So far, live migration with shared storage meant that the image is in a
not-really-ready don't-touch-me state on the destination while the
source is still actively using it, but after completing the migration,
the image was fully opened on both sides. This is bad.
This patch adds a block driver callback to inactivate images on the
source before completing the migration. Inactivation means that it goes
to a state as if it was just live migrated to the qemu instance on the
source (i.e. BDRV_O_INACTIVE is set). You're then supposed to continue
either on the source or on the destination, which takes ownership of the
image.
A typical migration looks like this now with respect to disk images:
1. Destination qemu is started, the image is opened with
BDRV_O_INACTIVE. The image is fully opened on the source.
2. Migration is about to complete. The source flushes the image and
inactivates it. Now both sides have the image opened with
BDRV_O_INACTIVE and are expecting the other side to still modify it.
3. One side (the destination on success) continues and calls
bdrv_invalidate_all() in order to take ownership of the image again.
This removes BDRV_O_INACTIVE on the resuming side; the flag remains
set on the other side.
This ensures that the same image isn't written to by both instances
(unless both are resumed, but then you get what you deserve). This is
important because .bdrv_close for non-BDRV_O_INACTIVE images could write
to the image file, which is definitely forbidden while another host is
using the image.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Instead of covering only the state of images on the migration
destination before the migration is completed, the flag will also cover
the state of images on the migration source after completion. This
common state implies that the image is technically still open, but no
writes will happen and any cached contents will be reloaded from disk if
and when the image leaves this state.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
We can only clear BDRV_O_INCOMING if the caches were actually
invalidated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
bdrv_common_open() modified bs->open_flags after inferring the set of
options to pass to the driver's .bdrv_open callback. This means that the
cache options were correctly set in bs->open_flags (and therefore
correctly displayed in 'info block'), but the image would actually be
opened with the default cache mode instead.
This patch removes the flags parameter to bdrv_common_open() (except for
BDRV_O_NO_BACKING it's the same as bs->open_flags anyway, and having two
names for the same thing is confusing), and moves the assignment of
open_flags down to immediately before calling into the block drivers. In
all other places, bs->open_flags is now used consistently.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Done with this Coccinelle semantic patch
@@
expression FMT, E1, E2;
expression list ARGS;
@@
- error_setg(E1, FMT, ARGS, error_get_pretty(E2));
+ error_propagate(E1, E2);/*###*/
+ error_prepend(E1, FMT/*@@@*/, ARGS);
followed by manual cleanup, first because I can't figure out how to
make Coccinelle transform strings, and second to get rid of now
superfluous error_propagate().
We now use or propagate the original error whole instead of just its
message obtained with error_get_pretty(). This avoids suppressing its
hint (see commit 50b7b00), but I can't see how the errors touched in
this commit could come with hints. It also improves the message
printed with &error_abort when we screw up (see commit 1e9b65b).
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
bdrv_create() sets an error and returns -errno on failure. When the
latter is interesting, the error is created with error_setg_errno().
bdrv_append_temp_snapshot() uses the error's message to create a new
one with error_setg_errno(). This adds a strerror() that is either
uninteresting or duplicate. Use error_setg() instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-7-git-send-email-armbru@redhat.com>
bdrv_close is used when ejecting a medium. Use a drained section to ensure
that all I/O goes to either the old medium or the bitbucket.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1450867706-19860-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add an opaque value which is to be passed to the bdrv_amend_options()
status callback.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds the cache mode options to the QDict, so that they can be
specified for child nodes (e.g. backing.cache.direct=off).
The cache modes are not removed from the flags at this point; instead,
options and flags are kept in sync. If the user specifies both flags and
options, the options take precedence.
Child node inherit cache modes as options now, they don't use flags any
more.
Note that this forbids specifying the cache mode for empty drives. It
didn't make sense anyway to specify it there, because it didn't have any
effect. blockdev_init() considers the cache options now bdrv_open()
options and therefore doesn't create an empty drive any more but calls
into bdrv_open(). This in turn will fail with no driver and filename
specified.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This patch adds a QemuOpts for generic block layer options to
bdrv_reopen_prepare(). The only two options that currently exist
(node-name and driver) cannot be changed, so the only thing we do is
putting them right back into the QDict so that we check at the end that
they are indeed unchanged.
We will add new options soon that can actually be changed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
bs->options doesn't only contain options that the user explicitly
requested, but also option that were derived from flags, the filename or
inherited from the parent node.
For reopen, it is important to know the difference because reopening the
parent can change inherited values in child nodes, but it shouldn't
change any options that were explicitly specified for the child.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The next patch distinguishes options that were explicitly set and
options that were derived. bdrv_fill_option() added options of both
types: Options given by json: syntax should be counted as explicit, but
the rest is derived.
In preparation for the distinction, move json: parse to a separate
function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Options are not actually inherited from the parent node yet, but this
commit lays the grounds for doing so.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The interesting part of reopening an image is from which sources the
effective options should be taken, i.e. which options take precedence
over which other options. This patch documents the precedence that will
be implemented in the following patches.
It also refactors bdrv_reopen_queue(), so that the top-level reopened
node is handled the same way as children are. Option/flag inheritance
from the parent becomes just one item in the list and is done at the
beginning of the function, similar to how the other items are/will be
handled.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
If the child was defined in the same context (-drive argument or
blockdev-add QMP command) as its parent, a reopen of the parent should
work the same and allow changing options of the child.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Instead of passing a separate drv argument to bdrv_open_common(), just
make sure that a "driver" option is set in the QDict. This also means
that a "driver" entry is consistently present in bs->options now.
This is another step towards keeping all options in the QDict (which is
the represenation of the blockdev-add QMP command).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
In order to decide whether a blkdebug: filename can be produced or a
json: one is necessary, blkdebug checked whether bs->options had more
options than just "config", "x-image" or "image" (the latter including
nested options). That doesn't work well when generic block layer options
are present.
This patch passes an option QDict to the driver that contains only
driver-specific options, i.e. the options for the general block layer as
well as child nodes are already filtered out. Works much better this
way.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Some drivers have nested options (e.g. blkdebug rule arrays), which
don't belong to a child node and shouldn't be removed. Don't remove all
options with "." in their name, but check for the complete prefixes of
actually existing child nodes.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The code already special-cased "node-name", which is currently the only
option passed in the QDict that isn't driver-specific. Generalise the
code to take all general block layer options into consideration.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
For bs->file, using references to existing BDSes has been possible for a
while already. This patch enables the same for bs->backing.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This fixes bdrv_reopen() calls like the following one:
qemu-io -c 'open -o overlap-check.template=all /tmp/test.qcow2' \
-c 'reopen -o overlap-check=none'
The approach taken so far would result in an options QDict that has both
"overlap-check.template=all" and "overlap-check=none", which obviously
conflicts. In this case, the old option should be overridden by the
newly specified option.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
No need to keep two separate enums, where editing one is likely
to forget the other. Now that we can specify a qapi enum prefix,
we don't even have to change the bulk of the uses.
get_event_by_name() could perhaps be replaced by qapi_enum_parse(),
but I left that for another day.
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-20-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The "need_check_timer" is used to clear the "NEED_CHECK" flag in the
image header after a grace period once metadata update has finished. In
compliance to the bdrv_drain semantics we should make sure it remains
deleted once .bdrv_drain is called.
We cannot reuse qed_need_check_timer_cb because here it doesn't satisfy
the assertion. Do the "plug" and "flush" calls manually.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1447064214-29930-10-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
A few uses of error_set(ERROR_CLASS_GENERIC_ERROR) were missed in
c6bd8c706, or have snuck in since. Nuke them.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447224690-9743-19-git-send-email-eblake@redhat.com>
Acked-by: Andreas Färber <afaerber@suse.de>
[Indentation tidied up, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
There are two ways to check for I/O limits in a BlockDriverState:
- bs->throttle_state: if this pointer is not NULL, it means that this
BDS is member of a throttling group, its ThrottleTimers structure
has been initialized and its I/O limits are ready to be applied.
- bs->io_limits_enabled: if true it means that the throttle_state
pointer is valid _and_ the limits are currently enabled.
The latter is used in several places to check whether a BDS has I/O
limits configured, but what it really checks is whether requests
are being throttled or not. For example, io_limits_enabled can be
temporarily set to false in cases like bdrv_read_unthrottled() without
otherwise touching the throtting configuration of that BDS.
This patch replaces bs->io_limits_enabled with bs->throttle_state in
all cases where what we really want to check is the existence of I/O
limits, not whether they are currently enabled or not.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Passing an empty string allows opening an image but not its backing
file. This was already described in the API documentation, only the
implementation was missing.
This is useful for creating snapshots using images opened with
blockdev-add, since they are not supposed to have a backing image
before the operation.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When inserting a BDS tree into a BB, we will need to add the root BDS to
this list. Since we will want to do that in the blockdev-insert-medium
implementation in blockdev.c, we will need access to it there.
This patch is not exactly elegant, but bdrv_states will be removed in
the future anyway because we no longer need it since we have BBs.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blk_bs() will not necessarily return a non-NULL value any more (unless
blk_is_available() is true or it can be assumed to otherwise, e.g.
because it is called immediately after a successful blk_new_with_bs() or
blk_new_open()).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These options are only relevant for the user of a whole BDS tree (like a
guest device or a block job) and should thus be moved into the
BlockBackend.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
As the comment above bdrv_get_stats() says, BlockAcctStats is something
which belongs to the device instead of each BlockDriverState. This patch
therefore moves it into the BlockBackend.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
guest_block_size is a guest device property so it should be moved into
the interface between block layer and guest devices, which is the
BlockBackend.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to handle host device passthrough, some guest device models
may call blk_is_inserted() to check whether the medium is inserted on
the host, when checking the guest tray status.
This tray status is inquired by blk_dev_change_media_cb(); because
bdrv_is_inserted() (invoked by blk_is_inserted()) always returns false
for BDS with drv set to NULL, blk_dev_change_media_cb() should therefore
be called before drv is set to NULL.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If bdrv_is_inserted() is called on the top level BDS, it should make
sure all nodes in the BDS tree are actually inserted.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make bdrv_is_inserted(), blk_is_inserted(), and the callback
BlockDriver.bdrv_is_inserted() return a bool.
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This flag should not be set for the root BDS only, but for any BDS that
is being created while incoming migration is pending, so setting it is
moved from blockdev_init() to bdrv_fill_options().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The coroutine files are currently referenced by the block-obj-y
variable. The coroutine functionality though is already used by
more than just the block code. eg migration code uses coroutine
yield. In the future the I/O channel code will also use the
coroutine yield functionality. Since the coroutine code is nicely
self-contained it can be easily built as part of the libqemuutil.a
library, making it widely available.
The headers are also moved into include/qemu, instead of the
include/block directory, since they are now part of the util
codebase, and the impl was never in the block/ directory
either.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If a node-name is not specified, automatically generate the node-name.
Generated node-names will use the "block" sub-system identifier.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_unref() can be called with a NULL argument and doesn't do anything
then. Make bdrv_unref_child() consistent with it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
bdrv_swap() is unused now. Remove it and all functions that have
no other users than bdrv_swap(). In particular, this removes the
.bdrv_rebind callbacks from block drivers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This cleans up the mess we left behind in the mirror code after the
previous patch. Instead of using bdrv_swap(), just change pointers.
The interface change of the mirror job that callers must consider is
that after job completion, their local BDS pointers still point to the
same node now. qemu-img must change its code accordingly (which makes it
easier to understand); the other callers stays unchanged because after
completion they don't do anything with the BDS, but just with the job,
and the job is still owned by the source BDS.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Remember all parent nodes and just change the pointers there instead of
swapping the contents of the BlockDriverState.
Handling of snapshot=on must be moved further down in bdrv_open()
because *pbs (which is the bs pointer in the BlockBackend) must already
be set before bdrv_append() is called. Otherwise bdrv_append() changes
the BB's pointer to the temporary snapshot, but bdrv_open() overwrites
it with the read-only original image.
We also need to be careful to update callers as the interface changes
(becomes less insane): Previously, the meaning of the two parameters was
inverted when bdrv_append() returns. Now any BDS pointers keep pointing
to the same node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
After bdrv_swap(), some fields must be moved back to their original BDS
to compensate for the effects that a swap of the contents of the objects
has while keeping the old addresses. Other fields must be moved back
because they should logically be moved and must stay on top
When replacing bdrv_swap() with operations changing the pointers in the
parents, we only need the latter and must avoid swapping the former.
Split the function accordingly.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This simplifies the code somewhat, especially when dropping whole
backing file subchains.
The exception is the mirroring code that does adventurous things with
bdrv_swap() and in order to keep it working, I had to duplicate most of
bdrv_set_backing_hd() locally. We'll get rid again of this ugliness
shortly.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.
After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
It is unused now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This patch removes the temporary duplication between bs->file and
bs->file_child by converting everything to BdrvChild.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Store the BdrvChild for bs->file. At this point, bs->file_child->bs just
duplicates the bs->file pointer. Later, it will completely replace it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Kevin Wolf