Commit c83f9fba authored by Kevin Wolf's avatar Kevin Wolf
Browse files

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: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent bfd18d1e

block.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

block/qapi.c

+4 −3
Original line number Diff line number Diff line
@@ -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;

        }

include/block/qapi.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

tests/qemu-iotests/142

+6 −1
Original line number Diff line number Diff line
@@ -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

tests/qemu-iotests/142.out

+47 −10
Original line number Diff line number Diff line
@@ -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