Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.
This patch addresses the allocations in the qcow1 block driver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Since we parse backing.* options to add a backing file from the command
line when the driver didn't assign one, it has been possible to have a
backing file for e.g. raw images (it just was never accessed).
This is obvious nonsense and should be rejected.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Now that all backend drivers are using QemuOpts, remove all
QEMUOptionParameter related codes.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Change block layer to support both QemuOpts and QEMUOptionParameter.
After this patch, it will change backend drivers one by one. At the end,
QEMUOptionParameter will be removed and only QemuOpts is kept.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Like qcow2 since commit 6d33e8e7, error out on invalid lengths instead
of silently truncating them to 1023.
Also don't rely on bdrv_pread() catching integer overflows that make len
negative, but use unsigned variables in the first place.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
A huge image size could cause s->l1_size to overflow. Make sure that
images never require a L1 table larger than what fits in s->l1_size.
This cannot only cause unbounded allocations, but also the allocation of
a too small L1 table, resulting in out-of-bounds array accesses (both
reads and writes).
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Too large L2 table sizes cause unbounded allocations. Images actually
created by qemu-img only have 512 byte or 4k L2 tables.
To keep things consistent with cluster sizes, allow ranges between 512
bytes and 64k (in fact, down to 1 entry = 8 bytes is technically
working, but L2 table sizes smaller than a cluster don't make a lot of
sense).
This also means that the number of bytes on the virtual disk that are
described by the same L2 table is limited to at most 8k * 64k or 2^29,
preventively avoiding any integer overflows.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Huge values for header.cluster_bits cause unbounded allocations (e.g.
for s->cluster_cache) and crash qemu this way. Less huge values may
survive those allocations, but can cause integer overflows later on.
The only cluster sizes that qemu can create are 4k (for standalone
images) and 512 (for images with backing files), so we can limit it
to 64k.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
We were relying on all compilers inserting the same padding in the
header struct that is used for the on-disk format. Let's not do that.
Mark the struct as packed and insert an explicit padding field for
compatibility.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Instead of blindly relying on a normal integer having a width of 32 bits
(which is a pretty good assumption, but we should not rely on it if
there is no need), use the correct format string macros.
This does not touch DEBUG output.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Returning "Wrong medium type" for an image that does not have a valid
header is a bit weird. Improve the error by mentioning what format
was trying to open it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add the bdrv_open() option BDRV_O_PROTOCOL which results in passing the
call to bdrv_file_open(). Additionally, make bdrv_file_open() static and
therefore bdrv_open() the only way to call it.
Consequently, all existing calls to bdrv_file_open() have to be adjusted
to use bdrv_open() with the BDRV_O_PROTOCOL flag instead.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Allow specifying a reference to an existing block device (by name) for
bdrv_file_open() instead of a filename and/or options.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add an Error ** parameter to bdrv_create and its associated functions to
allow more specific error messages.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add an Error ** parameter to bdrv_open, bdrv_file_open and associated
functions to allow more specific error messages.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.
Signed-off-by: Max Reitz <mreitz@redhat.com>
For now, bdrv_get_block_status is just another name for bdrv_is_allocated.
The next patches will add more flags.
This also touches all block drivers with a mostly mechanical rename. The
sole exception is cow; because it calls cow_co_is_allocated from the read
code, we keep that function and make cow_co_get_block_status a wrapper.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Manage BlockDriverState lifecycle with refcnt, so bdrv_delete() is no
longer public and should be called by bdrv_unref() if refcnt is
decreased to 0.
This is an identical change because effectively, there's no multiple
reference of BDS now: no caller of bdrv_ref() yet, only bdrv_new() sets
bs->refcnt to 1, so all bdrv_unref() now actually delete the BDS.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
.has_zero_init defaults to 1 for all formats and protocols.
this is a dangerous default since this means that all
new added drivers need to manually overwrite it to 0 if
they do not ensure that a device is zero initialized
after bdrv_create().
if a driver needs to explicitly set this value to
1 its easier to verify the correctness in the review process.
during review of the existing drivers it turned out
that ssh and gluster had a wrong default of 1.
both protocols support host_devices as backend
which are not by default zero initialized. this
wrong assumption will lead to possible corruption
if qemu-img convert is used to write to such a backend.
vpc and vmdk also defaulted to 1 altough they support
fixed respectively flat extends. this has to be addresses
in separate patches. both formats as well as the mentioned
ssh and gluster are turned to the default of 0 with this
patch for safety.
a similar problem with the wrong default existed for
iscsi most likely because the driver developer did
oversee the default value of 1.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Compression in qcow requires image length to be a multiple of the
cluster size. Lift this requirement by zero-padding the final cluster
when necessary. The virtual disk size is still not cluster-aligned, so
the guest cannot access the zero sectors.
Note that this is almost identical to the qcow2 version of this code.
qcow2's compression code is drawn from qcow.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Move aes.h from include/block to include/qemu to show it can be reused
by other subsystems.
Cc: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This improves error reports for bochs, cow, qcow, qcow2, qed and vmdk
when a file with the wrong format is selected.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These are the stubs for the file reopen drivers for the qcow format.
There is currently nothing that needs to be done by the qcow driver
in reopen.
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It now allows specifying offset within qiov to start from and
amount of bytes to copy. Actual implementation is just a call
to iov_to_buf().
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Similar to
qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
int c, size_t bytes);
the new prototype is:
qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
const void *buf, size_t bytes);
The processing starts at offset bytes within qiov.
This way, we may copy a bounce buffer directly to
a middle of qiov.
This is exactly the same function as iov_from_buf() from
iov.c, so use the existing implementation and rename it
to qemu_iovec_from_buf() to be shorter and to match the
utility function.
As with utility implementation, we now assert that the
offset is inside actual iovec. Nothing changed for
current callers, because `offset' parameter is new.
While at it, stop using "bounce-qiov" in block/qcow2.c
and copy decrypted data directly from cluster_data
instead of recreating a temp qiov for doing that.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Since common file operation functions lack of error detection and use
much more I/O syscalls, so change them to bdrv series functions and
reduce I/O request.
Signed-off-by: Li Zhi Hui <zhihuili@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The qcow2, qcow, and vmdk block drivers are based on coroutines. They have a
coroutine mutex which protects internal state. We can convert the
.bdrv_is_allocated() function to .bdrv_co_is_allocated() by holding the mutex
around the cluster lookup operation.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Looks better when reviewing these source files.
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>
There are two different types of flush that you can do: Flushing one level up
to the OS (i.e. writing data to the host page cache) or flushing it all the way
down to the disk. The existing functions flush to the disk, reflect this in the
function name.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Since coroutine operation is now mandatory, convert all bdrv_flush
implementations to coroutines. For qcow2, this means taking the lock.
Other implementations are simpler and just forward bdrv_flush to the
underlying protocol, so they can avoid the lock.
The bdrv_flush callback is then unused and can be eliminated.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Block drivers now only need to provide either of .bdrv_co_flush,
.bdrv_aio_flush() or for legacy drivers .bdrv_flush(). Remove
the redundant .bdrv_flush() implementations.
[Paolo Bonzini: change raw driver to bdrv_co_flush]
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
cppcheck reported this error:
qemu/block/qcow.c:599: error: Mismatching allocation and deallocation: cluster_data
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Embed qcow_aio_read_cb into qcow_co_readv and qcow_aio_write_cb into qcow_co_writev
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
remove unused field from this structure and put some of them in qcow_aio_read_cb and qcow_aio_write_cb
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
commit 52b8eb6013 added a mutex,
but never initialized it. This caused a segfault.
Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The old qcow format is another user of the AsyncContext infrastructure.
Converting it to coroutines (and therefore CoMutexes) allows to remove
AsyncContexts.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_aio_* must not call the callback before returning to its caller. In qcow,
this could happen in some error cases. This starts the real requests processing
in a BH to avoid this situation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch is similar to 171e3d6b99
which fixed qcow2:
Returning -EIO is far from optimal, but at least it's an error code.
In addition to read/write failures, -EIO is also returned when
decompress_cluster failed.
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All drivers use bs->file instead of s->hd for quite a while now, so it's time
to remove s->hd.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This changes bdrv_flush to return 0 on success and -errno in case of failure.
It's a requirement for implementing proper error handle in users of bdrv_flush.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Format drivers shouldn't need to bother with things like file names, but rather
just get an open BlockDriverState for the underlying protocol. This patch
introduces this behaviour for bdrv_open implementation. For protocols which
need to access the filename to open their file/device/connection/... a new
callback bdrv_file_open is introduced which doesn't get an underlying file
opened.
For now, also some of the more obscure formats use bdrv_file_open because they
open() the file themselves instead of using the block.c functions. They need to
be fixed in later patches.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
CC block/qcow.o
cc1: warnings being treated as errors
block/qcow.c: In function 'qcow_create':
block/qcow.c:804: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow.c:806: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/qcow.c:811: error: ignoring return value of 'write', declared with attribute warn_unused_result
make: *** [block/qcow.o] Error 1
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Now that we do not have to flush the backing device anymore implementing
the bdrv_aio_flush method for image formats is trivial.
[hch: forward ported to qemu mainline from a product tree]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This patch adds a small help text to each of the options in the block drivers
which can be displayed by using qemu-img create -f fmt -o ?
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that we have a separate aio pool structure we can remove those
aio pool details from BlockDriver.
Every driver supporting AIO now needs to declare a static AIOPool
with the aiocb size and the cancellation method. This cleans up the
current code considerably and will make it cleaner and more obvious
to support two different aio implementations behind a single
BlockDriver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
[this one is required for [PATCH] fully split aio_pool from BlockDriver,
sorry for not sending it out earlier]
Add a qcow_aio_setup helper to qcow to shared common code between
the aio_readv and aio_writev methods. Based on the function with
the same name in qcow2.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
There is only one (internal) user left and it can be switched to the normal
emulation provided in block.c
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Now we can make use of the newly introduced option structures. Instead of
having bdrv_create carry more and more parameters (which are format specific in
most cases), just pass a option structure as defined by the driver itself.
bdrv_create2() contains an emulation of the old interface to simplify the
transition.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
