qcow2: Take locks for accessing bs->file

This updates the qcow2 code to add GRAPH_RDLOCK annotations for all
places that read bs->file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <202

qcow2: Take locks for accessing bs->file

This updates the qcow2 code to add GRAPH_RDLOCK annotations for all
places that read bs->file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-22-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: Take locks for accessing bs->file

This updates the qcow2 code to add GRAPH_RDLOCK annotations for all
places that read bs->file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <202

qcow2: Take locks for accessing bs->file

This updates the qcow2 code to add GRAPH_RDLOCK annotations for all
places that read bs->file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-22-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: keep reference on zeroize with discard-no-unref enabled

When the discard-no-unref flag is enabled, we keep the reference for
normal discard requests.
But when a discard is executed on a snaps

qcow2: keep reference on zeroize with discard-no-unref enabled

When the discard-no-unref flag is enabled, we keep the reference for
normal discard requests.
But when a discard is executed on a snapshot/qcow2 image with backing,
the discards are saved as zero clusters in the snapshot image.

When committing the snapshot to the backing file, not
discard_in_l2_slice is called but zero_in_l2_slice. Which did not had
any logic to keep the reference when discard-no-unref is enabled.

Therefor we add logic in the zero_in_l2_slice call to keep the reference
on commit.

Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1621
Signed-off-by: Jean-Louis Dupond <jean-louis@dupond.be>
Message-Id: <20231003125236.216473-2-jean-louis@dupond.be>
[hreitz: Made the documentation change more verbose, as discussed
on-list]
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

qcow2: keep reference on zeroize with discard-no-unref enabled

When the discard-no-unref flag is enabled, we keep the reference for
normal discard requests.
But when a discard is executed on a snaps

qcow2: keep reference on zeroize with discard-no-unref enabled

When the discard-no-unref flag is enabled, we keep the reference for
normal discard requests.
But when a discard is executed on a snapshot/qcow2 image with backing,
the discards are saved as zero clusters in the snapshot image.

When committing the snapshot to the backing file, not
discard_in_l2_slice is called but zero_in_l2_slice. Which did not had
any logic to keep the reference when discard-no-unref is enabled.

Therefor we add logic in the zero_in_l2_slice call to keep the reference
on commit.

Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1621
Signed-off-by: Jean-Louis Dupond <jean-louis@dupond.be>
Message-Id: <20231003125236.216473-2-jean-louis@dupond.be>
[hreitz: Made the documentation change more verbose, as discussed
on-list]
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_signal_corruption() need to hold a reader lock for the graph
becaus

qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_signal_corruption() need to hold a reader lock for the graph
because it calls bdrv_get_node_name(), which accesses the parents list
of a node.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-15-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_signal_corruption() need to hold a reader lock for the graph
becaus

qcow2: Mark qcow2_signal_corruption() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
qcow2_signal_corruption() need to hold a reader lock for the graph
because it calls bdrv_get_node_name(), which accesses the parents list
of a node.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-15-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: use bdrv_co_debug_event in coroutine context

bdrv_co_debug_event was recently introduced, with bdrv_debug_event
becoming a wrapper for use in unknown context. Because most of the
time bdrv_d

block: use bdrv_co_debug_event in coroutine context

bdrv_co_debug_event was recently introduced, with bdrv_debug_event
becoming a wrapper for use in unknown context. Because most of the
time bdrv_debug_event is used on a BdrvChild via the wrapper macro
BLKDBG_EVENT, introduce a similar macro BLKDBG_CO_EVENT that calls
bdrv_co_debug_event, and switch whenever possible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-13-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: mark more functions as coroutine_fns and GRAPH_RDLOCK

Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use

qcow2: mark more functions as coroutine_fns and GRAPH_RDLOCK

Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-11-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: use bdrv_co_debug_event in coroutine context

bdrv_co_debug_event was recently introduced, with bdrv_debug_event
becoming a wrapper for use in unknown context. Because most of the
time bdrv_d

block: use bdrv_co_debug_event in coroutine context

bdrv_co_debug_event was recently introduced, with bdrv_debug_event
becoming a wrapper for use in unknown context. Because most of the
time bdrv_debug_event is used on a BdrvChild via the wrapper macro
BLKDBG_EVENT, introduce a similar macro BLKDBG_CO_EVENT that calls
bdrv_co_debug_event, and switch whenever possible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-13-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: mark more functions as coroutine_fns and GRAPH_RDLOCK

Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use

qcow2: mark more functions as coroutine_fns and GRAPH_RDLOCK

Mark functions as coroutine_fn when they are only called by other coroutine_fns
and they can suspend. Change calls to co_wrappers to use the non-wrapped
functions, which in turn requires adding GRAPH_RDLOCK annotations.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20230601115145.196465-11-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: add discard-no-unref option

When we for example have a sparse qcow2 image and discard: unmap is enabled,
there can be a lot of fragmentation in the image after some time. Especially on VM's
t

qcow2: add discard-no-unref option

When we for example have a sparse qcow2 image and discard: unmap is enabled,
there can be a lot of fragmentation in the image after some time. Especially on VM's
that do a lot of writes/deletes.
This causes the qcow2 image to grow even over 110% of its virtual size,
because the free gaps in the image get too small to allocate new
continuous clusters. So it allocates new space at the end of the image.

Disabling discard is not an option, as discard is needed to keep the
incremental backup size as low as possible. Without discard, the
incremental backups would become large, as qemu thinks it's just dirty
blocks but it doesn't know the blocks are unneeded.
So we need to avoid fragmentation but also 'empty' the unneeded blocks in
the image to have a small incremental backup.

In addition, we also want to send the discards further down the stack, so
the underlying blocks are still discarded.

Therefor we introduce a new qcow2 option "discard-no-unref".
When setting this option to true, discards will no longer have the qcow2
driver relinquish cluster allocations. Other than that, the request is
handled as normal: All clusters in range are marked as zero, and, if
pass-discard-request is true, it is passed further down the stack.
The only difference is that the now-zero clusters are preallocated
instead of being unallocated.
This will avoid fragmentation on the qcow2 image.

Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1621
Signed-off-by: Jean-Louis Dupond <jean-louis@dupond.be>
Message-Id: <20230605084523.34134-2-jean-louis@dupond.be>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK

Functions that can do I/O (including calling bdrv_is_allocated
and bdrv_block_status functions) are prime candidates for being
coroutin

qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK

Functions that can do I/O (including calling bdrv_is_allocated
and bdrv_block_status functions) are prime candidates for being
coroutine_fns. Make the change for those that are themselves called
only from coroutine_fns. Also annotate that they are called with the
graph rdlock taken, thus allowing them to call bdrv_co_*() functions
for I/O.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20230309084456.304669-9-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK

Functions that can do I/O (including calling bdrv_is_allocated
and bdrv_block_status functions) are prime candidates for being
coroutin

qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK

Functions that can do I/O (including calling bdrv_is_allocated
and bdrv_block_status functions) are prime candidates for being
coroutine_fns. Make the change for those that are themselves called
only from coroutine_fns. Also annotate that they are called with the
graph rdlock taken, thus allowing them to call bdrv_co_*() functions
for I/O.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20230309084456.304669-9-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK

Functions that can do I/O (including calling bdrv_is_allocated
and bdrv_block_status functions) are prime candidates for being
coroutin

qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK

Functions that can do I/O (including calling bdrv_is_allocated
and bdrv_block_status functions) are prime candidates for being
coroutine_fns. Make the change for those that are themselves called
only from coroutine_fns. Also annotate that they are called with the
graph rdlock taken, thus allowing them to call bdrv_co_*() functions
for I/O.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20230309084456.304669-9-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotatio

block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotation to public functions yet.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotatio

block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotation to public functions yet.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotatio

block: Mark read/write in block/io.c GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_driver_*() need to hold a reader lock for the graph. It doesn't add
the annotation to public functions yet.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-11-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

block/block.h
-> block/block-io.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac8.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>

show more ...

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

include/block: Untangle inclusion loops

We have two inclusion loops:

block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

block/block.h
-> block/block-io.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac8.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>

show more ...

qcow2: switch to *_co_* functions

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-20-pbonzini@redhat.com>
Revie

qcow2: switch to *_co_* functions

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-20-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: manually add more coroutine_fn annotations

The validity of these was double-checked with Alberto Faria's static
analyzer.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <2022

qcow2: manually add more coroutine_fn annotations

The validity of these was double-checked with Alberto Faria's static
analyzer.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-13-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

qcow2: switch to *_co_* functions

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-20-pbonzini@redhat.com>
Revie

qcow2: switch to *_co_* functions

Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-20-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...