block/qapi: Use blk_enable_write_cache()

Now that WCE is handled on the BlockBackend level, the flag is
meaningless for BDSes. As the schema requires us to fill the field,
we return an enabled write cache for them.

Note that this means that querying the BlockBackend name may return
writethrough as the cache information, whereas querying the node-name of
the root of that same BlockBackend will return writeback.

This may appear odd at first, but it actually makes sense because it
correctly repesents the layer that implements the WCE handling. This
becomes more apparent when you consider nodes that are the root node of
multiple BlockBackends, where each BB can have its own WCE setting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-03-03 11:37:48 +01:00
parent bfd18d1e0b
commit c83f9fba2a
5 changed files with 60 additions and 16 deletions

View File

@ -2917,7 +2917,7 @@ BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
list = NULL;
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
BlockDeviceInfo *info = bdrv_block_device_info(bs, errp);
BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
if (!info) {
qapi_free_BlockDeviceInfoList(list);
return NULL;

View File

@ -34,7 +34,8 @@
#include "sysemu/block-backend.h"
#include "qemu/cutils.h"
BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs, Error **errp)
BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
BlockDriverState *bs, Error **errp)
{
ImageInfo **p_image_info;
BlockDriverState *bs0;
@ -48,7 +49,7 @@ BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs, Error **errp)
info->cache = g_new(BlockdevCacheInfo, 1);
*info->cache = (BlockdevCacheInfo) {
.writeback = bdrv_enable_write_cache(bs),
.writeback = blk ? blk_enable_write_cache(blk) : true,
.direct = !!(bs->open_flags & BDRV_O_NOCACHE),
.no_flush = !!(bs->open_flags & BDRV_O_NO_FLUSH),
};
@ -343,7 +344,7 @@ static void bdrv_query_info(BlockBackend *blk, BlockInfo **p_info,
if (bs && bs->drv) {
info->has_inserted = true;
info->inserted = bdrv_block_device_info(bs, errp);
info->inserted = bdrv_block_device_info(blk, bs, errp);
if (info->inserted == NULL) {
goto err;
}

View File

@ -29,7 +29,8 @@
#include "block/block.h"
#include "block/snapshot.h"
BlockDeviceInfo *bdrv_block_device_info(BlockDriverState *bs, Error **errp);
BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
BlockDriverState *bs, Error **errp);
int bdrv_query_snapshot_info_list(BlockDriverState *bs,
SnapshotInfoList **p_list,
Error **errp);

View File

@ -134,7 +134,8 @@ echo
# First check the inherited cache mode after opening the image.
hmp_cmds="info block image
hmp_cmds="info block none0
info block image
info block file
info block backing
info block backing-file"
@ -164,6 +165,7 @@ echo
# new cache mode is specified in the flags, not as an option.
hmp_cmds='qemu-io none0 "reopen -c none"
info block none0
info block image
info block file
info block backing
@ -179,6 +181,7 @@ echo
# new cache mode is specified as an option, not in the flags.
hmp_cmds='qemu-io none0 "reopen -o cache.direct=on"
info block none0
info block image
info block file
info block backing
@ -214,6 +217,7 @@ echo
# options from its parent node.
hmp_cmds="qemu-io none0 \"reopen -o cache.writeback=off,cache.direct=on,cache.no-flush=on\"
info block none0
info block image
info block blkdebug
info block file"
@ -321,6 +325,7 @@ echo "--- Basic reopen ---"
echo
hmp_cmds='qemu-io none0 "reopen -o backing.cache.direct=on"
info block none0
info block image
info block file
info block backing

View File

@ -39,14 +39,17 @@ cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
@ -56,6 +59,7 @@ cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
@ -64,6 +68,7 @@ cache.writeback=off on none0
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Can't set writethrough mode except for the root
@ -80,14 +85,17 @@ cache.no-flush=on on none0
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback
Cache mode: writeback
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
@ -97,6 +105,7 @@ cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
--- Cache modes after reopen (live snapshot) ---
@ -182,24 +191,28 @@ cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on none0
@ -207,6 +220,7 @@ cache.writeback=off on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Can't set writethrough mode except for the root
@ -223,14 +237,17 @@ cache.no-flush=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
@ -240,6 +257,7 @@ cache.no-flush=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
--- Change cache modes with reopen (qemu-io command, options) ---
@ -249,24 +267,28 @@ cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on none0
@ -274,6 +296,7 @@ cache.writeback=off on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.writeback=off on file
QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Can't set writethrough mode except for the root
@ -290,14 +313,17 @@ cache.no-flush=on on none0
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on backing
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
@ -307,6 +333,7 @@ cache.no-flush=on on backing-file
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct, ignore flushes
--- Change cache modes after snapshot ---
@ -389,6 +416,7 @@ cache.no-flush=on on backing-file
Cache mode: writethrough, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, ignore flushes
=== Check that referenced BDSes don't inherit ===
@ -422,28 +450,28 @@ cache.direct=on on backing-file
cache.writeback=off on blk
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on file
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
cache.no-flush=on on blk
@ -511,7 +539,7 @@ cache.writeback=off on blk
cache.writeback=off on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
@ -519,7 +547,7 @@ cache.writeback=off on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing-file
@ -527,7 +555,7 @@ cache.writeback=off on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
cache.no-flush=on on blk
@ -593,21 +621,21 @@ cache.writeback=off on blk
cache.writeback=off on file
Cache mode: writeback, direct
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
cache.writeback=off on backing-file
Cache mode: writeback, direct
Cache mode: writeback
Cache mode: writeback
Cache mode: writethrough
Cache mode: writeback
cache.no-flush=on on blk
@ -644,20 +672,24 @@ cache.direct=on on none0
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.direct=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
@ -667,6 +699,7 @@ cache.direct=on on backing-file
cache.writeback=off on none0
Cache mode: writethrough
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct
Cache mode: writeback, direct
@ -681,24 +714,28 @@ QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t
cache.no-flush=on on none0
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, ignore flushes
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, ignore flushes
Cache mode: writeback, direct
Cache mode: writeback, direct
cache.no-flush=on on backing
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
cache.no-flush=on on backing-file
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback
Cache mode: writeback, direct