block: Mark bdrv_first_blk() and bdrv_is_root_node() GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_first_blk() and bdrv_is_root_node() need to hold a reader lock
fo

block: Mark bdrv_first_blk() and bdrv_is_root_node() GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_first_blk() and bdrv_is_root_node() need to hold a reader lock
for the graph. These functions are the only functions in block-backend.c
that access the parent list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-5-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Mark bdrv_parent_perms_conflict() and callers GRAPH_RDLOCK

The function reads the parents list, so it needs to hold the graph lock.

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

block: Mark bdrv_parent_perms_conflict() and callers GRAPH_RDLOCK

The function reads the parents list, so it needs to hold the graph lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20230911094620.45040-14-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: add blk_in_drain() API

The BlockBackend quiesce_counter is greater than zero during drained
sections. Add an API to check whether the BlockBackend is in a drained
section.

The next patch wil

block: add blk_in_drain() API

The BlockBackend quiesce_counter is greater than zero during drained
sections. Add an API to check whether the BlockBackend is in a drained
section.

The next patch will use this API.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230516190238.8401-10-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: bdrv/blk_co_unref() for calls in coroutine context

These functions must not be called in coroutine context, because they
need write access to the graph.

Cc: qemu-stable@nongnu.org
Signed-off

block: bdrv/blk_co_unref() for calls in coroutine context

These functions must not be called in coroutine context, because they
need write access to the graph.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230504115750.54437-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Create no_co_wrappers for open functions

Images can't be opened in coroutine context because opening needs to
change the block graph. Add no_co_wrappers so that coroutines have a
simple way o

block: Create no_co_wrappers for open functions

Images can't be opened in coroutine context because opening needs to
change the block graph. Add no_co_wrappers so that coroutines have a
simple way of opening images in a BH instead.

At the same time, mark the wrapped functions as no_coroutine_fn.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230126172432.436111-3-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: return errors from bdrv_register_buf()

Registering an I/O buffer is only a performance optimization hint but it
is still necessary to return errors when it fails.

Later patches will need to

block: return errors from bdrv_register_buf()

Registering an I/O buffer is only a performance optimization hint but it
is still necessary to return errors when it fails.

Later patches will need to detect errors when registering buffers but an
immediate advantage is that error_report() calls are no longer needed in
block driver .bdrv_register_buf() functions.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-8-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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block: pass size to bdrv_unregister_buf()

The only implementor of bdrv_register_buf() is block/nvme.c, where the
size is not needed when unregistering a buffer. This is because
util/vfio-helpers.c c

block: pass size to bdrv_unregister_buf()

The only implementor of bdrv_register_buf() is block/nvme.c, where the
size is not needed when unregistering a buffer. This is because
util/vfio-helpers.c can look up mappings by address.

Future block drivers that implement bdrv_register_buf() may not be able
to do their job given only the buffer address. Add a size argument to
bdrv_unregister_buf().

Also document the assumptions about
bdrv_register_buf()/bdrv_unregister_buf() calls. The same <host, size>
values that were given to bdrv_register_buf() must be given to
bdrv_unregister_buf().

gcc 11.2.1 emits a spurious warning that img_bench()'s buf_size local
variable might be uninitialized, so it's necessary to silence the
compiler.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20221013185908.1297568-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

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Clean up header guards that don't match their file name

Header guard symbols should match their file name to make guard
collisions less likely.

Cleaned up with scripts/clean-header-guards.pl, follo

Clean up header guards that don't match their file name

Header guard symbols should match their file name to make guard
collisions less likely.

Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220506134911.2856099-2-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[Change to generated file ebpf/rss.bpf.skeleton.h backed out]

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include/sysemu/block-backend: split header into I/O and global state (GS) API

Similarly to the previous patches, split block-backend.h
in block-backend-io.h and block-backend-global-state.h

In addi

include/sysemu/block-backend: split header into I/O and global state (GS) API

Similarly to the previous patches, split block-backend.h
in block-backend-io.h and block-backend-global-state.h

In addition, remove "block/block.h" include as it seems
it is not necessary anymore, together with "qemu/iov.h"

block-backend-common.h contains the structures shared between
the two headers, and the functions that can't be categorized as
I/O or global state.

Assertions are added in the next patch.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220303151616.325444-8-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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