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[Qemu-block] [PATCH v4 19/38] block: Prepare remaining BB functions for
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH v4 19/38] block: Prepare remaining BB functions for NULL BDS |
Date: |
Mon, 20 Jul 2015 19:45:46 +0200 |
There are several BlockBackend functions which, in theory, cannot fail.
This patch makes them cope with the BlockDriverState pointer being NULL
by making them fall back to some default action like ignoring the value
in setters and returning the default in getters.
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
block/block-backend.c | 76 ++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 60 insertions(+), 16 deletions(-)
diff --git a/block/block-backend.c b/block/block-backend.c
index b3ada37..99429df 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -657,7 +657,11 @@ int64_t blk_getlength(BlockBackend *blk)
void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr)
{
- bdrv_get_geometry(blk->bs, nb_sectors_ptr);
+ if (!blk->bs) {
+ *nb_sectors_ptr = 0;
+ } else {
+ bdrv_get_geometry(blk->bs, nb_sectors_ptr);
+ }
}
int64_t blk_nb_sectors(BlockBackend *blk)
@@ -889,17 +893,27 @@ int blk_is_read_only(BlockBackend *blk)
int blk_is_sg(BlockBackend *blk)
{
+ if (!blk->bs) {
+ return 0;
+ }
+
return bdrv_is_sg(blk->bs);
}
int blk_enable_write_cache(BlockBackend *blk)
{
+ if (!blk->bs) {
+ return 0;
+ }
+
return bdrv_enable_write_cache(blk->bs);
}
void blk_set_enable_write_cache(BlockBackend *blk, bool wce)
{
- bdrv_set_enable_write_cache(blk->bs, wce);
+ if (blk->bs) {
+ bdrv_set_enable_write_cache(blk->bs, wce);
+ }
}
void blk_invalidate_cache(BlockBackend *blk, Error **errp)
@@ -924,12 +938,16 @@ bool blk_is_available(BlockBackend *blk)
void blk_lock_medium(BlockBackend *blk, bool locked)
{
- bdrv_lock_medium(blk->bs, locked);
+ if (blk->bs) {
+ bdrv_lock_medium(blk->bs, locked);
+ }
}
void blk_eject(BlockBackend *blk, bool eject_flag)
{
- bdrv_eject(blk->bs, eject_flag);
+ if (blk->bs) {
+ bdrv_eject(blk->bs, eject_flag);
+ }
}
int blk_get_flags(BlockBackend *blk)
@@ -943,7 +961,11 @@ int blk_get_flags(BlockBackend *blk)
int blk_get_max_transfer_length(BlockBackend *blk)
{
- return blk->bs->bl.max_transfer_length;
+ if (blk->bs) {
+ return blk->bs->bl.max_transfer_length;
+ } else {
+ return 0;
+ }
}
void blk_set_guest_block_size(BlockBackend *blk, int align)
@@ -958,22 +980,32 @@ void *blk_blockalign(BlockBackend *blk, size_t size)
bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp)
{
+ if (!blk->bs) {
+ return false;
+ }
+
return bdrv_op_is_blocked(blk->bs, op, errp);
}
void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason)
{
- bdrv_op_unblock(blk->bs, op, reason);
+ if (blk->bs) {
+ bdrv_op_unblock(blk->bs, op, reason);
+ }
}
void blk_op_block_all(BlockBackend *blk, Error *reason)
{
- bdrv_op_block_all(blk->bs, reason);
+ if (blk->bs) {
+ bdrv_op_block_all(blk->bs, reason);
+ }
}
void blk_op_unblock_all(BlockBackend *blk, Error *reason)
{
- bdrv_op_unblock_all(blk->bs, reason);
+ if (blk->bs) {
+ bdrv_op_unblock_all(blk->bs, reason);
+ }
}
AioContext *blk_get_aio_context(BlockBackend *blk)
@@ -993,15 +1025,19 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB
*acb)
void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
{
- bdrv_set_aio_context(blk->bs, new_context);
+ if (blk->bs) {
+ bdrv_set_aio_context(blk->bs, new_context);
+ }
}
void blk_add_aio_context_notifier(BlockBackend *blk,
void (*attached_aio_context)(AioContext *new_context, void *opaque),
void (*detach_aio_context)(void *opaque), void *opaque)
{
- bdrv_add_aio_context_notifier(blk->bs, attached_aio_context,
- detach_aio_context, opaque);
+ if (blk->bs) {
+ bdrv_add_aio_context_notifier(blk->bs, attached_aio_context,
+ detach_aio_context, opaque);
+ }
}
void blk_remove_aio_context_notifier(BlockBackend *blk,
@@ -1010,23 +1046,31 @@ void blk_remove_aio_context_notifier(BlockBackend *blk,
void (*detach_aio_context)(void *),
void *opaque)
{
- bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context,
- detach_aio_context, opaque);
+ if (blk->bs) {
+ bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context,
+ detach_aio_context, opaque);
+ }
}
void blk_add_close_notifier(BlockBackend *blk, Notifier *notify)
{
- bdrv_add_close_notifier(blk->bs, notify);
+ if (blk->bs) {
+ bdrv_add_close_notifier(blk->bs, notify);
+ }
}
void blk_io_plug(BlockBackend *blk)
{
- bdrv_io_plug(blk->bs);
+ if (blk->bs) {
+ bdrv_io_plug(blk->bs);
+ }
}
void blk_io_unplug(BlockBackend *blk)
{
- bdrv_io_unplug(blk->bs);
+ if (blk->bs) {
+ bdrv_io_unplug(blk->bs);
+ }
}
BlockAcctStats *blk_get_stats(BlockBackend *blk)
--
2.4.6
- [Qemu-block] [PATCH v4 27/38] blockdev: Add blockdev-close-tray, (continued)
- [Qemu-block] [PATCH v4 27/38] blockdev: Add blockdev-close-tray, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 26/38] blockdev: Add blockdev-open-tray, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 28/38] blockdev: Add blockdev-remove-medium, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 29/38] blockdev: Add blockdev-insert-medium, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 33/38] qmp: Introduce blockdev-change-medium, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 35/38] blockdev: read-only-mode for blockdev-change-medium, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 37/38] iotests: More options for VM.add_drive(), Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 34/38] hmp: Use blockdev-change-medium for change command, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 30/38] blockdev: Implement eject with basic operations, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 32/38] block: Inquire tray state before tray-moved events, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 19/38] block: Prepare remaining BB functions for NULL BDS,
Max Reitz <=
- [Qemu-block] [PATCH v4 36/38] hmp: Add read-only-mode option to change command, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 31/38] blockdev: Implement change with basic operations, Max Reitz, 2015/07/20
- [Qemu-block] [PATCH v4 38/38] iotests: Add test for change-related QMP commands, Max Reitz, 2015/07/20