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-rw-r--r--block.c7
-rw-r--r--blockdev.c19
-rwxr-xr-xtests/qemu-iotests/14250
-rw-r--r--tests/qemu-iotests/142.out98
4 files changed, 68 insertions, 106 deletions
diff --git a/block.c b/block.c
index d050c4bb58..4158a3a36f 100644
--- a/block.c
+++ b/block.c
@@ -975,6 +975,13 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
/* Apply cache mode options */
update_flags_from_options(&bs->open_flags, opts);
+
+ if (!bs->blk && (bs->open_flags & BDRV_O_CACHE_WB) == 0) {
+ error_setg(errp, "Can't set writethrough mode except for the root");
+ ret = -EINVAL;
+ goto free_and_fail;
+ }
+
bdrv_set_enable_write_cache(bs, bs->open_flags & BDRV_O_CACHE_WB);
/* Open the image, either directly or using a protocol */
diff --git a/blockdev.c b/blockdev.c
index 91a21eb0b8..d8e3e31975 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1773,6 +1773,12 @@ static void external_snapshot_prepare(BlkActionState *common,
flags |= BDRV_O_NO_BACKING;
}
+ /* There is no BB attached during bdrv_open(), so we can't set a
+ * writethrough mode. bdrv_append() will swap the WCE setting so that the
+ * backing file becomes unconditionally writeback (which is what backing
+ * files should always be) and the new overlay gets the original setting. */
+ flags |= BDRV_O_CACHE_WB;
+
assert(state->new_bs == NULL);
ret = bdrv_open(&state->new_bs, new_image_file, snapshot_ref, options,
flags, errp);
@@ -2517,6 +2523,7 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
BlockBackend *blk;
BlockDriverState *medium_bs = NULL;
int bdrv_flags, ret;
+ bool writethrough;
QDict *options = NULL;
Error *err = NULL;
@@ -2535,6 +2542,12 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
bdrv_flags &= ~(BDRV_O_TEMPORARY | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING |
BDRV_O_PROTOCOL);
+ /* Must open the image in writeback mode as long as no BlockBackend is
+ * attached. The right mode can be set as the final step after changing the
+ * medium. */
+ writethrough = !(bdrv_flags & BDRV_O_CACHE_WB);
+ bdrv_flags |= BDRV_O_CACHE_WB;
+
if (!has_read_only) {
read_only = BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN;
}
@@ -2592,6 +2605,8 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
goto fail;
}
+ bdrv_set_enable_write_cache(medium_bs, !writethrough);
+
qmp_blockdev_close_tray(device, errp);
fail:
@@ -3217,7 +3232,7 @@ static void do_drive_backup(const char *device, const char *target,
goto out;
}
- flags = bs->open_flags | BDRV_O_RDWR;
+ flags = bs->open_flags | BDRV_O_CACHE_WB | BDRV_O_RDWR;
/* See if we have a backing HD we can use to create our new image
* on top of. */
@@ -3512,7 +3527,7 @@ void qmp_drive_mirror(const char *device, const char *target,
format = mode == NEW_IMAGE_MODE_EXISTING ? NULL : bs->drv->format_name;
}
- flags = bs->open_flags | BDRV_O_RDWR;
+ flags = bs->open_flags | BDRV_O_CACHE_WB | BDRV_O_RDWR;
source = backing_bs(bs);
if (!source && sync == MIRROR_SYNC_MODE_TOP) {
sync = MIRROR_SYNC_MODE_FULL;
diff --git a/tests/qemu-iotests/142 b/tests/qemu-iotests/142
index 8aa50f8d71..80834b5d8f 100755
--- a/tests/qemu-iotests/142
+++ b/tests/qemu-iotests/142
@@ -96,36 +96,36 @@ function check_cache_all()
# bs->backing
echo -e "cache.direct=on on none0"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.direct=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
echo -e "\ncache.direct=on on file"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.direct=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
echo -e "\ncache.direct=on on backing"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.direct=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
echo -e "\ncache.direct=on on backing-file"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.direct=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.direct=on | grep -e "Cache" -e "[Cc]annot|[Cc]ould not|[Cc]an't"
# cache.writeback is supposed to be inherited by bs->backing; bs->file
# always gets cache.writeback=on
echo -e "\n\ncache.writeback=off on none0"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.writeback=off | grep "Cache"
+ echo "$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","$ids",file.cache.writeback=off | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.writeback=off on backing"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.writeback=off | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.writeback=off on backing-file"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.writeback=off | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
# cache.no-flush is supposed to be inherited by both bs->file and bs->backing
echo -e "\n\ncache.no-flush=on on none0"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.no-flush=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.no-flush=on on file"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.no-flush=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",file.cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.no-flush=on on backing"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.no-flush=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.no-flush=on on backing-file"
- echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.no-flush=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$files","$ids",backing.file.cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
}
echo
@@ -218,7 +218,7 @@ info block image
info block blkdebug
info block file"
-echo "$hmp_cmds" | run_qemu -drive if=none,file="blkdebug::json:{\"filename\":\"$TEST_IMG\",,\"cache\":{\"writeback\":false,,\"direct\":false}}",node-name=image,file.node-name=blkdebug,file.image.node-name=file | grep "Cache"
+echo "$hmp_cmds" | run_qemu -drive if=none,file="blkdebug::json:{\"filename\":\"$TEST_IMG\",,\"cache\":{\"direct\":false}}",node-name=image,file.node-name=blkdebug,file.image.node-name=file | grep "Cache"
echo
echo "=== Check that referenced BDSes don't inherit ==="
@@ -234,35 +234,35 @@ function check_cache_all_separate()
# Check cache.direct
echo -e "cache.direct=on on blk"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.direct=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.direct=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.direct=on on file"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.direct=on -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.direct=on -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.direct=on on backing"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.direct=on -drive "$drv_file" -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.direct=on -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.direct=on on backing-file"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.direct=on -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.direct=on -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
# Check cache.writeback
echo -e "\n\ncache.writeback=off on blk"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.writeback=off | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.writeback=off | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.writeback=off on file"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.writeback=off -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.writeback=off -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.writeback=off on backing"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.writeback=off -drive "$drv_file" -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.writeback=off -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.writeback=off on backing-file"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.writeback=off -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.writeback=off -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
# Check cache.no-flush
echo -e "\n\ncache.no-flush=on on blk"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.no-flush=on | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img",cache.no-flush=on | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.no-flush=on on file"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.no-flush=on -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk" -drive "$drv_file",cache.no-flush=on -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.no-flush=on on backing"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.no-flush=on -drive "$drv_file" -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile" -drive "$drv_bk",cache.no-flush=on -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
echo -e "\ncache.no-flush=on on backing-file"
- echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.no-flush=on -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep "Cache"
+ echo "$hmp_cmds" | run_qemu -drive "$drv_bkfile",cache.no-flush=on -drive "$drv_bk" -drive "$drv_file" -drive "$drv_img" | grep -e "Cache" -e "[Cc]annot\|[Cc]ould not\|[Cc]an't"
}
echo
diff --git a/tests/qemu-iotests/142.out b/tests/qemu-iotests/142.out
index abe94c3320..5dd5bd0cd4 100644
--- a/tests/qemu-iotests/142.out
+++ b/tests/qemu-iotests/142.out
@@ -66,22 +66,13 @@ cache.writeback=off on none0
Cache mode: writeback
cache.writeback=off on file
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback
- Cache mode: writeback
+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
cache.writeback=off on backing
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback
+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
cache.writeback=off on backing-file
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
+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
cache.no-flush=on on none0
@@ -147,25 +138,13 @@ cache.writeback=off on none0
Cache mode: writeback
cache.writeback=off on file
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback
- Cache mode: writeback
+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
cache.writeback=off on backing
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback
+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
cache.writeback=off on backing-file
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
+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
cache.no-flush=on on none0
@@ -230,22 +209,13 @@ cache.writeback=off on none0
Cache mode: writeback, direct
cache.writeback=off on file
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
- Cache mode: writeback, direct
- Cache mode: writeback, direct
+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
cache.writeback=off on backing
- Cache mode: writeback, direct
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
- Cache mode: writeback, direct
+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
cache.writeback=off on backing-file
- Cache mode: writeback, direct
- Cache mode: writeback, direct
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
+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
cache.no-flush=on on none0
@@ -306,22 +276,13 @@ cache.writeback=off on none0
Cache mode: writeback, direct
cache.writeback=off on file
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
- Cache mode: writeback, direct
- Cache mode: writeback, direct
+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
cache.writeback=off on backing
- Cache mode: writeback, direct
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
- Cache mode: writeback, direct
+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
cache.writeback=off on backing-file
- Cache mode: writeback, direct
- Cache mode: writeback, direct
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
+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
cache.no-flush=on on none0
@@ -387,25 +348,13 @@ cache.writeback=off on none0
Cache mode: writeback
cache.writeback=off on file
- Cache mode: writeback, direct
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback
- Cache mode: writeback
+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
cache.writeback=off on backing
- Cache mode: writeback, direct
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback
+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
cache.writeback=off on backing-file
- Cache mode: writeback, direct
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough
+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
cache.no-flush=on on none0
@@ -440,7 +389,7 @@ cache.no-flush=on on backing-file
Cache mode: writethrough, direct, ignore flushes
Cache mode: writeback, direct, ignore flushes
- Cache mode: writethrough, ignore flushes
+ Cache mode: writeback, ignore flushes
=== Check that referenced BDSes don't inherit ===
@@ -722,22 +671,13 @@ cache.writeback=off on none0
Cache mode: writeback, direct
cache.writeback=off on file
- Cache mode: writeback
- Cache mode: writethrough
- Cache mode: writeback, direct
- Cache mode: writeback, direct
+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
cache.writeback=off on backing
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writethrough, direct
- Cache mode: writeback, direct
+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
cache.writeback=off on backing-file
- Cache mode: writeback
- Cache mode: writeback
- Cache mode: writeback, direct
- Cache mode: writethrough, direct
+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
cache.no-flush=on on none0
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-26 08:49:44 +0000