[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v0 1/2] block: check for read-only on copy-on-read s
From: |
Denis Plotnikov |
Subject: |
[Qemu-devel] [PATCH v0 1/2] block: check for read-only on copy-on-read setting |
Date: |
Wed, 13 Jun 2018 18:47:10 +0300 |
We should always check whether block device is in the
read-only state before enabling copy-on-read.
The patch embeds the check in the copy-on-read setter.
Signed-off-by: Denis Plotnikov <address@hidden>
---
block.c | 4 +---
block/io.c | 10 ++++++++--
block/stream.c | 5 +++--
include/block/block.h | 2 +-
4 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/block.c b/block.c
index 50887087f3..e73fccd397 100644
--- a/block.c
+++ b/block.c
@@ -1370,9 +1370,7 @@ static int bdrv_open_common(BlockDriverState *bs,
BlockBackend *file,
assert(atomic_read(&bs->copy_on_read) == 0);
if (bs->open_flags & BDRV_O_COPY_ON_READ) {
- if (!bs->read_only) {
- bdrv_enable_copy_on_read(bs);
- } else {
+ if (!bdrv_enable_copy_on_read(bs)) {
error_setg(errp, "Can't use copy-on-read on read-only device");
ret = -EINVAL;
goto fail_opts;
diff --git a/block/io.c b/block/io.c
index b7beaeeb9f..6ec008dbdc 100644
--- a/block/io.c
+++ b/block/io.c
@@ -131,9 +131,15 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error
**errp)
* use the feature without worrying about clobbering its previous state.
* Copy-on-read stays enabled until all users have called to disable it.
*/
-void bdrv_enable_copy_on_read(BlockDriverState *bs)
+bool bdrv_enable_copy_on_read(BlockDriverState *bs)
{
- atomic_inc(&bs->copy_on_read);
+ if (bs->read_only) {
+ return false;
+ } else {
+ atomic_inc(&bs->copy_on_read);
+ }
+
+ return true;
}
void bdrv_disable_copy_on_read(BlockDriverState *bs)
diff --git a/block/stream.c b/block/stream.c
index 9264b68a1e..033e24f22c 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -130,8 +130,9 @@ static void coroutine_fn stream_run(void *opaque)
* backing chain since the copy-on-read operation does not take base into
* account.
*/
- if (!base) {
- bdrv_enable_copy_on_read(bs);
+ if (!base && !bdrv_enable_copy_on_read(bs)) {
+ ret = -EPERM;
+ goto out;
}
for ( ; offset < len; offset += n) {
diff --git a/include/block/block.h b/include/block/block.h
index e677080c4e..dddfd032f9 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -490,7 +490,7 @@ void *qemu_try_blockalign(BlockDriverState *bs, size_t
size);
void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
-void bdrv_enable_copy_on_read(BlockDriverState *bs);
+bool bdrv_enable_copy_on_read(BlockDriverState *bs);
void bdrv_disable_copy_on_read(BlockDriverState *bs);
void bdrv_ref(BlockDriverState *bs);
--
2.17.0
[Qemu-devel] [PATCH v0 1/2] block: check for read-only on copy-on-read setting,
Denis Plotnikov <=