Commit Graph

202 Commits

Author SHA1 Message Date
Eric Blake 77d6a21558 qcow2: Don't allow overflow during cluster allocation
Our code was already checking that we did not attempt to
allocate more clusters than what would fit in an INT64 (the
physical maximimum if we can access a full off_t's worth of
data).  But this does not catch smaller limits enforced by
various spots in the qcow2 image description: L1 and normal
clusters of L2 are documented as having bits 63-56 reserved
for other purposes, capping our maximum offset at 64PB (bit
55 is the maximum bit set).  And for compressed images with
2M clusters, the cap drops the maximum offset to bit 48, or
a maximum offset of 512TB.  If we overflow that offset, we
would write compressed data into one place, but try to
decompress from another, which won't work.

It's actually possible to prove that overflow can cause image
corruption without this patch; I'll add the iotests separately
in the next commit.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-11-19 12:51:40 +01:00
Liam Merwick 7cb6d3c9be qcow2: Read outside array bounds in qcow2_pre_write_overlap_check()
The commit for 0e4e4318ea increments QCOW2_OL_MAX_BITNR but does not
add an array entry for QCOW2_OL_BITMAP_DIRECTORY_BITNR to metadata_ol_names[].
As a result, an array dereference of metadata_ol_names[8] in
qcow2_pre_write_overlap_check() could result in a read outside of the array bounds.

Fixes: 0e4e4318ea ('qcow2: add overlap check for bitmap directory')

Cc: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1541453919-25973-6-git-send-email-Liam.Merwick@oracle.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-11-12 17:49:21 +01:00
Peter Maydell 7851f1a706 Block layer patches:
- Copy offloading fixes for when the copy increases the image size
 - Temporary revert of the removal of deprecated -drive options
 - Fix request serialisation in the image fleecing scenario
 - Fix copy-on-read crash with unaligned image size
 - Fix another drain crash
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- Copy offloading fixes for when the copy increases the image size
- Temporary revert of the removal of deprecated -drive options
- Fix request serialisation in the image fleecing scenario
- Fix copy-on-read crash with unaligned image size
- Fix another drain crash

# gpg: Signature made Tue 10 Jul 2018 16:37:52 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (24 commits)
  block: Use common write req handling in truncate
  block: Fix bdrv_co_truncate overlap check
  block: Use common req handling in copy offloading
  block: Use common req handling for discard
  block: Fix handling of image enlarging write
  block: Extract common write req handling
  block: Use uint64_t for BdrvTrackedRequest byte fields
  block: Use BdrvChild to discard
  block: Add copy offloading trace points
  block: Prefix file driver trace points with "file_"
  Revert "block: Remove deprecated -drive geometry options"
  Revert "block: Remove deprecated -drive option addr"
  Revert "block: Remove deprecated -drive option serial"
  Revert "block: Remove dead deprecation warning code"
  block/blklogwrites: Make sure the log sector size is not too small
  qapi/block-core.json: Add missing documentation for blklogwrites log-append option
  block/backup: fix fleecing scheme: use serialized writes
  block: add BDRV_REQ_SERIALISING flag
  block: split flags in copy_range
  block/io: fix copy_range
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-10 17:28:29 +01:00
Fam Zheng 0b9fd3f467 block: Use BdrvChild to discard
Other I/O functions are already using a BdrvChild pointer in the API, so
make discard do the same. It makes it possible to initiate the same
permission checks before doing I/O, and much easier to share the
helper functions for this, which will be added and used by write,
truncate and copy range paths.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 16:01:52 +02:00
Vladimir Sementsov-Ogievskiy 0e4e4318ea qcow2: add overlap check for bitmap directory
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180705151515.779173-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-07-09 19:43:24 +02:00
Max Reitz 3cce51c919 qcow2: Repair OFLAG_COPIED when fixing leaks
Repairing OFLAG_COPIED is usually safe because it is done after the
refcounts have been repaired.  Therefore, it we did not find anyone else
referencing a data or L2 cluster, it makes no sense to not set
OFLAG_COPIED -- and the other direction (clearing OFLAG_COPIED) is
always safe, anyway, it may just induce leaks.

Furthermore, if OFLAG_COPIED is actually consistent with a wrong (leaky)
refcount, we will decrement the refcount with -r leaks, but OFLAG_COPIED
will then be wrong.  qemu-img check should not produce images that are
more corrupted afterwards then they were before.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1527085
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20180509200059.31125-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11 16:18:45 +02:00
Michael S. Tsirkin 0d8c41dae5 block: use local path for local headers
When pulling in headers that are in the same directory as the C file (as
opposed to one in include/), we should use its relative path, without a
directory.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-05-31 04:16:06 +03:00
Alberto Garcia 74c44a5934 Fix error message about compressed clusters with OFLAG_COPIED
Compressed clusters are not supposed to have the COPIED bit set.
"qemu-img check" detects that and prints an error message reporting
the number of the affected host cluster. This doesn't make much sense
because compressed clusters are not aligned to host clusters, so it
would be better to report the offset instead. Plus, the calculation is
wrong and it uses the raw L2 entry as if it was simply an offset.

This patch fixes the error message and reports the offset of the
compressed cluster.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 0f687957feb72e80c740403191a47e607c2463fe.1523376013.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-15 16:15:21 +02:00
Alberto Garcia abf754fe40 qcow2: Reset free_cluster_index when allocating a new refcount block
When we try to allocate new clusters we first look for available ones
starting from s->free_cluster_index and once we find them we increase
their reference counts. Before we get to call update_refcount() to do
this last step s->free_cluster_index is already pointing to the next
cluster after the ones we are trying to allocate.

During update_refcount() it may happen however that we also need to
allocate a new refcount block in order to store the refcounts of these
new clusters (and to complicate things further that may also require
us to grow the refcount table). After all this we don't know if the
clusters that we originally tried to allocate are still available, so
we return -EAGAIN to ask the caller to restart the search for free
clusters.

This is what can happen in a common scenario:

  1) We want to allocate a new cluster and we see that cluster N is
     free.

  2) We try to increase N's refcount but all refcount blocks are full,
     so we allocate a new one at N+1 (where s->free_cluster_index was
     pointing at).

  3) Once we're done we return -EAGAIN to look again for a free
     cluster, but now s->free_cluster_index points at N+2, so that's
     the one we allocate. Cluster N remains unallocated and we have a
     hole in the qcow2 file.

This can be reproduced easily:

     qemu-img create -f qcow2 -o cluster_size=512 hd.qcow2 1M
     qemu-io -c 'write 0 124k' hd.qcow2

After this the image has 132608 bytes (256 clusters), and the refcount
block is full. If we write 512 more bytes it should allocate two new
clusters: the data cluster itself and a new refcount block.

     qemu-io -c 'write 124k 512' hd.qcow2

However the image has now three new clusters (259 in total), and the
first one of them is empty (and unallocated):

     dd if=hd.qcow2 bs=512c skip=256 count=1 | hexdump -C

If we write larger amounts of data in the last step instead of the 512
bytes used in this example we can create larger holes in the qcow2
file.

What this patch does is reset s->free_cluster_index to its previous
value when alloc_refcount_block() returns -EAGAIN. This way the caller
will try to allocate again the original clusters if they are still
free.

The output of iotest 026 also needs to be updated because now that
images have no holes some tests fail at a different point and the
number of leaked clusters is different.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-26 12:16:00 +02:00
Alberto Garcia 0c2ada8136 qcow2: Make qemu-img check detect corrupted L1 tables in snapshots
'qemu-img check' cannot detect if a snapshot's L1 table is corrupted.
This patch checks the table's offset and size and reports corruption
if the values are not valid.

This patch doesn't add code to fix that corruption yet, only to detect
and report it.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Alberto Garcia c7a9d81d70 qcow2: Check snapshot L1 tables in qcow2_check_metadata_overlap()
The inactive-l2 overlap check iterates uses the L1 tables from all
snapshots, but it does not validate them first.

We now have a function to take care of this, so let's use it.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Paolo Bonzini 8b220eb7c8 qcow2: introduce qcow2_write_caches and qcow2_flush_caches
They will be used to avoid recursively taking s->lock during
bdrv_open or bdrv_check.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-7-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Alberto Garcia 9e029689e1 qcow2: Replace align_offset() with ROUND_UP()
The align_offset() function is equivalent to the ROUND_UP() macro so
there's no need to use the former. The ROUND_UP() name is also a bit
more explicit.

This patch uses ROUND_UP() instead of the slower QEMU_ALIGN_UP()
because align_offset() already requires that the second parameter is a
power of two.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180215131008.5153-1-berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-03-02 18:39:56 +01:00
Alberto Garcia 83ad165be7 qcow2: Update qcow2_update_snapshot_refcount() to support L2 slices
qcow2_update_snapshot_refcount() increases the refcount of all
clusters of a given snapshot. In order to do that it needs to load all
its L2 tables and iterate over their entries. Since we'll be loading
L2 slices instead of full tables we need to add an extra loop that
iterates over all slices of each L2 table.

This function doesn't need any additional changes so apart from that
this patch simply updates the variable name from l2_table to l2_slice.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 5f4db199b9637f4833b58487135124d70add8cf0.1517840877.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 17:00:00 +01:00
Alberto Garcia ca62dd5c2b qcow2: Prepare qcow2_update_snapshot_refcount() for adding L2 slice support
Adding support for L2 slices to qcow2_update_snapshot_refcount() needs
(among other things) an extra loop that iterates over all slices of
each L2 table.

Putting all changes in one patch would make it hard to read because
all semantic changes would be mixed with pure indentation changes.

To make things easier this patch simply creates a new block and
changes the indentation of all lines of code inside it. Thus, all
modifications in this patch are cosmetic. There are no semantic
changes and no variables are renamed yet. The next patch will take
care of that.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 8ffaa5e55bd51121f80e498f4045b64902a94293.1517840877.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 17:00:00 +01:00
Alberto Garcia 6e6fa7605e qcow2: Remove BDS parameter from qcow2_cache_is_table_offset()
This function was only using the BlockDriverState parameter to pass it
to qcow2_cache_get_table_addr(). This is no longer necessary so this
parameter can be removed.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: eb0ed90affcf302e5a954bafb5931b5215483d3a.1517840877.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 16:59:59 +01:00
Alberto Garcia 77aadd7bed qcow2: Remove BDS parameter from qcow2_cache_discard()
This function was only using the BlockDriverState parameter to pass it
to qcow2_cache_get_table_idx() and qcow2_cache_table_release(). This
is no longer necessary so this parameter can be removed.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 9724f7e38e763ad3be32627c6b7fe8df9edb1476.1517840877.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 16:59:59 +01:00
Alberto Garcia 2013c3d44d qcow2: Remove BDS parameter from qcow2_cache_put()
This function was only using the BlockDriverState parameter to pass it
to qcow2_cache_get_table_idx(). This is no longer necessary so this
parameter can be removed.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 6f98155489054a457563da77cdad1a66ebb3e896.1517840876.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 16:59:59 +01:00
Alberto Garcia 2d135ee92d qcow2: Remove BDS parameter from qcow2_cache_entry_mark_dirty()
This function was only using the BlockDriverState parameter to pass it
to qcow2_cache_get_table_idx(). This is no longer necessary so this
parameter can be removed.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 5c40516a91782b083c1428b7b6a41bb9e2679bfb.1517840876.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 16:59:59 +01:00
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
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
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 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
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 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
Pavel Butsykin f71c08ea8e qcow2: add qcow2_cache_discard
Whenever l2/refcount table clusters are discarded from the file we can
automatically drop unnecessary content of the cache tables. This reduces
the chance of eviction useful cache data and eliminates inconsistent data
in the cache with the data in the 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: 20170918124230.8152-3-pbutsykin@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-09-26 15:00:32 +02:00
Philippe Mathieu-Daudé f80ac75d0e qcow2: fix null pointer dereference
It seems this assert() was somehow misplaced.

block/qcow2-refcount.c:2193:42: warning: Array access (from variable 'on_disk_reftable') results in a null pointer dereference
        on_disk_reftable[refblock_index] = refblock_offset;
        ~~~~~~~~~~~~~~~~                 ^

Reported-by: Clang Static Analyzer
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-07-31 13:06:38 +03:00
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 60c48a29b7 block/qcow2: Rename "fail_block" to just "fail"
Now alloc_refcount_block() only contains a single fail label, so it
makes more sense to just name it "fail" instead of "fail_block".

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-14-mreitz@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 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
Vladimir Sementsov-Ogievskiy 88ddffae8f qcow2: add bitmaps extension
Add bitmap extension as specified in docs/specs/qcow2.txt.
For now, just mirror extension header into Qcow2 state and check
constraints. Also, calculate refcounts for qcow2 bitmaps, to not break
qemu-img check.

For now, disable image resize if it has bitmaps. It will be fixed later.

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: 20170628120530.31251-9-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:57 +02:00
Vladimir Sementsov-Ogievskiy 8a5bb1f114 qcow2-refcount: rename inc_refcounts() and make it public
This is needed for the following patch, which will introduce refcounts
checking for qcow2 bitmaps.

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: 20170628120530.31251-8-vsementsov@virtuozzo.com
[mreitz: s/inc_refcounts/qcow2_inc_refcounts_imrt/ in one more (new)
         place]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:57 +02:00
Daniel P. Berrange 4652b8f3e1 qcow2: add support for LUKS encryption format
This adds support for using LUKS as an encryption format
with the qcow2 file, using the new encrypt.format parameter
to request "luks" format. e.g.

  # qemu-img create --object secret,data=123456,id=sec0 \
       -f qcow2 -o encrypt.format=luks,encrypt.key-secret=sec0 \
       test.qcow2 10G

The legacy "encryption=on" parameter still results in
creation of the old qcow2 AES format (and is equivalent
to the new 'encryption-format=aes'). e.g. the following are
equivalent:

  # qemu-img create --object secret,data=123456,id=sec0 \
       -f qcow2 -o encryption=on,encrypt.key-secret=sec0 \
       test.qcow2 10G

 # qemu-img create --object secret,data=123456,id=sec0 \
       -f qcow2 -o encryption-format=aes,encrypt.key-secret=sec0 \
       test.qcow2 10G

With the LUKS format it is necessary to store the LUKS
partition header and key material in the QCow2 file. This
data can be many MB in size, so cannot go into the QCow2
header region directly. Thus the spec defines a FDE
(Full Disk Encryption) header extension that specifies
the offset of a set of clusters to hold the FDE headers,
as well as the length of that region. The LUKS header is
thus stored in these extra allocated clusters before the
main image payload.

Aside from all the cryptographic differences implied by
use of the LUKS format, there is one further key difference
between the use of legacy AES and LUKS encryption in qcow2.
For LUKS, the initialiazation vectors are generated using
the host physical sector as the input, rather than the
guest virtual sector. This guarantees unique initialization
vectors for all sectors when qcow2 internal snapshots are
used, thus giving stronger protection against watermarking
attacks.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-14-berrange@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:56 +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
Eric Blake 3ef9521893 qcow2: Name typedef for cluster type
Although it doesn't add all that much type safety (this is C, after
all), it does add a bit of legibility to use the name QCow2ClusterType
instead of a plain int.

In particular, qcow2_get_cluster_offset() has an overloaded return
type; a QCow2ClusterType on success, and -errno on failure; keeping
the cluster type in a separate variable makes it slightly easier for
the next patch to make further computations based on the type.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170507000552.20847-6-eblake@redhat.com
[mreitz: Use the new type in two more places (one of them pulled from
         the next patch)]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11 14:28:06 +02:00
Eric Blake bbd995d830 qcow2: Use consistent switch indentation
Fix a couple of inconsistent indentations, before an upcoming
patch further tweaks the switch statements.
(best viewed with 'git diff -b').

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170507000552.20847-3-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11 14:28:06 +02:00
Eric Blake b32cbae111 qcow2: Nicer variable names in qcow2_update_snapshot_refcount()
In order to keep checkpatch happy when the next patch changes
indentation, we first have to shorten some long lines.  The easiest
approach is to use a new variable in place of
'offset & L2E_OFFSET_MASK', except that 'offset' is the best name
for that variable.  Change '[old_]offset' to '[old_]entry' to
make room.

While touching things, also fix checkpatch warnings about unusual
'for' statements.

Suggested by Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170507000552.20847-2-eblake@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11 14:28:06 +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 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
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 0c51a893b6 block: Convert bdrv_discard() to byte-based
Another step towards byte-based interfaces everywhere.  Replace
the sector-based bdrv_discard() with a new byte-based
bdrv_pdiscard(), which silently ignores any unaligned head
or tail.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468624988-423-3-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20 14:11:55 +01:00
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 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
Eduardo Habkost 9be385980d coccinelle: Remove unnecessary variables for function return value
Use Coccinelle script to replace 'ret = E; return ret' with
'return E'. The script will do the substitution only when the
function return type and variable type are the same.

Manual fixups:

* audio/audio.c: coding style of "read (...)" and "write (...)"
* block/qcow2-cluster.c: wrap line to make it shorter
* block/qcow2-refcount.c: change indentation of wrapped line
* target-tricore/op_helper.c: fix coding style of
  "remainder|quotient"
* target-mips/dsp_helper.c: reverted changes because I don't
  want to argue about checkpatch.pl
* ui/qemu-pixman.c: fix line indentation
* block/rbd.c: restore blank line between declarations and
  statements

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-4-git-send-email-ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unused Coccinelle rule name dropped along with a redundant comment;
whitespace touched up in block/qcow2-cluster.c; stale commit message
paragraph deleted]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-06-20 16:38:13 +02:00
Laurent Vivier d737b78cc1 qcow/qcow2: Use DIV_ROUND_UP
Replace (((n) + (d) - 1) /(d)) by DIV_ROUND_UP(n,d).

This patch is the result of coccinelle script
scripts/coccinelle/round.cocci

CC: qemu-block@nongnu.org
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2016-06-07 18:19:24 +03:00
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
Markus Armbruster da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00