Commit Graph

2525 Commits

Author SHA1 Message Date
John Snow
e4808881cb mirror: limit niov to IOV_MAX elements, again
During the refactor of mirror_iteration in e5b43573,
we regressed the fix introduced in cae98cb8.

This patch re-adds IOV_MAX checking to cases where we
aren't checking alignment (and size) already.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466625064-11280-3-git-send-email-jsnow@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:53:03 -04:00
John Snow
176129552f mirror: clarify mirror_do_read return code
mirror_do_read intends to return the number of sectors processed after
the starting sector, without regard to how many sectors were processed
before the starting sector due to alignment.

Clean up the comments and code to hopefully illustrate this more clearly.

This also fixes an issue in initialization where if the mirror buffer size
is initialized to smaller than the number of sectors being requested for
transfer, we report back an incorrectly large number to the caller.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466625064-11280-2-git-send-email-jsnow@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:53:03 -04:00
Jeff Cody
7eac868a50 block/gluster: add support for selecting debug logging level
This adds commandline support for the logging level of the
gluster protocol driver, output to stdout.  The option is 'debug',
e.g.:

-drive filename=gluster://192.168.15.180/gv2/test.qcow2,debug=9

Debug levels are 0-9, with 9 being the most verbose, and 0 representing
no debugging output.  The default is the same as it was before, which
is a level of 4.  The current logging levels defined in the gluster
source are:

    0 - None
    1 - Emergency
    2 - Alert
    3 - Critical
    4 - Error
    5 - Warning
    6 - Notice
    7 - Info
    8 - Debug
    9 - Trace

(From: glusterfs/logging.h)

Reviewed-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:52:45 -04:00
Denis V. Lunev
ff04198bf5 mirror: fix trace_mirror_yield_in_flight usage in mirror_iteration()
trace_mirror_yield_in_flight accepts 2nd arguments in sectors while here
we pass chunks instead.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1466518157-27140-1-git-send-email-den@openvz.org
CC: Jeff Cody <jcody@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:52:45 -04:00
Peter Lieven
d99b26c42a block/nfs: add support for libnfs pagecache
upcoming libnfs will have support for a read cache that can
significantly help to speed up requests since libnfs by design
circumvents the kernel cache.

Example:
 qemu -cdrom nfs://127.0.0.1/iso/my.iso?pagecache=1024

The pagecache parameters takes the maximum amount of pages to
cache.  A page in libnfs is always the NFS_BLKSIZE which is
4KB.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1463662083-20814-3-git-send-email-pl@kamp.de
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:52:45 -04:00
Peter Lieven
38f8d5e025 block/nfs: refuse readahead if cache.direct is on
if we open a NFS export with disabled cache we should refuse
the readahead feature as it will cache data inside libnfs.

If a export was opened with readahead enabled it should
futher not be allowed to disable the cache while running.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1463662083-20814-2-git-send-email-pl@kamp.de
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:52:45 -04:00
Niels de Vos
947eb2030e block/gluster: add support for SEEK_DATA/SEEK_HOLE
GlusterFS 3.8 contains support for SEEK_DATA and SEEK_HOLE. This makes
it possible to detect sparse areas in files.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
2016-06-28 22:52:45 -04:00
Peter Maydell
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Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

# gpg: Signature made Mon 20 Jun 2016 21:29:27 BST
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request: (42 commits)
  trace: split out trace events for linux-user/ directory
  trace: split out trace events for qom/ directory
  trace: split out trace events for target-ppc/ directory
  trace: split out trace events for target-s390x/ directory
  trace: split out trace events for target-sparc/ directory
  trace: split out trace events for net/ directory
  trace: split out trace events for audio/ directory
  trace: split out trace events for ui/ directory
  trace: split out trace events for hw/alpha/ directory
  trace: split out trace events for hw/arm/ directory
  trace: split out trace events for hw/acpi/ directory
  trace: split out trace events for hw/vfio/ directory
  trace: split out trace events for hw/s390x/ directory
  trace: split out trace events for hw/pci/ directory
  trace: split out trace events for hw/ppc/ directory
  trace: split out trace events for hw/9pfs/ directory
  trace: split out trace events for hw/i386/ directory
  trace: split out trace events for hw/isa/ directory
  trace: split out trace events for hw/sd/ directory
  trace: split out trace events for hw/sparc/ directory
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-20 22:30:34 +01:00
Daniel P. Berrange
b54ca48e40 trace: split out trace events for block/ directory
Move all trace-events for files in the block/ directory to
their own file.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-7-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20 17:22:14 +01:00
Peter Maydell
7fa124b273 Error reporting patches for 2016-06-20
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Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2016-06-20' into staging

Error reporting patches for 2016-06-20

# gpg: Signature made Mon 20 Jun 2016 15:56:15 BST
# gpg:                using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2016-06-20:
  log: Fix qemu_set_log_filename() error handling
  log: Fix qemu_set_dfilter_ranges() error reporting
  log: Plug memory leak on multiple -dfilter
  coccinelle: Remove unnecessary variables for function return value
  error: Remove unnecessary local_err variables
  error: Remove NULL checks on error_propagate() calls
  vl: Error messages need to go to stderr, fix some

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-20 16:19:18 +01:00
Eduardo Habkost
9be385980d coccinelle: Remove unnecessary variables for function return value
Use Coccinelle script to replace 'ret = E; return ret' with
'return E'. The script will do the substitution only when the
function return type and variable type are the same.

Manual fixups:

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

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-4-git-send-email-ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unused Coccinelle rule name dropped along with a redundant comment;
whitespace touched up in block/qcow2-cluster.c; stale commit message
paragraph deleted]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-06-20 16:38:13 +02:00
Eduardo Habkost
6b62d96137 error: Remove unnecessary local_err variables
This patch simplifies code that uses a local_err variable just to
immediately use it for an error_propagate() call.

Coccinelle patch used to perform the changes added to
scripts/coccinelle/remove_local_err.cocci.

Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-3-git-send-email-ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Blank line in s390-virtio-ccw.c restored]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-06-20 16:38:13 +02:00
Eduardo Habkost
621ff94d50 error: Remove NULL checks on error_propagate() calls
error_propagate() already ignores local_err==NULL, so there's no
need to check it before calling.

Coccinelle patch used to perform the changes added to
scripts/coccinelle/error_propagate_null.cocci.

Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-2-git-send-email-ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-06-20 16:38:13 +02:00
Stefan Hajnoczi
5ab4b69ce2 backup: follow AioContext change gracefully
Move s->target to the new AioContext when there is an AioContext change.

The backup_run() coroutine does not use asynchronous I/O so there is no
need to wait for in-flight requests in a BlockJobDriver->pause()
callback.

Guest writes are intercepted by the backup job.  Treat them as guest
activity and do it even while the job is paused.  This is necessary
since the only alternative would be to fail a job that experienced guest
writes during pause once the job is resumed.  In practice the guest
writes don't interfere with AioContext switching since bdrv_drain() is
used by bdrv_set_aio_context().

Loops already contain pause points because of block_job_sleep_ns() calls
in the yield_and_check() helper function.  It is necessary to convert a
raw qemu_coroutine_yield() to block_job_yield() so the
MIRROR_SYNC_MODE_NONE case can pause.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466096189-6477-9-git-send-email-stefanha@redhat.com
2016-06-20 14:25:41 +01:00
Stefan Hajnoczi
565ac01f8d mirror: follow AioContext change gracefully
Add block_job_pause_point() calls to mark quiescent points and make sure
to complete in-flight requests when switching AioContexts.

This patch solves undefined behavior in the mirror block job when the
BDS AioContext is changed by dataplane.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466096189-6477-8-git-send-email-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20 14:25:41 +01:00
Denis V. Lunev
ec050f77a5 block: process before_write_notifiers in bdrv_co_discard
This is mandatory for correct backup creation. In the other case the
content under this area would be lost.

Dirty bits are set exactly like in bdrv_aligned_pwritev, i.e. they are set
even if notifier has returned a error.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1466093381-6120-4-git-send-email-den@openvz.org
CC: Fam Zheng <famz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20 11:44:12 +01:00
Denis V. Lunev
968d8b0627 block: fix race in bdrv_co_discard with drive-mirror
Actually we must set dirty bitmap dirty after we have written all our
zeroes for correct processing in drive mirror code. In the other case
we can face not zeroes in this area in mirror_iteration.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1466093381-6120-3-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20 11:44:12 +01:00
Denis V. Lunev
3a36e474f2 block: fixed BdrvTrackedRequest filling in bdrv_co_discard
The request area is specified in bytes, not in sectors.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1466093381-6120-2-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20 11:44:12 +01:00
Paolo Bonzini
02d0e09503 os-posix: include sys/mman.h
qemu/osdep.h checks whether MAP_ANONYMOUS is defined, but this check
is bogus without a previous inclusion of sys/mman.h.  Include it in
sysemu/os-posix.h and remove it from everywhere else.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16 18:39:03 +02:00
Max Reitz
67882b1535 block/null: Implement bdrv_refresh_filename()
The null block driver ignores any filename used for creating its BDSs,
which allows creating such BDSs even without any filename at all. In
that case, we currently construct a JSON filename when queried instead
of a plain "null-co://" or "null-aio://". This patch implements
bdrv_refresh_filename() to remedy this behavior.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20160610185750.30956-4-mreitz@redhat.com
[mreitz@redhat.com: Added commit message]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Max Reitz
274fccee2b block/mirror: Fix target backing BDS
Currently, we are trying to move the backing BDS from the source to the
target in bdrv_replace_in_backing_chain() which is called from
mirror_exit(). However, mirror_complete() already tries to open the
target's backing chain with a call to bdrv_open_backing_file().

First, we should only set the target's backing BDS once. Second, the
mirroring block job has a better idea of what to set it to than the
generic code in bdrv_replace_in_backing_chain() (in fact, the latter's
conditions on when to move the backing BDS from source to target are not
really correct).

Therefore, remove that code from bdrv_replace_in_backing_chain() and
leave it to mirror_complete().

Depending on what kind of mirroring is performed, we furthermore want to
use different strategies to open the target's backing chain:

- If blockdev-mirror is used, we can assume the user made sure that the
  target already has the correct backing chain. In particular, we should
  not try to open a backing file if the target does not have any yet.

- If drive-mirror with mode=absolute-paths is used, we can and should
  reuse the already existing chain of nodes that the source BDS is in.
  In case of sync=full, no backing BDS is required; with sync=top, we
  just link the source's backing BDS to the target, and with sync=none,
  we use the source BDS as the target's backing BDS.
  We should not try to open these backing files anew because this would
  lead to two BDSs existing per physical file in the backing chain, and
  we would like to avoid such concurrent access.

- If drive-mirror with mode=existing is used, we have to use the
  information provided in the physical image file which means opening
  the target's backing chain completely anew, just as it has been done
  already.
  If the target's backing chain shares images with the source, this may
  lead to multiple BDSs per physical image file. But since we cannot
  reliably ascertain this case, there is nothing we can do about it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20160610185750.30956-3-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Vikhyat Umrao
87cd3d20e1 rbd:change error_setg() to error_setg_errno()
Ceph RBD block driver does not use error_setg_errno() where
it is possible to use. This patch replaces error_setg()
from error_setg_errno().

Signed-off-by: Vikhyat Umrao <vumrao@redhat.com>
Message-id: 1462780319-5796-1-git-send-email-vumrao@redhat.com
Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Alberto Garcia
834fe28ddf block: Create the commit block job before reopening any image
If the base or overlay images need to be reopened in read-write mode
but the block_job_create() call fails then no one will put those
images back in read-only mode.

We can solve this problem easily by calling block_job_create() first.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: aa495045770a6f1a7cc5d408397a17c75097fdd8.1464346103.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Alberto Garcia
eb1364ceac block: use the block job list in bdrv_drain_all()
bdrv_drain_all() pauses all block jobs by using bdrv_next() to iterate
over all top-level BlockDriverStates. Therefore the code is unable to
find block jobs in other nodes.

This patch uses block_job_next() to iterate over all block jobs.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 55ee7d7d4a65c28aa1a1b28823897ef326f328e2.1464346103.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Kevin Wolf
c9d20029f4 block: Remove bs->zero_beyond_eof
It is always true for open images now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:56 +02:00
Kevin Wolf
734a77584a qcow2: Let vmstate call qcow2_co_preadv/pwrite directly
We don't really want to go through the block layer in order to read from
or write to the vmstate in a qcow2 image. Doing so required a few ugly
hacks like saving and restoring the old image size (because writing to
vmstate offsets would increase the image size) or disabling the "reads
after EOF = zeroes" logic. When calling the right functions directly,
these hacks aren't necessary any more.

Note that .bdrv_vmstate_load/save() return 0 instead of the number of
bytes in case of success now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:56 +02:00
Kevin Wolf
1a8ae82217 block: Make bdrv_load/save_vmstate coroutine_fns
This allows drivers to share code between normal I/O and vmstate
accesses.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:56 +02:00
Kevin Wolf
b433d9424d block: Allow .bdrv_load/save_vmstate() to return 0/-errno
The return value of .bdrv_load/save_vmstate() can be any non-negative
number in case of success now. It used to be bytes/-errno.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
5ddda0b8f0 block: Make .bdrv_load_vmstate() vectored
This brings it in line with .bdrv_save_vmstate().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
f1e8474115 block: Introduce bdrv_preadv()
We already have a byte-based bdrv_pwritev(), but the read counterpart
was still missing. This commit adds it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
ccb9dc1012 linux-aio: Cancel BH if not needed
linux-aio uses a BH in order to make sure that the remaining completions
are processed even in nested event loops of completion callbacks in
order to avoid deadlocks.

There is no need, however, to have the BH overhead for the first call
into qemu_laio_completion_bh() or after all pending completions have
already been processed. Therefore, this patch calls directly into
qemu_laio_completion_bh() in qemu_laio_completion_cb() and cancels
the BH after qemu_laio_completion_bh() has processed all pending
completions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
23b0d9fb1d block: Don't enforce 512 byte minimum alignment
If block drivers say that they can do an alignment < 512 bytes, let's
just suppose they mean it. raw-posix used to be an offender with respect
to this, but it can actually deal with byte-aligned requests now.

The default is still 512 bytes for any drivers that only implement
sector-based interfaces, but it is 1 now for drivers that implement
.bdrv_co_preadv.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
9d52aa3c38 raw-posix: Implement .bdrv_co_preadv/pwritev
The raw-posix block driver actually supports byte-aligned requests now
on non-O_DIRECT images, like it already (and previously incorrectly)
claimed in bs->request_alignment.

For some block drivers this means that a RMW cycle can be avoided when
they write sub-sector metadata e.g. for cluster allocation.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
2174f12bde raw-posix: Switch to bdrv_co_* interfaces
In order to use the modern byte-based .bdrv_co_preadv/pwritev()
interface, this patch switches raw-posix to coroutine-based interfaces
as a first step. In terms of semantics and performance, it doesn't make
a difference with the existing code whether we go from a coroutine to a
callback-based interface already in block/io.c or only in linux-aio.c

As there have been concerns in the past that this change may be a step
in the wrong direction with respect to a possible AIO fast path, the
old callback-based interface for linux-aio is left around and can be
reactivated when a fast path (e.g. directly from virtio-blk dataplane,
bypassing the whole block layer) is implemented.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
9896c8765f block: Prepare bdrv_aligned_pwritev() for byte-aligned requests
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
49c0752600 block: Prepare bdrv_aligned_preadv() for byte-aligned requests
This patch makes bdrv_aligned_preadv() ready to accept byte-aligned
requests. Note that this doesn't mean that such requests are actually
made. The caller still ensures that all requests are aligned to at least
512 bytes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
244483e64e block: Byte-based bdrv_co_do_copy_on_readv()
In a first step to convert the common I/O path to work on bytes rather
than sectors, this converts the copy-on-read logic that is used by
bdrv_aligned_preadv().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Daniel P. Berrange
8c0dcbc4ad block: drop support for using qcow[2] encryption with system emulators
Back in the 2.3.0 release we declared qcow[2] encryption as
deprecated, warning people that it would be removed in a future
release.

  commit a1f688f415
  Author: Markus Armbruster <armbru@redhat.com>
  Date:   Fri Mar 13 21:09:40 2015 +0100

    block: Deprecate QCOW/QCOW2 encryption

The code still exists today, but by a (happy?) accident we entirely
broke the ability to use qcow[2] encryption in the system emulators
in the 2.4.0 release due to

  commit 8336aafae1
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Tue May 12 17:09:18 2015 +0100

    qcow2/qcow: protect against uninitialized encryption key

This commit was designed to prevent future coding bugs which
might cause QEMU to read/write data on an encrypted block
device in plain text mode before a decryption key is set.

It turns out this preventative measure was a little too good,
because we already had a long standing bug where QEMU read
encrypted data in plain text mode during system emulator
startup, in order to guess disk geometry:

  Thread 10 (Thread 0x7fffd3fff700 (LWP 30373)):
  #0  0x00007fffe90b1a28 in raise () at /lib64/libc.so.6
  #1  0x00007fffe90b362a in abort () at /lib64/libc.so.6
  #2  0x00007fffe90aa227 in __assert_fail_base () at /lib64/libc.so.6
  #3  0x00007fffe90aa2d2 in  () at /lib64/libc.so.6
  #4  0x000055555587ae19 in qcow2_co_readv (bs=0x5555562accb0, sector_num=0, remaining_sectors=1, qiov=0x7fffffffd260) at block/qcow2.c:1229
  #5  0x000055555589b60d in bdrv_aligned_preadv (bs=bs@entry=0x5555562accb0, req=req@entry=0x7fffd3ffea50, offset=offset@entry=0, bytes=bytes@entry=512, align=align@entry=512, qiov=qiov@entry=0x7fffffffd260, flags=0) at block/io.c:908
  #6  0x000055555589b8bc in bdrv_co_do_preadv (bs=0x5555562accb0, offset=0, bytes=512, qiov=0x7fffffffd260, flags=<optimized out>) at block/io.c:999
  #7  0x000055555589c375 in bdrv_rw_co_entry (opaque=0x7fffffffd210) at block/io.c:544
  #8  0x000055555586933b in coroutine_thread (opaque=0x555557876310) at coroutine-gthread.c:134
  #9  0x00007ffff64e1835 in g_thread_proxy (data=0x5555562b5590) at gthread.c:778
  #10 0x00007ffff6bb760a in start_thread () at /lib64/libpthread.so.0
  #11 0x00007fffe917f59d in clone () at /lib64/libc.so.6

  Thread 1 (Thread 0x7ffff7ecab40 (LWP 30343)):
  #0  0x00007fffe91797a9 in syscall () at /lib64/libc.so.6
  #1  0x00007ffff64ff87f in g_cond_wait (cond=cond@entry=0x555555e085f0 <coroutine_cond>, mutex=mutex@entry=0x555555e08600 <coroutine_lock>) at gthread-posix.c:1397
  #2  0x00005555558692c3 in qemu_coroutine_switch (co=<optimized out>) at coroutine-gthread.c:117
  #3  0x00005555558692c3 in qemu_coroutine_switch (from_=0x5555562b5e30, to_=to_@entry=0x555557876310, action=action@entry=COROUTINE_ENTER) at coroutine-gthread.c:175
  #4  0x0000555555868a90 in qemu_coroutine_enter (co=0x555557876310, opaque=0x0) at qemu-coroutine.c:116
  #5  0x0000555555859b84 in thread_pool_completion_bh (opaque=0x7fffd40010e0) at thread-pool.c:187
  #6  0x0000555555859514 in aio_bh_poll (ctx=ctx@entry=0x5555562953b0) at async.c:85
  #7  0x0000555555864d10 in aio_dispatch (ctx=ctx@entry=0x5555562953b0) at aio-posix.c:135
  #8  0x0000555555864f75 in aio_poll (ctx=ctx@entry=0x5555562953b0, blocking=blocking@entry=true) at aio-posix.c:291
  #9  0x000055555589c40d in bdrv_prwv_co (bs=bs@entry=0x5555562accb0, offset=offset@entry=0, qiov=qiov@entry=0x7fffffffd260, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:591
  #10 0x000055555589c503 in bdrv_rw_co (bs=bs@entry=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845, is_write=is_write@entry=false, flags=flags@entry=(unknown: 0)) at block/io.c:614
  #11 0x000055555589c562 in bdrv_read_unthrottled (nb_sectors=21845, buf=0x7fffffffd2e0 "\321,", sector_num=0, bs=0x5555562accb0) at block/io.c:622
  #12 0x000055555589c562 in bdrv_read_unthrottled (bs=0x5555562accb0, sector_num=sector_num@entry=0, buf=buf@entry=0x7fffffffd2e0 "\321,", nb_sectors=nb_sectors@entry=21845) at block/io.c:634
    nb_sectors@entry=1) at block/block-backend.c:504
  #14 0x0000555555752e9f in guess_disk_lchs (blk=blk@entry=0x5555562a5290, pcylinders=pcylinders@entry=0x7fffffffd52c, pheads=pheads@entry=0x7fffffffd530, psectors=psectors@entry=0x7fffffffd534) at hw/block/hd-geometry.c:68
  #15 0x0000555555752ff7 in hd_geometry_guess (blk=0x5555562a5290, pcyls=pcyls@entry=0x555557875d1c, pheads=pheads@entry=0x555557875d20, psecs=psecs@entry=0x555557875d24, ptrans=ptrans@entry=0x555557875d28) at hw/block/hd-geometry.c:133
  #16 0x0000555555752b87 in blkconf_geometry (conf=conf@entry=0x555557875d00, ptrans=ptrans@entry=0x555557875d28, cyls_max=cyls_max@entry=65536, heads_max=heads_max@entry=16, secs_max=secs_max@entry=255, errp=errp@entry=0x7fffffffd5e0) at hw/block/block.c:71
  #17 0x0000555555799bc4 in ide_dev_initfn (dev=0x555557875c80, kind=IDE_HD) at hw/ide/qdev.c:174
  #18 0x0000555555768394 in device_realize (dev=0x555557875c80, errp=0x7fffffffd640) at hw/core/qdev.c:247
  #19 0x0000555555769a81 in device_set_realized (obj=0x555557875c80, value=<optimized out>, errp=0x7fffffffd730) at hw/core/qdev.c:1058
  #20 0x00005555558240ce in property_set_bool (obj=0x555557875c80, v=<optimized out>, opaque=0x555557875de0, name=<optimized out>, errp=0x7fffffffd730)
        at qom/object.c:1514
  #21 0x0000555555826c87 in object_property_set_qobject (obj=obj@entry=0x555557875c80, value=value@entry=0x55555784bcb0, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/qom-qobject.c:24
  #22 0x0000555555825760 in object_property_set_bool (obj=obj@entry=0x555557875c80, value=value@entry=true, name=name@entry=0x55555591cb3d "realized", errp=errp@entry=0x7fffffffd730) at qom/object.c:905
  #23 0x000055555576897b in qdev_init_nofail (dev=dev@entry=0x555557875c80) at hw/core/qdev.c:380
  #24 0x0000555555799ead in ide_create_drive (bus=bus@entry=0x555557629630, unit=unit@entry=0, drive=0x5555562b77e0) at hw/ide/qdev.c:122
  #25 0x000055555579a746 in pci_ide_create_devs (dev=dev@entry=0x555557628db0, hd_table=hd_table@entry=0x7fffffffd830) at hw/ide/pci.c:440
  #26 0x000055555579b165 in pci_piix3_ide_init (bus=<optimized out>, hd_table=0x7fffffffd830, devfn=<optimized out>) at hw/ide/piix.c:218
  #27 0x000055555568ca55 in pc_init1 (machine=0x5555562960a0, pci_enabled=1, kvmclock_enabled=<optimized out>) at /home/berrange/src/virt/qemu/hw/i386/pc_piix.c:256
  #28 0x0000555555603ab2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4249

So the safety net is correctly preventing QEMU reading cipher
text as if it were plain text, during startup and aborting QEMU
to avoid bad usage of this data.

For added fun this bug only happens if the encrypted qcow2
file happens to have data written to the first cluster,
otherwise the cluster won't be allocated and so qcow2 would
not try the decryption routines at all, just return all 0's.

That no one even noticed, let alone reported, this bug that
has shipped in 2.4.0, 2.5.0 and 2.6.0 shows that the number
of actual users of encrypted qcow2 is approximately zero.

So rather than fix the crash, and backport it to stable
releases, just go ahead with what we have warned users about
and disable any use of qcow2 encryption in the system
emulators. qemu-img/qemu-io/qemu-nbd are still able to access
qcow2 encrypted images for the sake of data conversion.

In the future, qcow2 will gain support for the alternative
luks format, but when this happens it'll be using the
'-object secret' infrastructure for getting keys, which
avoids this problematic scenario entirely.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-16 15:19:55 +02:00
Eric Blake
fa16653874 block: Assert that flags are in range
Add a new BDRV_REQ_MASK constant, and use it to make sure that
caller flags are always valid.

Tested with 'make check' and with qemu-iotests on both '-raw'
and '-qcow2'; the only failure turned up was fixed in the
previous commit.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-16 15:19:55 +02:00
Eric Blake
73698c30ca block: Avoid bogus flags during mirroring
Commit e253f4b8 converted mirroring from sector-based bdrv_aio_*
to byte-based blk_aio_*, but failed to account for the subtle
difference in signatures (the former takes a semi-redundant length,
the latter takes a flags parameter).  Since all of our flags are
currently smaller in size than BDRV_SECTOR_SIZE, it has no ill
effects until we either perform sub-sector mirroring, or we start
asserting that no unexpected flags are set.  I found it while
testing new asserts when qemu-iotests 132 started warning about an
unknown flag 0x200000.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
d46a0bb24d qcow2: Implement .bdrv_co_pwritev()
This changes qcow2 to implement the byte-based .bdrv_co_pwritev
interface rather than the sector-based old one.

As preallocation uses the same allocation function as normal writes, and
the interface of that function needs to be changed, it is converted in
the same patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
8556739355 qcow2: Use bytes instead of sectors for QCowL2Meta
In preparation for implementing .bdrv_co_pwritev in qcow2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
aaa4d20b49 qcow2: Make copy_sectors() byte based
This will allow copy on write operations where the overwritten part of
the cluster is not aligned to sector boundaries.

Also rename the function because it has nothing to do with sectors any
more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
ecfe186380 qcow2: Implement .bdrv_co_preadv()
Reading from qcow2 images is now byte granularity.

Most of the affected code in qcow2 actually gets simpler with this
change. The only exception is encryption, which is fixed on 512 bytes
blocks; in order to keep this working, bs->request_alignment is set for
encrypted images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
b2f65d6b02 qcow2: Work with bytes in qcow2_get_cluster_offset()
This patch changes the units that qcow2_get_cluster_offset() uses
internally, without touching the interface just yet. This will be done
in another patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-16 15:19:55 +02:00
Kevin Wolf
515c2f431e block: Don't emulate natively supported pwritev flags
Drivers that implement .bdrv_co_pwritev() get the flags passed as an
argument to said function, but we also unconditionally emulate the flags
anyway. We shouldn't do that.

Fix this by clearing all flags that the driver supports natively after
it returns from .bdrv_co_pwritev().

Fixes: 4df863f3 ('block: Make supported_write_flags a per-bds property')
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-06-08 10:21:09 +02:00
Kevin Wolf
2a9170bcd4 block: Fix bdrv_all_delete_snapshot() error handling
The code to exit the loop after bdrv_snapshot_delete_by_id_or_name()
returned failure was duplicated. The first copy of it was too early so
that the AioContext lock would not be freed. This patch removes it so
that only the second, correct copy remains.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-08 10:21:09 +02:00
Denis V. Lunev
f3c3b87dae qcow2: avoid extra flushes in qcow2
The problem with excessive flushing was found by a couple of performance
tests:
  - parallel directory tree creation (from 2 processes)
  - 32 cached writes + fsync at the end in a loop

For the first one results improved from 2.6 loops/sec to 3.5 loops/sec.
Each loop creates 10^3 directories with 10 files in each.

For the second one results improved from ~600 fsync/sec to ~1100
fsync/sec. Though, it was run on SSD so it probably won't show such
performance gain on rotational media.

qcow2_cache_flush() calls bdrv_flush() unconditionally after writing
cache entries of a particular cache. This can lead to as many as
2 additional fdatasyncs inside bdrv_flush.

We can simply skip all fdatasync calls inside qcow2_co_flush_to_os
as bdrv_flush for sure will do the job. These flushes are necessary to
keep the right order of writes to the different caches. Though this is
not necessary in the current code base as this ordering is ensured through
the flush in qcow2_cache_flush_dependency().

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Pavel Borzenkov <pborzenkov@virtuozzo.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:09 +02:00
Fam Zheng
6f6071745b raw-posix: Fetch max sectors for host block device
This is sometimes a useful value we should count in.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:09 +02:00
Eric Blake
c1499a5e73 block: Kill bdrv_co_write_zeroes()
Now that all drivers have been converted to a byte interface,
we no longer need a sector interface.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:08 +02:00