In order to switch the backing file, qcow2 issues multiple write
requests that only changed a part of the image header. Any failure after
the first one would leave the header in an corrupted state. With this
patch, the whole header is written at once, so we can't fail in the
middle.
At the same time, this gives us a reusable functions that updates all
fields of the qcow2 header and not only the backing file.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The geometry calculation algorithm from the VHD spec rounds the image
size down if it doesn't exactly match a geometry. During image
conversion, this causes the image to be truncated. For dynamic images,
we already have code in place to round up instead, let's do the same for
fixed images.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The Virtual Hard Disk Image Format Specification allows for three
types of hard disk formats, Fixed, Dynamic, and Differencing. Qemu
currently only supports Dynamic disks. This patch adds support for
the Fixed Disk format.
Usage:
Example 1: qemu-img create -f vpc -o type=fixed <filename> [size]
Example 2: qemu-img convert -O vpc -o type=fixed <input filename> <output filename>
While it is also allowed to specify '-o type=dynamic', the default disk type
remains Dynamic and is what is used when the type is left unspecified.
Signed-off-by: Charles Arnold <carnold@suse.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch adds configuration variables for iSCSI to set
initiator-name to use when logging in to the target,
which type of header-digest to negotiate with the target
and username and password for CHAP authentication.
This allows specifying a initiator-name either from the command line
-iscsi initiator-name=iqn.2004-01.com.example:test
or from a configuration file included with -readconfig
[iscsi]
initiator-name = iqn.2004-01.com.example:test
header-digest = CRC32C|CRC32C-NONE|NONE-CRC32C|NONE
user = CHAP username
password = CHAP password
If you use several different targets, you can also configure this on a per
target basis by using a group name:
[iscsi "iqn.target.name"]
...
The configuration file can be read using -readconfig.
Example :
qemu-system-i386 -drive file=iscsi://127.0.0.1/iqn.ronnie.test/1
-readconfig iscsi.conf
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Zero writes are a dedicated interface for writing regions of zeroes into
the image file. If clusters are not yet allocated it is possible to use
an efficient metadata representation which keeps the image file compact
and does not store individual zero bytes.
Implementing this for the QED image format is fairly straightforward.
The only issue is that when a zero write touches an existing cluster we
have to allocate a bounce buffer and perform a regular write.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Per-request attributes like read/write are currently implemented as bool
fields in the QEDAIOCB struct. This becomes unwiedly as the number of
attributes grows. For example, the qed_aio_setup() function would have
to take multiple bool arguments and at call sites it would be hard to
distinguish the meaning of each bool.
Instead use a flags field with bitmask constants. This will be used
when zero write support is added.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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 new block was filled with zero when it was allocated by g_malloc0,
but when it was reused later and only partially used, data from the
previously allocated block were still present and written to the new
block.
This caused the problems reported by bug #919242
(https://bugs.launchpad.net/qemu/+bug/919242).
Now the unused parts of the new block which are before and after the data
are always filled with zero, so it is no longer necessary to zero the whole
block with g_malloc0.
I also updated the copyright comment.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add support for streaming data from an intermediate section of the
image chain (see patch and documentation for details).
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch implements rate-limiting for image streaming. If we've
exceeded the bandwidth quota for a 100 ms time slice we sleep the
coroutine until the next slice begins.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Most of the codebase as been converted to use glib memory allocation
functions. There are still a few instances of malloc/calloc in the
block layer and qemu-io. Replace them, especially since they do not
check the strdup/malloc/calloc return value.
Reported-by: Dr David Alan Gilbert <davidagilbert@uk.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Greg Farnum <gregory.farnum@dreamhost.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All files under GPLv2 will get GPLv2+ changes starting tomorrow.
event_notifier.c and exec-obsolete.h were only ever touched by Red Hat
employees and can be relicensed now.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Allow sending up to 16 requests, and drive the replies to the coroutine
that did the request. The code is written to be exactly the same as
before this patch when MAX_NBD_REQUESTS == 1 (modulo the extra mutex
and state).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-nbd has a limit of slightly less than 1M per request. Work
around this in the nbd block driver.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Outside coroutines, avoid busy waiting on EAGAIN by temporarily
making the socket blocking.
The API of qemu_recvv/qemu_sendv is slightly different from
do_readv/do_writev because they do not handle coroutines. It
returns the number of bytes written before encountering an
EAGAIN. The specificity of yielding on EAGAIN is entirely in
qemu-coroutine.c.
Reviewed-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The caller expects psn_tab to be NULL when there are no snapshots or
an error occurs. This results in calling g_free on an invalid address.
Reported-by: Oliver Francke <Oliver@filoo.de>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Li Zhi Hui <zhihuili@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Initially done with the following semantic patch:
@ rule1 @
expression E;
statement S;
@@
E = qemu_aio_get (...);
(
- if (E == NULL) { ... }
|
- if (E)
{ <... S ...> }
)
which however missed occurrences in linux-aio.c and posix-aio-compat.c.
Those were done by hand.
The change in vdi_aio_setup's caller was also done by hand.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Initially done with the following semantic patch:
@ rule1 @
expression E;
statement S;
@@
E =
(
bdrv_aio_readv
| bdrv_aio_writev
| bdrv_aio_flush
| bdrv_aio_discard
| bdrv_aio_ioctl
)
(...);
(
- if (E == NULL) { ... }
|
- if (E)
{ <... S ...> }
)
which however missed the occurrence in block/blkverify.c
(as it should have done), and left behind some unused
variables.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Double semicolons should be single.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Now that bdrv_co_is_allocated() is available we can use it instead of
the synchronous bdrv_is_allocated() interface. This is a follow-up that
Kevin Wolf <kwolf@redhat.com> pointed out after applying the series that
introduces bdrv_co_is_allocated().
It is safe to make cow_read() a coroutine_fn because its only caller is
a coroutine_fn.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It's common to wake up all waiting coroutines. Introduce the
qemu_co_queue_restart_all() function to do this instead of looping over
qemu_co_queue_next() in every caller.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The cow block driver does not keep internal state for cluster lookups.
This means it is safe to perform cluster lookups in coroutine context
without risk of race conditions that corrupt internal state.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It is trivial to switch from the synchronous .bdrv_is_allocated()
interface to .bdrv_co_is_allocated() since vdi_is_allocated() does not
block.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It is trivial to switch from the synchronous .bdrv_is_allocated()
interface to .bdrv_co_is_allocated() since vvfat_is_allocated() does not
block.
Signed-off-by: Stefan Hajnoczi <stefanha@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>
The bdrv_qed_is_allocated() function is a synchronous wrapper around
qed_find_cluster(), which performs the cluster lookup. In order to
convert the synchronous function to a coroutine function we yield
instead of using qemu_aio_wait(). Note that QED's cache is already safe
for parallel requests so no locking is needed.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the bdrv_read() of the snapshot's L1 table fails, return the right
error code and make sure that the old L1 table is still loaded and we
don't break the BlockDriverState completely.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
First the snapshot must be deleted and only then the refcounts can be
decreased.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
The refcount updates must be moved so that in the worst case we can get
cluster leaks, but refcounts may never be too low.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Besides fixing the return code, this adds some comments that make clear
how the code works and that it potentially breaks images if we fail in
the wrong place. Actually fixing this is left for the next patch.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Increase refcounts only after allocating a new L1 table has succeeded in
order to make leaks less likely. If writing the snapshot table fails,
revert in-memory state to be consistent with that on disk.
While at it, make it return the real error codes instead of -1.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
sn->id_str could be leaked before this. The rest of this patch changes
comments, fixes coding style or removes checks that are unnecessary with
g_malloc.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Failing in the middle wouldn't help with the integrity of the image, so
doing everything in a single request seems better.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Doesn't immediately fix anything as the callers don't use the return
value, but they will be fixed next.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.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>
Since common file operation functions lack of error detection,
so change them to bdrv series functions.
Signed-off-by: Li Zhi Hui <zhihuili@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
