Commit Graph

454 Commits

Author SHA1 Message Date
Edgar Kaziakhmedov
546a7dc40e qcow2: get rid of qcow2_backing_read1 routine
Since bdrv_co_preadv does all neccessary checks including
reading after the end of the backing file, avoid duplication
of verification before bdrv_co_preadv call.

Signed-off-by: Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:03:41 +01:00
Max Reitz
791fff504c qcow2: check_errors are fatal
When trying to repair a dirty image, qcow2_check() may apparently
succeed (no really fatal error occurred that would prevent the check
from continuing), but if check_errors in the result object is non-zero,
we cannot trust the image to be usable.

Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1728639
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:30 +01:00
Anton Nefedov
3e3b838ffe qcow2: reject unaligned offsets in write compressed
Misaligned compressed write is not supported.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Message-id: 1510654613-47868-2-git-send-email-anton.nefedov@virtuozzo.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:30 +01:00
Eric Blake
4096974e18 qcow2: fix image corruption on commit with persistent bitmap
If an image contains persistent bitmaps, we cannot use the
fast path of bdrv_make_empty() to clear the image during
qemu-img commit, because that will lose the clusters related
to the bitmaps.

Also leave a comment in qcow2_read_extensions to remind future
feature additions to think about fast-path removal, since we
just barely fixed the same bug for LUKS encryption.

It's a pain that qemu-img has not yet been taught to manipulate,
or even at a very minimum display, information about persistent
bitmaps; instead, we have to use QMP commands.  It's also a
pain that only qeury-block and x-debug-block-dirty-bitmap-sha256
will allow bitmap introspection; but the former requires the
node to be hooked to a block device, and the latter is experimental.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-17 18:21:01 +01:00
Daniel P. Berrange
f06033295b qcow2: fix image corruption after committing qcow2 image into base
After committing the qcow2 image contents into the base image, qemu-img
will call bdrv_make_empty to drop the payload in the layered image.

When this is done for qcow2 images, it blows away the LUKS encryption
header, making the resulting image unusable. There are two codepaths
for emptying a qcow2 image, and the second (slower) codepath leaves
the LUKS header intact, so force use of that codepath.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-17 13:36:03 +01:00
Daniel P. Berrange
f66afbe26f qcow2: don't permit changing encryption parameters
Currently if trying to change encryption parameters on a qcow2 image, qemu-img
will abort. We already explicitly check for attempt to change encrypt.format
but missed other parameters like encrypt.key-secret. Rather than list each
parameter, just blacklist changing of all parameters with a 'encrypt.' prefix.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-17 13:35:59 +01:00
Alberto Garcia
c9b83e9c23 qcow2: Assert that the crypto header does not overlap other metadata
The crypto header is initialized only when QEMU is creating a new
image, so there's no chance of this happening on a corrupted image.

If QEMU is really trying to allocate the header overlapping other
existing metadata sections then this is a serious bug in QEMU itself
so let's add an assertion.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: ae3d77f312fc0c5e0ac2bbd71676c0112eebe2e5.1509718618.git.berto@igalia.com
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Alberto Garcia
951053a9ec qcow2: Don't open images with header.refcount_table_clusters == 0
qcow2_do_open() is checking that header.refcount_table_clusters is not
too large, but it doesn't check that it's greater than zero. Apart
from the fact that an image like that is obviously corrupted, trying
to use it crashes QEMU since we end up with a null s->refcount_table
after qcow2_refcount_init().

These images can however be repaired, so allow opening them if the
BDRV_O_CHECK flag is set.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: f9750f50c80359babba11062e88f5075a47e8e16.1509718618.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Max Reitz
572b07bea1 qcow2: Always execute preallocate() in a coroutine
Some qcow2 functions (at least perform_cow()) expect s->lock to be
taken.  Therefore, if we want to make use of them, we should execute
preallocate() (as "preallocate_co") in a coroutine so that we can use
the qemu_co_mutex_* functions.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171009215533.12530-3-mreitz@redhat.com
Cc: qemu-stable@nongnu.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-26 15:01:14 +02:00
Max Reitz
e400ad1e1f qcow2: Fix unaligned preallocated truncation
A qcow2 image file's length is not required to have a length that is a
multiple of the cluster size.  However, qcow2_refcount_area() expects an
aligned value for its @start_offset parameter, so we need to round
@old_file_size up to the next cluster boundary.

Reported-by: Ping Li <pingl@redhat.com>
Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1414049
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171009215533.12530-2-mreitz@redhat.com
Cc: qemu-stable@nongnu.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-26 15:01:14 +02:00
Max Reitz
233521b199 qcow2: Emit errp when truncating the image tail
bdrv_truncate() has an errp parameter which is always set when an error
occurs.  Let's use that instead of a plain strerror().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171009155431.14093-1-mreitz@redhat.com
Reviewed-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-26 15:01:14 +02:00
Alberto Garcia
a35f87f50d qcow2: Use BDRV_SECTOR_BITS instead of its literal value
BDRV_SECTOR_BITS is defined to be 9 in block.h (and BDRV_SECTOR_SIZE
is calculated from that), but there are still a couple of places where
we are using the literal value instead of the macro.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20171009153856.20387-1-berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-26 15:01:13 +02:00
Eric Blake
8cbf74b23c qcow2: Reduce is_zero() rounding
Now that bdrv_is_allocated accepts non-aligned inputs, we can
remove the TODO added in earlier refactoring.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
3182664220 block: Convert bdrv_get_block_status_above() to bytes
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the name of the function from bdrv_get_block_status_above()
to bdrv_block_status_above() ensures that the compiler enforces that
all callers are updated.  Likewise, since it a byte interface allows
an offset mapping that might not be sector aligned, split the mapping
out of the return value and into a pass-by-reference parameter.  For
now, the io.c layer still assert()s that all uses are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status in the drivers.

For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_block_status(), plus
updates for the new split return interface.  But some code,
particularly bdrv_block_status(), gets a lot simpler because it no
longer has to mess with sectors.  Likewise, mirror code no longer
computes s->granularity >> BDRV_SECTOR_BITS, and can therefore drop
an assertion about alignment because the loop no longer depends on
alignment (never mind that we don't really have a driver that
reports sub-sector alignments, so it's not really possible to test
the effect of sub-sector mirroring).  Fix a neighboring assertion to
use is_power_of_2 while there.

For ease of review, bdrv_get_block_status() was tackled separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
f06f6b66c7 qcow2: Switch is_zero_sectors() to byte-based
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Convert another internal
function (no semantic change), and rename it to is_zero() in the
process.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
298a1665a2 block: Allow NULL file for bdrv_get_block_status()
Not all callers care about which BDS owns the mapping for a given
range of the file.  This patch merely simplifies the callers by
consolidating the logic in the common call point, while guaranteeing
a non-NULL file to all the driver callbacks, for no semantic change.
The only caller that does not care about pnum is bdrv_is_allocated,
as invoked by vvfat; we can likewise add assertions that the rest
of the stack does not have to worry about a NULL pnum.

Furthermore, this will also set the stage for a future cleanup: when
a caller does not care about which BDS owns an offset, it would be
nice to allow the driver to optimize things to not have to return
BDRV_BLOCK_OFFSET_VALID in the first place.  In the case of fragmented
allocation (for example, it's fairly easy to create a qcow2 image
where consecutive guest addresses are not at consecutive host
addresses), the current contract requires bdrv_get_block_status()
to clamp *pnum to the limit where host addresses are no longer
consecutive, but allowing a NULL file means that *pnum could be
set to the full length of known-allocated data.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Pavel Butsykin
163bc39d2c qcow2: truncate the tail of the image file after shrinking the image
Now after shrinking the image, at the end of the image file, there might be a
tail that probably will never be used. So we can find the last used cluster and
cut the tail.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170929121613.25997-3-pbutsykin@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-06 16:30:48 +02:00
Pavel Butsykin
76a2a30a99 qcow2: fix return error code in qcow2_truncate()
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170929121613.25997-2-pbutsykin@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-06 16:30:48 +02:00
Daniel P. Berrange
4609742a49 block: convert qcrypto_block_encrypt|decrypt to take bytes offset
Instead of sector offset, take the bytes offset when encrypting
or decrypting data.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170927125340.12360-6-berrange@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-06 16:30:47 +02:00
Eric Blake
b85ee45334 qcow2: Switch qcow2_measure() to byte-based iteration
This is new code, but it is easier to read if it makes passes over
the image using bytes rather than sectors (and will get easier in
the future when bdrv_get_block_status is converted to byte-based).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Pavel Butsykin
46b732cdf3 qcow2: add shrink image support
This patch add shrinking of the image file for qcow2. As a result, this allows
us to reduce the virtual image size and free up space on the disk without
copying the image. Image can be fragmented and shrink is done by punching holes
in the image file.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170918124230.8152-4-pbutsykin@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-09-26 15:00:32 +02:00
Alistair Francis
55d527a94d Convert remaining error_report() to warn_report()
In a previous patch (3dc6f86936) we
converted uses of error_report("warning:"... to use warn_report()
instead. This was to help standardise on a single method of printing
warnings to the user.

There appears to have been some cases that slipped through in patch sets
applied around the same time, this patch catches the few remaining
cases.

All of the warnings were changed using this command:
  find ./* -type f -exec sed -i \
    's|error_report(".*warning[,:] |warn_report("|Ig' {} +

Indentation fixed up manually afterwards.

Two messages were manually fixed up as well.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <eec8cba0d5434bd828639e5e45f12182490ff47d.1505158760.git.alistair.francis@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 14:09:34 +02:00
Pavel Butsykin
83a8c775a8 qcow2: move qcow2_store_persistent_dirty_bitmaps() before cache flushing
After calling qcow2_inactivate(), all qcow2 caches must be flushed, but this
may not happen, because the last call qcow2_store_persistent_dirty_bitmaps()
can lead to marking l2/refcont cache as dirty.

Let's move qcow2_store_persistent_dirty_bitmaps() before the caсhe flushing
to fix it.

Cc: qemu-stable@nongnu.org
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-06 14:40:18 +02:00
Marc-André Lureau
f7abe0ecd4 qapi: Change data type of the FOO_lookup generated for enum FOO
Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

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

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

The sentinel will be dropped next.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com>
[Basically redone]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com>
[Rebased]
2017-09-04 13:09:13 +02:00
Markus Armbruster
977c736f80 qapi: Mechanically convert FOO_lookup[...] to FOO_str(...)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-14-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-09-04 13:09:13 +02:00
Markus Armbruster
5b5f825d44 qapi: Generate FOO_str() macro for QAPI enum FOO
The next commit will put it to use.  May look pointless now, but we're
going to change the FOO_lookup's type, and then it'll help.

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

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-3-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Rebased, commit message corrected]
2017-09-04 13:09:13 +02:00
Stefan Hajnoczi
3e4c705212 qcow2: allocate cluster_cache/cluster_data on demand
Most qcow2 files are uncompressed so it is wasteful to allocate (32 + 1)
* cluster_size + 512 bytes upfront.  Allocate s->cluster_cache and
s->cluster_data when the first read operation is performance on a
compressed cluster.

The buffers are freed in .bdrv_close().  .bdrv_open() no longer has any
code paths that can allocate these buffers, so remove the free functions
in the error code path.

This patch can result in significant memory savings when many qcow2
disks are attached or backing file chains are long:

Before 12.81% (1,023,193,088B)
After   5.36% (393,893,888B)

Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170821135530.32344-1-stefanha@redhat.com
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-08-30 18:02:10 +01:00
Alberto Garcia
c3a8fe331e misc: Remove unused Error variables
There's a few cases which we're passing an Error pointer to a function
only to discard it immediately afterwards without checking it. In
these cases we can simply remove the variable and pass NULL instead.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170829120836.16091-1-berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-08-30 11:58:26 +01:00
Eric Blake
d0d5d0e31a qcow2: Check failure of bdrv_getlength()
qcow2_co_pwritev_compressed() should not call bdrv_truncate()
if determining the size failed.

Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-11 13:23:47 +02:00
Eric Blake
c40fe9c06c qcow2: Drop debugging dump_refcounts()
It's been #if 0'd since its introduction in 2006, commit 585f8587.
We can revive dead code if we need it, but in the meantime, it has
bit-rotted (for example, not checking for failure in bdrv_getlength()).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-11 13:23:45 +02:00
Daniel P. Berrange
0696ae2c92 qcow: fix memory leaks related to encryption
Fix leak of the 'encryptopts' string, which was mistakenly
declared const.

Fix leak of QemuOpts entry which should not have been deleted
from the opts array.

Reported by: coverity
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170714103105.5781-1-berrange@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-25 16:33:31 +02:00
Eric Blake
24bae02b19 qcow2: Fix sector calculation in qcow2_measure()
We used MAX() instead of the intended MIN() when computing how many
sectors to view in the current loop iteration of qcow2_measure(),
and passed in a value of INT_MAX sectors instead of our more usual
limit of BDRV_REQUEST_MAX_SECTORS (the latter avoids 32-bit overflow
on conversion to bytes).  For small files, the bug is harmless:
bdrv_get_block_status_above() clamps its *pnum answer to the BDS
size, regardless of any insanely larger input request.  However, for
any file at least 2T in size, we can very easily end up going into an
infinite loop (the maximum of 0x100000000 sectors and INT_MAX is a
64-bit quantity, which becomes 0 when assigned to int; once nb_sectors
is 0, we never make progress).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-24 15:06:04 +02:00
Paolo Bonzini
a8c57408cd qcow2: call CoQueue APIs under CoMutex
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170629132749.997-2-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-07-17 11:28:15 +08:00
Max Reitz
772d1f973f block/qcow2: falloc/full preallocating growth
Implement the preallocation modes falloc and full for growing qcow2
images.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170613202107.10125-15-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:02 +02:00
Max Reitz
12cc30a8cb block/qcow2: Add qcow2_refcount_area()
This function creates a collection of self-describing refcount
structures (including a new refcount table) at the end of a qcow2 image
file. Optionally, these structures can also describe a number of
additional clusters beyond themselves; this will be important for
preallocated truncation, which will place the data clusters and L2
tables there.

For now, we can use this function to replace the part of
alloc_refcount_block() that grows the refcount table (from which it is
actually derived).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-13-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:02 +02:00
Max Reitz
95b98f343b block/qcow2: Metadata preallocation for truncate
We can support PREALLOC_MODE_METADATA by invoking preallocate() in
qcow2_truncate().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170613202107.10125-12-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:02 +02:00
Max Reitz
652fecd005 block/qcow2: Lock s->lock in preallocate()
preallocate() is and will be called only from places that do not
otherwise need to lock s->lock: Currently that is qcow2_create2(), as of
a future patch it will be called from qcow2_truncate(), too.

It therefore makes sense to move locking that mutex into preallocate()
itself.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-11-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:02 +02:00
Max Reitz
7bc45dc172 block/qcow2: Generalize preallocate()
This patch adds two new parameters to the preallocate() function so we
will be able to use it not just for preallocating a new image but also
for preallocated image growth.

The offset parameter allows the caller to specify a virtual offset from
which to start preallocating. For newly created images this is always 0,
but for preallocating growth this will be the old image length.

The new_length parameter specifies the supposed new length of the image
(basically the "end offset" for preallocation). During image truncation,
bdrv_getlength() will return the old image length so we cannot rely on
its return value then.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:02 +02:00
Max Reitz
3a691c50f1 block: Add PreallocMode to blk_truncate()
blk_truncate() itself will pass that value to bdrv_truncate(), and all
callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF
for now.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Max Reitz
7ea37c3066 block: Add PreallocMode to bdrv_truncate()
For block drivers that just pass a truncate request to the underlying
protocol, we can now pass the preallocation mode instead of aborting if
it is not PREALLOC_MODE_OFF.

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

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Stefan Hajnoczi
c501c35220 qcow2: add bdrv_measure() support
Use qcow2_calc_prealloc_size() to get the required file size.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-7-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:00 +02:00
Stefan Hajnoczi
0eb4a8c1df qcow2: extract image creation option parsing
The image creation options parsed by qcow2_create() are also needed to
implement .bdrv_measure().  Extract the parsing code, including input
validation.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-6-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:00 +02:00
Stefan Hajnoczi
7c5bcc4212 qcow2: make refcount size calculation conservative
The refcount metadata size calculation is inaccurate and can produce
numbers that are too small.  This is bad because we should calculate a
conservative number - one that is guaranteed to be large enough.

This patch switches the approach to a fixed point calculation because
the existing equation is hard to solve when inaccuracies are taken care
of.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-5-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:00 +02:00
Stefan Hajnoczi
95c67e3bd7 qcow2: extract preallocation calculation function
Calculating the preallocated image size will be needed to implement
.bdrv_measure().  Extract the code out into a separate function.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-4-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:00 +02:00
Vladimir Sementsov-Ogievskiy
469c71edc7 qcow2: add .bdrv_remove_persistent_dirty_bitmap
Realize .bdrv_remove_persistent_dirty_bitmap interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-29-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
da0eb242ad qcow2: add .bdrv_can_store_new_dirty_bitmap
Realize .bdrv_can_store_new_dirty_bitmap interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-23-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
169b879359 qcow2: store bitmaps on reopening image as read-only
Store bitmaps and mark them read-only on reopening image as read-only.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-21-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
5f72826e7f qcow2: add persistent dirty bitmaps support
Store persistent dirty bitmaps in qcow2 image.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-20-vsementsov@virtuozzo.com
[mreitz: Always assign ret in store_bitmap() in case of an error]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00