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[Qemu-devel] [PATCH v2 17/37] block: Prepare remaining BB functions for
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH v2 17/37] block: Prepare remaining BB functions for NULL BDS |
Date: |
Mon, 9 Feb 2015 12:11:17 -0500 |
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>
---
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 524cf59..c3418f7 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -644,7 +644,11 @@ 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)
@@ -871,17 +875,27 @@ 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)
@@ -906,12 +920,16 @@ 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)
@@ -925,7 +943,11 @@ 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)
@@ -940,22 +962,32 @@ 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)
@@ -975,15 +1007,19 @@ 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,
@@ -992,23 +1028,31 @@ 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)
--
2.1.0
- Re: [Qemu-devel] [PATCH v2 01/37] blockdev: Allow creation of BDS trees without BB, (continued)
- [Qemu-devel] [PATCH v2 03/37] hw/block/fdc: Implement tray status, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 02/37] iotests: Only create BB if necessary, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 08/37] block: Make bdrv_is_inserted() recursive, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 10/37] block: Move guest_block_size into BlockBackend, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 09/37] block/quorum: Implement bdrv_is_inserted(), Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 11/37] block: Remove wr_highest_sector from BlockAcctStats, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 17/37] block: Prepare remaining BB functions for NULL BDS,
Max Reitz <=
- [Qemu-devel] [PATCH v2 14/37] block: Add BlockBackendRootState, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 18/37] blockdev: Use BB for blockdev-backup transaction, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 16/37] block: Fail requests to empty BlockBackend, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 13/37] block: Move I/O status and error actions into BB, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 15/37] block: Make some BB functions fall back to BBRS, Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 19/37] block: Add blk_insert_bs(), Max Reitz, 2015/02/09
- [Qemu-devel] [PATCH v2 21/37] blockdev: Do not create BDS for empty drive, Max Reitz, 2015/02/09