block: Make backing files child_of_bds children

Make all parents of backing files pass the appropriate BdrvChildRole.
By doing so, we can switch their BdrvChildClass over to the generic
child_of_bds

block: Make backing files child_of_bds children

Make all parents of backing files pass the appropriate BdrvChildRole.
By doing so, we can switch their BdrvChildClass over to the generic
child_of_bds, which will do the right thing when given a correct
BdrvChildRole.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513110544.176672-24-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Pass parent_is_format to .inherit_options()

We plan to unify the generic .inherit_options() functions. The
resulting common function will need to decide whether to force-enable
format probin

block: Pass parent_is_format to .inherit_options()

We plan to unify the generic .inherit_options() functions. The
resulting common function will need to decide whether to force-enable
format probing, force-disable it, or leave it as-is. To make this
decision, it will need to know whether the parent node is a format node
or not (because we never want format probing if the parent is a format
node already (except for the backing chain)).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-9-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Pass BdrvChildRole to .inherit_options()

For now, all callers (effectively) pass 0 and no callee evaluates thie
value. Later patches will change both.

Signed-off-by: Max Reitz <mreitz@redha

block: Pass BdrvChildRole to .inherit_options()

For now, all callers (effectively) pass 0 and no callee evaluates thie
value. Later patches will change both.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-8-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Pass BdrvChildRole to bdrv_child_perm()

For now, all callers pass 0 and no callee evaluates this value. Later
patches will change both.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed

block: Pass BdrvChildRole to bdrv_child_perm()

For now, all callers pass 0 and no callee evaluates this value. Later
patches will change both.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-7-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Add BdrvChildRole to BdrvChild

For now, it is always set to 0. Later patches in this series will
ensure that all callers pass an appropriate combination of flags.

Signed-off-by: Max Reitz <

block: Add BdrvChildRole to BdrvChild

For now, it is always set to 0. Later patches in this series will
ensure that all callers pass an appropriate combination of flags.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Rename BdrvChildRole to BdrvChildClass

This structure nearly only contains parent callbacks for child state
changes. It cannot really reflect a child's role, because different
roles may over

block: Rename BdrvChildRole to BdrvChildClass

This structure nearly only contains parent callbacks for child state
changes. It cannot really reflect a child's role, because different
roles may overlap (as we will see when real roles are introduced), and
because parents can have custom callbacks even when the child fulfills a
standard role.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200513110544.176672-4-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Use bdrv_make_empty() where possible

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <202004291

block: Use bdrv_make_empty() where possible

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200429141126.85159-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Comment cleanups

It's been a while since we got rid of the sector-based bdrv_read and
bdrv_write (commit 2e11d756); let's finish the job on a few remaining
comments.

Signed-off-by: Eric Blak

block: Comment cleanups

It's been a while since we got rid of the sector-based bdrv_read and
bdrv_write (commit 2e11d756); let's finish the job on a few remaining
comments.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428213807.776655-1-eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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block/vvfat: Do not unref qcow on closing backing bdrv

Before this commit, BDRVVVFATState.qcow is unrefed in write_target_close
on closing backing bdrv of vvfat. However, qcow bdrv is opend as a chi

block/vvfat: Do not unref qcow on closing backing bdrv

Before this commit, BDRVVVFATState.qcow is unrefed in write_target_close
on closing backing bdrv of vvfat. However, qcow bdrv is opend as a child
of vvfat in enable_write_target() so it will be also unrefed on closing
vvfat itself. This causes use-after-free of qcow on freeing vvfat which
has backing bdrv and qcow bdrv as children in this order because
bdrv_close(vvfat) tries to free qcow bdrv after freeing backing bdrv
as QLIST_FOREACH_SAFE() loop keeps next pointer, but BdrvChild of qcow
is already freed in bdrv_close(backing bdrv).

Signed-off-by: Hikaru Nishida <hikarupsp@gmail.com>
Message-Id: <20200209175156.85748-1-hikarupsp@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Use QEMU_IS_ALIGNED

Replace instances of:

(n & (BDRV_SECTOR_SIZE - 1)) == 0

And:

(n & ~BDRV_SECTOR_MASK) == 0

With:

QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)

Which reveals the int

block: Use QEMU_IS_ALIGNED

Replace instances of:

(n & (BDRV_SECTOR_SIZE - 1)) == 0

And:

(n & ~BDRV_SECTOR_MASK) == 0

With:

QEMU_IS_ALIGNED(n, BDRV_SECTOR_SIZE)

Which reveals the intent of the code better, and makes it easier to
locate the code checking alignment.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827185913.27427-2-nsoffer@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

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qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-3-armbru@redhat.com>
Reviewed-by: Richard Henderson <rich

qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-3-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

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vvfat: Replace bdrv_{read,write}() with bdrv_{pread,pwrite}()

There's only a couple of bdrv_read() and bdrv_write() calls left in
the vvfat code, and they can be trivially replaced with the byte-bas

vvfat: Replace bdrv_{read,write}() with bdrv_{pread,pwrite}()

There's only a couple of bdrv_read() and bdrv_write() calls left in
the vvfat code, and they can be trivially replaced with the byte-based
bdrv_pread() and bdrv_pwrite().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: Add strong_runtime_opts to BlockDriver

This new field can be set by block drivers to list the runtime options
they accept that may influence the contents of the respective BDS. As of
a follow

block: Add strong_runtime_opts to BlockDriver

This new field can be set by block drivers to list the runtime options
they accept that may influence the contents of the respective BDS. As of
a follow-up patch, this list will be used by the common
bdrv_refresh_filename() implementation to decide which options to put
into BDS.full_open_options (and consequently whether a JSON filename has
to be created), thus freeing the drivers of having to implement that
logic themselves.

Additionally, this patch adds the field to all of the block drivers that
need it and sets it accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-22-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

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vvfat: Fix memory leak

Don't leak 'cluster' in the mapping == NULL case. Found by Coverity
(CID 1055918).

Fixes: 8d9401c2791ee2d2805b741b1ee3006041edcd3e
Signed-off-by: Kevin Wolf <kwolf@redhat.com

vvfat: Fix memory leak

Don't leak 'cluster' in the mapping == NULL case. Found by Coverity
(CID 1055918).

Fixes: 8d9401c2791ee2d2805b741b1ee3006041edcd3e
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

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block: Fix potential Null pointer dereferences in vvfat.c

The calls to find_mapping_for_cluster() may return NULL but it
isn't always checked for before dereferencing the value returned.
Additionall

block: Fix potential Null pointer dereferences in vvfat.c

The calls to find_mapping_for_cluster() may return NULL but it
isn't always checked for before dereferencing the value returned.
Additionally, add some asserts to cover cases where NULL can't
be returned but which might not be obvious at first glance.

Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
Message-id: 1541453919-25973-5-git-send-email-Liam.Merwick@oracle.com
[mreitz: Dropped superfluous check of "mapping" following an assertion
that it is not NULL, and fixed some indentation]
Signed-off-by: Max Reitz <mreitz@redhat.com>

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block: Require auto-read-only for existing fallbacks

Some block drivers have traditionally changed their node to read-only
mode without asking the user. This behaviour has been marked deprecated
sin

block: Require auto-read-only for existing fallbacks

Some block drivers have traditionally changed their node to read-only
mode without asking the user. This behaviour has been marked deprecated
since 2.11, expecting users to provide an explicit read-only=on option.

Now that we have auto-read-only=on, enable these drivers to make use of
the option.

This is the only use of bdrv_set_read_only(), so we can make it a bit
more specific and turn it into a bdrv_apply_auto_read_only() that is
more convenient for drivers to use.

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

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block: Add auto-read-only option

If a management application builds the block graph node by node, the
protocol layer doesn't inherit its read-only option from the format
layer any more, so it must b

block: Add auto-read-only option

If a management application builds the block graph node by node, the
protocol layer doesn't inherit its read-only option from the format
layer any more, so it must be set explicitly.

Backing files should work on read-only storage, but at the same time, a
block job like commit should be able to reopen them read-write if they
are on read-write storage. However, without option inheritance, reopen
only changes the read-only option for the root node (typically the
format layer), but not the protocol layer, so reopening fails (the
format layer wants to get write permissions, but the protocol layer is
still read-only).

A simple workaround for the problem in the management tool would be to
open the protocol layer always read-write and to make only the format
layer read-only for backing files. However, sometimes the file is
actually stored on read-only storage and we don't know whether the image
can be opened read-write (for example, for NBD it depends on the server
we're trying to connect to). This adds an option that makes QEMU try to
open the image read-write, but allows it to degrade to a read-only mode
without returning an error.

The documentation for this option is consciously phrased in a way that
allows QEMU to switch to a better model eventually: Instead of trying
when the image is first opened, making the read-only flag dynamic and
changing it automatically whenever the first BLK_PERM_WRITE user is
attached or the last one is detached would be much more useful
behaviour.

Unfortunately, this more useful behaviour is also a lot harder to
implement, and libvirt needs a solution now before it can switch to
-blockdev, so let's start with this easier approach for now.

Instead of adding a new auto-read-only option, turning the existing
read-only into an enum (with a bool alternate for compatibility) was
considered, but it complicated the implementation to the point that it
didn't seem to be worth it.

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

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block/vvfat: Fix crash when reporting error about too many files in directory

When using the vvfat driver with a directory that contains too many files,
QEMU currently crashes. This can be triggered

block/vvfat: Fix crash when reporting error about too many files in directory

When using the vvfat driver with a directory that contains too many files,
QEMU currently crashes. This can be triggered like this for example:

mkdir /tmp/vvfattest
cd /tmp/vvfattest
for ((x=0;x<=513;x++)); do mkdir $x; done
qemu-system-x86_64 -drive \
file.driver=vvfat,file.dir=.,read-only=on,media=cdrom

Seems like read_directory() is changing the mapping->path variable. Make
sure we use the right pointer instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block/vvfat: Disable debug message by default

It's annoying to see this debug message every time you use vvfat.
Disable it with the DLOG() macro by default, as it is done with the
other debug messag

block/vvfat: Disable debug message by default

It's annoying to see this debug message every time you use vvfat.
Disable it with the DLOG() macro by default, as it is done with the
other debug messages in this file.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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block: ignore_bds_parents parameter for drain functions

In the future, bdrv_drained_all_begin/end() will drain all invidiual
nodes separately rather than whole subtrees. This means that we don't
wan

block: ignore_bds_parents parameter for drain functions

In the future, bdrv_drained_all_begin/end() will drain all invidiual
nodes separately rather than whole subtrees. This means that we don't
want to propagate the drain to all parents any more: If the parent is a
BDS, it will already be drained separately. Recursing to all parents is
unnecessary work and would make it an O(n²) operation.

Prepare the drain function for the changed drain_all by adding an
ignore_bds_parents parameter to the internal implementation that
prevents the propagation of the drain to BDS parents. We still (have to)
propagate it to non-BDS parents like BlockBackends or Jobs because those
are not drained separately.

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

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block: Add block-specific QDict header

There are numerous QDict functions that have been introduced for and are
used only by the block layer. Move their declarations into an own
header file to refl

block: Add block-specific QDict header

There are numerous QDict functions that have been introduced for and are
used only by the block layer. Move their declarations into an own
header file to reflect that.

While qdict_extract_subqdict() is in fact used outside of the block
layer (in util/qemu-config.c), it is still a function related very
closely to how the block layer works with nested QDicts, namely by
sometimes flattening them. Therefore, its declaration is put into this
header as well and util/qemu-config.c includes it with a comment stating
exactly which function it needs.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20180509165530.29561-7-mreitz@redhat.com>
[Copyright note tweaked, superfluous includes dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF

Now that we can safely call QOBJECT() on QObject * as well as its
subtypes, we can have macros qobject_ref() / qobject_unref() that wor

qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF

Now that we can safely call QOBJECT() on QObject * as well as its
subtypes, we can have macros qobject_ref() / qobject_unref() that work
everywhere instead of having to use QINCREF() / QDECREF() for QObject
and qobject_incref() / qobject_decref() for its subtypes.

The replacement is mechanical, except I broke a long line, and added a
cast in monitor_qmp_cleanup_req_queue_locked(). Unlike
qobject_decref(), qobject_unref() doesn't accept void *.

Note that the new macros evaluate their argument exactly once, thus no
need to shout them.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180419150145.24795-4-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, semantic conflict resolved, commit message improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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vvfat: Fix inherit_options flags

Overriding flags violates the precedence rules of
bdrv_reopen_queue_child. Just like the read-only option, no-flush should
be put into the options. The same is done

vvfat: Fix inherit_options flags

Overriding flags violates the precedence rules of
bdrv_reopen_queue_child. Just like the read-only option, no-flush should
be put into the options. The same is done in bdrv_temp_snapshot_options.

Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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vvfat: Switch to .bdrv_co_block_status()

We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vvfat driver accordingly. Note that we
can rely on the block driv

vvfat: Switch to .bdrv_co_block_status()

We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vvfat driver accordingly. Note that we
can rely on the block driver having already clamped limits to our
block size, and simplify accordingly.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

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Move include qemu/option.h from qemu-common.h to actual users

qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add

Move include qemu/option.h from qemu-common.h to actual users

qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add it
to the places that actually need it.

While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.

This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]

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