block: add close notifiers

The first user of close notifiers will be the embedded NBD server.
It would be possible to use them to do some of the ad hoc processing
(e.g. for block jobs and I/O limits) that is currently done by
bdrv_close.

Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/Makefile.objs b/Makefile.objs
index 3f16d67dac9835e0a21b15ed45206b1aded1aaab..ca67885778fc21876a666d76d179ed040e256403 100644 (file)
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -43,7 +43,7 @@ coroutine-obj-$(CONFIG_WIN32) += coroutine-win32.o
 
 block-obj-y = cutils.o iov.o cache-utils.o qemu-option.o module.o async.o
 block-obj-y += nbd.o block.o blockjob.o aio.o aes.o qemu-config.o
-block-obj-y += qemu-progress.o qemu-sockets.o uri.o
+block-obj-y += qemu-progress.o qemu-sockets.o uri.o notify.o
 block-obj-y += $(coroutine-obj-y) $(qobject-obj-y) $(version-obj-y)
 block-obj-$(CONFIG_POSIX) += posix-aio-compat.o
 block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
@@ -94,7 +94,7 @@ common-obj-y += bt-host.o bt-vhci.o
 common-obj-y += dma-helpers.o
 common-obj-y += iov.o acl.o
 common-obj-$(CONFIG_POSIX) += compatfd.o
-common-obj-y += notify.o event_notifier.o
+common-obj-y += event_notifier.o
 common-obj-y += qemu-timer.o qemu-timer-common.o
 common-obj-y += qtest.o
 common-obj-y += vl.o

diff --git a/block.c b/block.c
index 2e4ddea2222e9401feb82c5e5040fd5880785169..56426a936a3ae187cd4afe9f8a49196387cc7cf9 100644 (file)
--- a/block.c
+++ b/block.c
@@ -30,6 +30,7 @@
 #include "module.h"
 #include "qjson.h"
 #include "sysemu.h"
+#include "notify.h"
 #include "qemu-coroutine.h"
 #include "qmp-commands.h"
 #include "qemu-timer.h"
@@ -312,9 +313,16 @@ BlockDriverState *bdrv_new(const char *device_name)
         QTAILQ_INSERT_TAIL(&bdrv_states, bs, list);
     }
     bdrv_iostatus_disable(bs);
+    notifier_list_init(&bs->close_notifiers);
+
     return bs;
 }
 
+void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify)
+{
+    notifier_list_add(&bs->close_notifiers, notify);
+}
+
 BlockDriver *bdrv_find_format(const char *format_name)
 {
     BlockDriver *drv1;
@@ -1102,6 +1110,7 @@ void bdrv_close(BlockDriverState *bs)
         block_job_cancel_sync(bs->job);
     }
     bdrv_drain_all();
+    notifier_list_notify(&bs->close_notifiers, bs);
 
     if (bs->drv) {
         if (bs == bs_snapshots) {

diff --git a/block.h b/block.h
index e2d89d7bc1c22b8d5c3ef56cbb52d6ca3db9cda9..aa608a8c996ff6e42d9fc2cfdaa1242bc50151f0 100644 (file)
--- a/block.h
+++ b/block.h
@@ -144,6 +144,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state,
 void bdrv_reopen_commit(BDRVReopenState *reopen_state);
 void bdrv_reopen_abort(BDRVReopenState *reopen_state);
 void bdrv_close(BlockDriverState *bs);
+void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify);
 int bdrv_attach_dev(BlockDriverState *bs, void *dev);
 void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);
 void bdrv_detach_dev(BlockDriverState *bs, void *dev);

diff --git a/block_int.h b/block_int.h
index f4bae044017773a6adc931450ea636c9b180659a..cedabbdd131df2789d960c80a5811fcc787a3534 100644 (file)
--- a/block_int.h
+++ b/block_int.h
@@ -233,6 +233,8 @@ struct BlockDriverState {
     BlockDriverState *backing_hd;
     BlockDriverState *file;
 
+    NotifierList close_notifiers;
+
     /* number of in-flight copy-on-read requests */
     unsigned int copy_on_read_in_flight;