[Qemu-devel] [PATCH v2 18/22] block: Move some bdrv_*_all() functions to BB

[Max Reitz <mreitz@redhat.com>]

Move bdrv_drain_all(), bdrv_commit_all(), bdrv_flush_all() and
bdrv_invalidate_cache_all() to BB.

The only operation left is bdrv_close_all(), which cannot be moved to
the BB because it should not only close all BBs, but also all
monitor-owned BDSs.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block.c                 |  97 --------------------------------------------
 block/block-backend.c   | 104 ++++++++++++++++++++++++++++++++++++++++++------
 include/block/block.h   |   4 --
 stubs/Makefile.objs     |   2 +-
 stubs/bdrv-commit-all.c |   7 ----
 stubs/blk-commit-all.c  |   7 ++++
 6 files changed, 100 insertions(+), 121 deletions(-)
 delete mode 100644 stubs/bdrv-commit-all.c
 create mode 100644 stubs/blk-commit-all.c

diff --git a/block.c b/block.c
index 3f3258c..94eb4e0 100644
--- a/block.c
+++ b/block.c
@@ -1977,37 +1977,6 @@ void bdrv_drain(BlockDriverState *bs)
     }
 }
 
-/*
- * Wait for pending requests to complete across all BlockDriverStates
- *
- * This function does not flush data to disk, use bdrv_flush_all() for that
- * after calling this function.
- *
- * Note that completion of an asynchronous I/O operation can trigger any
- * number of other I/O operations on other devices---for example a coroutine
- * can be arbitrarily complex and a constant flow of I/O can come until the
- * coroutine is complete.  Because of this, it is not possible to have a
- * function to drain a single device's I/O queue.
- */
-void bdrv_drain_all(void)
-{
-    /* Always run first iteration so any pending completion BHs run */
-    bool busy = true;
-    BlockDriverState *bs;
-
-    while (busy) {
-        busy = false;
-
-        QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
-            AioContext *aio_context = bdrv_get_aio_context(bs);
-
-            aio_context_acquire(aio_context);
-            busy |= bdrv_drain_one(bs);
-            aio_context_release(aio_context);
-        }
-    }
-}
-
 /* make a BlockDriverState anonymous by removing from bdrv_state and
  * graph_bdrv_state list.
    Also, NULL terminate the device_name to prevent double remove */
@@ -2300,26 +2269,6 @@ ro_cleanup:
     return ret;
 }
 
-int bdrv_commit_all(void)
-{
-    BlockDriverState *bs;
-
-    QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
-        AioContext *aio_context = bdrv_get_aio_context(bs);
-
-        aio_context_acquire(aio_context);
-        if (bs->drv && bs->backing_hd) {
-            int ret = bdrv_commit(bs);
-            if (ret < 0) {
-                aio_context_release(aio_context);
-                return ret;
-            }
-        }
-        aio_context_release(aio_context);
-    }
-    return 0;
-}
-
 /**
  * Remove an active request from the tracked requests list
  *
@@ -3794,14 +3743,6 @@ BlockDriverState *bdrv_next_node(BlockDriverState *bs)
     return QTAILQ_NEXT(bs, node_list);
 }
 
-BlockDriverState *bdrv_next(BlockDriverState *bs)
-{
-    if (!bs) {
-        return QTAILQ_FIRST(&bdrv_states);
-    }
-    return QTAILQ_NEXT(bs, device_list);
-}
-
 const char *bdrv_get_node_name(const BlockDriverState *bs)
 {
     return bs->node_name;
@@ -3818,26 +3759,6 @@ int bdrv_get_flags(BlockDriverState *bs)
     return bs->open_flags;
 }
 
-int bdrv_flush_all(void)
-{
-    BlockDriverState *bs;
-    int result = 0;
-
-    QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
-        AioContext *aio_context = bdrv_get_aio_context(bs);
-        int ret;
-
-        aio_context_acquire(aio_context);
-        ret = bdrv_flush(bs);
-        if (ret < 0 && !result) {
-            result = ret;
-        }
-        aio_context_release(aio_context);
-    }
-
-    return result;
-}
-
 int bdrv_has_zero_init_1(BlockDriverState *bs)
 {
     return 1;
@@ -4997,24 +4918,6 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
     }
 }
 
-void bdrv_invalidate_cache_all(Error **errp)
-{
-    BlockDriverState *bs;
-    Error *local_err = NULL;
-
-    QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
-        AioContext *aio_context = bdrv_get_aio_context(bs);
-
-        aio_context_acquire(aio_context);
-        bdrv_invalidate_cache(bs, &local_err);
-        aio_context_release(aio_context);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            return;
-        }
-    }
-}
-
 int bdrv_flush(BlockDriverState *bs)
 {
     Coroutine *co;
diff --git a/block/block-backend.c b/block/block-backend.c
index ead1dfc..e4a4675 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -372,6 +372,9 @@ void blk_remove_bs(BlockBackend *blk)
     notifier_list_notify(&blk->remove_bs_notifiers, blk);
 
     blk_update_root_state(blk);
+    /* After this function, the BDS may longer be accessible to blk_*_all()
+     * functions */
+    blk_drain_all();
 
     bdrv_unref(blk->bs);
     blk->bs->blk = NULL;
@@ -897,16 +900,6 @@ int blk_flush(BlockBackend *blk)
     return bdrv_flush(blk->bs);
 }
 
-int blk_flush_all(void)
-{
-    return bdrv_flush_all();
-}
-
-void blk_drain_all(void)
-{
-    bdrv_drain_all();
-}
-
 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
                       BlockdevOnError on_write_error)
 {
@@ -1266,12 +1259,99 @@ BlockBackendRootState *blk_get_root_state(BlockBackend *blk)
     return &blk->root_state;
 }
 
+/*
+ * Wait for pending requests to complete across all BlockBackends
+ *
+ * This function does not flush data to disk, use blk_flush_all() for that
+ * after calling this function.
+ *
+ * Note that completion of an asynchronous I/O operation can trigger any
+ * number of other I/O operations on other devices---for example a coroutine
+ * can be arbitrarily complex and a constant flow of I/O can come until the
+ * coroutine is complete.  Because of this, it is not possible to have a
+ * function to drain a single device's I/O queue.
+ */
+void blk_drain_all(void)
+{
+    /* Always run first iteration so any pending completion BHs run */
+    bool busy = true;
+    BlockBackend *blk;
+
+    while (busy) {
+        busy = false;
+
+        QTAILQ_FOREACH(blk, &blk_backends, link) {
+            AioContext *aio_context = blk_get_aio_context(blk);
+
+            if (!blk_is_inserted(blk)) {
+                continue;
+            }
+
+            aio_context_acquire(aio_context);
+            busy |= bdrv_drain_one(blk->bs);
+            aio_context_release(aio_context);
+        }
+    }
+}
+
 int blk_commit_all(void)
 {
-    return bdrv_commit_all();
+    BlockBackend *blk;
+
+    QTAILQ_FOREACH(blk, &blk_backends, link) {
+        AioContext *aio_context = blk_get_aio_context(blk);
+
+        aio_context_acquire(aio_context);
+        if (blk_is_available(blk) && blk->bs->drv && blk->bs->backing_hd) {
+            int ret = bdrv_commit(blk->bs);
+            if (ret < 0) {
+                aio_context_release(aio_context);
+                return ret;
+            }
+        }
+        aio_context_release(aio_context);
+    }
+    return 0;
+}
+
+int blk_flush_all(void)
+{
+    BlockBackend *blk;
+    int result = 0;
+
+    QTAILQ_FOREACH(blk, &blk_backends, link) {
+        AioContext *aio_context = blk_get_aio_context(blk);
+        int ret;
+
+        aio_context_acquire(aio_context);
+        if (blk_is_inserted(blk)) {
+            ret = blk_flush(blk);
+            if (ret < 0 && !result) {
+                result = ret;
+            }
+        }
+        aio_context_release(aio_context);
+    }
+
+    return result;
 }
 
 void blk_invalidate_cache_all(Error **errp)
 {
-    bdrv_invalidate_cache_all(errp);
+    BlockBackend *blk;
+    Error *local_err = NULL;
+
+    QTAILQ_FOREACH(blk, &blk_backends, link) {
+        AioContext *aio_context = blk_get_aio_context(blk);
+
+        aio_context_acquire(aio_context);
+        if (blk_is_inserted(blk)) {
+            blk_invalidate_cache(blk, &local_err);
+        }
+        aio_context_release(aio_context);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
 }
diff --git a/include/block/block.h b/include/block/block.h
index 8274dbd..2df5bc5 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -239,7 +239,6 @@ int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 void bdrv_refresh_limits(BlockDriverState *bs, Error **errp);
 int bdrv_commit(BlockDriverState *bs);
-int bdrv_commit_all(void);
 int bdrv_change_backing_file(BlockDriverState *bs,
     const char *backing_file, const char *backing_fmt);
 void bdrv_register(BlockDriver *bdrv);
@@ -325,15 +324,12 @@ BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
 
 /* Invalidate any cached metadata used by image formats */
 void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp);
-void bdrv_invalidate_cache_all(Error **errp);
 
 /* Ensure contents are flushed to disk.  */
 int bdrv_flush(BlockDriverState *bs);
 int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
-int bdrv_flush_all(void);
 void bdrv_close_all(void);
 void bdrv_drain(BlockDriverState *bs);
-void bdrv_drain_all(void);
 
 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index 5e347d0..56eb2e8 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -1,5 +1,5 @@
 stub-obj-y += arch-query-cpu-def.o
-stub-obj-y += bdrv-commit-all.o
+stub-obj-y += blk-commit-all.o
 stub-obj-y += chr-baum-init.o
 stub-obj-y += chr-msmouse.o
 stub-obj-y += chr-testdev.o
diff --git a/stubs/bdrv-commit-all.c b/stubs/bdrv-commit-all.c
deleted file mode 100644
index a8e0a95..0000000
--- a/stubs/bdrv-commit-all.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include "qemu-common.h"
-#include "block/block.h"
-
-int bdrv_commit_all(void)
-{
-    return 0;
-}
diff --git a/stubs/blk-commit-all.c b/stubs/blk-commit-all.c
new file mode 100644
index 0000000..90b59e5
--- /dev/null
+++ b/stubs/blk-commit-all.c
@@ -0,0 +1,7 @@
+#include "qemu-common.h"
+#include "sysemu/block-backend.h"
+
+int blk_commit_all(void)
+{
+    return 0;
+}
-- 
2.1.0