Commit graph

4227 commits

Author SHA1 Message Date
Kevin Wolf 37be14036b qcow2: Prepare qcow2_co_block_status() for data file
Offset 0 cannot be assumed to mean an unallocated cluster any more.
Instead, the cluster type needs to be checked.

*file must refer to the data file instead of the image file if a valid
offset is returned from qcow2_co_block_status().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf 77e023ff79 qcow2: Return 0/-errno in qcow2_alloc_compressed_cluster_offset()
qcow2_alloc_compressed_cluster_offset() used to return the cluster
offset for success and 0 for error. This doesn't only conflict with 0 as
a valid host offset, but also loses the error code.

Similar to the change made to qcow2_alloc_cluster_offset() for
uncompressed clusters in commit 148da7ea9d, make the function return
0/-errno and return the allocated cluster offset in a by-reference
parameter.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf c6d619cc12 qcow2: Don't assume 0 is an invalid cluster offset
The cluster allocation code uses 0 as an invalid offset that is used in
case of errors or as "offset not yet determined". With external data
files, a host cluster offset of 0 becomes valid, though.

Define a constant INV_OFFSET (which is not cluster aligned and will
therefore never be a valid offset) that can be used for such purposes.

This removes the additional host_offset == 0 check that commit
ff52aab2df introduced; the confusion between an invalid offset and
(erroneous) allocation at offset 0 is removed with this change.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf b8c8353a38 qcow2: Prepare count_contiguous_clusters() for external data file
Offset 0 can be valid for normal (allocated) clusters now, so use
qcow2_get_cluster_type() instead.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf a4ea184d8a qcow2: Prepare qcow2_get_cluster_type() for external data file
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf 808c2bb4c4 qcow2: Pass bs to qcow2_get_cluster_type()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf 93c2493646 qcow2: Basic definitions for external data files
This adds basic constants, struct fields and helper function for
external data file support to the implementation.

QCOW2_INCOMPAT_MASK and QCOW2_AUTOCLEAR_MASK are not updated yet so that
opening images with an external data file still fails (we don't handle
them correctly yet).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Kevin Wolf c5e86ebc11 qcow2: Simplify preallocation code
Image creation already involves a bdrv_co_truncate() call, which allows
to specify a preallocation mode. Just pass the right mode there and
remove the code that is made redundant by this.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Alberto Garcia af39bd0d9a qcow2: Default to 4KB for the qcow2 cache entry size
QEMU 2.12 (commit 1221fe6f63) introduced
a new setting called l2-cache-entry-size that allows making entries on
the qcow2 L2 cache smaller than the cluster size.

I have been performing several tests with different cluster and entry
sizes and all of them show that reducing the entry size (aka L2 slice)
consistently improves I/O performance, notably during random I/O (all
tests done with sequential I/O show similar results). This is to be
expected because loading and evicting an L2 slice is more expensive
the larger the slice is.

Here are some numbers on fully populated 40GB qcow2 images. The
rightmost column represents the maximum L2 cache size in both cases.

   Cluster size = 64 KB
   |-------------+--------------+--------------+--------------|
   |             | 1MB L2 cache | 3MB L2 cache | 5MB L2 cache |
   |-------------+--------------+--------------+--------------|
   |  4KB slices |    6545 IOPS |   12045 IOPS |   55680 IOPS |
   | 16KB slices |    5177 IOPS |    9798 IOPS |   56278 IOPS |
   | 64KB slices |    2718 IOPS |    5326 IOPS |   57355 IOPS |
   |-------------+--------------+--------------+--------------|

   Cluster size = 256 KB
   |--------------+----------------+--------------+-----------------|
   |              | 512KB L2 cache | 1MB L2 cache | 1280KB L2 cache |
   |--------------+----------------+--------------+-----------------|
   |   4KB slices |      8539 IOPS |   21071 IOPS |      55417 IOPS |
   |  64KB slices |      3598 IOPS |    9772 IOPS |      57687 IOPS |
   | 256KB slices |      1415 IOPS |    4120 IOPS |      58001 IOPS |
   |--------------+----------------+--------------+-----------------|

As can be seen in the numbers, the only exception to the rule is when
the cache is large enough to hold all L2 tables. This is also to be
expected because in this case no cache entry is ever evicted so
reducing its size doesn't bring any benefit.

This patch sets the default L2 cache entry size to 4KB except when the
cache is large enough for the whole disk.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Peter Maydell adf2e451f3 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
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJcc/knAAoJEH8JsnLIjy/WptQP/3F8Lh52H4egXaP7NUUuDjQM
 AhqhuDAp/EZBS+xim9kLTogNJADe/rMWdSX/YB5aLpSPYbjasC66NgaLhd6QewgQ
 VIcsLUdlYAyZ5ZjJytimfMTLwm1X02RmVIe55y52DTY8LlfViZzOlf3qwqPm00ao
 EJB2cl8UJLM+PVEu59cCw3R0/06LY+WIJRB32d3tnCBRTkaJwfR9h4lrp/juVcFZ
 U+2eWU68KMbUHSYiWANowN+KRV3uPY4HVA98v3F0vDmcBxlVHOeBg6S+PcT7tK8p
 huzCMwcdwUyPMJgVs/+WBtUnbG0jN6SHUYmFLz859UMVgBnCw5tzBMf8qw1wOA4A
 Iw+zor27Pxj4IlxcLPp5f97YZ8k9acdMR2VKPH6xLJZ1JF+sKa54RfzESd5EJeIj
 Mfcp773H0lIaWcFJ6RY1F0L1E1ta7QigwNBiWMdYfh0a0EWHnDvGyYeaSPYEQ+rl
 e8bZOcfrYwVI7DTDiZOIkGA9D8DXEPDNp+sl6s1DxeY69D0NNaXTtCPqFNNAbFbd
 20uD7yDRZlWq32cQB/K9D5cSkZRSOzdUpLfLU3nQU2+dz11x6OpM6m7DVboSrztD
 1HtPPDzDEvH5dOP7ibd60s+ntjkSiNfNkUgnuVrBE/d/PocC1eHHpZt5V7f43Ofb
 RxVwH5+smzQ9nsNBfQR0
 =gaah
 -----END PGP SIGNATURE-----

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>
2019-02-26 19:04:47 +00:00
yuchenlin 26c9296c31 vmdk: false positive of compat6 with hwversion not set
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>
2019-02-25 15:11:28 +01:00
Stefan Hajnoczi 61914f8906 qcow2: include LUKS payload overhead in qemu-img measure
LUKS encryption reserves clusters for its own payload data.  The size of
this area must be included in the qemu-img measure calculation so that
we arrive at the correct minimum required image size.

(Ab)use the qcrypto_block_create() API to determine the payload
overhead.  We discard the payload data that qcrypto thinks will be
written to the image.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190218104525.23674-2-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:28 +01:00
Max Reitz 1e47cb7f52 block/null: Generate filename even with latency-ns
While we cannot represent the latency-ns option in a filename, it is not
a strong option so not being able to should not stop us from generating
a filename nonetheless.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-30-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz 937c007b6e block/curl: Implement bdrv_refresh_filename()
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-29-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz 712b64e8f3 block/curl: Harmonize option defaults
Both of the defaults we currently have in the curl driver are named
based on a slightly different schema, let's unify that and call both
CURL_BLOCK_OPT_${NAME}_DEFAULT.

While at it, we can add a macro for the third option for which a default
exists, namely "sslverify".

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-28-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz cc61b0740f block/nvme: Fix bdrv_refresh_filename()
Currently, nvme's bdrv_refresh_filename() is an exact copy of null's
implementation.  However, for null, "null-co://" and "null-aio://" are
indeed valid filenames -- for nvme, they are not, as a device address is
still required.

The correct implementation should generate a filename of the form
"nvme://[PCI address]/[namespace]" (as the comment above
nvme_parse_filename() describes).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-27-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz 998b3a1e5a block: Purify .bdrv_refresh_filename()
Currently, BlockDriver.bdrv_refresh_filename() is supposed to both
refresh the filename (BDS.exact_filename) and set BDS.full_open_options.
Now that we have generic code in the central bdrv_refresh_filename() for
creating BDS.full_open_options, we can drop the latter part from all
BlockDriver.bdrv_refresh_filename() implementations.

This also means that we can drop all of the existing default code for
this from the global bdrv_refresh_filename() itself.

Furthermore, we now have to call BlockDriver.bdrv_refresh_filename()
after having set BDS.full_open_options, because the block driver's
implementation should now be allowed to depend on BDS.full_open_options
being set correctly.

Finally, with this patch we can drop the @options parameter from
BlockDriver.bdrv_refresh_filename(); also, add a comment on this
function's purpose in block/block_int.h while touching its interface.

This completely obsoletes blklogwrite's implementation of
.bdrv_refresh_filename().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-25-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz abc521a9aa block: Add BlockDriver.bdrv_gather_child_options
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>
2019-02-25 15:11:27 +01:00
Max Reitz 2654267cc1 block: Add strong_runtime_opts to BlockDriver
This new field can be set by block drivers to list the runtime options
they accept that may influence the contents of the respective BDS. As of
a follow-up patch, this list will be used by the common
bdrv_refresh_filename() implementation to decide which options to put
into BDS.full_open_options (and consequently whether a JSON filename has
to be created), thus freeing the drivers of having to implement that
logic themselves.

Additionally, this patch adds the field to all of the block drivers that
need it and sets it accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-22-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz 0dcbc54a95 block/nfs: Implement bdrv_dirname()
While the basic idea is obvious and could be handled by the default
bdrv_dirname() implementation, we cannot generate a directory name if
the gid or uid are set, so we have to explicitly return NULL in those
cases.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-19-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz 8a6239c071 block/nbd: Make bdrv_dirname() return NULL
The generic bdrv_dirname() implementation would be able to generate some
form of directory name for many NBD nodes, but it would be always wrong.
Therefore, we have to explicitly make it an error (until NBD has some
form of specification for export paths, if it ever will).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190201192935.18394-18-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz f3037bd254 quorum: Make bdrv_dirname() return NULL
While the common implementation for bdrv_dirname() should return NULL
for quorum BDSs already (because they do not have a file node and their
exact_filename field should be empty), there is no reason not to make
that explicit.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-17-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz 27953572a5 blkverify: Make bdrv_dirname() return NULL
blkverify's BDSs have a file BDS, but we do not want this to be
preferred over the raw node. There is no way to decide between the two
(and not really a reason to, either), so just return NULL in blkverify's
implementation of bdrv_dirname().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-16-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz 6b6833c1b4 block: bdrv_get_full_backing_filename's ret. val.
Make bdrv_get_full_backing_filename() return an allocated string instead
of placing the result in a caller-provided buffer.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-12-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz 645ae7d88e block: bdrv_get_full_backing_filename_from_...'s ret. val.
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>
2019-02-25 15:11:26 +01:00
Max Reitz 009b03aaa2 block: Make path_combine() return the path
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>
2019-02-25 15:11:26 +01:00
Max Reitz 998c201923 block: Add BDS.auto_backing_file
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>
2019-02-25 15:11:25 +01:00
Max Reitz e24518e303 block: Use children list in bdrv_refresh_filename
bdrv_refresh_filename() should invoke itself recursively on all
children, not just on file.

With that change, we can remove the manual invocations in blkverify,
quorum, commit, mirror, and blklogwrites.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:25 +01:00
Max Reitz f30c66ba6e block: Use bdrv_refresh_filename() to pull
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>
2019-02-25 15:11:25 +01:00
Thomas Huth 83c68e149a block/nvme: Remove QEMU_PACKED from naturally aligned NVMeRegs struct
The QEMU_PACKED is causing a compiler warning/error with GCC 9:

  CC      block/nvme.o
block/nvme.c: In function ‘nvme_create_queue_pair’:
block/nvme.c:209:22: error: taking address of packed member of
 ‘struct <anonymous>’ may result in an unaligned pointer value
 [-Werror=address-of-packed-member]
  209 |     q->sq.doorbell = &s->regs->doorbells[idx * 2 * s->doorbell_scale];

All members of the struct are naturally aligned, so there should
not be the need for QEMU_PACKED here, and the following QEMU_BUILD_BUG_ON
also ensures that there is no padding. Thus simply remove the QEMU_PACKED
here.

Buglink: https://bugs.launchpad.net/qemu/+bug/1817525
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:09:48 +01:00
Alberto Garcia c1c4399084 qcow2: Assert that L2 table offsets fit in the L1 table
L1 table entries have a field to store the offset of an L2 table.
The rest of the bits of the entry are currently reserved except from
bit 63, which stores the COPIED flag.

The offset is always taken from the entry using L1E_OFFSET_MASK to
ensure that we only use the bits that belong to that field.

While that mask is used every time we read from the L1 table, it is
never used when we write to it. Due to the limits set elsewhere in the
code QEMU can never produce L2 table offsets that don't fit in that
field so any such offset when allocating an L2 table would indicate a
bug in QEMU.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:05:23 +01:00
Kevin Wolf 28e0b2d2e1 nbd: Increase bs->in_flight during AioContext switch
bdrv_drain() must not leave connection_co scheduled, so bs->in_flight
needs to be increased while the coroutine is waiting to be scheduled
in the new AioContext after nbd_client_attach_aio_context().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:19 +01:00
Kevin Wolf d3bd5b9089 nbd: Use low-level QIOChannel API in nbd_read_eof()
Instead of using the convenience wrapper qio_channel_read_all_eof(), use
the lower level QIOChannel API. This means duplicating some code, but
we'll need this because this coroutine yield is special: We want it to
be interruptible so that nbd_client_attach_aio_context() can correctly
reenter the coroutine.

This moves the bdrv_dec/inc_in_flight() pair into nbd_read_eof(), so
that connection_co will always sit in this exact qio_channel_yield()
call when bdrv_drain() returns.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25 15:03:19 +01:00
Kevin Wolf 5ad81b4946 nbd: Restrict connection_co reentrance
nbd_client_attach_aio_context() schedules connection_co in the new
AioContext and this way reenters it in any arbitrary place that has
yielded. We can restrict this a bit to the function call where the
coroutine actually sits waiting when it's idle.

This doesn't solve any bug yet, but it shows where in the code we need
to support this random reentrance and where we don't have to care.

Add FIXME comments for the existing bugs that the rest of this series
will fix.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25 15:03:19 +01:00
Kevin Wolf c90e2a9cfd block-backend: Make blk_inc/dec_in_flight public
For some users of BlockBackends, just increasing the in_flight counter
is easier than implementing separate handlers in BlockDevOps. Make the
helper functions for this public.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:19 +01:00
Alberto Garcia 2468eed3be commit: Replace commit_top_bs on failure after deleting the block job
If there's an error in commit_start() then the block job must be
deleted before replacing commit_top_bs, otherwise it will fail because
of lack of permissions. This happens since the permission system was
introduced in 8dfba27977.

Fortunately this bug doesn't seem to be possible to reproduce at the
moment without changing the code.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:19 +01:00
Daniel Henrique Barboza 161e612d20 qcow2-snapshot: remove redundant find_snapshot_by_id_and_name call
In qcow2_snapshot_create there is the following code block:

    /* Generate an ID */
    find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));

    /* Check that the ID is unique */
    if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) {
        return -EEXIST;
    }

find_new_snapshot_id cycles through all snapshots, getting the id_str
as an unsigned long int, calculating the max id_max value of all the
existing id_strs and writing in the id_str pointer id_max + 1:

    for(i = 0; i < s->nb_snapshots; i++) {
        sn = s->snapshots + i;
        id = strtoul(sn->id_str, NULL, 10);
        if (id > id_max)
            id_max = id;
    }
    snprintf(id_str, id_str_size, "%lu", id_max + 1);

Here, sn_info->id_str will have the unique value id_max + 1. Right
after that, find_snapshot_by_id_and_name is called with
id = sn_info->id_str and name = NULL. This will cause the function
to execute the following:

    } else if (id) {
        for (i = 0; i < s->nb_snapshots; i++) {
            if (!strcmp(s->snapshots[i].id_str, id)) {
                return i;
            }
        }
    }

In short, we're searching the existing snapshots to see if sn_info->id_str
matches any existing id, right after we set in the previous line a
sn_info->id_str value that is already unique.

The first code block goes way back to commit 585f8587ad, a 2006 commit from
Fabrice Bellard that simply says "new qcow2 disk image format". No more
info is provided about this logic in any subsequent commits that moved
this code block around.

I can't say about the original design, but the current logic is redundant.
bdrv_snapshot_create is called in aio_context lock, forbidding any
concurrent call to accidentally create a new snapshot between
the find_new_snapshot_id and find_snapshot_by_id_and_name calls. What
we're ending up doing is to cycle through the snapshots two times
for no viable reason.

This patch eliminates the redundancy by removing the 'id is unique'
check that calls find_snapshot_by_id_and_name.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:19 +01:00
Daniel Henrique Barboza 8c04093c8c block/snapshot: remove bdrv_snapshot_delete_by_id_or_name
After the previous patch, the only instance of this function left
is inside qemu-img.c.

qemu-img is using it inside the 'img_snapshot' function to delete
snapshots in the SNAPSHOT_DELETE case, based on a "snapshot_name"
string that refers to the tag, not ID, of the QEMUSnapshotInfo struct.
This can be verified by checking the SNAPSHOT_CREATE case that
comes shortly before SNAPSHOT_DELETE. In that case, the same
"snapshot_name" variable is being strcpy to the 'name' field
of the QEMUSnapshotInfo struct sn:

pstrcpy(sn.name, sizeof(sn.name), snapshot_name);

Based on that, it is unlikely that "snapshot_name" might contain
an "id" in SNAPSHOT_DELETE.

This patch changes SNAPSHOT_DELETE to use snapshot_find() and
snapshot_delete() instead of bdrv_snapshot_delete_by_id_or_name.
After that, there is no instances left of bdrv_snapshot_delete_by_id_or_name
in the code, so it is safe to remove it entirely.

Suggested-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:18 +01:00
Daniel Henrique Barboza 6ca080453e block/snapshot.c: eliminate use of ID input in snapshot operations
At this moment, QEMU attempts to create/load/delete snapshots
by using either an ID (id_str) or a name. The problem is that the code
isn't consistent of whether the entered argument is an ID or a name,
causing unexpected behaviors.

For example, when creating snapshots via savevm <arg>, what happens is that
"arg" is treated as both name and id_str. In a guest without snapshots, create
a single snapshot via savevm:

(qemu) savevm 0
(qemu) info snapshots
List of snapshots present on all disks:
ID        TAG                 VM SIZE                DATE       VM CLOCK
--        0                      741M 2018-07-31 13:39:56   00:41:25.313

A snapshot with name "0" is created. ID is hidden from the user, but the
ID is a non-zero integer that starts at "1". Thus, this snapshot has
id_str=1, TAG="0". Creating a second snapshot with arg = 1, the first one
is deleted:

(qemu) savevm 1
(qemu) info snapshots
List of snapshots present on all disks:
ID        TAG                 VM SIZE                DATE       VM CLOCK
--        1                      741M 2018-07-31 13:42:14   00:41:55.252

What happened?

- when creating the second snapshot, a verification is done inside
bdrv_all_delete_snapshot to delete any existing snapshots that matches an
string argument. Here, the code calls bdrv_all_delete_snapshot("1", ...);

- bdrv_all_delete_snapshot calls bdrv_snapshot_find(..., "1") for each
BlockDriverState of the guest. And this is where things goes tilting:
bdrv_snapshot_find does a search by both id_str and name. It finds
out that there is a snapshot that has id_str = 1, stores a reference
to the snapshot in the sn_info pointer and then returns match found;

- since a match was found, a call to bdrv_snapshot_delete_by_id_or_name() is
made. This function ignores the pointer written by bdrv_snapshot_find. Instead,
it deletes the snapshot using bdrv_snapshot_delete() calling it first with
id_str = 1. If it fails to delete, then it calls it again with name = 1.

- after all that, QEMU creates the new snapshot, that has id_str = 1 and
name = 1. The user is left wondering that happened with the first snapshot
created. Similar bugs can be triggered when using loadvm and delvm.

Before contemplating discarding the use of ID input in these operations,
I've searched the code of what would be the implications. My findings
are:

- the RBD and Sheepdog drivers don't care. Both uses the 'name' field as
key in their logic, making id_str = name when appropriate.
replay-snapshot.c does not make any special use of id_str;

- qcow2 uses id_str as an unique identifier but it is automatically
calculated, not being influenced by user input. Other than that, there are
no distinguish operations made only with id_str;

- in blockdev.c, the delete operation uses a match of both id_str AND
name. Given that id_str is either a copy of 'name' or auto-generated,
we're fine here.

This gives motivation to not consider ID as a valid user input in HMP
commands - sticking with 'name' input only is more consistent. To
accomplish that, the following changes were made in this patch:

- bdrv_snapshot_find() does not match for id_str anymore, only 'name'. The
function is called in save_snapshot(), load_snapshot(), bdrv_all_delete_snapshot()
and bdrv_all_find_snapshot(). This change makes the search function more
predictable and does not change the behavior of any underlying code that uses
these affected functions, which are related to HMP (which is fine) and the
main loop inside vl.c (which doesn't care about it anyways);

- bdrv_all_delete_snapshot() does not call bdrv_snapshot_delete_by_id_or_name
anymore. Instead, it uses the pointer returned by bdrv_snapshot_find to
erase the snapshot with the exact match of id_str an name. This function
is called in save_snapshot and hmp_delvm, thus this change  produces the
intended effect;

- documentation changes to reflect the new behavior. I consider this to
be an API fix instead of an API change - the user was already creating
snapshots using 'name', but now he/she will also enjoy a consistent
behavior.

Ideally we would get rid of the id_str field entirely, but this would have
repercussions on existing snapshots. Another day perhaps.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:18 +01:00
Vladimir Sementsov-Ogievskiy 199d95b043 block/vmdk: use qemu_iovec_init_buf
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>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy 342544f98b block/qed: use qemu_iovec_init_buf
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: 20190218140926.333779-11-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-11-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy c793d4ff20 block/qcow2: use qemu_iovec_init_buf
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: 20190218140926.333779-10-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-10-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy 30d780f8fe block/qcow: use qemu_iovec_init_buf
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: 20190218140926.333779-9-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-9-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy b2589d66b4 block/parallels: use QEMU_IOVEC_INIT_BUF
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: 20190218140926.333779-8-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-8-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy 8040446d30 block/stream: use QEMU_IOVEC_INIT_BUF
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: 20190218140926.333779-7-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-7-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy ee7a883ace block/commit: use QEMU_IOVEC_INIT_BUF
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: 20190218140926.333779-6-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-6-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy 31e0a6e1af block/backup: use qemu_iovec_init_buf
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: 20190218140926.333779-5-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-5-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy ae5a9592ce block/block-backend: use QEMU_IOVEC_INIT_BUF
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: 20190218140926.333779-4-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-4-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Vladimir Sementsov-Ogievskiy 0d93ed0845 block/io: use qemu_iovec_init_buf
Use new qemu_iovec_init_buf() instead of
qemu_iovec_init_external( ... , 1), which simplifies the code.

While being here, use qemu_try_blockalign0 as well.

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: 20190218140926.333779-3-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-3-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
John Snow 73ab5d601c block/dirty-bitmap: Documentation and Comment fixups
The meaning of the states has changed subtly over time,
this should bring the understanding more in-line with the
current, actual usages.

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190202011048.12343-1-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-02-19 17:49:43 -05:00
Eric Blake f67cf661f8 dirty-bitmap: Expose persistent flag to 'query-block'
Since qemu currently doesn't flush persistent bitmaps to disk until
shutdown (which might be MUCH later), it's useful if 'query-block'
at least shows WHICH bitmaps will (eventually) make it to persistent
storage.  Update affected iotests.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190204210512.27458-1-eblake@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-02-19 17:49:43 -05:00
Andrey Shinkevich b8968c875f qcow2: Add list of bitmaps to ImageInfoSpecificQCow2
In the 'Format specific information' section of the 'qemu-img info'
command output, the supplemental information about existing QCOW2
bitmaps will be shown, such as a bitmap name, flags and granularity:

image: /vz/vmprivate/VM1/harddisk.hdd
file format: qcow2
virtual size: 64G (68719476736 bytes)
disk size: 3.0M
cluster_size: 1048576
Format specific information:
    compat: 1.1
    lazy refcounts: true
    bitmaps:
        [0]:
            flags:
                [0]: in-use
                [1]: auto
            name: back-up1
            granularity: 65536
        [1]:
            flags:
                [0]: in-use
                [1]: auto
            name: back-up2
            granularity: 65536
    refcount bits: 16
    corrupt: false

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1549638368-530182-3-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-11 14:35:43 -06:00
Andrey Shinkevich 1bf6e9ca92 bdrv_query_image_info Error parameter added
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>
2019-02-11 14:35:43 -06:00
Vladimir Sementsov-Ogievskiy bc5a03350c block/nbd-client: rename read_reply_co to connection_co
This coroutine will serve nbd reconnects, so, rename it to be something
more generic.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190201130138.94525-7-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy 88ed4e1bf0 block/nbd-client: don't check ioc
We have several paranoid checks for ioc != NULL. But ioc may become
NULL only on close, which should not happen during requests handling.
Also, we check ioc only sometimes, not after each yield, which is
inconsistent. Let's drop these checks. However, for safety, let's leave
asserts instead.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190201130138.94525-6-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy 65e01d4765 block/nbd-client: fix nbd_reply_chunk_iter_receive
Use exported report, not the variable to be reused (should not really
matter).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190201130138.94525-5-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy b0e4b5a58f block/nbd-client: split connection from initialization
Split connection code to reuse it for reconnect.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190201130138.94525-4-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy d42f78e940 block/nbd: move connection code from block/nbd to block/nbd-client
Keep all connection code in one file, to be able to implement reconnect
in further patches.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190201130138.94525-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: format tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy 7f86068dc1 block/nbd-client: split channel errors from export errors
To implement nbd reconnect in further patches, we need to distinguish
error codes, returned by nbd server, from channel errors, to reconnect
only in the latter case.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190201130138.94525-2-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy e6798f06a6 nbd: generalize usage of nbd_read
We generally do very similar things around nbd_read: error_prepend
specifying what we have tried to read, and be_to_cpu conversion of
integers.

So, it seems reasonable to move common things to helper functions,
which:
1. simplify code a bit
2. generalize nbd_read error descriptions, all starting with
   "Failed to read"
3. make it more difficult to forget to convert things from BE

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190128165830.165170-1-vsementsov@virtuozzo.com>
[eblake: rename macro to DEF_NBD_READ_N and formatting tweaks;
checkpatch has false positive complaint]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Markus Armbruster 14632122b8 block: Eliminate the S_1KiB, S_2KiB, ... macros
We define 54 macros for the powers of two >= 1024.  We use six, in six
macro definitions.  Four of them could just as well use the common MiB
macro, so do that.  The remaining two can't, because they get passed
to stringify.  Replace the macro by the literal number there.
Slightly harder to read in one instance (1048576 vs. S_1MiB), so add a
comment there.  The other instance is a wash: 65536 vs S_64KiB.  65536
has been good enough for more than seven years there.

This effectively reverts commit 540b849261 and 1240ac558d.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:45 +01:00
Thomas Huth d09ea2d227 block: Remove blk_attach_dev_legacy() / legacy_dev code
The last user of blk_attach_dev_legacy() was the code in xen_disk which
has recently been reworked. Now there is no user for this legacy function
anymore. Thus we can finally remove all code related to the "legacy_dev"
flag, too, and turn the related "void *" in block-backend.c into proper
"DeviceState *" to fix some of the remaining TODOs there.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:45 +01:00
Peter Maydell 1324f06384 uuid: Make qemu_uuid_bswap() take and return a QemuUUID
Currently qemu_uuid_bswap() takes a pointer to the QemuUUID to
be byte-swapped. This means it can't be used when the UUID
to be swapped is in a packed member of a struct. It's also
out of line with the general bswap*() functions we provide
in bswap.h, which take the value to be swapped and return it.

Make qemu_uuid_bswap() take a QemuUUID and return the swapped version.

This fixes some clang warnings about taking the address of
a packed struct member in block/vdi.c.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:45 +01:00
Peter Maydell ac928b8ee8 block/vdi: Don't take address of fields in packed structs
Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this.

Instead of passing UUID related functions the address of a possibly
unaligned QemuUUID struct, use local variables and then copy to/from
the struct field as appropriate.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:44 +01:00
Peter Maydell 0dbaaa7981 block/vpc: Don't take address of fields in packed structs
Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this. Avoid the bug by generating the
UUID into a local variable which is definitely safely aligned and
then copying it into place.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:44 +01:00
Kevin Wolf 4a960ece17 vmdk: Reject excess extents in blockdev-create
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>
2019-02-01 13:46:44 +01:00
Fam Zheng 3015372dd0 vmdk: Implement .bdrv_co_create callback
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>
2019-02-01 13:46:44 +01:00
Fam Zheng 5be28490ca vmdk: Refactor vmdk_create_extent
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>
2019-02-01 13:46:44 +01:00
Kevin Wolf 4720cbeea1 block: Fix hangs in synchronous APIs with iothreads
In the block layer, synchronous APIs are often implemented by creating a
coroutine that calls the asynchronous coroutine-based implementation and
then waiting for completion with BDRV_POLL_WHILE().

For this to work with iothreads (more specifically, when the synchronous
API is called in a thread that is not the home thread of the block
device, so that the coroutine will run in a different thread), we must
make sure to call aio_wait_kick() at the end of the operation. Many
places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if
the condition has long become false.

Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This
corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is
generally not enough for most other operations because they haven't set
the return value in the coroutine entry stub yet. To avoid race
conditions there, we need to kick after setting the return value.

The race window is small enough that the problem doesn't usually surface
in the common path. However, it does surface and causes easily
reproducible hangs if the operation can return early before even calling
bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op
success paths).

The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is
slightly different: These functions even neglected to schedule the
coroutine in the home thread of the node. This avoids the hang, but is
obviously wrong, too. Fix those to schedule the coroutine in the right
AioContext in addition to adding aio_wait_kick() calls.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-01 13:46:44 +01:00
Markus Armbruster 4e20c1becb block: Replace qdict_put() by qdict_put_obj() where appropriate
Patch created mechanically by rerunning:

  $  spatch --sp-file scripts/coccinelle/qobject.cocci \
	    --macro-file scripts/cocci-macro-file.h \
	    --dir block --in-place

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:44 +01:00
Alberto Garcia cdc674c736 qcow2: Assert that refcount block offsets fit in the refcount table
Refcount table entries have a field to store the offset of the
refcount block. The rest of the bits of the entry are currently
reserved.

The offset is always taken from the entry using REFT_OFFSET_MASK to
ensure that we only use the bits that belong to that field.

While that mask is used every time we read from the refcount table, it
is never used when we write to it. Due to the other constraints of the
qcow2 format QEMU can never produce refcount block offsets that don't
fit in that field so any such offset when allocating a refcount block
would indicate a bug in QEMU.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:44 +01:00
Alberto Garcia 67b24427fe mirror: Block the source BlockDriverState in mirror_start_job()
The mirror_start_job() function used for the commit-active job blocks
the source, target and all intermediate nodes for the duration of the
job.

   target <- intermediate <- source

Since 4ef85a9c23 this function creates a dummy mirror_top_bs that
goes on top of the source node, and it is this dummy node that gets
blocked instead. The source node is never blocked or added to the
job's list of nodes.

   target <- intermediate <- source <- mirror_top

At the moment I don't think it is possible to exploit this problem
because any additional job on 'source' would either be forbidden for
other reasons or it would need to involve an additional node that is
blocked, causing an error.

This can be seen in the error messages, however, because they never
refer to the source node being blocked:

  $ qemu-img create -f qcow2 hd0.qcow2 1M
  $ qemu-img create -f qcow2 -b hd0.qcow2 hd1.qcow2
  $ qemu-io -c 'write 0 1M' hd0.qcow2
  $ $QEMU -drive if=none,file=hd1.qcow2,node-name=hd1
  { "execute": "qmp_capabilities" }
  { "execute": "block-commit", "arguments": {"device": "hd1", "speed": 256}}
  { "execute": "block-stream", "arguments": {"device": "hd1"}}
  { "error": {"class": "GenericError",
    "desc": "Node 'hd0' is busy: block device is in use by block job: commit"}}

After this patch the error message refers to 'hd1', as it should.

The expected output of iotest 141 also needs to be updated for the
same reason.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:44 +01:00
Alberto Garcia e917e2cb2a mirror: Release the dirty bitmap if mirror_start_job() fails
At the moment I don't see how to make this function fail after the
dirty bitmap has been created, but if that was possible then we would
hit the assert(QLIST_EMPTY(&bs->dirty_bitmaps)) in bdrv_close().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-01 13:46:44 +01:00
Laurent Vivier 70018a149c block/sheepdog: Convert from DPRINTF() macro to trace events
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181213162727.17438-5-lvivier@redhat.com
[mreitz: Fixed sheepdog_snapshot_create_inode's format string to use
         PRIx32 for uint32_ts]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Laurent Vivier 4f7d28d738 block/file-posix: Convert from DPRINTF() macro to trace events
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181213162727.17438-4-lvivier@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Laurent Vivier ed2a66deb9 block/curl: Convert from DPRINTF() macro to trace events
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181213162727.17438-3-lvivier@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Laurent Vivier 023908a24d block/ssh: Convert from DPRINTF() macro to trace events
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181213162727.17438-2-lvivier@redhat.com
[mreitz: Fixed type of ssh_{read,write}_return's parameter to be ssize_t
         instead of size_t]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Vladimir Sementsov-Ogievskiy 5d3b4e9946 qapi: add x-debug-query-block-graph
Add a new command, returning block nodes (and their users) graph.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181221170909.25584-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Stefan Hajnoczi bc19a0a6e4 throttle-groups: fix restart coroutine iothread race
The following QMP command leads to a crash when iothreads are used:

  { 'execute': 'device_del', 'arguments': {'id': 'data'} }

The backtrace involves the queue restart coroutine where
tgm->throttle_state is a NULL pointer because
throttle_group_unregister_tgm() has already been called:

  (gdb) bt full
  #0  0x00005585a7a3b378 in qemu_mutex_lock_impl (mutex=0xffffffffffffffd0, file=0x5585a7bb3d54 "block/throttle-groups.c", line=412) at util/qemu-thread-posix.c:64
        err = <optimized out>
        __PRETTY_FUNCTION__ = "qemu_mutex_lock_impl"
        __func__ = "qemu_mutex_lock_impl"
  #1  0x00005585a79be074 in throttle_group_restart_queue_entry (opaque=0x5585a9de4eb0) at block/throttle-groups.c:412
        _f = <optimized out>
        data = 0x5585a9de4eb0
        tgm = 0x5585a9079440
        ts = 0x0
        tg = 0xffffffffffffff98
        is_write = false
        empty_queue = 255

This coroutine should not execute in the iothread after the throttle
group member has been unregistered!

The root cause is that the device_del code path schedules the restart
coroutine in the iothread while holding the AioContext lock.  Therefore
the iothread cannot execute the coroutine until after device_del
releases the lock - by this time it's too late.

This patch adds a reference count to ThrottleGroupMember so we can
synchronously wait for restart coroutines to complete.  Once they are
done it is safe to unregister the ThrottleGroupMember.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190114133257.30299-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-24 10:02:28 +00:00
Peter Maydell 952bc8b3c2 nbd patches for 2019-01-21
Add 'qemu-nbd --list' for probing a remote NBD server's advertisements.
 
 - Eric Blake: 0/21 nbd: add qemu-nbd --list
 -----BEGIN PGP SIGNATURE-----
 
 iQEcBAABCAAGBQJcRktLAAoJEKeha0olJ0NqY8cIAJqcHDAuk1GwcDE/NIAASY9E
 2PsaEL2pM65bEWUwsnVkFyRb4y4S4QX9VtAR/c9G6jR0YHuDvCCz7VGjiHh3eGso
 9AWKzuh5C4mayAN5dTOlbjryOx7hlcz8wDDjP5OQNqIlBvmWVAnLeh5Kkqlc7KDk
 f1SH8kJfqegDAhKDeDhi/HGlL1UVzMr5A2sR6I1wbb5IbBru5JtAKzgqAmdBH893
 lWZ9EDXqajwPCo8ASwZNyawmtmjx+VBeFjO2juA3qTWvf262roiB3XT5W/3n/CCb
 Er5CBwQQvSFBUfF9bRYDziyjwQwTXoIQJ6nuJLzPGx2cUpQbJ/svphoRQ6rBOjY=
 =gywW
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-01-21' into staging

nbd patches for 2019-01-21

Add 'qemu-nbd --list' for probing a remote NBD server's advertisements.

- Eric Blake: 0/21 nbd: add qemu-nbd --list

# gpg: Signature made Mon 21 Jan 2019 22:44:27 GMT
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-01-21: (21 commits)
  iotests: Enhance 223, 233 to cover 'qemu-nbd --list'
  nbd/client: Work around 3.0 bug for listing meta contexts
  qemu-nbd: Add --list option
  nbd/client: Add meta contexts to nbd_receive_export_list()
  nbd/client: Add nbd_receive_export_list()
  nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO
  nbd/client: Pull out oldstyle size determination
  nbd/client: Split handshake into two functions
  nbd/client: Refactor return of nbd_receive_negotiate()
  nbd/client: Split out nbd_receive_one_meta_context()
  nbd/client: Split out nbd_send_meta_query()
  nbd/client: Change signature of nbd_negotiate_simple_meta_context()
  nbd/client: Move export name into NBDExportInfo
  nbd/client: Refactor nbd_receive_list()
  qemu-nbd: Avoid strtol open-coding
  nbd/server: Favor [u]int64_t over off_t
  nbd/server: Hoist length check to qmp_nbd_server_add
  qemu-nbd: Sanity check partition bounds
  qemu-nbd: Enhance man page
  maint: Allow for EXAMPLES in texi2pod
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-01-22 17:56:21 +00:00
Thomas Huth df71ca84e4 block: Work-around a bug in libiscsi 1.9.0 when used in gnu99 mode
The header "scsi-lowlevel.h" of libiscsi 1.9.0 contains some bad
"inline" prototype definitions which GCC refuses to compile in its
gnu99 mode:

In file included from block/iscsi.c:52:0:
/usr/include/iscsi/scsi-lowlevel.h:810:13: error: inline function
‘scsi_set_uint16’ declared but never defined [-Werror]
 inline void scsi_set_uint16(unsigned char *c, uint16_t val);
             ^
/usr/include/iscsi/scsi-lowlevel.h:809:13: error: inline function
‘scsi_set_uint32’ declared but never defined [-Werror]
 inline void scsi_set_uint32(unsigned char *c, uint32_t val);
             ^
[...]

This has been fixed by upstream libiscsi in version 1.10.0 (see
https://github.com/sahlberg/libiscsi/commit/7692027d6c11 ), but
since we still want to support 1.9.0 for CentOS 7 / RHEL7, we
have to work-around the issue by redefining the "inline" keyword
to use the old "gnu89" mode behavior via "gnu_inline" instead.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-01-22 06:26:32 +01:00
Eric Blake 2df94eb52b nbd/client: Change signature of nbd_negotiate_simple_meta_context()
Pass 'info' instead of three separate parameters related to info,
when requesting the server to set the meta context.  Update the
NBDExportInfo struct to rename the received id field to match the
fact that we are currently overloading the field to match whatever
context the user supplied through the x-dirty-bitmap hack, as well
as adding a TODO comment to remind future patches about a desire
to request two contexts at once.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-11-eblake@redhat.com>
2019-01-21 15:49:52 -06:00
Eric Blake 6dc1667d68 nbd/client: Move export name into NBDExportInfo
Refactor the 'name' parameter of nbd_receive_negotiate() from
being a separate parameter into being part of the in-out 'info'.
This also spills over to a simplification of nbd_opt_go().

The main driver for this refactoring is that an upcoming patch
would like to add support to qemu-nbd to list information about
all exports available on a server, where the name(s) will be
provided by the server instead of the client.  But another benefit
is that we can now allow the client to explicitly specify the
empty export name "" even when connecting to an oldstyle server
(even if qemu is no longer such a server after commit 7f7dfe2a).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-10-eblake@redhat.com>
2019-01-21 15:49:52 -06:00
Peter Maydell 51c1c13560 pci, pc, virtio: fixes, features
tpm physical presence interface
 rsc support in virtio net
 ivshmem is removed
 misc cleanups and fixes all over the place
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
 -----BEGIN PGP SIGNATURE-----
 
 iQEcBAABAgAGBQJcQTW/AAoJECgfDbjSjVRpY34H/0wniUqht3CVVihAfC9qnL7N
 jgAJ41OGgrrCmXLrwa5P5iWxIKRjp2Odo7DQ2dl+9sqYshe6WoBBXmqEa8bDeldE
 69EJ3xSnZjkpScqXKoSaDO3dtibUGpdvlTKpjuh7q2FFBOvNvf3hQubhyt/vINsO
 qoDMqycjXJkHSaZLfdNb3P/LAkAuHI4veNk8KEbog3XTijSUbZlb2GYc8vT/agka
 0SldiEVi9CTIh7co0L2BkcLVeTMVrF3OZuWDek3tVHXPxPaNbQM3GMvHZaxqZusU
 SZinnNhcnI++kgLZVHuurxo7e1S9d8Oy0QuHGX8CZ1sfeqy3vzxer0Hbb7BdLIY=
 =GhIM
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pci, pc, virtio: fixes, features

tpm physical presence interface
rsc support in virtio net
ivshmem is removed
misc cleanups and fixes all over the place

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Fri 18 Jan 2019 02:11:11 GMT
# gpg:                using RSA key 281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (49 commits)
  migration: Use strnlen() for fixed-size string
  migration: Fix stringop-truncation warning
  hw/acpi: Use QEMU_NONSTRING for non NUL-terminated arrays
  block/sheepdog: Use QEMU_NONSTRING for non NUL-terminated arrays
  qemu/compiler: Define QEMU_NONSTRING
  acpi: update expected files
  hw: acpi: Fix memory hotplug AML generation error
  tpm: clear RAM when "memory overwrite" requested
  acpi: add ACPI memory clear interface
  acpi: build TPM Physical Presence interface
  acpi: expose TPM/PPI configuration parameters to firmware via fw_cfg
  tpm: allocate/map buffer for TPM Physical Presence interface
  tpm: add a "ppi" boolean property
  hw/misc/edu: add msi_uninit() for pci_edu_uninit()
  virtio: Make disable-legacy/disable-modern compat properties optional
  globals: Allow global properties to be optional
  virtio: virtio 9p really requires CONFIG_VIRTFS to work
  virtio: split virtio crypto bits from virtio-pci.h
  virtio: split virtio gpu bits from virtio-pci.h
  virtio: split virtio serial bits from virtio-pci
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-01-18 14:58:58 +00:00
Philippe Mathieu-Daudé 97b583f46c block/sheepdog: Use QEMU_NONSTRING for non NUL-terminated arrays
GCC 8 added a -Wstringop-truncation warning:

  The -Wstringop-truncation warning added in GCC 8.0 via r254630 for
  bug 81117 is specifically intended to highlight likely unintended
  uses of the strncpy function that truncate the terminating NUL
  character from the source string.

This new warning leads to compilation failures:

    CC      block/sheepdog.o
  qemu/block/sheepdog.c: In function 'find_vdi_name':
  qemu/block/sheepdog.c:1239:5: error: 'strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
       strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN);
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  make: *** [qemu/rules.mak:69: block/sheepdog.o] Error 1

As described previous to the strncpy() calls, the use of strncpy() is
correct here:

    /* This pair of strncpy calls ensures that the buffer is zero-filled,
     * which is desirable since we'll soon be sending those bytes, and
     * don't want the send_req to read uninitialized data.
     */
    strncpy(buf, filename, SD_MAX_VDI_LEN);
    strncpy(buf + SD_MAX_VDI_LEN, tag, SD_MAX_VDI_TAG_LEN);

Use the QEMU_NONSTRING attribute, since this array is intended to store
character arrays that do not necessarily contain a terminating NUL.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-01-17 21:10:57 -05:00
Vladimir Sementsov-Ogievskiy 19c021e194 Revert "hbitmap: Add @advance param to hbitmap_iter_next()"
This reverts commit a33fbb4f8b.

The functionality is unused.

Note: in addition to automatic revert, drop second parameter in
hbitmap_iter_next() call from hbitmap_next_dirty_area() too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2019-01-15 18:26:50 -05:00
Vladimir Sementsov-Ogievskiy 166cd55125 Revert "block/dirty-bitmap: Add bdrv_dirty_iter_next_area"
This reverts commit 72d10a9421.

The function is unused now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2019-01-15 18:26:50 -05:00
Vladimir Sementsov-Ogievskiy 1eaf1b0fdf block/mirror: fix and improve do_sync_target_write
Use bdrv_dirty_bitmap_next_dirty_area() instead of
bdrv_dirty_iter_next_area(), because of the following problems of
bdrv_dirty_iter_next_area():

1. Using HBitmap iterators we should carefully handle unaligned offset,
as first call to hbitmap_iter_next() may return a value less than
original offset (actually, it will be original offset rounded down to
bitmap granularity). This handling is not done in
do_sync_target_write().

2. bdrv_dirty_iter_next_area() handles unaligned max_offset
incorrectly:

look at the code:
    if (max_offset == iter->bitmap->size) {
        /* If max_offset points to the image end, round it up by the
         * bitmap granularity */
        gran_max_offset = ROUND_UP(max_offset, granularity);
    } else {
        gran_max_offset = max_offset;
    }

    ret = hbitmap_iter_next(&iter->hbi, false);
    if (ret < 0 || ret + granularity > gran_max_offset) {
        return false;
    }

and assume that max_offset != iter->bitmap->size but still unaligned.
if 0 < ret < max_offset we found dirty area, but the function can
return false in this case (if ret + granularity > max_offset).

3. bdrv_dirty_iter_next_area() uses inefficient loop to find the end of
the dirty area. Let's use more efficient hbitmap_next_zero instead
(bdrv_dirty_bitmap_next_dirty_area() do so)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-15 18:26:50 -05:00
Vladimir Sementsov-Ogievskiy a78a1a48cd dirty-bitmap: add bdrv_dirty_bitmap_next_dirty_area
The function alters bdrv_dirty_iter_next_area(), which is wrong and
less efficient (see further commit
"block/mirror: fix and improve do_sync_target_write" for description).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-15 18:26:50 -05:00
Vladimir Sementsov-Ogievskiy 76d570dc49 dirty-bitmap: improve bdrv_dirty_bitmap_next_zero
Add bytes parameter to the function, to limit searched range.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-15 18:26:49 -05:00
John Snow 07d5a8df6a block/dirty-bitmap: remove assertion from restore
When making a backup of a dirty bitmap (for transactions), we want to
restore that backup whether or not the bitmap is enabled.

It is perfectly valid to write into bitmaps that are disabled. It is
only illegitimate for the guest to have done so.

Remove this assertion.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20181221093529.23855-3-jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-01-14 10:09:46 -06:00
Paolo Bonzini 7d37435bd5 avoid TABs in files that only contain a few
Most files that have TABs only contain a handful of them.  Change
them to spaces so that we don't confuse people.

disas, standard-headers, linux-headers and libdecnumber are imported
from other projects and probably should be exempted from the check.
Outside those, after this patch the following files still contain both
8-space and TAB sequences at the beginning of the line.  Many of them
have a majority of TABs, or were initially committed with all tabs.

    bsd-user/i386/target_syscall.h
    bsd-user/x86_64/target_syscall.h
    crypto/aes.c
    hw/audio/fmopl.c
    hw/audio/fmopl.h
    hw/block/tc58128.c
    hw/display/cirrus_vga.c
    hw/display/xenfb.c
    hw/dma/etraxfs_dma.c
    hw/intc/sh_intc.c
    hw/misc/mst_fpga.c
    hw/net/pcnet.c
    hw/sh4/sh7750.c
    hw/timer/m48t59.c
    hw/timer/sh_timer.c
    include/crypto/aes.h
    include/disas/bfd.h
    include/hw/sh4/sh.h
    libdecnumber/decNumber.c
    linux-headers/asm-generic/unistd.h
    linux-headers/linux/kvm.h
    linux-user/alpha/target_syscall.h
    linux-user/arm/nwfpe/double_cpdo.c
    linux-user/arm/nwfpe/fpa11_cpdt.c
    linux-user/arm/nwfpe/fpa11_cprt.c
    linux-user/arm/nwfpe/fpa11.h
    linux-user/flat.h
    linux-user/flatload.c
    linux-user/i386/target_syscall.h
    linux-user/ppc/target_syscall.h
    linux-user/sparc/target_syscall.h
    linux-user/syscall.c
    linux-user/syscall_defs.h
    linux-user/x86_64/target_syscall.h
    slirp/cksum.c
    slirp/if.c
    slirp/ip.h
    slirp/ip_icmp.c
    slirp/ip_icmp.h
    slirp/ip_input.c
    slirp/ip_output.c
    slirp/mbuf.c
    slirp/misc.c
    slirp/sbuf.c
    slirp/socket.c
    slirp/socket.h
    slirp/tcp_input.c
    slirp/tcpip.h
    slirp/tcp_output.c
    slirp/tcp_subr.c
    slirp/tcp_timer.c
    slirp/tftp.c
    slirp/udp.c
    slirp/udp.h
    target/cris/cpu.h
    target/cris/mmu.c
    target/cris/op_helper.c
    target/sh4/helper.c
    target/sh4/op_helper.c
    target/sh4/translate.c
    tcg/sparc/tcg-target.inc.c
    tests/tcg/cris/check_addo.c
    tests/tcg/cris/check_moveq.c
    tests/tcg/cris/check_swap.c
    tests/tcg/multiarch/test-mmap.c
    ui/vnc-enc-hextile-template.h
    ui/vnc-enc-zywrle.h
    util/envlist.c
    util/readline.c

The following have only TABs:

    bsd-user/i386/target_signal.h
    bsd-user/sparc64/target_signal.h
    bsd-user/sparc64/target_syscall.h
    bsd-user/sparc/target_signal.h
    bsd-user/sparc/target_syscall.h
    bsd-user/x86_64/target_signal.h
    crypto/desrfb.c
    hw/audio/intel-hda-defs.h
    hw/core/uboot_image.h
    hw/sh4/sh7750_regnames.c
    hw/sh4/sh7750_regs.h
    include/hw/cris/etraxfs_dma.h
    linux-user/alpha/termbits.h
    linux-user/arm/nwfpe/fpopcode.h
    linux-user/arm/nwfpe/fpsr.h
    linux-user/arm/syscall_nr.h
    linux-user/arm/target_signal.h
    linux-user/cris/target_signal.h
    linux-user/i386/target_signal.h
    linux-user/linux_loop.h
    linux-user/m68k/target_signal.h
    linux-user/microblaze/target_signal.h
    linux-user/mips64/target_signal.h
    linux-user/mips/target_signal.h
    linux-user/mips/target_syscall.h
    linux-user/mips/termbits.h
    linux-user/ppc/target_signal.h
    linux-user/sh4/target_signal.h
    linux-user/sh4/termbits.h
    linux-user/sparc64/target_syscall.h
    linux-user/sparc/target_signal.h
    linux-user/x86_64/target_signal.h
    linux-user/x86_64/termbits.h
    pc-bios/optionrom/optionrom.h
    slirp/mbuf.h
    slirp/misc.h
    slirp/sbuf.h
    slirp/tcp.h
    slirp/tcp_timer.h
    slirp/tcp_var.h
    target/i386/svm.h
    target/sparc/asi.h
    target/xtensa/core-dc232b/xtensa-modules.inc.c
    target/xtensa/core-dc233c/xtensa-modules.inc.c
    target/xtensa/core-de212/core-isa.h
    target/xtensa/core-de212/xtensa-modules.inc.c
    target/xtensa/core-fsf/xtensa-modules.inc.c
    target/xtensa/core-sample_controller/core-isa.h
    target/xtensa/core-sample_controller/xtensa-modules.inc.c
    target/xtensa/core-test_kc705_be/core-isa.h
    target/xtensa/core-test_kc705_be/xtensa-modules.inc.c
    tests/tcg/cris/check_abs.c
    tests/tcg/cris/check_addc.c
    tests/tcg/cris/check_addcm.c
    tests/tcg/cris/check_addoq.c
    tests/tcg/cris/check_bound.c
    tests/tcg/cris/check_ftag.c
    tests/tcg/cris/check_int64.c
    tests/tcg/cris/check_lz.c
    tests/tcg/cris/check_openpf5.c
    tests/tcg/cris/check_sigalrm.c
    tests/tcg/cris/crisutils.h
    tests/tcg/cris/sys.c
    tests/tcg/i386/test-i386-ssse3.c
    ui/vgafont.h

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20181213223737.11793-3-pbonzini@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:56 +01:00
Paolo Bonzini b58deb344d qemu/queue.h: leave head structs anonymous unless necessary
Most list head structs need not be given a name.  In most cases the
name is given just in case one is going to use QTAILQ_LAST, QTAILQ_PREV
or reverse iteration, but this does not apply to lists of other kinds,
and even for QTAILQ in practice this is only rarely needed.  In addition,
we will soon reimplement those macros completely so that they do not
need a name for the head struct.  So clean up everything, not giving a
name except in the rare case where it is necessary.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:55 +01:00
Stefan Hajnoczi 88e94fd238 block/iscsi: cancel libiscsi task when ABORT TASK TMF completes
The libiscsi iscsi_task_mgmt_async() API documentation says:

  abort_task will also cancel the scsi task. The callback for the scsi
  task will be invoked with SCSI_STATUS_CANCELLED

The libiscsi implementation does not fulfil this promise.  The task's
callback is not invoked and its struct iscsi_pdu remains in the internal
list (effectively leaked).

This patch invokes the libiscsi iscsi_scsi_cancel_task() API to force
the task's callback to be invoked with SCSI_STATUS_CANCELLED when the
ABORT TASK TMF completes and the task's callback hasn't been invoked
yet.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180215111526.2464-1-stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Stefan Hajnoczi c100448790 block/iscsi: fix ioctl cancel use-after-free
iscsi_aio_cancel() does not increment the request's reference count,
causing a use-after-free when ABORT TASK finishes after the request has
already completed.

There are some additional issues with iscsi_aio_cancel():
1. Several ABORT TASKs may be sent for the same task if
   iscsi_aio_cancel() is invoked multiple times.  It's better to avoid
   this just in case the command identifier is reused.
2. The iscsilun->mutex protection is missing in iscsi_aio_cancel().

Reported-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-4-stefanha@redhat.com>
Reviewed-by: Felipe Franciosi <felipe@nutanix.com>
Tested-by: Sreejith Mohanan <sreejit.mohanan@nutanix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Stefan Hajnoczi 83d11973fa block/iscsi: take iscsilun->mutex in iscsi_timed_check_events()
Commit d045c466d9 ("iscsi: do not use
aio_context_acquire/release") introduced iscsilun->mutex but appears to
have overlooked iscsi_timed_check_events() when introducing the mutex.

iscsi_service() and iscsi_set_events() must be called with
iscsilun->mutex held.

iscsi_timed_check_events() is invoked from the AioContext and does not
take the mutex.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-3-stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Stefan Hajnoczi f92fa85f98 block/iscsi: drop unused IscsiAIOCB->buf field
The IscsiAIOCB->buf field has not been used since commit
e49ab19fca ("block/iscsi: bump libiscsi
requirement to 1.9.0").  It used to be a linear buffer for old libiscsi
versions that didn't support scatter-gather.  The minimum libiscsi
version supports scatter-gather so we don't linearize buffers anymore.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180203061621.7033-2-stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 13:57:24 +01:00
Li Feng 2916405a11 block/nvme: optimize the performance of nvme driver based on vfio-pci
When the IO size is larger than 2 pages, we move the the pointer one by
one in the pagelist, this is inefficient.

This is a simple benchmark result:

Before:
$ qemu-io -c 'write 0 1G' nvme://0000:00:04.0/1

wrote 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:02.41 (424.504 MiB/sec and 0.4146 ops/sec)

 $ qemu-io -c 'read 0 1G' nvme://0000:00:04.0/1

read 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:02.03 (503.055 MiB/sec and 0.4913 ops/sec)

After:
$ qemu-io -c 'write 0 1G' nvme://0000:00:04.0/1

wrote 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:02.17 (471.517 MiB/sec and 0.4605 ops/sec)

 $ qemu-io -c 'read 0 1G' nvme://0000:00:04.0/1

read 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:01.94 (526.770 MiB/sec and 0.5144 ops/sec)

Signed-off-by: Li Feng <lifeng1519@gmail.com>
Message-Id: <20181101103807.25862-1-lifeng1519@gmail.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2019-01-09 09:38:34 +08:00
Peter Maydell a29644590f nbd patches for 2019-01-05
Error and trace improvements in NBD code, such as less noise for
 common disconnect scenarios.
 
 - Vladimir Sementsov-Ogievskiy: 0/3 nbd-client: drop extra error noise
 - Eric Blake: portions of 0/22 nbd: add qemu-nbd --list
 -----BEGIN PGP SIGNATURE-----
 
 iQEcBAABCAAGBQJcMLgeAAoJEKeha0olJ0NqzXgH/RVRrCtmz0dOrrAkoJUfFX3t
 AcnOSb8nTWXTLGvGpU6x5l9yGL77VaN83j3z/4tXAraGA3sZsFx4cNNepT7P3zBB
 GlyT/b/Aie4EQAJPjuZdIZBe5pR6seSLoMFoGiga2oS2ik/wx4Wxxn9Gf9ZHUwVO
 muCtsJQypNrfbv7GY2Qf5NKyB2IQxt4ljSCqOmi0/T2//mQrdmRhcHbgTTDUA5HS
 3Rpr9gPV0u6YzA9foCu+UqUpyhF3RBQY9sSMLS+Y9L6W72WgynrG7y0A637o4Q61
 W+2UDDjuvyyCDR8DjD+LnWyGn4QuxIglfta2kFRcFGoPr1GqcmP4gDLeqqdJKFs=
 =R1PV
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-01-05' into staging

nbd patches for 2019-01-05

Error and trace improvements in NBD code, such as less noise for
common disconnect scenarios.

- Vladimir Sementsov-Ogievskiy: 0/3 nbd-client: drop extra error noise
- Eric Blake: portions of 0/22 nbd: add qemu-nbd --list

# gpg: Signature made Sat 05 Jan 2019 13:58:54 GMT
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-01-05:
  nbd/client: Drop pointless buf variable
  qemu-nbd: Fail earlier for -c/-d on non-linux
  nbd/client: More consistent error messages
  nbd: Document timeline of various features
  qemu-nbd: Use program name in error messages
  block/nbd-client: use traces instead of noisy error_report_err
  nbd/client: Trace all server option error messages
  nbd: publish _lookup functions

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-01-07 11:55:52 +00:00
Vladimir Sementsov-Ogievskiy d8b4bad846 block/nbd-client: use traces instead of noisy error_report_err
Reduce extra noise of nbd-client, change 083 correspondingly.

In various commits (be41c100 in 2.10, f140e300 in 2.11, 78a33ab
in 2.12), we added spots where qemu as an NBD client would report
problems communicating with the server to stderr, because there
was no where else to send the error to.  However, this is racy,
particularly since the most common source of these errors is when
either the client or the server abruptly hangs up, leaving one
coroutine to report the error only if it wins (or loses) the
race in attempting the read from the server before another
thread completes its cleanup of a protocol error that caused the
disconnect in the first place.  The race is also apparent in the
fact that differences in the flush behavior of the server can
alter the frequency of encountering the race in the client (see
commit 6d39db96).

Rather than polluting stderr, it's better to just trace these
situations, for use by developers debugging a flaky connection,
particularly since the real error that either triggers the abrupt
disconnection in the first place, or that results from the EIO
when a request can't receive a reply, DOES make it back to the
user in the normal Error propagation channels.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181102151152.288399-4-vsementsov@virtuozzo.com>
[eblake: drop depedence on error hint, enhance commit message]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-01-04 17:34:58 -06:00