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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Switch the qcow/qcow2 block driver over to use the generic cipher
API, this allows it to use the pluggable AES implementations,
instead of being hardcoded to use QEMU's built-in impl.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-10-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To prepare for a generic internal cipher API, move the
built-in AES implementation into the crypto/ directory
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-3-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
These macros expand into error class enumeration constant, comma,
string. Unclean. Has been that way since commit 13f59ae.
The error class is always ERROR_CLASS_GENERIC_ERROR since the previous
commit.
Clean up as follows:
* Prepend every use of a QERR_ macro by ERROR_CLASS_GENERIC_ERROR, and
delete it from the QERR_ macro. No change after preprocessing.
* Rewrite error_set(ERROR_CLASS_GENERIC_ERROR, ...) into
error_setg(...). Again, no change after preprocessing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
If a relatively large cluster size is chosen, the default of 1 MB L2
cache is not really appropriate. In this case, unless overridden by the
user, the default cache size should not be determined by its size in
bytes but by the number of L2 tables (clusters) it is supposed to
contain.
Note that without this patch, MIN_L2_CACHE_SIZE will effectively take
over the same role. However, providing space for just two L2 tables is
not enough to be the default.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>