If we have a backup L2 table, we currently flush once after writing to
the active L2 table and again after writing to the backup table. A
single flush is enough and makes things a little less slow.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200430133007.170335-6-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If a cluster is already zeroed, we don't have to call vmdk_L2update(),
which is rather slow because it flushes the image file.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200430133007.170335-5-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When overwriting a zero cluster, we must not perform copy-on-write from
the backing file, but from a zeroed buffer.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200430133007.170335-4-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
m_data must contain valid data even for zero clusters when no cluster
was allocated in the image file. Without this, zero writes segfault with
images that have zeroed_grain=on.
For zero writes, we don't want to allocate a cluster in the image file
even in compressed files.
Fixes: 524089bce4
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200430133007.170335-3-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
m_data is used for zero clusters even though valid == 0. It really only
means that a new cluster was allocated in the image file. Rename it to
reflect this.
While at it, change it from int to bool, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200430133007.170335-2-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There are several callers that need to create a new block backend from
an existing BDS; make the task slightly easier with a common helper
routine.
Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424190903.522087-2-eblake@redhat.com>
[mreitz: Set @ret only in error paths, see
https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-2-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that block drivers can support flags for .bdrv_co_truncate, expose
the parameter in the node level interfaces bdrv_co_truncate() and
bdrv_truncate().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-3-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Description copied from Linux kernel commit from Gustavo A. R. Silva
(see [3]):
--v-- description start --v--
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to
declare variable-length types such as these ones is a flexible
array member [1], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler
warning in case the flexible array does not occur last in the
structure, which will help us prevent some kind of undefined
behavior bugs from being unadvertenly introduced [2] to the
Linux codebase from now on.
--^-- description end --^--
Do the similar housekeeping in the QEMU codebase (which uses
C99 since commit 7be41675f7).
All these instances of code were found with the help of the
following command (then manual analysis, without modifying
structures only having a single flexible array member, such
QEDTable in block/qed.h):
git grep -F '[0];'
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f
[3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1
Inspired-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk. Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.
This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around. All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior. Future patches take care
of that.
Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Compressed writes generally have to write full clusters, not just in
theory but also in practice when it comes to vmdk's streamOptimized
subformat. It currently is just silently broken for writes with
non-zero in-cluster offsets:
$ qemu-img create -f vmdk -o subformat=streamOptimized foo.vmdk 1M
$ qemu-io -c 'write 4k 4k' -c 'read 4k 4k' foo.vmdk
wrote 4096/4096 bytes at offset 4096
4 KiB, 1 ops; 00.01 sec (443.724 KiB/sec and 110.9309 ops/sec)
read failed: Invalid argument
(The technical reason is that vmdk_write_extent() just writes the
incomplete compressed data actually to offset 4k. When reading the
data, vmdk_read_extent() looks at offset 0 and finds the compressed data
size to be 0, because that is what it reads from there. This yields an
error.)
For incomplete writes with zero in-cluster offsets, the error path when
reading the rest of the cluster is a bit different, but the result is
the same:
$ qemu-img create -f vmdk -o subformat=streamOptimized foo.vmdk 1M
$ qemu-io -c 'write 0k 4k' -c 'read 4k 4k' foo.vmdk
wrote 4096/4096 bytes at offset 0
4 KiB, 1 ops; 00.01 sec (362.641 KiB/sec and 90.6603 ops/sec)
read failed: Invalid argument
(Here, vmdk_read_extent() finds the data and then sees that the
uncompressed data is short.)
It is better to reject invalid writes than to make the user believe they
might have succeeded and then fail when trying to read it back.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190815153638.4600-5-mreitz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This makes iotest 033 pass with e.g. subformat=monolithicFlat. It also
turns a former error in 059 into success.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190815153638.4600-3-mreitz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Fixes: 69f47505ee
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190725155512.9827-3-mreitz@redhat.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Until ESXi 6.5 VMware used the vmfsSparse format for snapshots (VMDK3 in
QEMU).
This format was lacking in the following:
* Grain directory (L1) and grain table (L2) entries were 32-bit,
allowing access to only 2TB (slightly less) of data.
* The grain size (default) was 512 bytes - leading to data
fragmentation and many grain tables.
* For space reclamation purposes, it was necessary to find all the
grains which are not pointed to by any grain table - so a reverse
mapping of "offset of grain in vmdk" to "grain table" must be
constructed - which takes large amounts of CPU/RAM.
The format specification can be found in VMware's documentation:
https://www.vmware.com/support/developer/vddk/vmdk_50_technote.pdf
In ESXi 6.5, to support snapshot files larger than 2TB, a new format was
introduced: SESparse (Space Efficient).
This format fixes the above issues:
* All entries are now 64-bit.
* The grain size (default) is 4KB.
* Grain directory and grain tables are now located at the beginning
of the file.
+ seSparse format reserves space for all grain tables.
+ Grain tables can be addressed using an index.
+ Grains are located in the end of the file and can also be
addressed with an index.
- seSparse vmdks of large disks (64TB) have huge preallocated
headers - mainly due to L2 tables, even for empty snapshots.
* The header contains a reverse mapping ("backmap") of "offset of
grain in vmdk" to "grain table" and a bitmap ("free bitmap") which
specifies for each grain - whether it is allocated or not.
Using these data structures we can implement space reclamation
efficiently.
* Due to the fact that the header now maintains two mappings:
* The regular one (grain directory & grain tables)
* A reverse one (backmap and free bitmap)
These data structures can lose consistency upon crash and result
in a corrupted VMDK.
Therefore, a journal is also added to the VMDK and is replayed
when the VMware reopens the file after a crash.
Since ESXi 6.7 - SESparse is the only snapshot format available.
Unfortunately, VMware does not provide documentation regarding the new
seSparse format.
This commit is based on black-box research of the seSparse format.
Various in-guest block operations and their effect on the snapshot file
were tested.
The only VMware provided source of information (regarding the underlying
implementation) was a log file on the ESXi:
/var/log/hostd.log
Whenever an seSparse snapshot is created - the log is being populated
with seSparse records.
Relevant log records are of the form:
[...] Const Header:
[...] constMagic = 0xcafebabe
[...] version = 2.1
[...] capacity = 204800
[...] grainSize = 8
[...] grainTableSize = 64
[...] flags = 0
[...] Extents:
[...] Header : <1 : 1>
[...] JournalHdr : <2 : 2>
[...] Journal : <2048 : 2048>
[...] GrainDirectory : <4096 : 2048>
[...] GrainTables : <6144 : 2048>
[...] FreeBitmap : <8192 : 2048>
[...] BackMap : <10240 : 2048>
[...] Grain : <12288 : 204800>
[...] Volatile Header:
[...] volatileMagic = 0xcafecafe
[...] FreeGTNumber = 0
[...] nextTxnSeqNumber = 0
[...] replayJournal = 0
The sizes that are seen in the log file are in sectors.
Extents are of the following format: <offset : size>
This commit is a strict implementation which enforces:
* magics
* version number 2.1
* grain size of 8 sectors (4KB)
* grain table size of 64 sectors
* zero flags
* extent locations
Additionally, this commit proivdes only a subset of the functionality
offered by seSparse's format:
* Read-only
* No journal replay
* No space reclamation
* No unmap support
Hence, journal header, journal, free bitmap and backmap extents are
unused, only the "classic" (L1 -> L2 -> data) grain access is
implemented.
However there are several differences in the grain access itself.
Grain directory (L1):
* Grain directory entries are indexes (not offsets) to grain
tables.
* Valid grain directory entries have their highest nibble set to
0x1.
* Since grain tables are always located in the beginning of the
file - the index can fit into 32 bits - so we can use its low
part if it's valid.
Grain table (L2):
* Grain table entries are indexes (not offsets) to grains.
* If the highest nibble of the entry is:
0x0:
The grain in not allocated.
The rest of the bytes are 0.
0x1:
The grain is unmapped - guest sees a zero grain.
The rest of the bits point to the previously mapped grain,
see 0x3 case.
0x2:
The grain is zero.
0x3:
The grain is allocated - to get the index calculate:
((entry & 0x0fff000000000000) >> 48) |
((entry & 0x0000ffffffffffff) << 12)
* The difference between 0x1 and 0x2 is that 0x1 is an unallocated
grain which results from the guest using sg_unmap to unmap the
grain - but the grain itself still exists in the grain extent - a
space reclamation procedure should delete it.
Unmapping a zero grain has no effect (0x2 will not change to 0x1)
but unmapping an unallocated grain will (0x0 to 0x1) - naturally.
In order to implement seSparse some fields had to be changed to support
both 32-bit and 64-bit entry sizes.
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Reviewed-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Sam Eiderman <shmuel.eiderman@oracle.com>
Message-id: 20190620091057.47441-4-shmuel.eiderman@oracle.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
512M of L1 entries is a very loose bound, only 32M are required to store
the maximal supported VMDK file size of 2TB.
Fixed qemu-iotest 59# - now failure occures before on impossible L1
table size.
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Reviewed-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Sam Eiderman <shmuel.eiderman@oracle.com>
Message-id: 20190620091057.47441-3-shmuel.eiderman@oracle.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Commit b0651b8c24 ("vmdk: Move l1_size check into vmdk_add_extent")
extended the l1_size check from VMDK4 to VMDK3 but did not update the
default coverage in the moved comment.
The previous vmdk4 calculation:
(512 * 1024 * 1024) * 512(l2 entries) * 65536(grain) = 16PB
The added vmdk3 calculation:
(512 * 1024 * 1024) * 4096(l2 entries) * 512(grain) = 1PB
Adding the calculation of vmdk3 to the comment.
In any case, VMware does not offer virtual disks more than 2TB for
vmdk4/vmdk3 or 64TB for the new undocumented seSparse format which is
not implemented yet in qemu.
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Reviewed-by: Eyal Moscovici <eyal.moscovici@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Sam Eiderman <shmuel.eiderman@oracle.com>
Message-id: 20190620091057.47441-2-shmuel.eiderman@oracle.com
Reviewed-by: yuchenlin <yuchenlin@synology.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).
The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit b69864e5a ("vmdk: Support version=3 in VMDK descriptor files")
fixed the probe function to correctly guess vmdk descriptors with
version=3.
This solves the issue where vmdk snapshot with parent vmdk descriptor
containing "version=3" would be treated as raw instead vmdk.
In the future case where a new vmdk version is introduced, we will again
experience this issue, even if the user will provide "-f vmdk" it will
only apply to the tip image and not to the underlying "misprobed" parent
image.
The code in vmdk.c already assumes that the backing file of vmdk must be
vmdk (see vmdk_is_cid_valid which returns 0 if backing file is not
vmdk).
So let's make it official by supplying the backing_format as vmdk.
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Reviewed-By: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Shmuel Eiderman <shmuel.eiderman@oracle.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <fam@euphon.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit 509d39aa22 added support for read
only VMDKs of version 3.
This commit fixes the probe function to correctly handle descriptors of
version 3.
This commit has two effects:
1. We no longer need to supply '-f vmdk' when pointing to descriptor
files of version 3 in qemu/qemu-img command line arguments.
2. This fixes the scenario where a VMDK points to a parent version 3
descriptor file which is being probed as "raw" instead of "vmdk".
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Reviewed-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Shmuel Eiderman <shmuel.eiderman@oracle.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
- Block graph change fixes (avoid loops, cope with non-tree graphs)
- bdrv_set_aio_context() related fixes
- HMP snapshot commands: Use only tag, not the ID to identify snapshots
- qmeu-img, commit: Error path fixes
- block/nvme: Build fix for gcc 9
- MAINTAINERS updates
- Fix various issues with bdrv_refresh_filename()
- Fix various iotests
- Include LUKS overhead in qemu-img measure for qcow2
- A fix for vmdk's image creation interface
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block layer patches:
- Block graph change fixes (avoid loops, cope with non-tree graphs)
- bdrv_set_aio_context() related fixes
- HMP snapshot commands: Use only tag, not the ID to identify snapshots
- qmeu-img, commit: Error path fixes
- block/nvme: Build fix for gcc 9
- MAINTAINERS updates
- Fix various issues with bdrv_refresh_filename()
- Fix various iotests
- Include LUKS overhead in qemu-img measure for qcow2
- A fix for vmdk's image creation interface
# gpg: Signature made Mon 25 Feb 2019 14:18:15 GMT
# gpg: using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6
* remotes/kevin/tags/for-upstream: (71 commits)
iotests: Skip 211 on insufficient memory
vmdk: false positive of compat6 with hwversion not set
iotests: add LUKS payload overhead to 178 qemu-img measure test
qcow2: include LUKS payload overhead in qemu-img measure
iotests.py: s/_/-/g on keys in qmp_log()
iotests: Let 045 be run concurrently
iotests: Filter SSH paths
iotests.py: Filter filename in any string value
iotests.py: Add is_str()
iotests: Fix 207 to use QMP filters for qmp_log
iotests: Fix 232 for LUKS
iotests: Remove superfluous rm from 232
iotests: Fix 237 for Python 2.x
iotests: Re-add filename filters
iotests: Test json:{} filenames of internal BDSs
block: BDS options may lack the "driver" option
block/null: Generate filename even with latency-ns
block/curl: Implement bdrv_refresh_filename()
block/curl: Harmonize option defaults
block/nvme: Fix bdrv_refresh_filename()
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In vmdk_co_create_opts, when it finds hw_version is undefined, it will
set it to 4, which misleading the compat6 and hwversion in
vmdk_co_do_create. Simply set hw_version to NULL after free, let
the logic in vmdk_co_do_create to decide the value of hw_version.
This bug can be reproduced by:
$ qemu-img convert -O vmdk -o subformat=streamOptimized,compat6
/home/yuchenlin/syno.qcow2 /home/yuchenlin/syno.vmdk
qemu-img: /home/yuchenlin/syno.vmdk: error while converting vmdk:
compat6 cannot be enabled with hwversion set
Signed-off-by: yuchenlin <yuchenlin@synology.com>
Message-id: 20190221110805.28239-1-yuchenlin@synology.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Some follow-up patches will rework the way bs->full_open_options is
refreshed in bdrv_refresh_filename(). The new implementation will remove
the need for the block drivers' bdrv_refresh_filename() implementations
to set bs->full_open_options; instead, it will be generic and use static
information from each block driver.
However, by implementing bdrv_gather_child_options(), block drivers will
still be able to override the way the full_open_options of their
children are incorporated into their own.
We need to implement this function for VMDK because we have to prevent
the generic implementation from gathering the options of all children:
It is not possible to specify options for the extents through the
runtime options.
For quorum, the child names that would be used by the generic
implementation and the ones that we actually (currently) want to use
differ. See quorum_gather_child_options() for more information.
Note that both of these are cases which are not ideal: In case of VMDK
it would probably be nice to be able to specify options for all extents.
In case of quorum, the current runtime option structure is simply broken
and needs to be fixed (but that is left for another patch).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-23-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Make bdrv_get_full_backing_filename_from_filename() return an allocated
string instead of placing the result in a caller-provided buffer.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-11-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Besides being safe for arbitrary path lengths, after some follow-up
patches all callers will want a freshly allocated buffer anyway.
In the meantime, path_combine_deprecated() is added which has the same
interface as path_combine() had before this patch. All callers to that
function will be converted in follow-up patches.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20190201192935.18394-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
If the backing file is overridden, this most probably does change the
guest-visible data of a BDS. Therefore, we will need to consider this
in bdrv_refresh_filename().
To see whether it has been overridden, we might want to compare
bs->backing_file and bs->backing->bs->filename. However,
bs->backing_file is changed by bdrv_set_backing_hd() (which is just used
to change the backing child at runtime, without modifying the image
header), so bs->backing_file most of the time simply contains a copy of
bs->backing->bs->filename anyway, so it is useless for such a
comparison.
This patch adds an auto_backing_file BDS field which contains the
backing file path as indicated by the image header, which is not changed
by bdrv_set_backing_hd().
Because of bdrv_refresh_filename() magic, however, a BDS's filename may
differ from what has been specified during bdrv_open(). Then, the
comparison between bs->auto_backing_file and bs->backing->bs->filename
may fail even though bs->backing was opened from bs->auto_backing_file.
To mitigate this, we can copy the real BDS's filename (after the whole
bdrv_open() and bdrv_refresh_filename() process) into
bs->auto_backing_file, if we know the former has been opened based on
the latter. This is only possible if no options modifying the backing
file's behavior have been specified, though. To simplify things, this
patch only copies the filename from the backing file if no options have
been specified for it at all.
Furthermore, there are cases where an overlay is created by qemu which
already contains a BDS's filename (e.g. in blockdev-snapshot-sync). We
do not need to worry about updating the overlay's bs->auto_backing_file
there, because we actually wrote a post-bdrv_refresh_filename() filename
into the image header.
So all in all, there will be false negatives where (as of a future
patch) bdrv_refresh_filename() will assume that the backing file differs
from what was specified in the image header, even though it really does
not. However, these cases should be limited to where (1) the user
actually did override something in the backing chain (e.g. by specifying
options for the backing file), or (2) the user executed a QMP command to
change some node's backing file (e.g. change-backing-file or
block-commit with @backing-file given) where the given filename does not
happen to coincide with qemu's idea of the backing BDS's filename.
Then again, (1) really is limited to -drive. With -blockdev or
blockdev-add, you have to adhere to the schema, so a user cannot give
partial "unimportant" options (e.g. by just setting backing.node-name
and leaving the rest to the image header). Therefore, trying to fix
this would mean trying to fix something for -drive only.
To improve on (2), we would need a full infrastructure to "canonicalize"
an arbitrary filename (+ options), so it can be compared against
another. That seems a bit over the top, considering that filenames
nowadays are there mostly for the user's entertainment.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-5-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Before this patch, bdrv_refresh_filename() is used in a pushing manner:
Whenever the BDS graph is modified, the parents of the modified edges
are supposed to be updated (recursively upwards). However, that is
nonviable, considering that we want child changes not to concern
parents.
Also, in the long run we want a pull model anyway: Here, we would have a
bdrv_filename() function which returns a BDS's filename, freshly
constructed.
This patch is an intermediate step. It adds bdrv_refresh_filename()
calls before every place a BDS.filename value is used. The only
exceptions are protocol drivers that use their own filename, which
clearly would not profit from refreshing that filename before.
Also, bdrv_get_encrypted_filename() is removed along the way (as a user
of BDS.filename), since it is completely unused.
In turn, all of the calls to bdrv_refresh_filename() before this patch
are removed, because we no longer have to call this function on graph
changes.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Use new qemu_iovec_init_buf() instead of
qemu_iovec_init_external( ... , 1), which simplifies the code.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190218140926.333779-12-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-12-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Inform a user in case qcow2_get_specific_info fails to obtain
QCOW2 image specific information. This patch is preliminary to
the one "qcow2: Add list of bitmaps to ImageInfoSpecificQCow2".
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1549638368-530182-2-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Clarify that the number of extents provided in BlockdevCreateOptionsVmdk
must match the number of extents that will actually be used. Providing
more extents will result in an error now.
This requires adapting the test case to provide the right number of
extents.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
This makes VMDK support blockdev-create. The implementation reuses the
image creation code in vmdk_co_create_opts which now acceptes a callback
pointer to "retrieve" BlockBackend pointers from the caller. This way we
separate the logic between file/extent acquisition and initialization.
The QAPI command parameters are mostly the same as the old create_opts
except the dropped legacy @compat6 switch, which is redundant with
@hwversion.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The extracted vmdk_init_extent takes a BlockBackend object and
initializes the format metadata. It is the common part between "qemu-img
create" and "blockdev-create".
Add a "BlockBackend *pbb" parameter to vmdk_create_extent, to return the
opened BB to the caller in the next patch.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
There is a rare case which the size of last compressed cluster
is larger than the cluster size, which will cause the file is
not aligned at the sector boundary.
There are three reasons to do it. First, if vmdk doesn't align at
the sector boundary, there may be many undefined behaviors,
such as, in vbox it will show VMDK: Compressed image is corrupted
'syno-vm-disk1.vmdk' (VERR_ZIP_CORRUPTED) when we try to import an
ova with unaligned vmdk. Second, all the cluster_sector is aligned
to sector, the last one should be like this, too. Third, it ease
reading with sector based I/Os.
Signed-off-by: yuchenlin <yuchenlin@synology.com>
Message-Id: <20180913082952.3675-1-yuchenlin@synology.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
VMDK performs a probing check in vmdk_co_create_opts() to prevent the
user from assigning non-VMDK files as a backing file, because it only
supports VMDK backing files. However, with the @backing runtime option,
it is possible to assign arbitrary nodes as backing nodes, regardless of
what the image header says. Therefore, VMDK may not just access backing
nodes assuming they are VMDK nodes -- which it does, because it needs to
compare the backing file's CID with the overlay's parentCID value, and
naturally the backing file only has a CID when it's a VMDK file.
Instead, it should report the CID of non-VMDK backing files not to match
the overlay because clearly a non-present CID does not match.
Without this change, vmdk_read_cid() reads from the backing file's
bs->file, which may be NULL (in which case we get a segfault). Also, it
interprets bs->opaque as a BDRVVmdkState and then reads from the
.desc_offset field, which usually will just return some arbitrary value
which then results in either garbage to be read, or bdrv_pread() to
return an error, both of which result in a non-matching CID to be
reported.
(In a very unlikely case, we could read something that looks like a
VMDK descriptor, and then get a CID which might actually match. But
that is highly unlikely, and the only result would be that VMDK accepts
the backing file which is not too bad (albeit unintentional).)
((And in theory, the seek to .desc_offset might leak data from another
block driver's opaque object. But then again, the user should realize
very quickly that a non-VMDK backing file does not work (because the
read will very likely fail, due to the reasons given above), so this
should not be exploitable.))
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180702210721.4847-2-mreitz@redhat.com
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
VMDK has a hard limitation of extent size, which is due to the size of grain
table entry is 32 bits. It means it can only point to a grain located at
offset = 2^32. To avoid writing the user data beyond limitation and record a useless offset
in grain table. We should return ERROR here.
Signed-off-by: yuchenlin <yuchenlin@synology.com>
Message-id: 20180322133337.28024-1-yuchenlin@synology.com
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-8-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
BlockDriver->bdrv_create() has been called from coroutine context since
commit 5b7e1542cf ("block: make
bdrv_create adopt coroutine").
Make this explicit by renaming to .bdrv_co_create_opts() and add the
coroutine_fn annotation. This makes it obvious to block driver authors
that they may yield, use CoMutex, or other coroutine_fn APIs.
bdrv_co_create is reserved for the QAPI-based version that Kevin is
working on.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20170705102231.20711-2-stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the vmdk driver accordingly. Drop the
now-unused vmdk_find_index_in_cluster().
Also, fix a pre-existing bug: if find_extent() fails (unlikely,
since the block layer did a bounds check), then we must return a
failure, rather than 0.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add it
to the places that actually need it.
While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.
This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
This is certainly not complete, but it includes at least write_aio and
read_aio.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171123020832.8165-5-mreitz@redhat.com
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Errors from the callees must be captured and propagated to our caller,
ensure this for both find_extent() and bdrv_getlength().
Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The function vmdk_read_cid() can fail if the read on the underlying
block device fails, or if there's a format error in the VMDK file.
However its API doesn't provide a mechanism to report these errors,
and in some cases we were returning a CID of 0 and in some cases a
CID of 0xffffffff, either of which might potentially be valid values.
Change the function to return 0 on success or a negative errno, and
return the CID via a uint32_t* argument. Update the callsites to
handle and propagate the error appropriately.
This fixes in passing a Coverity-spotted issue (CID 1350038) where
we weren't checking the return value from sscanf().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
This allows us to remove lots of includes of migration/migration.h
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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>
blk_new_open() is a convenience function that processes flags rather
than QDict options as a simple way to just open an image file.
In order to keep it convenient in the future, it must automatically
request the necessary permissions. This can easily be inferred from the
flags for read and write, but we need another flag that tells us whether
to get the resize permission.
We can't just always request it because that means that no block jobs
can run on the resulting BlockBackend (which is something that e.g.
qemu-img commit wants to do), but we also can't request it never because
most of the .bdrv_create() implementations call blk_truncate().
The solution is to introduce another flag that is passed by all users
that want to resize the image.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This makes use of the .bdrv_child_perm() implementation for formats that
we just added. All format drivers expose the permissions they actually
need nows, so that they can be set accordingly and updated when parents
are attached or detached.
The only format not included here is raw, which was already converted
with the other filter drivers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The way that attaching bs->file worked was a bit unusual in that it was
the only child that would be attached to a node which is not opened yet.
Because of this, the block layer couldn't know yet which permissions the
driver would eventually need.
This patch moves the point where bs->file is attached to the beginning
of the individual .bdrv_open() implementations, so drivers already know
what they are going to do with the child. This is also more consistent
with how driver-specific children work.
For a moment, bdrv_open() gets its own BdrvChild to perform image
probing, but instead of directly assigning this BdrvChild to the BDS, it
becomes a temporary one and the node name is passed as an option to the
drivers, so that they can simply use bdrv_open_child() to create another
reference for their own use.
This duplicated child for (the not opened yet) bs is not the final
state, a follow-up patch will change the image probing code to use a
BlockBackend, which is completely independent of bs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The problem was triggered by qemu-iotests case 055. It failed when it
was comparing the compressed vmdk image with original test.img.
The cause is that buf_len in vmdk_write_extent wasn't converted to
little-endian before it was stored to disk. But later vmdk_read_extent
read it and converted it from little-endian to cpu endian.
If the cpu is big-endian like s390, the problem will happen and
the data length read by vmdk_read_extent will become invalid!
The fix is to add the conversion in vmdk_write_extent, meanwhile,
repair the endianness problem of lba field which shall also be converted
to little-endian before storing to disk.
Cc: qemu-stable@nongnu.org
Signed-off-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: Jing Liu <liujbjl@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20161216052040.53067-2-haoqf@linux.vnet.ibm.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
