Error management is important for mirroring; otherwise, an error on the
target (even something as "innocent" as ENOSPC) requires to start again
with a full copy. Similar to on_read_error/on_write_error, two separate
knobs are provided for on_source_error (reads) and on_target_error (writes).
The default is 'report' for both.
The 'ignore' policy will leave the sector dirty, so that it will be
retried later. Thus, it will not cause corruption.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds the monitor commands that start the mirroring job.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Even for jobs that need to be manually completed, management may want
to take care itself of the completion, not requiring the user to issue
a command to terminate the job. In this case we want to avoid that
they poll us continuously, waiting for completion to become available.
Thus, add a new event that signals the phase switch and the availability
of the block-job-complete command.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
While streaming can be dropped as soon as it progressed through the whole
image, mirroring needs to be completed manually for two reasons: 1) so that
management knows exactly when the VM switches to the target; 2) because
for other use cases such as replication, we may leave the operation running
for the whole life of the virtual machine.
Add a new block job command that manually completes background operations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This simplifies some code and error checking, and also fixes a bug.
bdrv_find_backing_image() should only be passed absolute filenames,
or filenames relative to the chain. In the QMP message handler for
block commit, when looking up the base do so from the determined top
image, so we know it is reachable from top.
Some of the error messages put out by block-commit have changed
slightly, which causes 2 tests cases for block-commit to fail.
This patch updates the test cases to look for the correct error
output.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch cleans up return sentences in the end of void functions.
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
This patch adds support for error management to streaming.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Do this while we are touching this part of the code, before introducing
more uses of "int is_read".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This will let block-stream reuse the enum. Places that used the enums
are renamed accordingly.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add QMP commands matching the functionality.
Paused jobs cannot be canceled without first resuming them. This
ensures that I/O errors are never missed by management. However, an
optional force argument can be specified to allow that.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Job pausing reuses the existing support for cancellable sleeps. A pause
happens at the next sleeping point and lasts until the coroutine is
re-entered explicitly. Cancellation was already doing a forced resume,
so implement it explicitly in terms of resume.
Paused jobs cannot be canceled without first resuming them. This ensures
that I/O errors are never missed by management.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Extract it out of the implementation of info block-jobs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The DeviceNotActive text is not a particularly good match, add
a separate text while keeping the same class.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The command for live block commit is added, which has the following
arguments:
device: the block device to perform the commit on (mandatory)
base: the base image to commit into; optional (if not specified,
it is the underlying original image)
top: the top image of the commit - all data from inside top down
to base will be committed into base (mandatory for now; see
note, below)
speed: maximum speed, in bytes/sec
Note: Eventually this command will support merging down the active layer,
but that code is not yet complete. If the active layer is passed
in as top, then an error will be returned. Once merging down the
active layer is supported, the 'top' argument may become optional,
and default to the active layer.
The is done as a block job, so upon completion a BLOCK_JOB_COMPLETED will
be emitted.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Currently, after a live snapshot of a drive, the image that has
been 'demoted' to be below the new active layer remains r/w.
This patch reopens it read-only.
Note that we do not check for error on the reopen(), because we
will not abort the snapshots if the reopen fails.
This patch depends on the bdrv_reopen() series.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If readonly=on is given at device creation time, the ->readonly flag
needs to be set in the block driver state for this device so that
readonly-ness is preserved across media changes (qmp change command).
Similarly, to preserve the snapshot property requires ->open_flags to
be correct.
Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now all major device models (IDE, SCSI, virtio) can choose between
writethrough and writeback at run-time, and virtio will even revert
to writethrough if the guest is not capable of sending flushes. So
we can change the default to writeback at last.
Tested, for lack of a better idea, with a breakpoint on bdrv_open
and all cache choices one by one.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For command line options which permit '?' meaning 'please list the
permitted values', add support for 'help' as a synonym, by abstracting
the check out into a helper function.
This change means that in some cases where we were being lazy in
our string parsing, "?junk" will now be rejected as an invalid option
rather than being (undocumentedly) treated the same way as "?".
Update the documentation to use 'help' rather than '?', since '?'
is a shell metacharacter and thus prone to fail confusingly if there
is a single character filename in the current working directory and
the '?' has not been escaped. It's therefore better to steer users
towards 'help', though '?' is retained for backwards compatibility.
We do not, however, update the output of the system emulator's -help
(or any documentation autogenerated from the qemu-options.hx which
is the source of the -help text) because libvirt parses our -help
output and will break. At a later date when QEMU provides a better
interface so libvirt can avoid having to do this, we can update the
-help text too.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
All current users (IDE, SCSI and virtio-blk) happen to share this 20
characters limit. Still, it should be left to device models. They
already enforce their limits. They have to, as the DriveInfo limit
only affects legacy -drive serial=..., not the qdev properties.
usb-storage, which doesn't limit serial number length, also uses
DriveInfo for -usbdevice. But that doesn't provide access to
DriveInfo serial.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There are two producers of these hints: drive_init() on behalf of
-drive, and hd_geometry_guess().
The only consumer of the hint is hd_geometry_guess().
The callers of hd_geometry_guess() call it only when drive_init()
didn't set the hints. Therefore, drive_init()'s hints are never used.
Thus, hd_geometry_guess() only ever sees hints it produced itself in a
prior call. Only the first call computes something, subsequent calls
just repeat the first call's results. However, hd_geometry_guess() is
never called more than once: the device models don't, and the block
device is destroyed on unplug. Thus, dropping the repeat feature
doesn't break anything now.
If a block device wasn't destroyed on unplug and could be reused with
a new device, then repeating old results would be wrong. Thus,
dropping the repeat feature prevents future breakage.
This renders the hints unused. Purge them from the block layer.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In preparation of purging it from the block layer, which will happen
later in this series.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the image is read-only then it's not possible to copy read data into
it. Therefore copy-on-read is automatically disabled for read-only
images.
Up until now this behavior was silent, add a warning so the user knows
why copy-on-read is not working.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit converts qemu_opts_create() from qerror_report() to
error_set().
Currently, most calls to qemu_opts_create() can't fail, so most
callers don't need any changes.
The two cases where code checks for qemu_opts_create() erros are:
1. Initialization code in vl.c. All of them print their own
error messages directly to stderr, no need to pass the Error
object
2. The functions opts_parse(), qemu_opts_from_qdict() and
qemu_chr_parse_compat() make use of the error information and
they can be called from HMP or QMP. In this case, to allow for
incremental conversion, we propagate the error up using
qerror_report_err(), which keeps the QError semantics
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-By: Laszlo Ersek <lersek@redhat.com>
Allow streaming operations to be started with an initial speed limit.
This eliminates the window of time between starting streaming and
issuing block-job-set-speed. Users should use the new optional 'speed'
parameter instead so that speed limits are in effect immediately when
the job starts.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
There are at least two different errors that can occur in
block_job_set_speed(): the job might not support setting speeds or the
value might be invalid.
Use the Error mechanism to report the error where it occurs.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
The block job API uses -errno return values internally and we convert
these to Error in the QMP functions. This is ugly because the Error
should be created at the point where we still have all the relevant
information. More importantly, it is hard to add new error cases to
this case since we quickly run out of -errno values without losing
information.
Go ahead and use Error directly and don't convert later.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Open images with BDRV_O_INCOMING in order to inform block drivers
that an incoming live migration is coming.
Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We do not want jobs to keep a device busy for a possibly very long
time, and management could become confused because they thought a
device was not even there anymore. So, cancel long-running jobs
as soon as their device is going to disappear.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
strncpy may not null-terminate the destination string.
Cc: kwolf@redhat.com
Signed-off-by: Floris Bos <dev@noc-ps.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Simplify the blockdev-snapshot-sync code and gain failsafe operation
by turning it into a wrapper around the new transaction command. A new
option is also added matching "mode".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The mode field lets a management application create the snapshot
destination outside QEMU.
Right now, the only modes are "existing" and "absolute-paths". Mirroring
introduces "no-backing-file". In the future "relative-paths" could be
implemented too.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We will add other kinds of operation. Prepare for this by adjusting
the schema.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Monitor operations that manipulate image files must not execute while a
background job (like image streaming) is in progress. This prevents
corruptions from happening when two pieces of code are manipulating the
image file without knowledge of each other.
The monitor "commit" command raises QERR_DEVICE_IN_USE when
bdrv_commit() returns -EBUSY but "commit all" has no error handling.
This is easy to fix, although note that we do not deliver a detailed
error about which device was busy in the "commit all" case.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is a QAPI/QMP only command to take a snapshot of a group of
devices. This is similar to the blockdev-snapshot-sync command, except
blockdev-group-snapshot-sync accepts a list devices, filenames, and
formats.
It is attempted to keep the snapshot of the group atomic; if the
creation or open of any of the new snapshots fails, then all of
the new snapshots are abandoned, and the name of the snapshot image
that failed is returned. The failure case should not interrupt
any operations.
Rather than use bdrv_close() along with a subsequent bdrv_open() to
perform the pivot, the original image is never closed and the new
image is placed 'in front' of the original image via manipulation
of the BlockDriverState fields. Thus, once the new snapshot image
has been successfully created, there are no more failure points
before pivoting to the new snapshot.
This allows the group of disks to remain consistent with each other,
even across snapshot failures.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add support for streaming data from an intermediate section of the
image chain (see patch and documentation for details).
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Unplugging a storage interface like virtio-blk causes the host block
device to be deleted too. Long-running operations like block migration
must take a DriveInfo reference to prevent the BlockDriverState from
being freed. For image streaming we can do the same thing.
Note that it is not possible to acquire/release the drive reference in
block.c where the block job functions live because
drive_get_ref()/drive_put_ref() are blockdev.c functions. Calling them
from block.c would be a layering violation - tools like qemu-img don't
even link against blockdev.c.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add query-block-jobs, which shows the progress of ongoing block device
operations.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add block_job_cancel, which stops an active block streaming operation.
When the operation has been cancelled the new BLOCK_JOB_CANCELLED event
is emitted.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add block_job_set_speed, which sets the maximum speed for a background
block operation.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
