block: Protect bs->file with graph_lock

Almost all functions that access bs->file already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as

block: Protect bs->file with graph_lock

Almost all functions that access bs->file already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as protected by the graph lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-25-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't ho

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't hold the graph lock while calling it), and afterwards many
operations that require holding the graph lock, e.g. for accessing
bs->file.

This changes block drivers that follow this pattern to take the graph
lock after opening the child node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-24-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Add missing GRAPH_RDLOCK annotations

This adds GRAPH_RDLOCK to some driver callbacks that are already called
with the graph lock held, and which will need the annotation because
they access b

block: Add missing GRAPH_RDLOCK annotations

This adds GRAPH_RDLOCK to some driver callbacks that are already called
with the graph lock held, and which will need the annotation because
they access bs->file, but don't have it yet.

This also covers a few callbacks that were not marked GRAPH_RDLOCK
before, but where updating BlockDriver is trivially possible.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-21-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Protect bs->file with graph_lock

Almost all functions that access bs->file already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as

block: Protect bs->file with graph_lock

Almost all functions that access bs->file already take the graph
lock now. Add locking to the remaining users and finally annotate the
struct field itself as protected by the graph lock.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-25-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't ho

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't hold the graph lock while calling it), and afterwards many
operations that require holding the graph lock, e.g. for accessing
bs->file.

This changes block drivers that follow this pattern to take the graph
lock after opening the child node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-24-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Add missing GRAPH_RDLOCK annotations

This adds GRAPH_RDLOCK to some driver callbacks that are already called
with the graph lock held, and which will need the annotation because
they access b

block: Add missing GRAPH_RDLOCK annotations

This adds GRAPH_RDLOCK to some driver callbacks that are already called
with the graph lock held, and which will need the annotation because
they access bs->file, but don't have it yet.

This also covers a few callbacks that were not marked GRAPH_RDLOCK
before, but where updating BlockDriver is trivially possible.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-21-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

cpr: relax blockdev migration blockers

Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the ol

cpr: relax blockdev migration blockers

Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the old and new qemu processes do not run concurrently, and if new qemu
starts on the same host as old, which is the case for cpr. Narrow the scope
of these blockers so they only apply to normal mode. They will not block
cpr modes when they are added in subsequent patches.

No functional change until a new mode is added.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1698263069-406971-4-git-send-email-steven.sistare@oracle.com>

show more ...

cpr: relax blockdev migration blockers

Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the ol

cpr: relax blockdev migration blockers

Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the old and new qemu processes do not run concurrently, and if new qemu
starts on the same host as old, which is the case for cpr. Narrow the scope
of these blockers so they only apply to normal mode. They will not block
cpr modes when they are added in subsequent patches.

No functional change until a new mode is added.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1698263069-406971-4-git-send-email-steven.sistare@oracle.com>

show more ...

cpr: relax blockdev migration blockers

Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the ol

cpr: relax blockdev migration blockers

Some blockdevs block migration because they do not support sharing across
hosts and/or do not support dirty bitmaps. These prohibitions do not apply
if the old and new qemu processes do not run concurrently, and if new qemu
starts on the same host as old, which is the case for cpr. Narrow the scope
of these blockers so they only apply to normal mode. They will not block
cpr modes when they are added in subsequent patches.

No functional change until a new mode is added.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1698263069-406971-4-git-send-email-steven.sistare@oracle.com>

show more ...

migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_

migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code. It also simplifies
the migrate_del_blocker call site.

In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode. A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.

No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>

show more ...

migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_

migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code. It also simplifies
the migrate_del_blocker call site.

In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode. A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.

No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>

show more ...

migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_

migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason. This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code. It also simplifies
the migrate_del_blocker call site.

In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode. A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.

No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>

show more ...

block: Mark bdrv_get_parent_name() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it a

block: Mark bdrv_get_parent_name() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it 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: <20230929145157.45443-13-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_get_parent_name() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it a

block: Mark bdrv_get_parent_name() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it 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: <20230929145157.45443-13-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

parallels: naive implementation of parallels_co_pwrite_zeroes

The zero flag is missed in the Parallels format specification. We can
resort to discard if we have no backing file.

Signed-off-by: Deni

parallels: naive implementation of parallels_co_pwrite_zeroes

The zero flag is missed in the Parallels format specification. We can
resort to discard if we have no backing file.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: naive implementation of parallels_co_pdiscard

* Discarding with backing stores is not supported by the format.
* There is no buffering/queueing of the discard operation.
* Only operations

parallels: naive implementation of parallels_co_pdiscard

* Discarding with backing stores is not supported by the format.
* There is no buffering/queueing of the discard operation.
* Only operations aligned to the cluster are supported.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: improve readability of allocate_clusters

Replace 'space' representing the amount of data to preallocate with
'bytes'.

Rationale:
* 'space' at each place is converted to bytes
* the unit

parallels: improve readability of allocate_clusters

Replace 'space' representing the amount of data to preallocate with
'bytes'.

Rationale:
* 'space' at each place is converted to bytes
* the unit is more close to the variable name

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: naive implementation of allocate_clusters with used bitmap

The access to the bitmap is not optimized completely.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Iva

parallels: naive implementation of allocate_clusters with used bitmap

The access to the bitmap is not optimized completely.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: update used bitmap in allocate_cluster

We should extend the bitmap if the file is extended and set the bit in
the image used bitmap once the cluster is allocated. Sanity check at
that mom

parallels: update used bitmap in allocate_cluster

We should extend the bitmap if the file is extended and set the bit in
the image used bitmap once the cluster is allocated. Sanity check at
that moment also looks like a good idea.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: accept multiple clusters in mark_used()

This would be useful in the next patch in allocate_clusters(). This
change would not imply serious performance drawbacks as usually image
is full o

parallels: accept multiple clusters in mark_used()

This would be useful in the next patch in allocate_clusters(). This
change would not imply serious performance drawbacks as usually image
is full of data or are at the end of the bitmap.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: collect bitmap of used clusters at open

If the operation is failed, we need to check image consistency if the
problem is not about memory allocation.

Bitmap adjustments in allocate_clust

parallels: collect bitmap of used clusters at open

If the operation is failed, we need to check image consistency if the
problem is not about memory allocation.

Bitmap adjustments in allocate_cluster are not performed yet.
They worth to be separate. This was proven useful during debug of this
series. Kept as is for future bissecting.

It should be specifically noted that used bitmap must be recalculated
if data_off has been fixed during image consistency check.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: fix broken parallels_check_data_off()

Once we have repaired data_off field in the header we should update
s->data_start which is calculated on the base of it.

Signed-off-by: Denis V. Lun

parallels: fix broken parallels_check_data_off()

Once we have repaired data_off field in the header we should update
s->data_start which is calculated on the base of it.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: create mark_used() helper which sets bit in used bitmap

This functionality is used twice already and next patch will add more
code with it.

Signed-off-by: Denis V. Lunev <den@openvz.org>

parallels: create mark_used() helper which sets bit in used bitmap

This functionality is used twice already and next patch will add more
code with it.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: refactor path when we need to re-check image in parallels_open

More conditions follows thus the check should be more scalable.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by:

parallels: refactor path when we need to re-check image in parallels_open

More conditions follows thus the check should be more scalable.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...

parallels: return earlier from parallels_open() function on error

At the beginning of the function we can return immediately until we
really allocate s->header.

Signed-off-by: Denis V. Lunev <den@o

parallels: return earlier from parallels_open() function on error

At the beginning of the function we can return immediately until we
really allocate s->header.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

show more ...