Commit Graph

1134 Commits

Author SHA1 Message Date
Kevin Wolf
1a63a90750 block: Keep nodes drained between reopen_queue/multiple
The bdrv_reopen*() implementation doesn't like it if the graph is
changed between queuing nodes for reopen and actually reopening them
(one of the reasons is that queuing can be recursive).

So instead of draining the device only in bdrv_reopen_multiple(),
require that callers already drained all affected nodes, and assert this
in bdrv_reopen_queue().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2017-12-22 15:05:32 +01:00
Kevin Wolf
d736f119da block: Allow graph changes in subtree drained section
We need to remember how many of the drain sections in which a node is
were recursive (i.e. subtree drain rather than node drain), so that they
can be correctly applied when children are added or removed during the
drained section.

With this change, it is safe to modify the graph even inside a
bdrv_subtree_drained_begin/end() section.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:05:32 +01:00
Kevin Wolf
0152bf400f block: Don't notify parents in drain call chain
This is in preparation for subtree drains, i.e. drained sections that
affect not only a single node, but recursively all child nodes, too.

Calling the parent callbacks for drain is pointless when we just came
from that parent node recursively and leads to multiple increases of
bs->quiesce_counter in a single drain call. Don't do it.

In order for this to work correctly, the parent callback must be called
for every bdrv_drain_begin/end() call, not only for the outermost one:

If we have a node N with two parents A and B, recursive draining of A
should cause the quiesce_counter of B to increase because its child N is
drained independently of B. If now B is recursively drained, too, A must
increase its quiesce_counter because N is drained independently of A
only now, even if N is going from quiesce_counter 1 to 2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:05:32 +01:00
Fam Zheng
cc954f01e3 block: Open backing image in force share mode for size probe
Management tools create overlays of running guests with qemu-img:

  $ qemu-img create -b /image/in/use.qcow2 -f qcow2 /overlay/image.qcow2

but this doesn't work anymore due to image locking:

    qemu-img: /overlay/image.qcow2: Failed to get shared "write" lock
    Is another process using the image?
    Could not open backing image to determine size.
Use the force share option to allow this use case again.

Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:03:41 +01:00
Kevin Wolf
5fbfabd313 block: Formats don't need CONSISTENT_READ with NO_IO
Commit 1f4ad7d fixed 'qemu-img info' for raw images that are currently
in use as a mirror target. It is not enough for image formats, though,
as these still unconditionally request BLK_PERM_CONSISTENT_READ.

As this permission is geared towards whether the guest-visible data is
consistent, and has no impact on whether the metadata is sane, and
'qemu-img info' does not read guest-visible data (except for the raw
format), it makes sense to not require BLK_PERM_CONSISTENT_READ if there
is not going to be any guest I/O performed, regardless of image format.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:03:41 +01:00
Paolo Bonzini
bd6458e410 block: avoid recursive AioContext acquire in bdrv_inactivate_all()
BDRV_POLL_WHILE() does not support recursive AioContext locking.  It
only releases the AioContext lock once regardless of how many times the
caller has acquired it.  This results in a hang since the IOThread does
not make progress while the AioContext is still locked.

The following steps trigger the hang:

  $ qemu-system-x86_64 -M accel=kvm -m 1G -cpu host \
                       -object iothread,id=iothread0 \
                       -device virtio-scsi-pci,iothread=iothread0 \
                       -drive if=none,id=drive0,file=test.img,format=raw \
                       -device scsi-hd,drive=drive0 \
                       -drive if=none,id=drive1,file=test.img,format=raw \
                       -device scsi-hd,drive=drive1
  $ qemu-system-x86_64 ...same options... \
                       -incoming tcp::1234
  (qemu) migrate tcp:127.0.0.1:1234
  ...hang...

Tested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20171207201320.19284-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-12-19 10:25:09 +00:00
Alberto Garcia
50a3efb0f0 block: Close a BlockDriverState completely even when bs->drv is NULL
bdrv_close() skips much of its logic when bs->drv is NULL. This is
fine when we're closing a BlockDriverState that has just been created
(because e.g the initialization process failed), but it's not enough
in other cases.

For example, when a valid qcow2 image is found to be corrupted then
QEMU marks it as such in the file header and then sets bs->drv to
NULL in order to make the BlockDriverState unusable. When that BDS is
later closed then many of its data structures are not freed (leaking
their memory) and none of its children are detached. This results in
bdrv_close_all() failing to close all BDSs and making this assertion
fail when QEMU is being shut down:

   bdrv_close_all: Assertion `QTAILQ_EMPTY(&all_bdrv_states)' failed.

This patch makes bdrv_close() do the full uninitialization process
in all cases. This fixes the problem with corrupted images and still
works fine with freshly created BDSs.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20171106145345.12038-1-berto@igalia.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-21 14:54:02 +01:00
Kevin Wolf
dacaa16238 block: Don't use BLK_PERM_CONSISTENT_READ for format probing
For format probing, we don't really care whether all of the image
content is consistent. The only thing we're looking at is the image
header, and specifically the magic numbers that are expected to never
change, no matter how inconsistent the guest visible disk content is.

Therefore, don't request BLK_PERM_CONSISTENT_READ. This allows to use
format probing, e.g. in the context of 'qemu-img info', even while the
guest visible data in the image is inconsistent during a running block
job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2017-11-21 14:48:22 +01:00
Max Reitz
5e003f17ec block: Make bdrv_next() keep strong references
On one hand, it is a good idea for bdrv_next() to return a strong
reference because ideally nearly every pointer should be refcounted.
This fixes intermittent failure of iotest 194.

On the other, it is absolutely necessary for bdrv_next() itself to keep
a strong reference to both the BB (in its first phase) and the BDS (at
least in the second phase) because when called the next time, it will
dereference those objects to get a link to the next one.  Therefore, it
needs these objects to stay around until then.  Just storing the pointer
to the next in the iterator is not really viable because that pointer
might become invalid as well.

Both arguments taken together means we should probably just invoke
bdrv_ref() and blk_ref() in bdrv_next().  This means we have to assert
that bdrv_next() is always called from the main loop, but that was
probably necessary already before this patch and judging from the
callers, it also looks to actually be the case.

Keeping these strong references means however that callers need to give
them up if they decide to abort the iteration early.  They can do so
through the new bdrv_next_cleanup() function.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110172545.32609-1-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Max Reitz
d470ad42ac block: Guard against NULL bs->drv
We currently do not guard everywhere against a NULL bs->drv where we
should be doing so.  Most of the places fixed here just do not care
about that case at all.

Some care implicitly, e.g. through a prior function call to
bdrv_getlength() which would always fail for an ejected BDS.  Add an
assert there to make it more obvious.

Other places seem to care, but do so insufficiently: Freeing clusters in
a qcow2 image is an error-free operation, but it may leave the image in
an unusable state anyway.  Giving qcow2_free_clusters() an error code is
not really viable, it is much easier to note that bs->drv may be NULL
even after a successful driver call.  This concerns bdrv_co_flush(), and
the way the check is added to bdrv_co_pdiscard() (in every iteration
instead of only once).

Finally, some places employ at least an assert(bs->drv); somewhere, that
may be reasonable (such as in the reopen code), but in
bdrv_has_zero_init(), it is definitely not.  Returning 0 there in case
of an ejected BDS saves us much headache instead.

Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1728660
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-4-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Max Reitz
54fd1b0d26 block: qobject_is_equal() in bdrv_reopen_prepare()
Currently, bdrv_reopen_prepare() assumes that all BDS options are
strings. However, this is not the case if the BDS has been created
through the json: pseudo-protocol or blockdev-add.

Note that the user-invokable reopen command is an HMP command, so you
can only specify strings there. Therefore, specifying a non-string
option with the "same" value as it was when originally created will now
return an error because the values are supposedly similar (and there is
no way for the user to circumvent this but to just not specify the
option again -- however, this is still strictly better than just
crashing).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20171114180128.17076-5-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:30 +01:00
Kevin Wolf
dafe096057 block: Fix permissions in image activation
Inactive images generally request less permissions for their image files
than they would if they were active (in particular, write permissions).
Activating the image involves extending the permissions, therefore.

drv->bdrv_invalidate_cache() can already require write access to the
image file, so we have to update the permissions earlier than that.
The current code does it only later, so we have to move up this part.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:06:12 +01:00
Kevin Wolf
398e6ad014 block: Deprecate bdrv_set_read_only() and users
bdrv_set_read_only() is used by some block drivers to override the
read-only option given by the user. This is not how read-only images
generally work in QEMU: Instead of second guessing what the user really
meant (which currently includes making an image read-only even if the
user didn't only use the default, but explicitly said read-only=off), we
should error out if we can't provide what the user requested.

This adds deprecation warnings to all callers of bdrv_set_read_only() so
that the behaviour can be corrected after the usual deprecation period.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-17 13:35:59 +01:00
Kevin Wolf
6473069416 block: Fix error path in bdrv_backing_update_filename()
error_setg_errno() takes a positive errno code. Spotted by Coverity
(CID 1381628).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-11-17 13:35:59 +01:00
Peter Krempa
6bff597bf6 block: don't add 'driver' to options when referring to backing via node name
When referring to a backing file of an image via node name
bdrv_open_backing_file would add the 'driver' option to the option list
filling it with the backing format driver. This breaks construction of
the backing chain via -blockdev, as bdrv_open_inherit reports an error
if both 'reference' and 'options' are provided.

$ qemu-img create -f raw /tmp/backing.raw 64M
$ qemu-img create -f qcow2 -F raw -b /tmp/backing.raw /tmp/test.qcow2
$ qemu-system-x86_64 \
  -blockdev driver=file,filename=/tmp/backing.raw,node-name=backing \
  -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing
qemu-system-x86_64: -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing: Could not open backing file: Cannot reference an existing block device with additional options or a new filename

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Kevin Wolf
bde70715b6 commit: Remove overlay_bs
We don't need to make any assumptions about the graph layout above the
top node of the commit operation any more. Remove the use of
bdrv_find_overlay() and related variables from the commit job code.

bdrv_drop_intermediate() doesn't use the 'active' parameter any more, so
we can just drop it.

The overlay node was previously added to the block job to get a
BLK_PERM_GRAPH_MOD. We really need to respect those permissions in
bdrv_drop_intermediate() now, but as long as we haven't figured out yet
how BLK_PERM_GRAPH_MOD is actually supposed to work, just leave a TODO
comment there.

With this change, it is now possible to perform another block job on an
overlay node without conflicts. qemu-iotests 030 is changed accordingly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
61f09cea01 commit: Support multiple roots above top node
This changes the commit block job to support operation in a graph where
there is more than a single active layer that references the top node.

This involves inserting the commit filter node not only on the path
between the given active node and the top node, but between the top node
and all of its parents.

On completion, bdrv_drop_intermediate() must consider all parents for
updating the backing file link. These parents may be backing files
themselves and as such read-only; reopen them temporarily if necessary.
Previously this was achieved by the bdrv_reopen() calls in the commit
block job that made overlay_bs read-write for the whole duration of the
block job, even though write access is only needed on completion.

Now that we consider all parents, overlay_bs is meaningless. It is left
in place in this commit, but we'll remove it soon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
6858eba09e block: Introduce BdrvChildRole.update_filename
There is no good reason for bdrv_drop_intermediate() to know the active
layer above the subchain it is operating on - even more so, because
the assumption that there is a single active layer above it is not
generally true.

In order to prepare removal of the active parameter, use a BdrvChildRole
callback to update the backing file string in the overlay image instead
of directly calling bdrv_change_backing_file().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
1b6cc579de dirty-bitmap: Avoid size query failure during truncate
We've previously fixed several places where we failed to account
for possible errors from bdrv_nb_sectors().  Fix another one by
making bdrv_dirty_bitmap_truncate() take the new size from the
caller instead of querying itself; then adjust the sole caller
bdrv_truncate() to pass the size just determined by a successful
resize, or to reuse the size given to the original truncate
operation when refresh_total_sectors() was not able to confirm the
actual size (the two sizes can potentially differ according to
rounding constraints), thus avoiding sizing the bitmaps to -1.
This also fixes a bug where not all failure paths in
bdrv_truncate() would set errp.

Note that bdrv_truncate() is still a bit awkward.  We may want
to revisit it later and clean up things to better guarantee that
a resize attempt either fails cleanly up front, or cannot fail
after guest-visible changes have been made (if temporary changes
are made, then they need to be cleanly rolled back).  But that
is a task for another day; for now, the goal is the bare minimum
fix to ensure that just bdrv_dirty_bitmap_truncate() cannot fail.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
a8b42a1c09 block: Make bdrv_img_create() size selection easier to read
All callers of bdrv_img_create() pass in a size, or -1 to read the
size from the backing file.  We then set that size as the QemuOpt
default, which means we will reuse that default rather than the
final parameter to qemu_opt_get_size() several lines later.  But
it is rather confusing to read subsequent checks of 'size == -1'
when it looks (without seeing the full context) like size defaults
to 0; it also doesn't help that a size of 0 is valid (for some
formats).

Rework the logic to make things more legible.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
3045025991 block: Fix permissions after bdrv_reopen()
If we switch between read-only and read-write, the permissions that
image format drivers need on bs->file change, too. Make sure to update
the permissions during bdrv_reopen().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Kevin Wolf
1857c97b76 block: reopen: Queue children after their parents
We will calculate the required new permissions in the prepare stage of a
reopen. Required permissions of children can be influenced by the
changes made to their parents, but parents are independent from their
children. This means that permissions need to be calculated top-down. In
order to achieve this, queue parents before their children rather than
queuing the children first.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Kevin Wolf
148eb13c84 block: Base permissions on rw state after reopen
When new permissions are calculated during bdrv_reopen(), they need to
be based on the state of the graph as it will be after the reopen has
completed, not on the current state of the involved nodes.

This patch makes bdrv_is_writable() optionally accept a BlockReopenQueue
from which the new flags are taken. This is then used for determining
the new bs->file permissions of format drivers as soon as we add the
code to actually pass a non-NULL reopen queue to the .bdrv_child_perm
callbacks.

While moving bdrv_is_writable(), make it static. It isn't used outside
block.c.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Kevin Wolf
3121fb45b0 block: Add reopen queue to bdrv_check_perm()
In the context of bdrv_reopen(), we'll have to look at the state of the
graph as it will be after the reopen. This interface addition is in
preparation for the change.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Kevin Wolf
e0995dc3da block: Add reopen_queue to bdrv_child_perm()
In the context of bdrv_reopen(), we'll have to look at the state of the
graph as it will be after the reopen. This interface addition is in
preparation for the change.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Manos Pitsidianakis
f024aee867 block: remove unused bdrv_media_changed
This function is not used anywhere, so remove it.

Markus Armbruster adds:
The i82078 floppy device model used to call bdrv_media_changed() to
implement its media change bit when backed by a host floppy.  This
went away in 21fcf36 "fdc: simplify media change handling".
Probably broke host floppy media change.  Host floppy pass-through
was dropped in commit f709623.  bdrv_media_changed() has never been
used for anything else.  Remove it.
(Source is Message-ID: <87y3ruaypm.fsf@dusky.pond.sub.org>)

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-04 18:31:13 +02:00
Manos Pitsidianakis
5a612c009e block: pass bdrv_* methods to bs->file by default in block filters
The following functions fail if bs->drv is a filter and does not
implement them:

bdrv_probe_blocksizes
bdrv_probe_geometry
bdrv_truncate
bdrv_has_zero_init
bdrv_get_info

Instead, the call should be passed to bs->file if it exists, to allow
filter drivers to support those methods without implementing them. This
commit makes `drv->is_filter = true` imply that these callbacks will be
forwarded to bs->file by default, so disabling support for these
functions must be done explicitly.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-04 18:31:13 +02:00
Marc-André Lureau
f7abe0ecd4 qapi: Change data type of the FOO_lookup generated for enum FOO
Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

A future patch will generate enums with "holes".  NULL-termination
will cease to work then.

To prepare for that, store the length in the FOO_lookup by wrapping it
in a struct and adding a member for the length.

The sentinel will be dropped next.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com>
[Basically redone]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com>
[Rebased]
2017-09-04 13:09:13 +02:00
Markus Armbruster
5b5f825d44 qapi: Generate FOO_str() macro for QAPI enum FOO
The next commit will put it to use.  May look pointless now, but we're
going to change the FOO_lookup's type, and then it'll help.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-13-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-09-04 13:09:13 +02:00
Markus Armbruster
06c60b6c46 qapi: Drop superfluous qapi_enum_parse() parameter max
The lookup tables have a sentinel, no need to make callers pass their
size.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-3-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Rebased, commit message corrected]
2017-09-04 13:09:13 +02:00
Stefan Hajnoczi
7d5b526110 block: Update open_flags after ->inactivate() callback
In the ->inactivate() callbacks, permissions are updated, which
typically involves a recursive check of the whole graph. Setting
BDRV_O_INACTIVE right before doing that creates a state that
bdrv_is_writable() returns false, which causes permission update
failure.

Reorder them so the flag is updated after calling the function. Note
that this doesn't break the assert in bdrv_child_cb_inactivate() because
for any specific BDS, we still update its flags first before calling
->inactivate() on it one level deeper in the recursion.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-5-famz@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-08-23 10:21:55 -05:00
Kevin Wolf
fd4520212b block: Set BDRV_O_ALLOW_RDWR during rw reopen
Reopening an image should be consistent with opening it, so we should
set BDRV_O_ALLOW_RDWR for any image that is reopened read-write like in
bdrv_open_inherit().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-08-08 15:19:16 +02:00
Kevin Wolf
54a32bfec1 block: Allow reopen rw without BDRV_O_ALLOW_RDWR
BDRV_O_ALLOW_RDWR is a flag that tells whether qemu can internally
reopen a node read-write temporarily because the user requested
read-write for the top-level image, but qemu decided that read-only is
enough for this node (a backing file).

bdrv_reopen() is different, it is also used for cases where the user
changed their mind and wants to update the options. There is no reason
to forbid making a node read-write in that case.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-08-08 15:19:16 +02:00
Kevin Wolf
8aecf1d1bd block: Fix order in bdrv_replace_child()
Commit 8ee03995 refactored the code incorrectly and broke the release of
permissions on the old BDS. Instead of changing the permissions to the
new required values after removing the old BDS from the list of
children, it only re-obtains the permissions it already had.

Change the order of operations so that the old BDS is removed again
before calculating the new required permissions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-08-08 15:19:16 +02:00
Manos Pitsidianakis
180ca19ae0 block: fix leaks in bdrv_open_driver()
bdrv_open_driver() is called in two places, bdrv_new_open_driver() and
bdrv_open_common(). In the latter, failure cleanup in is in its caller,
bdrv_open_inherit(), which unrefs the bs->file of the failed driver open
if it exists.

Let's move the bs->file cleanup to bdrv_open_driver() to take care of
all callers and do not set bs->drv to NULL unless the driver's open
function failed. When bs is destroyed by removing its last reference, it
calls bdrv_close() which checks bs->drv to perform the needed cleanups
and also call the driver's close function. Since it cleans up options
and opaque we must take care not leave dangling pointers.

The error paths in bdrv_open_driver() are now two:
If open fails, drv->bdrv_close() should not be called. Unref the child
if it exists, free what we allocated and set bs->drv to NULL. Return the
error and let callers free their stuff.

If open succeeds but we fail after, return the error and let callers
unref and delete their bs, while cleaning up their allocations.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-01 18:09:33 +02:00
Manos Pitsidianakis
998cbd6a44 block: fix dangling bs->explicit_options in block.c
In some error paths it is possible to QDECREF a freed dangling
explicit_options, resulting in a heap overflow crash.  For example
bdrv_open_inherit()'s fail unrefs it, then calls bdrv_unref which calls
bdrv_close which also unrefs it.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-01 18:09:33 +02:00
Kevin Wolf
d3c8c67469 block: Skip implicit nodes in query-block/blockstats
Commits 0db832f and 6cdbceb introduced the automatic insertion of filter
nodes above the top layer of mirror and commit block jobs. The
assumption made there was that since libvirt doesn't do node-level
management of the block layer yet, it shouldn't be affected by added
nodes.

This is true as far as commands issued by libvirt are concerned. It only
uses BlockBackend names to address nodes, so any operations it performs
still operate on the root of the tree as intended.

However, the assumption breaks down when you consider query commands,
which return data for the wrong node now. These commands also return
information on some child nodes (bs->file and/or bs->backing), which
libvirt does make use of, and which refer to the wrong nodes, too.

One of the consequences is that oVirt gets wrong information about the
image size and stops the VM in response as long as a mirror or commit
job is running:

https://bugzilla.redhat.com/show_bug.cgi?id=1470634

This patch fixes the problem by hiding the implicit nodes created
automatically by the mirror and commit block jobs in the output of
query-block and BlockBackend-based query-blockstats as long as the user
doesn't indicate that they are aware of those nodes by providing a node
name for them in the QMP command to start the block job.

The node-based commands query-named-block-nodes and query-blockstats
with query-nodes=true still show all nodes, including implicit ones.
This ensures that users that are capable of node-level management can
still access the full information; users that only know BlockBackends
won't use these commands.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
2017-07-24 15:06:04 +02:00
John Snow
6e6e55f5c2 qemu-img: Check for backing image if specified during create
Or, rather, force the open of a backing image if one was specified
for creation. Using a similar -unsafe option as rebase, allow qemu-img
to ignore the backing file validation if possible.

It may not always be possible, as in the existing case when a filesize
for the new image was not specified.

This is accomplished by shifting around the conditionals in
bdrv_img_create, such that a backing file is always opened unless we
provide BDRV_O_NO_BACKING. qemu-img is adjusted to pass this new flag
when -u is provided to create.

Sorry for the heinous looking diffstat, but it's mostly whitespace.

Inspired by: https://bugzilla.redhat.com/show_bug.cgi?id=1213786

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-18 15:27:37 +02:00
Peter Maydell
a309b290aa Error reporting patches for 2017-07-13
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Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2017-07-13' into staging

Error reporting patches for 2017-07-13

# gpg: Signature made Thu 13 Jul 2017 12:55:45 BST
# gpg:                using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2017-07-13:
  Convert error_report*_err() to warn_report*_err()
  error: Implement the warn and free Error functions
  char-socket: Report TCP socket waiting as information
  Convert error_report() to warn_report()
  error: Functions to report warnings and informational messages
  util/qemu-error: Rename error_print_loc() to be more generic
  websock: Don't try to set *errp directly
  block: Don't try to set *errp directly
  xilinx: Fix latent error handling bug

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-07-14 09:36:40 +01:00
Eduardo Habkost
57ef3f1278 block: Don't try to set *errp directly
Assigning directly to *errp is not valid, as errp may be NULL,
&error_fatal, or &error_abort.  Use error_propagate() instead.

With this, there's no need to check if errp is NULL anymore, as
error_propagate() and error_prepend() are able to handle that.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170608133906.12737-3-ehabkost@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-07-13 13:45:53 +02:00
Max Reitz
7ea37c3066 block: Add PreallocMode to bdrv_truncate()
For block drivers that just pass a truncate request to the underlying
protocol, we can now pass the preallocation mode instead of aborting if
it is not PREALLOC_MODE_OFF.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Max Reitz
8243ccb743 block: Add PreallocMode to BD.bdrv_truncate()
Add a PreallocMode parameter to the bdrv_truncate() function implemented
by each block driver. Currently, we always pass PREALLOC_MODE_OFF and no
driver accepts anything else.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Stefan Hajnoczi
90880ff107 block: add bdrv_measure() API
bdrv_measure() provides a conservative maximum for the size of a new
image.  This information is handy if storage needs to be allocated (e.g.
a SAN or an LVM volume) ahead of time.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-2-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:00 +02:00
Vladimir Sementsov-Ogievskiy
615b5dcf2d block: release persistent bitmaps on inactivate
We should release them here to reload on invalidate cache.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-31-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
67b792f5ed block: add bdrv_can_store_new_dirty_bitmap
This will be needed to check some restrictions before making bitmap
persistent in qmp-block-dirty-bitmap-add (this functionality will be
added by future patch)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-22-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
cca43ae1e1 block: bdrv_close: release bitmaps after drv->bdrv_close
Release bitmaps after 'if (bs->drv) { ... }' block. This will allow
format driver to save persistent bitmaps, which will appear in following
commits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-17-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
cb9ff6c25a block: new bdrv_reopen_bitmaps_rw interface
Add format driver handler, which should mark loaded read-only
bitmaps as 'IN_USE' in the image and unset read_only field in
corresponding BdrvDirtyBitmap's.

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: 20170628120530.31251-14-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
50bf65bab6 block: refactor bdrv_reopen_commit
Add bs local variable to simplify code.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-13-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
sochin.jiang
5ce6bfe255 mirror: Fix inconsistent backing AioContext for after mirroring
mirror_complete opens the backing chain, which should have the same
AioContext as the top when using iothreads. Make the code guarantee
this, which fixes a failed assertion in bdrv_attach_child.

Signed-off-by: sochin.jiang <sochin.jiang@huawei.com>
Message-id: 1498475064-39816-1-git-send-email-sochin.jiang@huawei.com
[mreitz: Reworded commit message]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:57 +02:00
Daniel P. Berrange
c01c214b69 block: remove all encryption handling APIs
Now that all encryption keys must be provided upfront via
the QCryptoSecret API and associated block driver properties
there is no need for any explicit encryption handling APIs
in the block layer. Encryption can be handled transparently
within the block driver. We only retain an API for querying
whether an image is encrypted or not, since that is a
potentially useful piece of metadata to report to the user.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-18-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:56 +02:00