Commit Graph

438 Commits

Author SHA1 Message Date
Eric Blake fdfab37dfe qcow2: Make distinction between zero cluster types obvious
Treat plain zero clusters differently from allocated ones, so that
we can simplify the logic of checking whether an offset is present.
Do this by splitting QCOW2_CLUSTER_ZERO into two new enums,
QCOW2_CLUSTER_ZERO_PLAIN and QCOW2_CLUSTER_ZERO_ALLOC.

I tried to arrange the enum so that we could use
'ret <= QCOW2_CLUSTER_ZERO_PLAIN' for all unallocated types, and
'ret >= QCOW2_CLUSTER_ZERO_ALLOC' for allocated types, although
I didn't actually end up taking advantage of the layout.

In many cases, this leads to simpler code, by properly combining
cases (sometimes, both zero types pair together, other times,
plain zero is more like unallocated while allocated zero is more
like normal).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170507000552.20847-7-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11 14:28:07 +02:00
Max Reitz 92413c16be qcow2: Fix preallocation size formula
When calculating the number of reftable entries, we should actually use
the number of refblocks and not (wrongly[1]) re-calculate it.

[1] "Wrongly" means: Dividing the number of clusters by the number of
    entries per refblock and rounding down instead of up.

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-11 12:08:24 +02:00
Eric Blake 46f5ac205a qobject: Use simpler QDict/QList scalar insertion macros
We now have macros in place to make it less verbose to add a scalar
to QDict and QList, so use them.

Patch created mechanically via:
  spatch --sp-file scripts/coccinelle/qobject.cocci \
    --macro-file scripts/cocci-macro-file.h --dir . --in-place
then touched up manually to fix a couple of '?:' back to original
spacing, as well as avoiding a long line in monitor.c.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-7-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09 09:13:51 +02:00
Eric Blake 048c5fd1bf qcow2: Allow discard of final unaligned cluster
As mentioned in commit 0c1bd46, we ignored requests to
discard the trailing cluster of an unaligned image.  While
discard is an advisory operation from the guest standpoint,
(and we are therefore free to ignore any request), our
qcow2 implementation exploits the fact that a discarded
cluster reads back as 0.  As long as we discard on cluster
boundaries, we are fine; but that means we could observe
non-zero data leaked at the tail of an unaligned image.

Enhance iotest 66 to cover this case, and fix the implementation
to honor a discard request on the final partial cluster.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170407013709.18440-1-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:03 +02:00
Max Reitz f59adb3256 block: Add .bdrv_truncate() error messages
Add missing error messages for the block driver implementations of
.bdrv_truncate(); drop the generic one from block.c's bdrv_truncate().

Since one of these changes touches a mis-indented block in
block/file-posix.c, this patch fixes that coding style issue along the
way.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-5-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:03 +02:00
Max Reitz 4bff28b81a block: Add errp to BD.bdrv_truncate()
Add an Error parameter to the block drivers' bdrv_truncate() interface.
If a block driver does not set this in case of an error, the generic
bdrv_truncate() implementation will do so.

Where it is obvious, this patch also makes some block drivers set this
value.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-4-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:03 +02:00
Max Reitz ed3d2ec98a block: Add errp to b{lk,drv}_truncate()
For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:02 +02:00
Kevin Wolf 55880601d8 block: Add BDRV_O_RESIZE for blk_new_open()
blk_new_open() is a convenience function that processes flags rather
than QDict options as a simple way to just open an image file.

In order to keep it convenient in the future, it must automatically
request the necessary permissions. This can easily be inferred from the
flags for read and write, but we need another flag that tells us whether
to get the resize permission.

We can't just always request it because that means that no block jobs
can run on the resulting BlockBackend (which is something that e.g.
qemu-img commit wants to do), but we also can't request it never because
most of the .bdrv_create() implementations call blk_truncate().

The solution is to introduce another flag that is passed by all users
that want to resize the image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf d7086422b1 block: Add error parameter to blk_insert_bs()
Now that blk_insert_bs() requests the BlockBackend permissions for the
node it attaches to, it can fail. Instead of aborting, pass the errors
to the callers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf 6d0eb64d5c block: Add permissions to blk_new()
We want every user to be specific about the permissions it needs, so
we'll pass the initial permissions as parameters to blk_new(). A user
only needs to call blk_set_perm() if it wants to change the permissions
after the fact.

The permissions are stored in the BlockBackend and applied whenever a
BlockDriverState should be attached in blk_insert_bs().

This does not include actually choosing the right set of permissions
everywhere yet. Instead, the usual FIXME comment is added to each place
and will be addressed in individual patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf 862f215fab block: Request child permissions in format drivers
This makes use of the .bdrv_child_perm() implementation for formats that
we just added. All format drivers expose the permissions they actually
need nows, so that they can be set accordingly and updated when parents
are attached or detached.

The only format not included here is raw, which was already converted
with the other filter drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf 4e4bf5c42c block: Attach bs->file only during .bdrv_open()
The way that attaching bs->file worked was a bit unusual in that it was
the only child that would be attached to a node which is not opened yet.
Because of this, the block layer couldn't know yet which permissions the
driver would eventually need.

This patch moves the point where bs->file is attached to the beginning
of the individual .bdrv_open() implementations, so drivers already know
what they are going to do with the child. This is also more consistent
with how driver-specific children work.

For a moment, bdrv_open() gets its own BdrvChild to perform image
probing, but instead of directly assigning this BdrvChild to the BDS, it
becomes a temporary one and the node name is passed as an option to the
drivers, so that they can simply use bdrv_open_child() to create another
reference for their own use.

This duplicated child for (the not opened yet) bs is not the final
state, a follow-up patch will change the image probing code to use a
BlockBackend, which is completely independent of bs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24 16:09:23 +01:00
Kevin Wolf 52cdbc5869 block: Pass BdrvChild to bdrv_truncate()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24 16:09:23 +01:00
Kevin Wolf 70b27f3643 qcow2: Use BB for resizing in qcow2_amend_options()
In order to able to convert bdrv_truncate() to take a BdrvChild and
later to correctly check the resize permission here, we need to use a
BlockBackend for resizing the image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24 16:09:23 +01:00
Alberto Garcia 7061a07898 qcow2: Optimize the refcount-block overlap check
The metadata overlap checks introduced in a40f1c2add help detect
corruption in the qcow2 image by verifying that data writes don't
overlap with existing metadata sections.

The 'refcount-block' check in particular iterates over the refcount
table in order to get the addresses of all refcount blocks and check
that none of them overlap with the region where we want to write.

The problem with the refcount table is that since it always occupies
complete clusters its size is usually very big. With the default
values of cluster_size=64KB and refcount_bits=16 this table holds 8192
entries, each one of them enough to map 2GB worth of host clusters.

So unless we're using images with several TB of allocated data this
table is going to be mostly empty, and iterating over it is a waste of
CPU. If the storage backend is fast enough this can have an effect on
I/O performance.

This patch keeps the index of the last used (i.e. non-zero) entry in
the refcount table and updates it every time the table changes. The
refcount-block overlap check then uses that index instead of reading
the whole table.

In my tests with a 4GB qcow2 file stored in RAM this doubles the
amount of write IOPS.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170201123828.4815-1-berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-02-12 00:47:43 +01:00
Eric Blake a3e1505dae qcow2: Don't strand clusters near 2G intervals during commit
The qcow2_make_empty() function is reached during 'qemu-img commit',
in order to clear out ALL clusters of an image.  However, if the
image cannot use the fast code path (true if the image is format
0.10, or if the image contains a snapshot), the cluster size is
larger than 512, and the image is larger than 2G in size, then our
choice of sector_step causes problems.  Since it is not cluster
aligned, but qcow2_discard_clusters() silently ignores an unaligned
head or tail, we are leaving clusters allocated.

Enhance the testsuite to expose the flaw, and patch the problem by
ensuring our step size is aligned.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-12-06 15:37:02 +01:00
Alberto Garcia 91203f08f0 qcow2: Allow 'cache-clean-interval' in Linux only
The cache-clean-interval option of qcow2 only works on Linux. However
we allow setting it in other systems regardless of whether it works or
not.

In those systems this option is not simply a no-op: it actually
invalidates perfectly valid cache tables for no good reason without
freeing their memory.

This patch forbids using that option in non-Linux systems.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-25 13:51:30 +01:00
Eric Blake 49228d1e95 block: Return -ENOTSUP rather than assert on unaligned discards
Right now, the block layer rounds discard requests, so that
individual drivers are able to assert that discard requests
will never be unaligned.  But there are some ISCSI devices
that track and coalesce multiple unaligned requests, turning it
into an actual discard if the requests eventually cover an
entire page, which implies that it is better to always pass
discard requests as low down the stack as possible.

In isolation, this patch has no semantic effect, since the
block layer currently never passes an unaligned request through.
But the block layer already has code that silently ignores
drivers that return -ENOTSUP for a discard request that cannot
be honored (as well as drivers that return 0 even when nothing
was done).  But the next patch will update the block layer to
fragment discard requests, so that clients are guaranteed that
they are either dealing with an unaligned head or tail, or an
aligned core, making it similar to the block layer semantics of
write zero fragmentation.

CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-22 15:59:22 +01:00
Eric Blake ecdbead659 qcow2: Inform block layer about discard boundaries
At the qcow2 layer, discard is only possible on a per-cluster
basis; at the moment, qcow2 silently rounds any unaligned
requests to this granularity.  However, an upcoming patch will
fix a regression in the block layer ignoring too much of an
unaligned discard request, by changing the block layer to
break up a discard request at alignment boundaries; for that
to work, the block layer must know about our limits.

However, we can't go one step further by changing
qcow2_discard_clusters() to assert that requests are always
aligned, since that helper function is reached on paths
outside of the block layer.

CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-11-22 15:59:22 +01:00
Fam Zheng 170f4b2e5c qcow2: Support BDRV_REQ_MAY_UNMAP
Handling this is similar to what is done to the L2 entry in the case of
compressed clusters.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-24 17:54:03 +02:00
Gonglei f844836ddc crypto: extend mode as a parameter in qcrypto_cipher_supports()
It can't guarantee all cipher modes are supported
if one cipher algorithm is supported by a backend.
Let's extend qcrypto_cipher_supports() to take both
the algorithm and mode as parameters.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-10-19 10:09:24 +01:00
Stefan Hajnoczi 0647d47cc1 qcow2: avoid memcpy(dst, NULL, len)
Section "7.1.4 Use of library functions" in the C99 standard says:

  If an argument to a function has an invalid value (such as [...]
  a null pointer [...]) [...] the behavior is undefined.

Additionally the "searching and sorting" functions are specified as
requiring valid pointer values as described in 7.1.4.

This patch fixes the following sanitizer errors:

  block/qcow2.c:1807:41: runtime error: null pointer passed as argument 2, which is declared to never be null
  block/qcow2-cluster.c:86:26: runtime error: null pointer passed as argument 2, which is declared to never be null

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1473758138-19260-1-git-send-email-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-13 11:00:55 +01:00
Pavel Butsykin 8b2bd09338 qcow2: fix iovec size at qcow2_co_pwritev_compressed
Use bytes as the size would be more exact than s->cluster_size.  Although
qemu_iovec_to_buf() will not allow to go beyond the qiov.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05 19:06:48 +02:00
Pavel Butsykin a2c0ca6f55 qcow2: cleanup qcow2_co_pwritev_compressed to avoid the recursion
Now that the function uses a vector instead of a buffer, there is no
need to use recursive code.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Jeff Cody <jcody@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05 19:06:48 +02:00
Pavel Butsykin fcccefc57f qcow2: add qcow2_co_pwritev_compressed
Added implementation of the qcow2_co_pwritev_compressed function that
will allow us to safely use compressed writes for the qcow2 from running
VMs.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Jeff Cody <jcody@redhat.com>
CC: Markus Armbruster <armbru@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05 19:06:48 +02:00
Vladimir Sementsov-Ogievskiy ebf7bba090 qcow2: do not allocate extra memory
There are no needs to allocate more than one cluster, as we set
avail_out for deflate to one cluster.

Zlib docs (http://www.zlib.net/manual.html) says:
"deflate compresses as much data as possible, and stops when the input
buffer becomes empty or the output buffer becomes full."

So, deflate will not write more than avail_out to output buffer. If
there is not enough space in output buffer for compressed data (it may
be larger than input data) deflate just returns Z_OK. (if all data is
compressed and written to output buffer deflate returns Z_STREAM_END).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 1468515565-81313-1-git-send-email-vsementsov@virtuozzo.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-26 17:46:37 +02:00
Eric Blake 82e8a7888b qcow2: Switch .bdrv_co_discard() to byte-based
Another step towards killing off sector-based block APIs.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468624988-423-15-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20 14:24:25 +01:00
Paolo Bonzini 0b8b8753e4 coroutine: move entry argument to qemu_coroutine_create
In practice the entry argument is always known at creation time, and
it is confusing that sometimes qemu_coroutine_enter is used with a
non-NULL argument to re-enter a coroutine (this happens in
block/sheepdog.c and tests/test-coroutine.c).  So pass the opaque value
at creation time, for consistency with e.g. aio_bh_new.

Mostly done with the following semantic patch:

@ entry1 @
expression entry, arg, co;
@@
- co = qemu_coroutine_create(entry);
+ co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry2 @
expression entry, arg;
identifier co;
@@
- Coroutine *co = qemu_coroutine_create(entry);
+ Coroutine *co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry3 @
expression entry, arg;
@@
- qemu_coroutine_enter(qemu_coroutine_create(entry), arg);
+ qemu_coroutine_enter(qemu_coroutine_create(entry, arg));

@ reentry @
expression co;
@@
- qemu_coroutine_enter(co, NULL);
+ qemu_coroutine_enter(co);

except for the aforementioned few places where the semantic patch
stumbled (as expected) and for test_co_queue, which would otherwise
produce an uninitialized variable warning.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00
Peter Maydell f1f7a1ddf3 block/qcow2: Don't use cpu_to_*w()
Don't use the cpu_to_*w() functions, which we are trying to deprecate.
Instead either just use cpu_to_*() to do the byteswap, or use
st*_be_p() if we need to do the store somewhere other than to a
variable that's already the correct type.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1466093177-17890-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-05 16:54:04 +02:00
Kevin Wolf a03ef88f77 block: Convert bdrv_co_preadv/pwritev to BdrvChild
This is the final patch for converting the common I/O path to take
a BdrvChild parameter instead of BlockDriverState.

The completion of this conversion means that all users that perform I/O
on an image need to actually hold a reference (in the form of BdrvChild,
possible as part of a BlockBackend) to that image. This also protects
against inconsistent use of BlockBackend vs. BlockDriverState functions
because direct use of a BlockDriverState isn't possible any more and
blk->root is private for block-backends.c.

In addition, we can now distinguish different users in the I/O path,
and the future op blockers work is going to add assertions based on
permissions stored in BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf 720ff280e7 block: Convert bdrv_pwrite_zeroes() to BdrvChild
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf d9ca2ea2e2 block: Convert bdrv_pwrite(v/_sync) to BdrvChild
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf cf2ab8fc34 block: Convert bdrv_pread(v) to BdrvChild
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf 18d51c4bac block: Convert bdrv_write() to BdrvChild
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Eric Blake 5411541270 block: Use bool as appropriate for BDS members
Using int for values that are only used as booleans is confusing.
While at it, rearrange a couple of members so that all the bools
are contiguous.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:26 +02:00
Eric Blake a5b8dd2ce8 block: Move request_alignment into BlockLimit
It makes more sense to have ALL block size limit constraints
in the same struct.  Improve the documentation while at it.

Simplify a couple of conditionals, now that we have audited and
documented that request_alignment is always non-zero.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:26 +02:00
Eric Blake a84178ccff qcow2: Set request_alignment during .bdrv_refresh_limits()
We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:25 +02:00
Eduardo Habkost 621ff94d50 error: Remove NULL checks on error_propagate() calls
error_propagate() already ignores local_err==NULL, so there's no
need to check it before calling.

Coccinelle patch used to perform the changes added to
scripts/coccinelle/error_propagate_null.cocci.

Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-2-git-send-email-ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-06-20 16:38:13 +02:00
Kevin Wolf 734a77584a qcow2: Let vmstate call qcow2_co_preadv/pwrite directly
We don't really want to go through the block layer in order to read from
or write to the vmstate in a qcow2 image. Doing so required a few ugly
hacks like saving and restoring the old image size (because writing to
vmstate offsets would increase the image size) or disabling the "reads
after EOF = zeroes" logic. When calling the right functions directly,
these hacks aren't necessary any more.

Note that .bdrv_vmstate_load/save() return 0 instead of the number of
bytes in case of success now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:56 +02:00
Kevin Wolf 5ddda0b8f0 block: Make .bdrv_load_vmstate() vectored
This brings it in line with .bdrv_save_vmstate().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Daniel P. Berrange 8c0dcbc4ad block: drop support for using qcow[2] encryption with system emulators
Back in the 2.3.0 release we declared qcow[2] encryption as
deprecated, warning people that it would be removed in a future
release.

  commit a1f688f415
  Author: Markus Armbruster <armbru@redhat.com>
  Date:   Fri Mar 13 21:09:40 2015 +0100

    block: Deprecate QCOW/QCOW2 encryption

The code still exists today, but by a (happy?) accident we entirely
broke the ability to use qcow[2] encryption in the system emulators
in the 2.4.0 release due to

  commit 8336aafae1
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Tue May 12 17:09:18 2015 +0100

    qcow2/qcow: protect against uninitialized encryption key

This commit was designed to prevent future coding bugs which
might cause QEMU to read/write data on an encrypted block
device in plain text mode before a decryption key is set.

It turns out this preventative measure was a little too good,
because we already had a long standing bug where QEMU read
encrypted data in plain text mode during system emulator
startup, in order to guess disk geometry:

  Thread 10 (Thread 0x7fffd3fff700 (LWP 30373)):
  #0  0x00007fffe90b1a28 in raise () at /lib64/libc.so.6
  #1  0x00007fffe90b362a in abort () at /lib64/libc.so.6
  #2  0x00007fffe90aa227 in __assert_fail_base () at /lib64/libc.so.6
  #3  0x00007fffe90aa2d2 in  () at /lib64/libc.so.6
  #4  0x000055555587ae19 in qcow2_co_readv (bs=0x5555562accb0, sector_num=0, remaining_sectors=1, qiov=0x7fffffffd260) at block/qcow2.c:1229
  #5  0x000055555589b60d in bdrv_aligned_preadv (bs=bs@entry=0x5555562accb0, req=req@entry=0x7fffd3ffea50, offset=offset@entry=0, bytes=bytes@entry=512, align=align@entry=512, qiov=qiov@entry=0x7fffffffd260, flags=0) at block/io.c:908
  #6  0x000055555589b8bc in bdrv_co_do_preadv (bs=0x5555562accb0, offset=0, bytes=512, qiov=0x7fffffffd260, flags=<optimized out>) at block/io.c:999
  #7  0x000055555589c375 in bdrv_rw_co_entry (opaque=0x7fffffffd210) at block/io.c:544
  #8  0x000055555586933b in coroutine_thread (opaque=0x555557876310) at coroutine-gthread.c:134
  #9  0x00007ffff64e1835 in g_thread_proxy (data=0x5555562b5590) at gthread.c:778
  #10 0x00007ffff6bb760a in start_thread () at /lib64/libpthread.so.0
  #11 0x00007fffe917f59d in clone () at /lib64/libc.so.6

  Thread 1 (Thread 0x7ffff7ecab40 (LWP 30343)):
  #0  0x00007fffe91797a9 in syscall () at /lib64/libc.so.6
  #1  0x00007ffff64ff87f in g_cond_wait (cond=cond@entry=0x555555e085f0 <coroutine_cond>, mutex=mutex@entry=0x555555e08600 <coroutine_lock>) at gthread-posix.c:1397
  #2  0x00005555558692c3 in qemu_coroutine_switch (co=<optimized out>) at coroutine-gthread.c:117
  #3  0x00005555558692c3 in qemu_coroutine_switch (from_=0x5555562b5e30, to_=to_@entry=0x555557876310, action=action@entry=COROUTINE_ENTER) at coroutine-gthread.c:175
  #4  0x0000555555868a90 in qemu_coroutine_enter (co=0x555557876310, opaque=0x0) at qemu-coroutine.c:116
  #5  0x0000555555859b84 in thread_pool_completion_bh (opaque=0x7fffd40010e0) at thread-pool.c:187
  #6  0x0000555555859514 in aio_bh_poll (ctx=ctx@entry=0x5555562953b0) at async.c:85
  #7  0x0000555555864d10 in aio_dispatch (ctx=ctx@entry=0x5555562953b0) at aio-posix.c:135
  #8  0x0000555555864f75 in aio_poll (ctx=ctx@entry=0x5555562953b0, blocking=blocking@entry=true) at aio-posix.c:291
  #9  0x000055555589c40d in bdrv_prwv_co (bs=bs@entry=0x5555562accb0, offset=offset@entry=0, qiov=qiov@entry=0x7fffffffd260, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:591
  #10 0x000055555589c503 in bdrv_rw_co (bs=bs@entry=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:614
  #11 0x000055555589c562 in bdrv_read_unthrottled (nb_sectors=21845, buf=0x7fffffffd2e0 "\321,", sector_num=0, bs=0x5555562accb0) at block/io.c:622
  #12 0x000055555589c562 in bdrv_read_unthrottled (bs=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845) at block/io.c:634
    nb_sectors@entry=1) at block/block-backend.c:504
  #14 0x0000555555752e9f in guess_disk_lchs (blk=blk@entry=0x5555562a5290, pcylinders=pcylinders@entry=0x7fffffffd52c, pheads=pheads@entry=0x7fffffffd530, psectors=psectors@entry=0x7fffffffd534) at hw/block/hd-geometry.c:68
  #15 0x0000555555752ff7 in hd_geometry_guess (blk=0x5555562a5290, pcyls=pcyls@entry=0x555557875d1c, pheads=pheads@entry=0x555557875d20, psecs=psecs@entry=0x555557875d24, ptrans=ptrans@entry=0x555557875d28) at hw/block/hd-geometry.c:133
  #16 0x0000555555752b87 in blkconf_geometry (conf=conf@entry=0x555557875d00, ptrans=ptrans@entry=0x555557875d28, cyls_max=cyls_max@entry=65536, heads_max=heads_max@entry=16, secs_max=secs_max@entry=255, errp=errp@entry=0x7fffffffd5e0) at hw/block/block.c:71
  #17 0x0000555555799bc4 in ide_dev_initfn (dev=0x555557875c80, kind=IDE_HD) at hw/ide/qdev.c:174
  #18 0x0000555555768394 in device_realize (dev=0x555557875c80, errp=0x7fffffffd640) at hw/core/qdev.c:247
  #19 0x0000555555769a81 in device_set_realized (obj=0x555557875c80, value=<optimized out>, errp=0x7fffffffd730) at hw/core/qdev.c:1058
  #20 0x00005555558240ce in property_set_bool (obj=0x555557875c80, v=<optimized out>, opaque=0x555557875de0, name=<optimized out>, errp=0x7fffffffd730)
        at qom/object.c:1514
  #21 0x0000555555826c87 in object_property_set_qobject (obj=obj@entry=0x555557875c80, value=value@entry=0x55555784bcb0, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/qom-qobject.c:24
  #22 0x0000555555825760 in object_property_set_bool (obj=obj@entry=0x555557875c80, value=value@entry=true, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/object.c:905
  #23 0x000055555576897b in qdev_init_nofail (dev=dev@entry=0x555557875c80) at hw/core/qdev.c:380
  #24 0x0000555555799ead in ide_create_drive (bus=bus@entry=0x555557629630, unit=unit@entry=0, drive=0x5555562b77e0) at hw/ide/qdev.c:122
  #25 0x000055555579a746 in pci_ide_create_devs (dev=dev@entry=0x555557628db0, hd_table=hd_table@entry=0x7fffffffd830) at hw/ide/pci.c:440
  #26 0x000055555579b165 in pci_piix3_ide_init (bus=<optimized out>, hd_table=0x7fffffffd830, devfn=<optimized out>) at hw/ide/piix.c:218
  #27 0x000055555568ca55 in pc_init1 (machine=0x5555562960a0, pci_enabled=1, kvmclock_enabled=<optimized out>) at /home/berrange/src/virt/qemu/hw/i386/pc_piix.c:256
  #28 0x0000555555603ab2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4249

So the safety net is correctly preventing QEMU reading cipher
text as if it were plain text, during startup and aborting QEMU
to avoid bad usage of this data.

For added fun this bug only happens if the encrypted qcow2
file happens to have data written to the first cluster,
otherwise the cluster won't be allocated and so qcow2 would
not try the decryption routines at all, just return all 0's.

That no one even noticed, let alone reported, this bug that
has shipped in 2.4.0, 2.5.0 and 2.6.0 shows that the number
of actual users of encrypted qcow2 is approximately zero.

So rather than fix the crash, and backport it to stable
releases, just go ahead with what we have warned users about
and disable any use of qcow2 encryption in the system
emulators. qemu-img/qemu-io/qemu-nbd are still able to access
qcow2 encrypted images for the sake of data conversion.

In the future, qcow2 will gain support for the alternative
luks format, but when this happens it'll be using the
'-object secret' infrastructure for getting keys, which
avoids this problematic scenario entirely.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf d46a0bb24d qcow2: Implement .bdrv_co_pwritev()
This changes qcow2 to implement the byte-based .bdrv_co_pwritev
interface rather than the sector-based old one.

As preallocation uses the same allocation function as normal writes, and
the interface of that function needs to be changed, it is converted in
the same patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf ecfe186380 qcow2: Implement .bdrv_co_preadv()
Reading from qcow2 images is now byte granularity.

Most of the affected code in qcow2 actually gets simpler with this
change. The only exception is encryption, which is fixed on 512 bytes
blocks; in order to keep this working, bs->request_alignment is set for
encrypted images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Denis V. Lunev f3c3b87dae qcow2: avoid extra flushes in qcow2
The problem with excessive flushing was found by a couple of performance
tests:
  - parallel directory tree creation (from 2 processes)
  - 32 cached writes + fsync at the end in a loop

For the first one results improved from 2.6 loops/sec to 3.5 loops/sec.
Each loop creates 10^3 directories with 10 files in each.

For the second one results improved from ~600 fsync/sec to ~1100
fsync/sec. Though, it was run on SSD so it probably won't show such
performance gain on rotational media.

qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
cache entries of a particular cache. This can lead to as many as
2 additional fdatasyncs inside bdrv_flush.

We can simply skip all fdatasync calls inside qcow2_co_flush_to_os
as bdrv_flush for sure will do the job. These flushes are necessary to
keep the right order of writes to the different caches. Though this is
not necessary in the current code base as this ordering is ensured through
the flush in qcow2_cache_flush_dependency().

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Pavel Borzenkov <pborzenkov@virtuozzo.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:09 +02:00
Eric Blake 5544b59f8e qcow2: Convert to bdrv_co_pwrite_zeroes()
Another step on our continuing quest to switch to byte-based
interfaces.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00
Eric Blake 74021bc497 block: Switch bdrv_write_zeroes() to byte interface
Rename to bdrv_pwrite_zeroes() to let the compiler ensure we
cater to the updated semantics.  Do the same for bdrv_co_write_zeroes().

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00
Eric Blake cf081fca4e block: Track write zero limits in bytes
Another step towards removing sector-based interfaces: convert
the maximum write and minimum alignment values from sectors to
bytes.  Rename the variables to let the compiler check that all
users are converted to the new semantics.

The maximum remains an int as long as BDRV_REQUEST_MAX_SECTORS
is constrained by INT_MAX (this means that we can't even
support a 2G write_zeroes, but just under it) - changing
operation lengths to unsigned or to 64-bits is a much bigger
audit, and debatable if we even want to do it (since at the
core, a 32-bit platform will still have ssize_t as its
underlying limit on write()).

Meanwhile, alignment is changed to 'uint32_t', since it makes no
sense to have an alignment larger than the maximum write, and
less painful to use an unsigned type with well-defined behavior
in bit operations than to have to worry about what happens if
a driver mistakenly supplies a negative alignment.

Add an assert that no one was trying to use sectors to get a
write zeroes larger than 2G, and therefore that a later conversion
to bytes won't be impacted by keeping the limit at 32 bits.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00
Eric Blake ebb718a5c7 qcow2: Catch more unaligned write_zero into zero cluster
is_zero_cluster() and is_zero_cluster_top_locked() are used only
by qcow2_co_write_zeroes().  The former is too broad (we don't
care if the sectors we are about to overwrite are non-zero, only
that all other sectors in the cluster are zero), so it needs to
be called up to twice but with smaller limits - rename it along
with adding the neeeded parameter.  The latter can be inlined for
more compact code.

The testsuite change shows that we now have a sparser top file
when an unaligned write_zeroes overwrites the only portion of
the backing file with data.

Based on a patch proposal by Denis V. Lunev.

CC: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00
Denis V. Lunev 5a64e94251 qcow2: add tracepoints for qcow2_co_write_zeroes
This patch follows guidelines of all other tracepoints in qcow2, like ones
in qcow2_co_writev. I think that they should dump values in the same
quantities or be changed all together.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1463476543-3087-4-git-send-email-den@openvz.org>
[eblake: typo fix in commit message]
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00
Denis V. Lunev ba142846b0 qcow2: simplify logic in qcow2_co_write_zeroes
Unaligned requests will occupy only one cluster. This is true since the
previous commit. Simplify the code taking this consideration into
account.

In other words, the caller is now buggy if it ever passes us an unaligned
request that crosses cluster boundaries (the only requests that can cross
boundaries will be aligned).

There are no other changes so far.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
CC: Eric Blake <eblake@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1463476543-3087-3-git-send-email-den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00
Peter Maydell 6bd8ab6889 Block layer patches
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Thu 19 May 2016 16:09:27 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream: (31 commits)
  qemu-iotests: Fix regression in 136 on aio_read invalid
  qemu-iotests: Simplify 109 with unaligned qemu-img compare
  qemu-io: Fix recent UI updates
  block: clarify error message for qmp-eject
  qemu-iotests: Some more write_zeroes tests
  qcow2: Fix write_zeroes with partially allocated backing file cluster
  qcow2: fix condition in is_zero_cluster
  block: Propagate AioContext change to all children
  block: Remove BlockDriverState.blk
  block: Don't return throttling info in query-named-block-nodes
  block: Avoid bs->blk in bdrv_next()
  block: Add bdrv_has_blk()
  block: Remove bdrv_aio_multiwrite()
  blockjob: Don't touch BDS iostatus
  blockjob: Don't set iostatus of target
  block: User BdrvChild callback for device name
  block: Use BdrvChild callbacks for change_media/resize
  block: Don't check throttled reqs in bdrv_requests_pending()
  Revert "block: Forbid I/O throttling on nodes with multiple parents for 2.6"
  block: Remove bdrv_move_feature_fields()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-05-19 16:54:12 +01:00
Kevin Wolf 5efdf53227 qcow2: Fix write_zeroes with partially allocated backing file cluster
In order to correctly check whether a given cluster is read as zero, we
don't only need to check whether bdrv_get_block_status_above() sets
BDRV_BLOCK_ZERO, but also if all sectors for the whole cluster have the
same status.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
2016-05-19 16:45:31 +02:00
Denis V. Lunev f575f145f4 qcow2: fix condition in is_zero_cluster
We should check for (res & BDRV_BLOCK_ZERO) only. The situation when we
will have !(res & BDRV_BLOCK_DATA) and will not have BDRV_BLOCK_ZERO is
not possible for images with bdi.unallocated_blocks_are_zero == true.

For those images where it's false, however, it can happen and we must
not consider the data zeroed then or we would corrupt the image.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-19 16:45:31 +02:00
Paolo Bonzini 58369e22cf qemu-common: stop including qemu/bswap.h from qemu-common.h
Move it to the actual users.  There are still a few includes of
qemu/bswap.h in headers; removing them is left for future work.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:28 +02:00
Fam Zheng c9e9e9c66c block: Drop superfluous invalidating bs->file from drivers
Now they are invalidated by the block layer, so it's not necessary to
do this in block drivers' implementations of .bdrv_invalidate_cache.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Denis V. Lunev 2928abce6d qcow2: improve qcow2_co_write_zeroes()
There is a possibility that qcow2_co_write_zeroes() will be called
with the partial block. This could be synthetically triggered with
    qemu-io -c "write -z 32k 4k"
and can happen in the real life in qemu-nbd. The latter happens under
the following conditions:
    (1) qemu-nbd is started with --detect-zeroes=on and is connected to the
        kernel NBD client
    (2) third party program opens kernel NBD device with O_DIRECT
    (3) third party program performs write operation with memory buffer
        not aligned to the page
In this case qcow2_co_write_zeroes() is unable to perform the operation
and mark entire cluster as zeroed and returns ENOTSUP. Thus the caller
switches to non-optimized version and writes real zeroes to the disk.

The patch creates a shortcut. If the block is read as zeroes, f.e. if
it is unallocated, the request is extended to cover full block.
User-visible situation with this block is not changed. Before the patch
the block is filled in the image with real zeroes. After that patch the
block is marked as zeroed in metadata. Thus any subsequent changes in
backing store chain are not affected.

Kevin, thank you for a cool suggestion.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Eric Blake 8341f00dc2 block: Allow BDRV_REQ_FUA through blk_pwrite()
We have several block drivers that understand BDRV_REQ_FUA,
and emulate it in the block layer for the rest by a full flush.
But without a way to actually request BDRV_REQ_FUA during a
pass-through blk_pwrite(), FUA-aware block drivers like NBD are
forced to repeat the emulation logic of a full flush regardless
of whether the backend they are writing to could do it more
efficiently.

This patch just wires up a flags argument; followup patches
will actually make use of it in the NBD driver and in qemu-io.

Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:08 +02:00
Max Reitz 4e876bcf2b qcow2: Prevent backing file names longer than 1023
We reject backing file names with a length of more than 1023 characters
when opening a qcow2 file, so we should not produce such files
ourselves.

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-04-12 18:06:51 +02:00
Kevin Wolf 72e775c7d9 block: Always set writeback mode in blk_new_open()
All callers of blk_new_open() either don't rely on the WCE bit set after
blk_new_open() because they explicitly set it anyway, or they pass
BDRV_O_CACHE_WB unconditionally.

This patch changes blk_new_open() so that it always enables writeback
mode and asserts that BDRV_O_CACHE_WB is clear. For those callers that
used to pass BDRV_O_CACHE_WB unconditionally, the flag is removed now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:01 +02:00
Daniel P. Berrange e6ff69bf5e block: move encryption deprecation warning into qcow code
For a couple of releases we have been warning

  Encrypted images are deprecated
  Support for them will be removed in a future release.
  You can use 'qemu-img convert' to convert your image to an unencrypted one.

This warning was issued by system emulators, qemu-img, qemu-nbd
and qemu-io. Such a broad warning was issued because the original
intention was to rip out all the code for dealing with encryption
inside the QEMU block layer APIs.

The new block encryption framework used for the LUKS driver does
not rely on the unloved block layer API for encryption keys,
instead using the QOM 'secret' object type. It is thus no longer
appropriate to warn about encryption unconditionally.

When the qcow/qcow2 drivers are converted to use the new encryption
framework too, it will be practical to keep AES-CBC support present
for use in qemu-img, qemu-io & qemu-nbd to allow for interoperability
with older QEMU versions and liberation of data from existing encrypted
qcow2 files.

This change moves the warning out of the generic block code and
into the qcow/qcow2 drivers. Further, the warning is set to only
appear when running the system emulators, since qemu-img, qemu-io,
qemu-nbd are expected to support qcow2 encryption long term now that
the maint burden has been eliminated.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-30 12:12:15 +02:00
Veronia Bahaa f348b6d1a5 util: move declarations out of qemu-common.h
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)

Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:17 +01:00
Eric Blake 32bafa8fdd qapi: Don't special-case simple union wrappers
Simple unions were carrying a special case that hid their 'data'
QMP member from the resulting C struct, via the hack method
QAPISchemaObjectTypeVariant.simple_union_type().  But by using
the work we started by unboxing flat union and alternate
branches, coupled with the ability to visit the members of an
implicit type, we can now expose the simple union's implicit
type in qapi-types.h:

| struct q_obj_ImageInfoSpecificQCow2_wrapper {
|     ImageInfoSpecificQCow2 *data;
| };
|
| struct q_obj_ImageInfoSpecificVmdk_wrapper {
|     ImageInfoSpecificVmdk *data;
| };
...
| struct ImageInfoSpecific {
|     ImageInfoSpecificKind type;
|     union { /* union tag is @type */
|         void *data;
|-        ImageInfoSpecificQCow2 *qcow2;
|-        ImageInfoSpecificVmdk *vmdk;
|+        q_obj_ImageInfoSpecificQCow2_wrapper qcow2;
|+        q_obj_ImageInfoSpecificVmdk_wrapper vmdk;
|     } u;
| };

Doing this removes asymmetry between QAPI's QMP side and its
C side (both sides now expose 'data'), and means that the
treatment of a simple union as sugar for a flat union is now
equivalent in both languages (previously the two approaches used
a different layer of dereferencing, where the simple union could
be converted to a flat union with equivalent C layout but
different {} on the wire, or to an equivalent QMP wire form
but with different C representation).  Using the implicit type
also lets us get rid of the simple_union_type() hack.

Of course, now all clients of simple unions have to adjust from
using su->u.member to using su->u.member.data; while this touches
a number of files in the tree, some earlier cleanup patches
helped minimize the change to the initialization of a temporary
variable rather than every single member access.  The generated
qapi-visit.c code is also affected by the layout change:

|@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member
|     }
|     switch (obj->type) {
|     case IMAGE_INFO_SPECIFIC_KIND_QCOW2:
|-        visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err);
|+        visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err);
|         break;
|     case IMAGE_INFO_SPECIFIC_KIND_VMDK:
|-        visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err);
|+        visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err);
|         break;
|     default:
|         abort();

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-03-18 10:29:26 +01:00
Max Reitz efaa7c4eeb blockdev: Split monitor reference from BB creation
Before this patch, blk_new() automatically assigned a name to the new
BlockBackend and considered it referenced by the monitor. This patch
removes the implicit monitor_add_blk() call from blk_new() (and
consequently the monitor_remove_blk() call from blk_delete(), too) and
thus blk_new() (and related functions) no longer take a BB name
argument.

In fact, there is only a single point where blk_new()/blk_new_open() is
called and the new BB is monitor-owned, and that is in blockdev_init().
Besides thus relieving us from having to invent names for all of the BBs
we use in qemu-img, this fixes a bug where qemu cannot create a new
image if there already is a monitor-owned BB named "image".

If a BB and its BDS tree are created in a single operation, as of this
patch the BDS tree will be created before the BB is given a name
(whereas it was the other way around before). This results in minor
change to the output of iotest 087, whose reference output is amended
accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:56 +01:00
Max Reitz a55448b368 qapi: Drop QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
Just specifying a custom string is simpler in basically all places that
used it, and in addition, specifying the BB or node name is something we
generally do not do in other error messages when opening a BDS, so we
should not do it here.

This changes the output for iotest 036 (to the better, in my opinion),
so the reference output needs to be changed accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-17 15:47:56 +01:00
Kevin Wolf 23588797b6 qcow2: Use BB functions in .bdrv_create()
All users of the block layers are supposed to go through a BlockBackend.
The .bdrv_create() implementation is one such user, so this patch
converts it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-14 16:46:43 +01:00
Kevin Wolf 6340472c54 block: Use writeback in .bdrv_create() implementations
There's no reason to use a writethrough cache mode while creating an
image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-14 16:46:43 +01:00
Fam Zheng 178b4db7e5 qcow2: Assign bs->file->bs to file in qcow2_co_get_block_status
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1453780743-16806-4-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-02-02 17:50:47 +01:00
Fam Zheng 67a0fd2a9b block: Add "file" output parameter to block status query functions
The added parameter can be used to return the BDS pointer which the
valid offset is referring to. Its value should be ignored unless
BDRV_BLOCK_OFFSET_VALID in ret is set.

Until block drivers fill in the right value, let's clear it explicitly
right before calling .bdrv_get_block_status.

The "bs->file" condition in bdrv_co_get_block_status is kept now to keep iotest
case 102 passing, and will be fixed once all drivers return the right file
pointer.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1453780743-16806-2-git-send-email-famz@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-02-02 17:50:47 +01:00
Kevin Wolf 191fb11bdf qcow2: Make image inaccessible after failed qcow2_invalidate_cache()
If qcow2_invalidate_cache() fails, we are in a state where qcow2_close()
has already been completed, but the image hasn't been reopened yet.
Calling into any qcow2 function for an image in this state will cause
crashes.

The real solution would be to get rid of the close/open pair and instead
do an atomic reset of the involved data structures, but this isn't
trivial, so let's just make the image inaccessible for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-20 13:36:24 +01:00
Kevin Wolf 140fd5a69c qcow2: Fix BDRV_O_INACTIVE handling in qcow2_invalidate_cache()
What qcow2_invalidate_cache() should do is close the image with
BDRV_O_INACTIVE set and reopen it with the flag cleared. In fact, it
used to do exactly the opposite: qcow2_close() relied on bs->open_flags,
which is already updated to have cleared BDRV_O_INACTIVE at this point,
whereas qcow2_open() was called with s->flags, which has the flag still
set. Fix this.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-20 13:36:23 +01:00
Kevin Wolf ec6d891224 qcow2: Implement .bdrv_inactivate
The callback has to ensure that closing or flushing the image afterwards
wouldn't cause a write access to the image files. This means that just
the caches have to be written out, which is part of the existing
.bdrv_close implementation.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-20 13:36:23 +01:00
Kevin Wolf 04c01a5c8f block: Rename BDRV_O_INCOMING to BDRV_O_INACTIVE
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>
2016-01-20 13:36:23 +01:00
Kevin Wolf b527c9b392 qcow2: Write full header on image creation
When creating a qcow2 image, we didn't necessarily call
qcow2_update_header(), but could end up with the basic header that
qcow2_create2() created manually. One thing that this basic header
lacks is the feature table. Let's make sure that it's always present.

This requires a few updates to test cases as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-20 13:36:23 +01:00
Kevin Wolf 1a4828c793 qcow2: Write feature table only for v3 images
Version 2 images don't have feature bits, so writing a feature table to
those images is kind of pointless.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-01-20 13:36:23 +01:00
Peter Maydell 80c71a241a block: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-20 13:36:23 +01:00
Markus Armbruster e43bfd9c87 error: Use error_prepend() where it makes obvious sense
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>
2016-01-13 15:16:17 +01:00
Denis V. Lunev b1fc8f934b qcow2: insert assert into qcow2_get_specific_info()
s->qcow_version is always set to 2 or 3. Let's assert if this is wrong.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-12-18 14:34:43 +01:00
Max Reitz 61ce55fc02 qcow2: Invoke refcount order amendment function
Make use of qcow2_change_refcount_order() to support changing the
refcount order with qemu-img amend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-12-18 14:34:43 +01:00
Max Reitz c293a80927 qcow2: Use intermediate helper CB for amend
If there is more than one time-consuming operation to be performed for
qcow2_amend_options(), we need an intermediate CB which coordinates the
progress of the individual operations and passes the result to the
original status callback.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-12-18 14:34:43 +01:00
Max Reitz 1038bbb803 qcow2: Split upgrade/downgrade paths for amend
If the image version should be upgraded, that is the first we should do;
if it should be downgraded, that is the last we should do. So split the
version change block into an upgrade part at the start and a downgrade
part at the end.

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>
2015-12-18 14:34:43 +01:00
Max Reitz 164e0f89cc qcow2: Use abort() instead of assert(false)
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>
2015-12-18 14:34:43 +01:00
Max Reitz 29d72431ef qcow2: Use error_report() in qcow2_amend_options()
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>
2015-12-18 14:34:43 +01:00
Max Reitz 8b13976d3f block: Add opaque value to the amend CB
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>
2015-12-18 14:34:43 +01:00
Kevin Wolf 5365f44dfa qcow2: Add .bdrv_join_options callback
qcow2 accepts a few driver-specific options that overlap semantically
(e.g. "overlap-check" is an alias of "overlap-check.template", and any
missing cache size option is derived from the given ones).

When bdrv_reopen() merges the set of updated options with left out
options that should be kept at their old value, we need to consider this
and filter out any duplicates (which would generally cause errors
because new and old value would contradict each other).

This patch adds a .bdrv_join_options callback to BlockDriver and
implements it for qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
2015-12-18 14:34:42 +01:00
Eric Blake 7fb1cf1606 qapi: Don't let implicit enum MAX member collide
Now that we guarantee the user doesn't have any enum values
beginning with a single underscore, we can use that for our
own purposes.  Renaming ENUM_MAX to ENUM__MAX makes it obvious
that the sentinel is generated.

This patch was mostly generated by applying a temporary patch:

|diff --git a/scripts/qapi.py b/scripts/qapi.py
|index e6d014b..b862ec9 100644
|--- a/scripts/qapi.py
|+++ b/scripts/qapi.py
|@@ -1570,6 +1570,7 @@ const char *const %(c_name)s_lookup[] = {
|     max_index = c_enum_const(name, 'MAX', prefix)
|     ret += mcgen('''
|     [%(max_index)s] = NULL,
|+// %(max_index)s
| };
| ''',
|                max_index=max_index)

then running:

$ cat qapi-{types,event}.c tests/test-qapi-types.c |
    sed -n 's,^// \(.*\)MAX,s|\1MAX|\1_MAX|g,p' > list
$ git grep -l _MAX | xargs sed -i -f list

The only things not generated are the changes in scripts/qapi.py.

Rejecting enum members named 'MAX' is now useless, and will be dropped
in the next patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-23-git-send-email-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
[Rebased to current master, commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Eric Blake 6a8f9661dc block: Convert to new qapi union layout
We have two issues with our qapi union layout:
1) Even though the QMP wire format spells the tag 'type', the
C code spells it 'kind', requiring some hacks in the generator.
2) The C struct uses an anonymous union, which places all tag
values in the same namespace as all non-variant members. This
leads to spurious collisions if a tag value matches a non-variant
member's name.

Make the conversion to the new layout for block-related code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-16-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:27 +01:00
Kevin Wolf 760e006384 block: Convert bs->backing_hd to BdrvChild
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>
2015-10-16 15:34:29 +02:00
Kevin Wolf 9a4f4c3156 block: Convert bs->file to BdrvChild
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>
2015-10-16 15:34:29 +02:00
Kevin Wolf 5b0959a7d4 qcow2: Support updating driver-specific options in reopen
For updating the cache sizes, disabling lazy refcounts and updating the
clean_cache_timer there is a bit more to do than just changing the
variables, but otherwise we're all set for changing options during
bdrv_reopen().

Just implement the missing pieces and hook the functions up in
bdrv_reopen().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:37 +02:00
Kevin Wolf ee55b17304 qcow2: Make qcow2_update_options() suitable for transactions
Before we can allow updating options at runtime with bdrv_reopen(), we
need to split the function into prepare/commit/abort parts.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:37 +02:00
Kevin Wolf c1344ded70 qcow2: Fix memory leak in qcow2_update_options() error path
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Kevin Wolf 007dbc396c qcow2: Leave s unchanged on qcow2_update_options() failure
On return, either all new options should be applied to BDRVQcowState (on
success), or all of the old settings should be preserved (on failure).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Kevin Wolf 94edf3fbe8 qcow2: Move rest of option handling to qcow2_update_options()
With this commit, the handling of driver-specific options in
qcow2_open() is completely separated out into qcow2_update_options().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Kevin Wolf 90efa0eaef qcow2: Move qcow2_update_options() call up
qcow2_update_options() only updates some variables in BDRVQcowState and
doesn't really depend on other parts of it being initialised yet, so it
can be moved so that it immediately follows the other half of option
handling code in qcow2_open().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Kevin Wolf 4c75d1a157 qcow2: Factor out qcow2_update_options()
Eventually we want to be able to change options at runtime. As a first
step towards that goal, separate some option handling code from the
general initialisation code in qcow2_open().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Kevin Wolf f113ae839e qcow2: Improve error message
Eric says that "any" sounds better than "either", and my non-native
feeling says the same, so let's change it.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Kevin Wolf ff99129ab8 qcow2: Rename BDRVQcowState to BDRVQcow2State
BDRVQcowState is already used by qcow1, and gdb is always confused which
one to use. Rename the qcow2 one so they can be distinguished.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
2015-09-14 16:51:36 +02:00
Max Reitz 6ebf9aa2ef block: Drop drv parameter from bdrv_open()
Now that this parameter is effectively unused, we can drop it and just
pass NULL on to bdrv_open_inherit().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-09-14 16:51:36 +02:00
Max Reitz e6641719fe block: Always pass NULL as drv for bdrv_open()
Change all callers of bdrv_open() to pass the driver name in the options
QDict instead of passing its BlockDriver pointer.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-09-14 16:51:36 +02:00
Alberto Garcia 279621c046 qcow2: add option to clean unused cache entries after some time
This adds a new 'cache-clean-interval' option that cleans all qcow2
cache entries that haven't been used in a certain interval, given in
seconds.

This allows setting a large L2 cache size so it can handle scenarios
with lots of I/O and at the same time use little memory during periods
of inactivity.

This feature currently relies on MADV_DONTNEED to free that memory, so
it is not useful in systems that don't follow that behavior.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: a70d12da60433df9360ada648b3f34b8f6f354ce.1438690126.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-09-04 21:00:32 +02:00