Commit Graph

45 Commits

Author SHA1 Message Date
Alberto Garcia
7be2025258 qcow2: Add the 'extended_l2' option and the QCOW2_INCOMPAT_EXTL2 bit
Now that the implementation of subclusters is complete we can finally
add the necessary options to create and read images with this feature,
which we call "extended L2 entries".

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <6476caaa73216bd05b7bb2d504a20415e1665176.1594396418.git.berto@igalia.com>
[mreitz: %s/5\.1/5.2/; fixed 302's and 303's reference output]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 09:19:55 +02:00
Alberto Garcia
fc2e6528d5 qcow2: Add subcluster support to check_refcounts_l2()
The offset field of an uncompressed cluster's L2 entry must be aligned
to the cluster size, otherwise it is invalid. If the cluster has no
data then it means that the offset points to a preallocation, so we
can clear the offset field without affecting the guest-visible data.
This is what 'qemu-img check' does when run in repair mode.

On traditional qcow2 images this can only happen when QCOW_OFLAG_ZERO
is set, and repairing such entries turns the clusters from ZERO_ALLOC
into ZERO_PLAIN.

Extended L2 entries have no ZERO_ALLOC clusters and no QCOW_OFLAG_ZERO
but the idea is the same: if none of the subclusters are allocated
then we can clear the offset field and leave the bitmap untouched.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <9f4ed1d0a34b0a545b032c31ecd8c14734065342.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-08-25 08:33:20 +02:00
Eric Blake
b66ff2c298 iotests: Specify explicit backing format where sensible
There are many existing qcow2 images that specify a backing file but
no format.  This has been the source of CVEs in the past, but has
become more prominent of a problem now that libvirt has switched to
-blockdev.  With older -drive, at least the probing was always done by
qemu (so the only risk of a changed format between successive boots of
a guest was if qemu was upgraded and probed differently).  But with
newer -blockdev, libvirt must specify a format; if libvirt guesses raw
where the image was formatted, this results in data corruption visible
to the guest; conversely, if libvirt guesses qcow2 where qemu was
using raw, this can result in potential security holes, so modern
libvirt instead refuses to use images without explicit backing format.

The change in libvirt to reject images without explicit backing format
has pointed out that a number of tools have been far too reliant on
probing in the past.  It's time to set a better example in our own
iotests of properly setting this parameter.

iotest calls to create, rebase, and convert are all impacted to some
degree.  It's a bit annoying that we are inconsistent on command line
- while all of those accept -o backing_file=...,backing_fmt=..., the
shortcuts are different: create and rebase have -b and -F, while
convert has -B but no -F.  (amend has no shortcuts, but the previous
patch just deprecated the use of amend to change backing chains).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-9-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Denis Plotnikov
572ad9783f qcow2: introduce compression type feature
The patch adds some preparation parts for incompatible compression type
feature to qcow2 allowing the use different compression methods for
image clusters (de)compressing.

It is implied that the compression type is set on the image creation and
can be changed only later by image conversion, thus compression type
defines the only compression algorithm used for the image, and thus,
for all image clusters.

The goal of the feature is to add support of other compression methods
to qcow2. For example, ZSTD which is more effective on compression than ZLIB.

The default compression is ZLIB. Images created with ZLIB compression type
are backward compatible with older qemu versions.

Adding of the compression type breaks a number of tests because now the
compression type is reported on image creation and there are some changes
in the qcow2 header in size and offsets.

The tests are fixed in the following ways:
    * filter out compression_type for many tests
    * fix header size, feature table size and backing file offset
      affected tests: 031, 036, 061, 080
      header_size +=8: 1 byte compression type
                       7 bytes padding
      feature_table += 48: incompatible feature compression type
      backing_file_offset += 56 (8 + 48 -> header_change + feature_table_change)
    * add "compression type" for test output matching when it isn't filtered
      affected tests: 049, 060, 061, 065, 082, 085, 144, 182, 185, 198, 206,
                      242, 255, 274, 280

Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
QAPI part:
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200507082521.29210-2-dplotnikov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-13 14:20:31 +02:00
Alberto Garcia
80f5c01183 qcow2: Forbid discard in qcow2 v2 images with backing files
A discard request deallocates the selected clusters so they read back
as zeroes. This is done by clearing the cluster offset field and
setting QCOW_OFLAG_ZERO in the L2 entry.

This flag is however only supported when qcow_version >= 3. In older
images the cluster is simply deallocated, exposing any possible stale
data from the backing file.

Since discard is an advisory operation it's safer to simply forbid it
in this scenario.

Note that we are adding this check to qcow2_co_pdiscard() and not to
qcow2_cluster_discard() or discard_in_l2_slice() because the last
two are also used by qcow2_snapshot_create() to discard the clusters
used by the VM state. In this case there's no risk of exposing stale
data to the guest and we really want that the clusters are always
discarded.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200331114345.29993-1-berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-04-07 13:51:09 +02:00
Max Reitz
0485e6ee4c iotests/qcow2.py: Split feature fields into bits
Print the feature fields as a set of bits so that filtering is easier.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-id: 20191107163708.833192-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-01-06 13:43:06 +01:00
Anton Nefedov
c8bb23cbdb qcow2: skip writing zero buffers to empty COW areas
If COW areas of the newly allocated clusters are zeroes on the backing
image, efficient bdrv_write_zeroes(flags=BDRV_REQ_NO_FALLBACK) can be
used on the whole cluster instead of writing explicit zero buffers later
in perform_cow().

iotest 060:
write to the discarded cluster does not trigger COW anymore.
Use a backing image instead.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Message-id: 20190516142749.81019-2-anton.nefedov@virtuozzo.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-05-28 20:30:55 +02:00
Eric Blake
de38b5005e qemu-img: Saner printing of large file sizes
Disk sizes close to INT64_MAX cause overflow, for some pretty
ridiculous output:

  $ ./nbdkit -U - memory size=$((2**63 - 512)) --run 'qemu-img info $nbd'
  image: nbd+unix://?socket=/tmp/nbdkitHSAzNz/socket
  file format: raw
  virtual size: -8388607T (9223372036854775296 bytes)
  disk size: unavailable

But there's no reason to have two separate implementations of integer
to human-readable abbreviation, where one has overflow and stops at
'T', while the other avoids overflow and goes all the way to 'E'. With
this patch, the output now claims 8EiB instead of -8388607T, which
really is the correct rounding of largest file size supported by qemu
(we could go 511 bytes larger if we used byte-accurate sizing instead
of rounding up to the next sector boundary, but that wouldn't change
the human-readable result).

Quite a few iotests need updates to expected output to match.

Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Max Reitz <mreitz@redhat.com>
2019-04-30 15:29:00 +02:00
Thomas Huth
36b9986b08 tests/qemu-iotests: Fix output of qemu-io related tests
One of the recent commits changed the way qemu-io prints out its
errors and warnings - they are now prefixed with the program name.
We've got to adapt the iotests accordingly to prevent that they
are failing.

Fixes: 99e98d7c9f ("qemu-io: Use error_[gs]et_progname()")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30 15:29:00 +02:00
Dominik Csapak
9254893882 qmp: Split ShutdownCause host-qmp into quit and system-reset
It is interesting to know whether the shutdown cause was 'quit' or
'reset', especially when using "--no-reboot". In that case, a management
layer can now determine if the guest wanted a reboot or shutdown, and
can act accordingly.

Changes the output of the reason in the iotests from 'host-qmp' to
'host-qmp-quit'. This does not break compatibility because
the field was introduced in the same version.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Message-Id: <20181205110131.23049-4-d.csapak@proxmox.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-18 07:55:47 +01:00
Dominik Csapak
ecd7a0d5bb qmp: Add reason to SHUTDOWN and RESET events
This makes it possible to determine what the exact reason was for
a RESET or a SHUTDOWN. A management layer might need the specific reason
of those events to determine which cleanups or other actions it needs to do.

This patch also updates the iotests to the new expected output that includes
the reason.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Message-Id: <20181205110131.23049-3-d.csapak@proxmox.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-12-18 07:55:47 +01:00
Peter Xu
cbc4ae2d1a tests: iotests: drop some stderr line
In my Out-Of-Band test, "check -qcow2 060" fail with this:

  --- /home/peterx/git/qemu/tests/qemu-iotests/060.out
  +++ /home/peterx/git/qemu/bin/tests/qemu-iotests/060.out.bad
  @@ -427,8 +427,8 @@
  QMP_VERSION
  {"return": {}}
  qcow2: Image is corrupt: L2 table offset 0x2a2a2a00 unaligned (L1
  index: 0); further non-fatal corruption events will be suppressed
  -{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_IMAGE_CORRUPTED", "data": {"device": "", "msg": "L2 table offset 0x2a2a2a0
  0 unaligned (L1 index: 0)", "node-name": "drive", "fatal": false}}
  read failed: Input/output error
  +{"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP}, "event": "BLOCK_IMAGE_CORRUPTED", "data": {"device": "", "msg": "L2 table offset 0x2a2a2a0
  0 unaligned (L1 index: 0)", "node-name": "drive", "fatal": false}}
  {"return": ""}
  {"return": {}}
  {"timestamp": {"seconds": TIMESTAMP, "microseconds": TIMESTAMP},
  "event": "SHUTDOWN", "data": {"guest": false}}

The order of the event and the in/out error line is swapped.  I didn't
dig up the reason, but AFAIU what we want to verify is the event rather
than stderr.  Let's drop the stderr line directly for this test.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180620073223.31964-5-peterx@redhat.com>
[Commit message touched up]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-06-30 17:50:48 +02:00
Max Reitz
c50abd175a iotests: Add case for a corrupted inactive image
Reviewed-by: John Snow <jsnow@redhat.com>
Tested-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180606193702.7113-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11 16:18:45 +02:00
Max Reitz
d1402b5026 block: Add Error parameter to bdrv_amend_options
Looking at the qcow2 code that is riddled with error_report() calls,
this is really how it should have been from the start.

Along the way, turn the target_version/current_version comparisons at
the beginning of qcow2_downgrade() into assertions (the caller has to
make sure these conditions are met), and rephrase the error message on
using compat=1.1 to get refcount widths other than 16 bits.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180509210023.20283-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11 16:18:45 +02:00
Max Reitz
ac5b787a6e qcow2: Repair unaligned preallocated zero clusters
We can easily repair unaligned preallocated zero clusters by discarding
them, so why not do it?

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203759.14018-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-01-23 12:34:42 +01:00
Alberto Garcia
50a3efb0f0 block: Close a BlockDriverState completely even when bs->drv is NULL
bdrv_close() skips much of its logic when bs->drv is NULL. This is
fine when we're closing a BlockDriverState that has just been created
(because e.g the initialization process failed), but it's not enough
in other cases.

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

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

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

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20171106145345.12038-1-berto@igalia.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-21 14:54:02 +01:00
Max Reitz
4efb1f7c61 qcow2: Refuse to get unaligned offsets from cache
Instead of using an assertion, it is better to emit a corruption event
here.  Checking all offsets for correct alignment can be tedious and it
is easily possible to forget to do so.  qcow2_cache_do_get() is a
function every L2 and refblock access has to go through, so this is a
good central point to add such a check.

And for good measure, let us also add an assertion that the offset is
non-zero.  Making this a corruption event is not feasible, because a
zero offset usually means something special (such as the cluster is
unused), so all callers should be checking this anyway.  If they do not,
it is their fault, hence the assertion here.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-6-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Max Reitz
23482f8a60 qcow2: Add bounds check to get_refblock_offset()
Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1728661
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-5-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Max Reitz
d470ad42ac block: Guard against NULL bs->drv
We currently do not guard everywhere against a NULL bs->drv where we
should be doing so.  Most of the places fixed here just do not care
about that case at all.

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

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

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

Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1728660
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-4-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Max Reitz
93bbaf03ff qcow2: Unaligned zero cluster in handle_alloc()
We should check whether the cluster offset we are about to use is
actually valid; that is, whether it is aligned to cluster boundaries.

Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1728643
Buglink: https://bugs.launchpad.net/qemu/+bug/1728657
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:30 +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
Alberto Garcia
bcb5270c75 qcow2: Check that corrupted images can be repaired in iotest 060
We just fixed a few bugs that caused QEMU to crash when trying to
write to corrupted qcow2 images, and iotest 060 was expanded to test
all those scenarios.

In almost all cases the corrupted images can be repaired using
qemu-img, so this patch verifies that.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 0b1b95340ecdfbc6927e36adf2fd42ae6198747a.1510143008.git.berto@igalia.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Alberto Garcia
ef083f61af qcow2: Add iotest for an empty refcount table
This patch adds a simple iotest in which we try to write to an image
with an empty refcount table (i.e. with all entries set to 0).

This scenario was already handled by the existing consistency checks,
but we add an explicit test case for completeness.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 7e48b0e2ae1a0a18e0ee303b3045f130feec0474.1509718618.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Alberto Garcia
5a45da5ef8 qcow2: Add iotest for an image with header.refcount_table_offset == 0
This patch adds a simple iotest in which we try to write to an image
with the refcount table offset set to 0.

This scenario was already handled by the existing consistency checks,
but we add an explicit test case for completeness.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: feeceada92486bb8790b90f303fc9fe82a27391a.1509718618.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@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
Alberto Garcia
8aa34834d5 qcow2: Prevent allocating compressed clusters at offset 0
If the refcount data is corrupted then we can end up trying to
allocate a new compressed cluster at offset 0 in the image, triggering
an assertion in qcow2_alloc_bytes() that would crash QEMU:

  qcow2_alloc_bytes: Assertion `offset' failed.

This patch adds an explicit check for this scenario and a new test
case.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: fb53467cf48e95ff3330def1cf1003a5b862b7d9.1509718618.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Alberto Garcia
9883975050 qcow2: Prevent allocating L2 tables at offset 0
If the refcount data is corrupted then we can end up trying to
allocate a new L2 table at offset 0 in the image, triggering an
assertion in the qcow2 cache that would crash QEMU:

  qcow2_cache_entry_mark_dirty: Assertion `c->entries[i].offset != 0' failed

This patch adds an explicit check for this scenario and a new test
case.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 92dac37191ae7844a2da22c122204eb493cc3133.1509718618.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Alberto Garcia
6bf45d59f9 qcow2: Prevent allocating refcount blocks at offset 0
Each entry in the qcow2 cache contains an offset field indicating the
location of the data in the qcow2 image. If the offset is 0 then it
means that the entry contains no data and is available to be used when
needed.

Because of that it is not possible to store in the cache the first
cluster of the qcow2 image (offset = 0). This is not a problem because
that cluster always contains the qcow2 header and we're not using this
cache for that.

However, if the qcow2 image is corrupted it can happen that we try to
allocate a new refcount block at offset 0, triggering this assertion
and crashing QEMU:

  qcow2_cache_entry_mark_dirty: Assertion `c->entries[i].offset != 0' failed

This patch adds an explicit check for this scenario and a new test
case.

This problem was originally reported here:

   https://bugs.launchpad.net/qemu/+bug/1728615

Reported-by: R.Nageswara Sastry <nasastry@in.ibm.com>
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 92a2fadd10d58b423f269c1d1a309af161cdc73f.1509718618.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-14 18:06:25 +01:00
Eric Blake
64ebf55648 qemu-io: Don't die on second open
Most callback commands in qemu-io return 0 to keep the interpreter
loop running, or 1 to quit immediately.  However, open_f() just
passed through the return value of openfile(), which has different
semantics of returning 0 if a file was opened, or 1 on any failure.

As a result of mixing the return semantics, we are forcing the
qemu-io interpreter to exit early on any failures, which is rather
annoying when some of the failures are obviously trying to give
the user a hint of how to proceed (if we didn't then kill qemu-io
out from under the user's feet):

$ qemu-io
qemu-io> open foo
qemu-io> open foo
file open already, try 'help close'
$ echo $?
0

In general, we WANT openfile() to report failures, since it is the
function used in the form 'qemu-io -c "$something" no_such_file'
for performing one or more -c options on a single file, and it is
not worth attempting $something if the file itself cannot be opened.
So the solution is to fix open_f() to always return 0 (when we are
in interactive mode, even failure to open should not end the
session), and save the return value of openfile() for command line
use in main().

Note, however, that we do have some qemu-iotests that do 'qemu-io
-c "open file" -c "$something"'; such tests will now proceed to
attempt $something whether or not the open succeeded, the same way
as if the two commands had been attempted in interactive mode.  As
such, the expected output for those tests has to be modified.  But it
also means that it is now possible to use -c close and have a single
qemu-io command line operate on more than one file even without
using interactive mode.  Although the '-c open' action is a subtle
change in behavior, remember that qemu-io is for debugging purposes,
so as long as it serves the needs of qemu-iotests while still being
reasonable for interactive use, it should not be a problem that we
are changing tests to the new behavior.

This has been awkward since at least as far back as commit
e3aff4f, in 2009.

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>
2017-07-10 13:18:05 +02:00
Eric Blake
bcb07dba92 block: Tweak error message related to qemu-img amend
When converting a 1.1 image down to 0.10, qemu-iotests 060 forces
a contrived failure where allocating a cluster used to replace a
zero cluster reads unaligned data.  Since it is a zero cluster
rather than a data cluster being converted, changing the error
message to match our earlier change in 'qcow2: Make distinction
between zero cluster types obvious' is worthwhile.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170508171302.17805-1-eblake@redhat.com
[mreitz: Commit message fixes]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-29 15:39:54 +02:00
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
Markus Armbruster
b988468149 qemu-io qemu-nbd: Use error_report() etc. instead of fprintf()
Just three instances left.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-16-git-send-email-armbru@redhat.com>
2016-01-13 15:16:18 +01:00
Max Reitz
0709c5a153 qcow2: Add refcount_bits to format-specific info
Add the bit width of every refcount entry to the format-specific
information.

In contrast to lazy_refcounts and the corrupt flag, this should be
always emitted, even for compat=0.10 although it does not support any
refcount width other than 16 bits. This is because if a boolean is
optional, one normally assumes it to be false when omitted; but if an
integer is not specified, it is rather difficult to guess its value.

This new field breaks some test outputs, fix them.

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>
2015-03-10 14:02:20 +01:00
Max Reitz
f30136b35a iotests: Add tests for more corruption cases
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-23 18:17:05 +01:00
Fam Zheng
7486458c33 qemu-iotests: Remove traling whitespaces in *.out
This is simply:

  $ cd tests/qemu-iotests; sed -i -e 's/ *$//' *.out

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1418110684-19528-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-12-12 16:52:33 +00:00
Kevin Wolf
e800e5d4e2 qemu-iotests: 060: Filter the real disk size
The real on-disk size of an image depends on things like the host
filesystem. _img_info already filters it out, use the function in 060.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Michael Mueller <mimu@linux.vnet.ibm.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2014-12-10 10:31:13 +01:00
Max Reitz
d26e6ec052 iotests: Fix test outputs
039, 060 and 061 all create images with referenced clusters having a
refcount of 0. Because previous commits changed handling of such errors,
these tests now have a different output. Fix it.

Furthermore, 060 created a refblock with a refcount greater than one
which now results in having to rebuild the refcount structure as well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23 15:34:01 +02:00
Max Reitz
f383611a0a iotests: qemu-img info output for corrupt image
The "corrupt" entry in the format-specific information section should be
"true".

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1412105489-7681-4-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-04 19:18:17 +01:00
Max Reitz
5b0ed2be88 iotests: Add more tests for qcow2 corruption
Add tests for unaligned L1/L2/reftable entries and non-fatal corruption
reports.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1409926039-29044-6-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-22 11:39:29 +01:00
Max Reitz
adb435522b qcow2: Use qcow2_signal_corruption() for overlaps
Use the new function in case of a failed overlap check.

This changes output in case of corruption, so adapt iotest 060's
reference output accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Message-id: 1409926039-29044-4-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-22 11:39:28 +01:00
Max Reitz
a42f8a3d05 iotests: Add test for image header overlap
Add a test for an image with an unallocated image header; instead of an
assertion, this should result in the image being marked corrupt.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15 15:07:16 +02:00
Max Reitz
98d39e34fe iotests: Test corruption during COW request
Extend test file 060 by a test case for corruption occuring concurrently
to a COW request. QEMU should not crash but rather return an appropriate
error message.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:23:27 +01:00
Max Reitz
34eeb82de6 qemu-iotests: Add test for inactive L2 overlap
Extend 060 by a test which creates a corrupted image with an active L2
entry pointing to an inactive L2 table and writes to the corresponding
guest offset.

Also, use overlap-check=all for all tests in 060.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:02 +02:00
Max Reitz
2c78857bf6 qemu-iotests: Adjustments due to error propagation
When opening/creating images, propagating errors instead of immediately
emitting them on occurrence results in errors generally being printed on
a single line rather than being split up into multiple ones. This in
turn requires adjustments to some test results.

Also, test 060 used a sed to filter out the test image directory and
format by removing everything from the affected line after a certain
keyword; this now also removes the error message itself, which can be
fixed by using _filter_testdir and _filter_imgfmt.

Finally, _make_test_img in common.rc did not filter out the test image
directory etc. from stderr. This has been fixed through a redirection of
stderr to stdout (which is already done in _check_test_img and
_img_info).

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz
ca0eca91b6 qemu-iotests: Overlapping cluster allocations
A new test on corrupted images with overlapping cluster allocations.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-02 10:15:15 +02:00