Commit Graph

556 Commits

Author SHA1 Message Date
Kevin Wolf
cfcc4c62ff qcow2: Support for feature table header extension
Instead of printing an ugly bitmask, qemu can now print a more helpful
string even for yet unknown features.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
6377af48b0 qcow2: Support reading zero clusters
This adds support for reading zero clusters in version 3 images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
6744cbab8c qcow2: Version 3 images
This adds the basic infrastructure to qcow2 to handle version 3 images.
It includes code to create v3 images, allow header updates for v3 images
and checks feature bits.

It still misses support for zero clusters, so this is not a fully
compliant implementation of v3 yet.

The default for creating new images stays at v2 for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
afdf0abe77 qcow2: Ignore reserved bits in check_refcounts
Also don't infer the cluster type directly from the L2 entries, but use
qcow2_get_cluster_type() to keep everything in a single place.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
76dc9e0c8f qcow2: Ignore reserved bits in refcount table entries
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:29 +02:00
Kevin Wolf
143550a83e qcow2: Simplify count_cow_clusters
count_cow_clusters() tries to reuse existing functions, and all it
achieves is to make things much more complicated than they really are:
Everything needs COW, unless it's a normal cluster with refcount 1.

This patch implements the obvious way of doing this, and by using
qcow2_get_cluster_type() it gets rid of all flag magic.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:28 +02:00
Kevin Wolf
c7a4c37a0f qcow2: Refactor qcow2_free_any_clusters
Zero clusters will add another cluster type. Refactor the open-coded
cluster type detection into a switch of QCOW2_CLUSTER_* options so that
the detection is in a single place. This makes it easier to add new
cluster types.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:28 +02:00
Kevin Wolf
8e37f681d5 qcow2: Ignore reserved bits in L1/L2 entries
This changes the still existing places that assume that the only flags
are QCOW_OFLAG_COPIED and QCOW_OFLAG_COMPRESSED to properly mask out
reserved bits.

It does not convert bdrv_check yet.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:28 +02:00
Kevin Wolf
b0b6862e5e qcow2: Fail write_compressed when overwriting data
qcow2_alloc_compressed_cluster_offset() already fails if the copied flag
is set, because qcow2_write_compressed() doesn't perform COW as it would
have to do to allow this.

However, what we really want to check here is whether the cluster is
allocated or not. With internal snapshots the copied flag may not be set
on allocated clusters. Check the cluster offset instead.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:27 +02:00
Kevin Wolf
2bfcc4a0a0 qcow2: Ignore reserved bits in count_contiguous_clusters()
Until now, count_contiguous_clusters() has an argument that allowed to
specify flags that should be ignored in the comparison, i.e. that are
allowed to change between contiguous clusters.

This patch changes the function so that it ignores all flags by default
now and you need to pass the flags on which it should stop.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:27 +02:00
Kevin Wolf
68d000a390 qcow2: Ignore reserved bits in get_cluster_offset
With this change, reading from a qcow2 image ignores all reserved bits
that are set in an L1 or L2 table entry.

Now get_cluster_offset() assigns *cluster_offset only the offset without
any other flags. The cluster type is not longer encoded in the offset,
but a positive return value in case of success.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:27 +02:00
Kevin Wolf
90b277593d qcow2: Save disk size in snapshot header
This allows that different snapshots of an image can have different
sizes, which is a requirement for enabling image resizing even with
images that have internal snapshots.

We don't do the actual support for it now, but make sure that the
additional field is present and not completely ignored in all version 3
images. When trying to load a snapshot of different size, it returns
an error.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:27 +02:00
Kevin Wolf
f24423bd90 qcow2: Fix refcount block allocation during qcow2_alloc_cluster_at()
Refcount block allocation and refcount table growth rely on
s->free_cluster_index pointing to somewhere after the current
allocation. Change qcow2_alloc_cluster_at() to fulfill this
assumption.

Without this change it could happen that a newly allocated refcount
block and the allocated data block point to the same area in the image
file, causing data corruption in the long run.

This fixes a bug that became first visible after commit 250196f1.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:56:19 +02:00
Paolo Bonzini
bafbd6a1c6 aio: remove process_queue callback and qemu_aio_process_queue
Both unused after the previous patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19 16:37:53 +02:00
Kevin Wolf
2795ecf681 qcow2: Fix return value of alloc_refcount_block
Someone forgot something in commit 29c1a730... Documenting the right
return value is not enough, you also need to actually return it in the
code.

This bug sometimes causes error return values even when everything has
succeeded: The new offset of the refcount block is truncated to 32 bits
and interpreted as signed. At least with small cluster sizes it's easy
to get a negative return value this way.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 16:03:27 +02:00
Kevin Wolf
8dc0a5e7a0 qcow2: Fix error handling in qcow2_alloc_cluster_offset
If do_alloc_cluster_offset() fails, the error handling code tried to
remove the request from the in-flight queue, to which it wasn't added
yet, resulting in a NULL pointer dereference.

m->nb_clusters really only becomes != 0 when the request is in the list.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19 16:03:27 +02:00
Stefan Weil
4e35b92a51 block: Fix spelling in comment (ineffcient -> inefficient)
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19 15:48:52 +02:00
Anthony Liguori
bb5d8dd757 Merge remote-tracking branch 'kwolf/for-anthony' into staging
* kwolf/for-anthony: (46 commits)
  qed: remove incoming live migration blocker
  qed: honor BDRV_O_INCOMING for incoming live migration
  migration: clear BDRV_O_INCOMING flags on end of incoming live migration
  qed: add bdrv_invalidate_cache to be called after incoming live migration
  blockdev: open images with BDRV_O_INCOMING on incoming live migration
  block: add a function to clear incoming live migration flags
  block: Add new BDRV_O_INCOMING flag to notice incoming live migration
  block stream: close unused files and update ->backing_hd
  qemu-iotests: Fix call syntax for qemu-io
  qemu-iotests: Fix call syntax for qemu-img
  qemu-iotests: Test unknown qcow2 header extensions
  qemu-iotests: qcow2.py
  sheepdog: fix send req helpers
  sheepdog: implement SD_OP_FLUSH_VDI operation
  block: bdrv_append() fixes
  qed: track dirty flag status
  qemu-img: add dirty flag status
  qed: image fragmentation statistics
  qemu-img: add image fragmentation statistics
  block: document job API
  ...
2012-04-10 08:16:12 -05:00
Benoît Canet
50d30c2675 qed: remove incoming live migration blocker
Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 16:29:12 +02:00
Benoît Canet
2d1f3c2360 qed: honor BDRV_O_INCOMING for incoming live migration
From original commit with Patchwork-id: 31108 by
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

"The QED image format includes a file header bit to mark images dirty.
QED normally checks dirty images on open and fixes inconsistent
metadata.  This is undesirable during live migration since the dirty bit
may be set if the source host is modifying the image file.  The check
should be postponed until migration completes.

Skip operations that modify the image file if the BDRV_O_INCOMING flag
is set."

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 16:29:04 +02:00
Benoît Canet
c82954e529 qed: add bdrv_invalidate_cache to be called after incoming live migration
The QED image is reopened to flush metadata and check consistency.

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 16:28:27 +02:00
Marcelo Tosatti
5a67a1048e block stream: close unused files and update ->backing_hd
Close the now unused images that were part of the previous backing file
chain and adjust ->backing_hd, backing_filename and backing_format
properly.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=801449

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 15:11:37 +02:00
Liu Yuan
eb09218077 sheepdog: fix send req helpers
We should return if reading of the header fails.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Acked-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:41 +02:00
Liu Yuan
47622c44d0 sheepdog: implement SD_OP_FLUSH_VDI operation
Flush operation is supposed to flush the write-back cache of
sheepdog cluster.

By issuing flush operation, we can assure the Guest of data
reaching the sheepdog cluster storage.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:41 +02:00
Dong Xu Wang
d68dbee80e qed: track dirty flag status
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:41 +02:00
Dong Xu Wang
11c9c615c8 qed: image fragmentation statistics
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
9f25eccc1c block: set job->speed in block_set_speed
There is no need to do this in every implementation of set_speed
(even though there is only one right now).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
3e914655f2 block: fix streaming/closing race
Streaming can issue I/O while qcow2_close is running.  This causes the
L2 caches to become very confused or, alternatively, could cause a
segfault when the streaming coroutine is reentered after closing its
block device.  The fix is to cancel streaming jobs when closing their
underlying device.

The cancellation must be synchronous, on the other hand qemu_aio_wait
will not restart a coroutine that is sleeping in co_sleep.  So add
a flag saying whether streaming has in-flight I/O.  If the busy flag
is false, the coroutine is quiescent and, when cancelled, will not
issue any new I/O.

This protects streaming against closing, but not against deleting.
We have a reference count protecting us against concurrent deletion,
but I still added an assertion to ensure nothing bad happens.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
eb9566d13e vdi: change goto to loop
Finally reindent all code and change goto statements to a loop.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
4eea78e634 vdi: do not create useless iovecs
Reads and writes to the underlying file can also occur with the simple
non-vectored I/O interfaces.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
a7a43aa199 vdi: leave bounce buffering to block layer
vdi.c really works as if it implemented bdrv_read and bdrv_write.  However,
because only vector I/O is supported by the asynchronous callbacks, it
went through extra pain to bounce-buffer the I/O.  This can be handled
by the block layer now that the format is coroutine-based.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
bfc45fc183 vdi: move aiocb fields to locals
Most of the AIOCB really holds local variables that need to persist
across callback invocation.  It can go away now.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
4de659e8eb vdi: merge aio_read_cb and aio_write_cb into callers
Now inline the former AIO callbacks into vdi_co_readv and vdi_co_writev.
While many cleanups are possible, the code now really looks synchronous.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
0c7bfc321b vdi: move end-of-I/O handling at the end
The next step is to take code that only triggers after the first operation,
and move it at the end of vdi_aio_read_cb and vdi_aio_write_cb.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
3d46a75aa5 vdi: basic conversion to coroutines
Even a basic conversion changing the bdrv_aio_readv/bdrv_aio_writev calls
to bdrv_co_readv/bdrv_co_writev, and callbacks to goto statements can
eliminate a lot of code.  This is because error handling is simplified
and indirections through bottom halves can go away.

After this patch, I/O to the underlying file already happens via
coroutines, but the code still looks a lot like if asynchronous I/O was
being used.

Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Zhang Shengju
c088b69136 block/vpc: write checksum back to footer after check
After validation check, the 'checksum' is not written back
to footer, which leave it with zero.

This results in errors while loadding it under Microsoft's
Hyper-V environment, and also errors from utilities like
Citrix's vhd-util.

Signed-off-by: Zhang Shengju <sean_zhang@trendmicro.com.cn>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
29cdb2513c block: push recursive flushing up from drivers
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:39 +02:00
Kevin Wolf
3948d1d487 qcow2: Remove unused parameter in get_cluster_table()
Since everything goes through the cache, callers don't use the L2 table
offset any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-04-05 14:54:39 +02:00
Stefan Weil
fb7c8e8a2d block/curl: Replace usleep by g_usleep
The function usleep is not available for all supported platforms:
at least some versions of MinGW don't support it.

usleep was also declared obsolete by POSIX.1-2001.

The function g_usleep is part of glib2.0, so it is available for
all supported platforms.

Using nanosleep would also be possible but needs more code.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-04-03 09:34:34 +01:00
Kevin Wolf
250196f19c qcow2: Reduce number of I/O requests
If the first part of a write request is allocated, but the second isn't
and it can be allocated so that the resulting area is contiguous, handle
it at once. This is a common case for sequential writes.

After this patch, alloc_cluster_offset() only checks if the clusters are
already allocated or how many new clusters can be allocated contigouosly.
The actual cluster allocation is split off into a new function
do_alloc_cluster_offset().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:07 +01:00
Kevin Wolf
256900b16b qcow2: Add qcow2_alloc_clusters_at()
This function allows to allocate clusters at a given offset in the image
file. This is useful if you want to allocate the second part of an area
that must be contiguous.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:07 +01:00
Kevin Wolf
bf319ece56 qcow2: Factor out count_cow_clusters
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:07 +01:00
Kevin Wolf
259b217310 qcow2: Add error messages in qcow2_truncate
qemu-img resize has some limitations with qcow2, but the user is only
told that "this image format does not support resize". Quite confusing,
so add some more detailed error_report() calls and change "this image
format" into "this image".

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:06 +01:00
Kevin Wolf
3cce16f44d qcow2: Add some tracing
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12 15:14:06 +01:00
Stefan Hajnoczi
14fe292d86 qed: do not evict in-use L2 table cache entries
The L2 table cache reduces QED metadata reads that would be required
when translating LBAs to offsets into the image file.  Since requests
execute in parallel it is possible to share an L2 table between multiple
requests.

There is a potential data corruption issue when an in-use L2 table is
evicted from the cache because the following situation occurs:

  1. An allocating write performs an update to L2 table "A".

  2. Another request needs L2 table "B" and causes table "A" to be
     evicted.

  3. A new read request needs L2 table "A" but it is not cached.

As a result the L2 update from #1 can overlap with the L2 fetch from #3.
We must avoid doing overlapping I/O requests here since the worst case
outcome is that the L2 fetch completes before the L2 update and yields
stale data.  In that case we would effectively discard the L2 update and
lose data clusters!

Thanks to Benoît Canet <benoit.canet@gmail.com> for extensive testing
and debugging which lead to discovery of this bug.

Reported-by: Benoît Canet <benoit.canet@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Tested-by: Benoît Canet <benoit.canet@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-03-12 15:14:06 +01:00
Stefan Weil
75d1234103 block/vmdk: Fix warning from splint (comparision of unsigned value)
l1_entry_sectors will never be less than 0.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-07 13:03:51 +00:00
Kevin Wolf
64ca6aee4f qcow2: Reject too large header extensions
Image files that make qemu-img info read several gigabytes into the
unknown header extensions list are bad. Just fail opening the image
if an extension claims to be larger than the header extension area.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29 12:48:47 +01:00
Kevin Wolf
fd29b4bbef qcow2: Fix offset in qcow2_read_extensions
The spec says that the length of extensions is padded to 8 bytes, not
the offset. Currently this is the same because the header size is a
multiple of 8, so this is only about compatibility with future changes
to the header size.

While touching it, move the calculation to a common place instead of
duplicating it for each header extension type.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29 12:48:47 +01:00
Kevin Wolf
423477e556 qcow2: Fix build with DEBUG_EXT enabled
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-29 12:48:47 +01:00
Luiz Capitulino
f36f394952 block: bdrv_eject(): Make eject_flag a real bool
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2012-02-22 17:23:05 -02:00