block: Remove BDRV_O_CACHE_WB

The previous patches have successively made blk->enable_write_cache the
true source for the information whether a writethrough mode must be
implemented. The corresponding BDRV_O_CACHE_WB is only useless baggage
we're carrying around, so now's the time to remove it.

At the same time, we remove the 'cache.writeback' option parsing on the
BDS level as the only effect was setting the BDRV_O_CACHE_WB flag.

This change requires test cases that explicitly enabled the option to
drop it. Other than that and the change of the error message when
writethrough is enabled on the BDS level (from "Can't set writethrough
mode" to "doesn't support the option"), there should be no change in
behaviour.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

4 files changed, 27 insertions, 27 deletions

diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index 7bfe9fffe1..88b3d91da8 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -218,7 +218,7 @@ run_qemu -drive driver=null-co,cache=invalid_value
 
 for cache in writeback writethrough unsafe invalid_value; do
     echo -e "info block\ninfo block file\ninfo block backing\ninfo block backing-file" | \
-    run_qemu -drive file="$TEST_IMG",cache=$cache,backing.file.filename="$TEST_IMG.base",backing.cache.no-flush=on,backing.cache.writeback=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=$device_id -nodefaults
+    run_qemu -drive file="$TEST_IMG",cache=$cache,backing.file.filename="$TEST_IMG.base",backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=$device_id -nodefaults
 done
 
 echo
diff --git a/tests/qemu-iotests/051.pc.out b/tests/qemu-iotests/051.pc.out
index 73cc15adeb..ec6d22229c 100644
--- a/tests/qemu-iotests/051.pc.out
+++ b/tests/qemu-iotests/051.pc.out
@@ -239,7 +239,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 Testing: -drive driver=null-co,cache=invalid_value
 QEMU_PROG: -drive driver=null-co,cache=invalid_value: invalid cache option
 
-Testing: -drive file=TEST_DIR/t.qcow2,cache=writeback,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.cache.writeback=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
+Testing: -drive file=TEST_DIR/t.qcow2,cache=writeback,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) iininfinfoinfo info binfo blinfo bloinfo blocinfo block
 drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
@@ -259,7 +259,7 @@ backing-file: TEST_DIR/t.qcow2.base (file, read-only)
     Cache mode:       writeback, ignore flushes
 (qemu) qququiquit
 
-Testing: -drive file=TEST_DIR/t.qcow2,cache=writethrough,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.cache.writeback=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
+Testing: -drive file=TEST_DIR/t.qcow2,cache=writethrough,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) iininfinfoinfo info binfo blinfo bloinfo blocinfo block
 drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
@@ -279,7 +279,7 @@ backing-file: TEST_DIR/t.qcow2.base (file, read-only)
     Cache mode:       writeback, ignore flushes
 (qemu) qququiquit
 
-Testing: -drive file=TEST_DIR/t.qcow2,cache=unsafe,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.cache.writeback=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
+Testing: -drive file=TEST_DIR/t.qcow2,cache=unsafe,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) iininfinfoinfo info binfo blinfo bloinfo blocinfo block
 drive0 (NODE_NAME): TEST_DIR/t.qcow2 (qcow2)
@@ -299,8 +299,8 @@ backing-file: TEST_DIR/t.qcow2.base (file, read-only)
     Cache mode:       writeback, ignore flushes
 (qemu) qququiquit
 
-Testing: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.cache.writeback=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.cache.writeback=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0: invalid cache option
+Testing: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0: invalid cache option
 
 
 === Specifying the protocol layer ===
diff --git a/tests/qemu-iotests/142 b/tests/qemu-iotests/142
index a035747904..3828c23b7b 100755
--- a/tests/qemu-iotests/142
+++ b/tests/qemu-iotests/142
@@ -110,11 +110,11 @@ function check_cache_all()
     echo -e "\n\ncache.writeback=off on none0"
     echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
     echo -e "\ncache.writeback=off on file"
-    echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
+    echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.writeback=off | grep -e "doesn't" -e "does not"
     echo -e "\ncache.writeback=off on backing"
-    echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
+    echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.writeback=off | grep -e "doesn't" -e "does not"
     echo -e "\ncache.writeback=off on backing-file"
-    echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
+    echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.writeback=off | grep -e "doesn't" -e "does not"
 
     # cache.no-flush is supposed to be inherited by both bs->file and bs->backing
 
diff --git a/tests/qemu-iotests/142.out b/tests/qemu-iotests/142.out
index 3d5ef5fe8d..600beca8fb 100644
--- a/tests/qemu-iotests/142.out
+++ b/tests/qemu-iotests/142.out
@@ -71,13 +71,13 @@ cache.writeback=off on none0
     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
+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: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-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,backing.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-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,backing.file.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -147,13 +147,13 @@ cache.writeback=off on none0
     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
+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: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-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,backing.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-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,backing.file.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -223,13 +223,13 @@ cache.writeback=off on none0
     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
+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: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-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,backing.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-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,backing.file.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -299,13 +299,13 @@ cache.writeback=off on none0
     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
+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: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-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,backing.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-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,backing.file.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -375,13 +375,13 @@ cache.writeback=off on none0
     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
+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: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-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,backing.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-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,backing.file.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -704,13 +704,13 @@ cache.writeback=off on none0
     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
+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: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-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,backing.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-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,backing.file.cache.writeback=off: Could not open backing file: Can't set writethrough mode except for the root
+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,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0