 /*
  * Sets the backing file link of a BDS. A new reference is created; callers
  * which don't need their own reference any more must call bdrv_unref().
@@ -1525,12 +1543,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
             return -ENODEV;
         }
 
-        if (bs->throttle_state) {
-            error_setg(errp, "Cannot reference an existing block device for "
-                       "which I/O throttling is enabled");
-            return -EINVAL;
-        }
-
         bdrv_ref(bs);
         *pbs = bs;
         return 0;
@@ -1682,9 +1694,7 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
     }
 
     if (!bdrv_key_required(bs)) {
-        if (bs->blk) {
-            blk_dev_change_media_cb(bs->blk, true);
-        }
+        bdrv_parent_cb_change_media(bs, true);
     } else if (!runstate_check(RUN_STATE_PRELAUNCH)
                && !runstate_check(RUN_STATE_INMIGRATE)
                && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */
@@ -2123,11 +2133,6 @@ static void bdrv_close(BlockDriverState *bs)
 
     assert(!bs->job);
 
-    /* Disable I/O limits and drain all pending throttled requests */
-    if (bs->throttle_state) {
-        bdrv_io_limits_disable(bs);
-    }
-
     bdrv_drained_begin(bs); /* complete I/O */
     bdrv_flush(bs);
     bdrv_drain(bs); /* in case flush left pending I/O */
@@ -2135,9 +2140,7 @@ static void bdrv_close(BlockDriverState *bs)
     bdrv_release_named_dirty_bitmaps(bs);
     assert(QLIST_EMPTY(&bs->dirty_bitmaps));
 
-    if (bs->blk) {
-        blk_dev_change_media_cb(bs->blk, false);
-    }
+    bdrv_parent_cb_change_media(bs, false);
 
     if (bs->drv) {
         BdrvChild *child, *next;
@@ -2218,26 +2221,11 @@ void bdrv_close_all(void)
     }
 }
 
-/* Fields that need to stay with the top-level BDS */
-static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
-                                     BlockDriverState *bs_src)
-{
-    /* move some fields that need to stay attached to the device */
-}
-
 static void change_parent_backing_link(BlockDriverState *from,
                                        BlockDriverState *to)
 {
     BdrvChild *c, *next;
 
-    if (from->blk) {
-        /* FIXME We bypass blk_set_bs(), so we need to make these updates
-         * manually. The root problem is not in this change function, but the
-         * existence of BlockDriverState.blk. */
-        to->blk = from->blk;
-        from->blk = NULL;
-    }
-
     QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
         assert(c->role != &child_backing);
         c->bs = to;
@@ -2248,22 +2236,6 @@ static void change_parent_backing_link(BlockDriverState *from,
     }
 }
 
-static void swap_feature_fields(BlockDriverState *bs_top,
-                                BlockDriverState *bs_new)
-{
-    BlockDriverState tmp;
-
-    bdrv_move_feature_fields(&tmp, bs_top);
-    bdrv_move_feature_fields(bs_top, bs_new);
-    bdrv_move_feature_fields(bs_new, &tmp);
-
-    assert(!bs_new->throttle_state);
-    if (bs_top->throttle_state) {
-        bdrv_io_limits_enable(bs_new, throttle_group_get_name(bs_top));
-        bdrv_io_limits_disable(bs_top);
-    }
-}
-
 /*
  * Add new bs contents at the top of an image chain while the chain is
  * live, while keeping required fields on the top layer.
@@ -2286,11 +2258,8 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
     assert(!bdrv_requests_pending(bs_new));
 
     bdrv_ref(bs_top);
-    change_parent_backing_link(bs_top, bs_new);
-
-    /* Some fields always stay on top of the backing file chain */
-    swap_feature_fields(bs_top, bs_new);
 
+    change_parent_backing_link(bs_top, bs_new);
     bdrv_set_backing_hd(bs_new, bs_top);
     bdrv_unref(bs_top);
 
@@ -2306,16 +2275,6 @@ void bdrv_replace_in_backing_chain(BlockDriverState *old, BlockDriverState *new)
 
     bdrv_ref(old);
 
-    if (old->blk) {
-        /* As long as these fields aren't in BlockBackend, but in the top-level
-         * BlockDriverState, it's not possible for a BDS to have two BBs.
-         *
-         * We really want to copy the fields from old to new, but we go for a
-         * swap instead so that pointers aren't duplicated and cause trouble.
-         * (Also, bdrv_swap() used to do the same.) */
-        assert(!new->blk);
-        swap_feature_fields(old, new);
-    }
     change_parent_backing_link(old, new);
 
     /* Change backing files if a previously independent node is added to the
@@ -2624,9 +2583,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
     if (ret == 0) {
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
         bdrv_dirty_bitmap_truncate(bs);
-        if (bs->blk) {
-            blk_dev_resize_cb(bs->blk);
-        }
+        bdrv_parent_cb_resize(bs);
     }
     return ret;
 }
@@ -2736,11 +2693,9 @@ int bdrv_set_key(BlockDriverState *bs, const char *key)
     if (ret < 0) {
         bs->valid_key = 0;
     } else if (!bs->valid_key) {
+        /* call the change callback now, we skipped it on open */
         bs->valid_key = 1;
-        if (bs->blk) {
-            /* call the change callback now, we skipped it on open */
-            blk_dev_change_media_cb(bs->blk, true);
-        }
+        bdrv_parent_cb_change_media(bs, true);
     }
     return ret;
 }
@@ -2907,34 +2862,33 @@ BlockDriverState *bdrv_next_node(BlockDriverState *bs)
     return QTAILQ_NEXT(bs, node_list);
 }
 
-/* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by
- * the monitor or attached to a BlockBackend */
-BlockDriverState *bdrv_next(BlockDriverState *bs)
+const char *bdrv_get_node_name(const BlockDriverState *bs)
 {
-    if (!bs || bs->blk) {
-        bs = blk_next_root_bs(bs);
-        if (bs) {
-            return bs;
-        }
-    }
-
-    /* Ignore all BDSs that are attached to a BlockBackend here; they have been
-     * handled by the above block already */
-    do {
-        bs = bdrv_next_monitor_owned(bs);
-    } while (bs && bs->blk);
-    return bs;
+    return bs->node_name;
 }
 
-const char *bdrv_get_node_name(const BlockDriverState *bs)
+const char *bdrv_get_parent_name(const BlockDriverState *bs)
 {
-    return bs->node_name;
+    BdrvChild *c;
+    const char *name;
+
+    /* If multiple parents have a name, just pick the first one. */
+    QLIST_FOREACH(c, &bs->parents, next_parent) {
+        if (c->role->get_name) {
+            name = c->role->get_name(c);
+            if (name && *name) {
+                return name;
+            }
+        }
+    }
+
+    return NULL;
 }
 
 /* TODO check what callers really want: bs->node_name or blk_name() */
 const char *bdrv_get_device_name(const BlockDriverState *bs)
 {
-    return bs->blk ? blk_name(bs->blk) : "";
+    return bdrv_get_parent_name(bs) ?: "";
 }
 
 /* This can be used to identify nodes that might not have a device
@@ -2943,7 +2897,7 @@ const char *bdrv_get_device_name(const BlockDriverState *bs)
  * absent, then this returns an empty (non-null) string. */
 const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
 {
-    return bs->blk ? blk_name(bs->blk) : bs->node_name;
+    return bdrv_get_parent_name(bs) ?: bs->node_name;
 }
 
 int bdrv_get_flags(BlockDriverState *bs)
@@ -3239,10 +3193,11 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
 
 void bdrv_invalidate_cache_all(Error **errp)
 {
-    BlockDriverState *bs = NULL;
+    BlockDriverState *bs;
     Error *local_err = NULL;
+    BdrvNextIterator *it = NULL;
 
-    while ((bs = bdrv_next(bs)) != NULL) {
+    while ((it = bdrv_next(it, &bs)) != NULL) {
         AioContext *aio_context = bdrv_get_aio_context(bs);
 
         aio_context_acquire(aio_context);
@@ -3284,10 +3239,11 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs,
 int bdrv_inactivate_all(void)
 {
     BlockDriverState *bs = NULL;
+    BdrvNextIterator *it = NULL;
     int ret = 0;
     int pass;
 
-    while ((bs = bdrv_next(bs)) != NULL) {
+    while ((it = bdrv_next(it, &bs)) != NULL) {
         aio_context_acquire(bdrv_get_aio_context(bs));
     }
 
@@ -3296,8 +3252,8 @@ int bdrv_inactivate_all(void)
      * the second pass sets the BDRV_O_INACTIVE flag so that no further write
      * is allowed. */
     for (pass = 0; pass < 2; pass++) {
-        bs = NULL;
-        while ((bs = bdrv_next(bs)) != NULL) {
+        it = NULL;
+        while ((it = bdrv_next(it, &bs)) != NULL) {
             ret = bdrv_inactivate_recurse(bs, pass);
             if (ret < 0) {
                 goto out;
@@ -3306,8 +3262,8 @@ int bdrv_inactivate_all(void)
     }
 
 out:
-    bs = NULL;
-    while ((bs = bdrv_next(bs)) != NULL) {
+    it = NULL;
+    while ((it = bdrv_next(it, &bs)) != NULL) {
         aio_context_release(bdrv_get_aio_context(bs));
     }
 
@@ -3653,6 +3609,7 @@ AioContext *bdrv_get_aio_context(BlockDriverState *bs)
 void bdrv_detach_aio_context(BlockDriverState *bs)
 {
     BdrvAioNotifier *baf;
+    BdrvChild *child;
 
     if (!bs->drv) {
         return;
@@ -3662,17 +3619,11 @@ void bdrv_detach_aio_context(BlockDriverState *bs)
         baf->detach_aio_context(baf->opaque);
     }
 
-    if (bs->throttle_state) {
-        throttle_timers_detach_aio_context(&bs->throttle_timers);
-    }
     if (bs->drv->bdrv_detach_aio_context) {
         bs->drv->bdrv_detach_aio_context(bs);
     }
-    if (bs->file) {
-        bdrv_detach_aio_context(bs->file->bs);
-    }
-    if (bs->backing) {
-        bdrv_detach_aio_context(bs->backing->bs);
+    QLIST_FOREACH(child, &bs->children, next) {
+        bdrv_detach_aio_context(child->bs);
     }
 
     bs->aio_context = NULL;
@@ -3682,6 +3633,7 @@ void bdrv_attach_aio_context(BlockDriverState *bs,
                              AioContext *new_context)
 {
     BdrvAioNotifier *ban;
+    BdrvChild *child;
 
     if (!bs->drv) {
         return;
@@ -3689,18 +3641,12 @@ void bdrv_attach_aio_context(BlockDriverState *bs,
 
     bs->aio_context = new_context;
 
-    if (bs->backing) {
-        bdrv_attach_aio_context(bs->backing->bs, new_context);
-    }
-    if (bs->file) {
-        bdrv_attach_aio_context(bs->file->bs, new_context);
+    QLIST_FOREACH(child, &bs->children, next) {
+        bdrv_attach_aio_context(child->bs, new_context);
     }
     if (bs->drv->bdrv_attach_aio_context) {
         bs->drv->bdrv_attach_aio_context(bs, new_context);
     }
-    if (bs->throttle_state) {
-        throttle_timers_attach_aio_context(&bs->throttle_timers, new_context);
-    }
 
     QLIST_FOREACH(ban, &bs->aio_notifiers, list) {
         ban->attached_aio_context(new_context, ban->opaque);
@@ -3806,10 +3752,11 @@ bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
  */
 bool bdrv_is_first_non_filter(BlockDriverState *candidate)
 {
-    BlockDriverState *bs = NULL;
+    BlockDriverState *bs;
+    BdrvNextIterator *it = NULL;
 
     /* walk down the bs forest recursively */
-    while ((bs = bdrv_next(bs)) != NULL) {
+    while ((it = bdrv_next(it, &bs)) != NULL) {
         bool perm;
 
         /* try to recurse in this top level bs */