Upcoming patches want to add some basic bitmap manipulation abilities
to qemu-img. But blockdev.o is too heavyweight to link into qemu-img
(among other things, it would drag in block jobs and transaction
support - qemu-img does offline manipulation, where atomicity is less
important because there are no concurrent modifications to compete
with), so it's time to split off the bare bones of what we will need
into a new file block/monitor/bitmap-qmp-cmds.o.
This is sufficient to expose 6 QMP commands for use by qemu-img (add,
remove, clear, enable, disable, merge), as well as move the three
helper functions touched in the previous patch. Regarding
MAINTAINERS, the new file is automatically part of block core, but
also makes sense as related to other dirty bitmap files.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513011648.166876-6-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
The next patch will split blockdev.c, which will require accessing
some previously-static functions from more than one .c file. But part
of promoting a function to public is picking a naming scheme that does
not reek of exposing too many internals (two of the three functions
were named starting with 'do_'). To make future code motion easier,
perform the function rename and non-static promotion into its own
patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200513011648.166876-5-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
There are several callers that need to create a new block backend from
an existing BDS; make the task slightly easier with a common helper
routine.
Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424190903.522087-2-eblake@redhat.com>
[mreitz: Set @ret only in error paths, see
https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-2-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The previous few commits have made this more obvious, and removed the
one exception. Time to clarify the documentation, and drop dead error
checking.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-13-armbru@redhat.com>
All callers of job_txn_apply hold a single job's lock, but different
jobs within a transaction can have different contexts, thus we need to
lock each one individually before applying the callback function.
Similar to job_completed_txn_abort this also requires releasing the
caller's context before and reacquiring it after to avoid recursive
locks which might break AIO_WAIT_WHILE in the callback. This is safe, since
existing code would already have to take this into account, lest
job_completed_txn_abort might have broken.
This also brings to light a different issue: When a callback function in
job_txn_apply moves it's job to a different AIO context, callers will
try to release the wrong lock (now that we re-acquire the lock
correctly, previously it would just continue with the old lock, leaving
the job unlocked for the rest of the return path). Fix this by not caching
the job's context.
This is only necessary for qmp_block_job_finalize, qmp_job_finalize and
job_exit, since everyone else calls through job_exit.
One test needed adapting, since it calls job_finalize directly, so it
manually needs to acquire the correct context.
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Message-Id: <20200407115651.69472-2-s.reiter@proxmox.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
external_snapshot_prepare() tries to move the overlay to the AioContext
of the backing file (the snapshotted node). However, it's possible that
this doesn't work, but the backing file can instead be moved to the
overlay's AioContext (e.g. opening the backing chain for a mirror
target).
bdrv_append() already indirectly uses bdrv_attach_node(), which takes
care to move nodes to make sure they use the same AioContext and which
tries both directions.
So the problem has a simple fix: Just delete the unnecessary extra
bdrv_try_set_aio_context() call in external_snapshot_prepare() and
instead assert in bdrv_append() that both nodes were indeed moved to the
same AioContext.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200310113831.27293-6-kwolf@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blockdev-snapshot returned an error if the overlay was already in use,
which it defined as having any BlockBackend parent. This is in fact both
too strict (some parents can tolerate the change of visible data caused
by attaching a backing file) and too loose (some non-BlockBackend
parents may not be happy with it).
One important use case that is prevented by the too strict check is live
storage migration with blockdev-mirror. Here, the target node is
usually opened without a backing file so that the active layer is
mirrored while its backing chain can be copied in the background.
The backing chain should be attached to the mirror target node when
finalising the job, just before switching the users of the source node
to the new copy (at which point the mirror job still has a reference to
the node). drive-mirror did this automatically, but with blockdev-mirror
this is the job of the QMP client, so it needs a way to do this.
blockdev-snapshot is the obvious way, so this patch makes it work in
this scenario. The new condition is that no parent uses CONSISTENT_READ
permissions. This will ensure that the operation will still be blocked
when the node is attached to the guest device, so blockdev-snapshot
remains safe.
(For the sake of completeness, x-blockdev-reopen can be used to achieve
the same, however it is a big hammer, performs the graph change
completely unchecked and is still experimental. So even with the option
of using x-blockdev-reopen, there are reasons why blockdev-snapshot
should be able to perform this operation.)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200310113831.27293-3-kwolf@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200308092440.23564-12-mlevitsk@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200308092440.23564-5-mlevitsk@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
These commands make only sense for system emulators and their
implementations call functions that don't exist in tools (e.g. to
resolve qdev IDs). Move them out so that blockdev.c can be linked to
qemu-storage-daemon.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-4-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When a management application manages node names there's no reason to
recurse into backing images in the output of query-named-block-nodes.
Add a parameter to the command which will return just the top level
structs.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Message-Id: <4470f8c779abc404dcf65e375db195cd91a80651.1579509782.git.pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[mreitz: Fixed coding style]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Block nodes that do not allow resizing should not share BLK_PERM_RESIZE.
It does not matter whether they are the first non-filter in their chain
or not.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200218103454.296704-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There is no good reason why we would allow external snapshots only on
the first non-filter node in a chain. Parent BDSs should not care
whether their child is replaced by a snapshot. (If they do care, they
should announce that via freezing the chain, which is checked in
bdrv_append() through bdrv_set_backing_hd().)
Before we had bdrv_is_first_non_filter() here (since 212a5a8f09), there
was a special function bdrv_check_ext_snapshot() that allowed snapshots
by default, but block drivers could override this. Only blkverify did
so, however.
It is not clear to me why blkverify would do so; maybe just so that the
testee block driver would not be replaced. The introducing commit
f6186f49e2 does not explain why. Maybe because 08b24cfe37 would have
been the correct solution? (Which adds a .supports_backing check.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200218103454.296704-2-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that the error handling in the common block job is fixed, we can
expose the on-error option in QMP instead of hard-coding it as 'report'
in qmp_block_commit().
This fulfills the promise that the old comment in that function made,
even if a bit later than expected: "This will be part of the QMP
command, if/when the BlockdevOnError change for blkmirror makes it in".
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200214200812.28180-7-kwolf@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
external_snapshot_abort() calls to bdrv_set_backing_hd(), which
returns state->old_bs to the main AioContext, as it's intended to be
used then the BDS is going to be released. As that's not the case when
aborting an external snapshot, return it to the AioContext it was
before the call.
This issue can be triggered by issuing a transaction with two actions,
a proper blockdev-snapshot-sync and a bogus one, so the second will
trigger a transaction abort. This results in a crash with an stack
trace like this one:
#0 0x00007fa1048b28df in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007fa10489ccf5 in __GI_abort () at abort.c:79
#2 0x00007fa10489cbc9 in __assert_fail_base
(fmt=0x7fa104a03300 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=0x557224014d30 "block.c", line=2240, function=<optimized out>) at assert.c:92
#3 0x00007fa1048aae96 in __GI___assert_fail
(assertion=assertion@entry=0x5572240b44d8 "bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)", file=file@entry=0x557224014d30 "block.c", line=line@entry=2240, function=function@entry=0x5572240b5d60 <__PRETTY_FUNCTION__.31620> "bdrv_replace_child_noperm") at assert.c:101
#4 0x0000557223e631f8 in bdrv_replace_child_noperm (child=0x557225b9c980, new_bs=new_bs@entry=0x557225c42e40) at block.c:2240
#5 0x0000557223e68be7 in bdrv_replace_node (from=0x557226951a60, to=0x557225c42e40, errp=0x5572247d6138 <error_abort>) at block.c:4196
#6 0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1731
#7 0x0000557223d069c4 in external_snapshot_abort (common=0x557225d7e170) at blockdev.c:1717
#8 0x0000557223d09013 in qmp_transaction (dev_list=<optimized out>, has_props=<optimized out>, props=0x557225cc7d70, errp=errp@entry=0x7ffe704c0c98) at blockdev.c:2360
#9 0x0000557223e32085 in qmp_marshal_transaction (args=<optimized out>, ret=<optimized out>, errp=0x7ffe704c0d08) at qapi/qapi-commands-transaction.c:44
#10 0x0000557223ee798c in do_qmp_dispatch (errp=0x7ffe704c0d00, allow_oob=<optimized out>, request=<optimized out>, cmds=0x5572247d3cc0 <qmp_commands>) at qapi/qmp-dispatch.c:132
#11 0x0000557223ee798c in qmp_dispatch (cmds=0x5572247d3cc0 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175
#12 0x0000557223e06141 in monitor_qmp_dispatch (mon=0x557225c69ff0, req=<optimized out>) at monitor/qmp.c:120
#13 0x0000557223e0678a in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:209
#14 0x0000557223f2f366 in aio_bh_call (bh=0x557225b9dc60) at util/async.c:117
#15 0x0000557223f2f366 in aio_bh_poll (ctx=ctx@entry=0x557225b9c840) at util/async.c:117
#16 0x0000557223f32754 in aio_dispatch (ctx=0x557225b9c840) at util/aio-posix.c:459
#17 0x0000557223f2f242 in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260
#18 0x00007fa10913467d in g_main_dispatch (context=0x557225c28e80) at gmain.c:3176
#19 0x00007fa10913467d in g_main_context_dispatch (context=context@entry=0x557225c28e80) at gmain.c:3829
#20 0x0000557223f31808 in glib_pollfds_poll () at util/main-loop.c:219
#21 0x0000557223f31808 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242
#22 0x0000557223f31808 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518
#23 0x0000557223d13201 in main_loop () at vl.c:1828
#24 0x0000557223bbfb82 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4504
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1779036
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Dirty map addition and removal functions are not acquiring to BDS
AioContext, while they may call to code that expects it to be
acquired.
This may trigger a crash with a stack trace like this one:
#0 0x00007f0ef146370f in __GI_raise (sig=sig@entry=6)
at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007f0ef144db25 in __GI_abort () at abort.c:79
#2 0x0000565022294dce in error_exit
(err=<optimized out>, msg=msg@entry=0x56502243a730 <__func__.16350> "qemu_mutex_unlock_impl") at util/qemu-thread-posix.c:36
#3 0x00005650222950ba in qemu_mutex_unlock_impl
(mutex=mutex@entry=0x5650244b0240, file=file@entry=0x565022439adf "util/async.c", line=line@entry=526) at util/qemu-thread-posix.c:108
#4 0x0000565022290029 in aio_context_release
(ctx=ctx@entry=0x5650244b01e0) at util/async.c:526
#5 0x000056502221cd08 in bdrv_can_store_new_dirty_bitmap
(bs=bs@entry=0x5650244dc820, name=name@entry=0x56502481d360 "bitmap1", granularity=granularity@entry=65536, errp=errp@entry=0x7fff22831718)
at block/dirty-bitmap.c:542
#6 0x000056502206ae53 in qmp_block_dirty_bitmap_add
(errp=0x7fff22831718, disabled=false, has_disabled=<optimized out>, persistent=<optimized out>, has_persistent=true, granularity=65536, has_granularity=<optimized out>, name=0x56502481d360 "bitmap1", node=<optimized out>) at blockdev.c:2894
#7 0x000056502206ae53 in qmp_block_dirty_bitmap_add
(node=<optimized out>, name=0x56502481d360 "bitmap1", has_granularity=<optimized out>, granularity=<optimized out>, has_persistent=true, persistent=<optimized out>, has_disabled=false, disabled=false, errp=0x7fff22831718) at blockdev.c:2856
#8 0x00005650221847a3 in qmp_marshal_block_dirty_bitmap_add
(args=<optimized out>, ret=<optimized out>, errp=0x7fff22831798)
at qapi/qapi-commands-block-core.c:651
#9 0x0000565022247e6c in do_qmp_dispatch
(errp=0x7fff22831790, allow_oob=<optimized out>, request=<optimized out>, cmds=0x565022b32d60 <qmp_commands>) at qapi/qmp-dispatch.c:132
#10 0x0000565022247e6c in qmp_dispatch
(cmds=0x565022b32d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>) at qapi/qmp-dispatch.c:175
#11 0x0000565022166061 in monitor_qmp_dispatch
(mon=0x56502450faa0, req=<optimized out>) at monitor/qmp.c:145
#12 0x00005650221666fa in monitor_qmp_bh_dispatcher
(data=<optimized out>) at monitor/qmp.c:234
#13 0x000056502228f866 in aio_bh_call (bh=0x56502440eae0)
at util/async.c:117
#14 0x000056502228f866 in aio_bh_poll (ctx=ctx@entry=0x56502440d7a0)
at util/async.c:117
#15 0x0000565022292c54 in aio_dispatch (ctx=0x56502440d7a0)
at util/aio-posix.c:459
#16 0x000056502228f742 in aio_ctx_dispatch
(source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260
#17 0x00007f0ef5ce667d in g_main_dispatch (context=0x56502449aa40)
at gmain.c:3176
#18 0x00007f0ef5ce667d in g_main_context_dispatch
(context=context@entry=0x56502449aa40) at gmain.c:3829
#19 0x0000565022291d08 in glib_pollfds_poll () at util/main-loop.c:219
#20 0x0000565022291d08 in os_host_main_loop_wait
(timeout=<optimized out>) at util/main-loop.c:242
#21 0x0000565022291d08 in main_loop_wait (nonblocking=<optimized out>)
at util/main-loop.c:518
#22 0x00005650220743c1 in main_loop () at vl.c:1828
#23 0x0000565021f20a72 in main
(argc=<optimized out>, argv=<optimized out>, envp=<optimized out>)
at vl.c:4504
Fix this by acquiring the AioContext at qmp_block_dirty_bitmap_add()
and qmp_block_dirty_bitmap_add().
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782175
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_try_set_aio_context() requires that the old context is held, and
the new context is not held. Fix all the occurrences where it's not
done this way.
Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Issuing a blockdev-backup from qmp_blockdev_backup takes a slightly
different path than when it's issued from a transaction. In the code,
this is manifested as some redundancy between do_blockdev_backup() and
blockdev_backup_prepare().
This change unifies both paths, merging do_blockdev_backup() and
blockdev_backup_prepare(), and changing qmp_blockdev_backup() to
create a transaction instead of calling do_backup_common() direcly.
As a side-effect, now qmp_blockdev_backup() is executed inside a
drained section, as it happens when creating a blockdev-backup
transaction. This change is visible from the user's perspective, as
the job gets paused and immediately resumed before starting the actual
work.
Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Issuing a drive-backup from qmp_drive_backup takes a slightly
different path than when it's issued from a transaction. In the code,
this is manifested as some redundancy between do_drive_backup() and
drive_backup_prepare().
This change unifies both paths, merging do_drive_backup() and
drive_backup_prepare(), and changing qmp_drive_backup() to create a
transaction instead of calling do_backup_common() direcly.
As a side-effect, now qmp_drive_backup() is executed inside a drained
section, as it happens when creating a drive-backup transaction. This
change is visible from the user's perspective, as the job gets paused
and immediately resumed before starting the actual work.
Also fix tests 141, 185 and 219 to cope with the extra
JOB_STATUS_CHANGE lines.
Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Fix a couple of minor coding style issues in drive_backup_prepare.
Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk. Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.
This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around. All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior. Future patches take care
of that.
Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Instead of using monitor_printf() to report errors, hmp_commit() should
use error_report() like other places do.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
This parameter has been deprecated since 2.12.0 and is eligible for
removal. Remove this parameter as it is actually completely ignored;
let's not give false hope.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191002232411.29968-1-jsnow@redhat.com
Add bs field to BdrvDirtyBitmap structure. Drop BlockDriverState
parameter from bitmap APIs where possible.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190916141911.5255-3-vsementsov@virtuozzo.com
[Rebased on top of block-copy. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire
aio context since 0a6c86d024. But this is not enough: we also must
lock qcow2 mutex when access in-image metadata. Especially it concerns
freeing qcow2 clusters.
To achieve this, move qcow2_can_store_new_dirty_bitmap and
qcow2_remove_persistent_dirty_bitmap to coroutine context.
Since we work in coroutines in correct aio context, we don't need
context acquiring in blockdev.c anymore, drop it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190920082543.23444-4-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
It's more comfortable to not deal with local_err.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190920082543.23444-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Drop write notifiers and use filter node instead.
= Changes =
1. Add filter-node-name argument for backup qmp api. We have to do it
in this commit, as 257 needs to be fixed.
2. There are no more write notifiers here, so is_write_notifier
parameter is dropped from block-copy paths.
3. To sync with in-flight requests at job finish we now have drained
removing of the filter, we don't need rw-lock.
4. Block-copy is now using BdrvChildren instead of BlockBackends
5. As backup-top owns these children, we also move block-copy state
into backup-top's ownership.
= Iotest changes =
56: op-blocker doesn't shoot now, as we set it on source, but then
check on filter, when trying to start second backup.
To keep the test we instead can catch another collision: both jobs will
get 'drive0' job-id, as job-id parameter is unspecified. To prevent
interleaving with file-posix locks (as they are dependent on config)
let's use another target for second backup.
Also, it's obvious now that we'd like to drop this op-blocker at all
and add a test-case for two backups from one node (to different
destinations) actually works. But not in these series.
141: Output changed: prepatch, "Node is in use" comes from bdrv_has_blk
check inside qmp_blockdev_del. But we've dropped block-copy blk
objects, so no more blk objects on source bs (job blk is on backup-top
filter bs). New message is from op-blocker, which is the next check in
qmp_blockdev_add.
257: The test wants to emulate guest write during backup. They should
go to filter node, not to original source node, of course. Therefore we
need to specify filter node name and use it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191001131409.14202-6-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
bdrv_has_zero_init() only has meaning for newly created images or image
areas. If the mirror job itself did not create the image, it cannot
rely on bdrv_has_zero_init()'s result to carry any meaning.
This is the case for drive-mirror with mode=existing and always for
blockdev-mirror.
Note that we only have to zero-initialize the target with sync=full,
because other modes actually do not promise that the target will contain
the same data as the source after the job -- sync=top only promises to
copy anything allocated in the top layer, and sync=none will only copy
new I/O. (Which is how mirror has always handled it.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-3-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We have detect_zeroes option, so at least for blockdev-backup user
should define it if zero-detection is needed. For drive-backup leave
detection enabled by default but do it through existing option instead
of open-coding.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190730163251.755248-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Accept bitmaps and sync policies for the other backup modes.
This allows us to do things like create a bitmap synced to a full backup
without a transaction, or start a resumable backup process.
Some combinations don't make sense, though:
- NEVER policy combined with any non-BITMAP mode doesn't do anything,
because the bitmap isn't used for input or output.
It's harmless, but is almost certainly never what the user wanted.
- sync=NONE is more questionable. It can't use on-success because this
job never completes with success anyway, and the resulting artifact
of 'always' is suspect: because we start with a full bitmap and only
copy out segments that get written to, the final output bitmap will
always be ... a fully set bitmap.
Maybe there's contexts in which bitmaps make sense for sync=none,
but not without more severe changes to the current job, and omitting
it here doesn't prevent us from adding it later.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190716000117.25219-11-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This is nicer to do in the unified QMP interface that we have now,
because it lets us use the right terminology back at the user.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190716000117.25219-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
It is used to do transactional movement of the bitmap (which is
possible in conjunction with merge command). Transactional bitmap
movement is needed in scenarios with external snapshot, when we don't
want to leave copy of the bitmap in the base image.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190708220502.12977-3-jsnow@redhat.com
[Edited "since" version to 4.2 --js]
Signed-off-by: John Snow <jsnow@redhat.com>
Commit 0a6c86d024 returned these locks back to add/remove
functionality, to protect from intersection of persistent bitmap
related IO with other IO. But other bitmap-related functions called
here are unrelated to the problem, and there are no needs to keep these
calls inside critical sections.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190708220502.12977-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
With the "never" sync policy, we actually can utilize readonly bitmaps
now. Loosen the check at the QMP level, and tighten it based on
provided arguments down at the job creation level instead.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-19-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
We don't need or want a new sync mode for simple differences in
semantics. Create a new mode simply named "BITMAP" that is designed to
make use of the new Bitmap Sync Mode field.
Because the only bitmap sync mode is 'on-success', this adds no new
functionality to the backup job (yet). The old incremental backup mode
is maintained as a syntactic sugar for sync=bitmap, mode=on-success.
Add all of the plumbing necessary to support this new instruction.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Create a common core that comprises the actual meat of what the backup API
boundary needs to do, and then switch drive-backup to use it.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
sysemu/sysemu.h is a rather unfocused dumping ground for stuff related
to the system-emulator. Evidence:
* It's included widely: in my "build everything" tree, changing
sysemu/sysemu.h still triggers a recompile of some 1100 out of 6600
objects (not counting tests and objects that don't depend on
qemu/osdep.h, down from 5400 due to the previous two commits).
* It pulls in more than a dozen additional headers.
Split stuff related to run state management into its own header
sysemu/runstate.h.
Touching sysemu/sysemu.h now recompiles some 850 objects. qemu/uuid.h
also drops from 1100 to 850, and qapi/qapi-types-run-state.h from 4400
to 4200. Touching new sysemu/runstate.h recompiles some 500 objects.
Since I'm touching MAINTAINERS to add sysemu/runstate.h anyway, also
add qemu/main-loop.h.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-30-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[Unbreak OS-X build]
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h). It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.
Include qemu/main-loop.h only where it's needed. Touching it now
recompiles only some 1700 objects. For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800. For the
others, they shrink only slightly.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
We forget to enable it for transaction .prepare, while it is already
enabled in do_drive_backup since commit a2d665c1bc
"blockdev: loosen restrictions on drive-backup source node"
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190618140804.59214-1-vsementsov@virtuozzo.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Drop remaining users of bs->job:
1. assertions actually duplicated by assert(!bs->refcnt)
2. trace-point seems not enough reason to change stream_start to return
BlockJob pointer
3. Restricting creation of two jobs based on same bs is bad idea, as
3.1 Some jobs creates filters to be their main node, so, this check
don't actually prevent creating second job on same real node (which
will create another filter node) (but I hope it is restricted by
other mechanisms)
3.2 Even without bs->job we have two systems of permissions:
op-blockers and BLK_PERM
3.3 We may want to run several jobs on one node one day
And finally, drop bs->job pointer itself. Hurrah!
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are going to remove bs->job pointer. Drop it's usage in
blockdev_mark_auto_del: instead of looking at bs->job let's check all
jobs for references to bs.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There are error messages which refer to an overlay node as the snapshot.
That is wrong, those are two different things.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190603202236.1342-3-mreitz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
in blockdev_backup_prepare, we check to make sure that the target is
associated with a compatible aio context. However, do_blockdev_backup is
called later and has some logic to move the target to a compatible
aio_context. The transaction version will fail certain commands
needlessly early as a result.
Allow blockdev_backup_prepare to simply call do_blockdev_backup, which
will ultimately decide if the contexts are compatible or not.
Note: the transaction version has always disallowed this operation since
its initial commit bd8baecd (2014), whereas the version of
qmp_blockdev_backup at the time, from commit c29c1dd312, tried to
enforce the aio_context switch instead. It's not clear, and I can't see
from the mailing list archives at the time, why the two functions take a
different approach. It wasn't until later in efd7556708 (2016) that the
standalone version tried to determine if it could set the context or
not.
Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1683498
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20190523170643.20794-2-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Monitor commands can handle errors, so they can easily be converted to
using the safer bdrv_try_set_aio_context() function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).
The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the bitmap can't be used for whatever reason, we skip putting down
the reference. Fix that.
In practice, this means that if you attempt to gracefully exit QEMU
after a backup command being rejected, bdrv_close_all will fail and
tell you some unpleasant things via assert().
Reported-by: aihua liang <aliang@redhat.com>
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1703916
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
