Now that all block drivers have been converted to
.bdrv_co_is_allocated() we can drop .bdrv_is_allocated().

Note that the public bdrv_is_allocated() interface is still available
but is in fact a synchronous wrapper around .bdrv_co_is_allocated().
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch adds the .bdrv_co_is_allocated() interface which is identical
to .bdrv_is_allocated() but runs in coroutine context.  Running in
coroutine context implies that other coroutines might be performing I/O
at the same time.   Therefore it must be safe to run while the following
BlockDriver functions are in-flight:

    .bdrv_co_readv()
    .bdrv_co_writev()
    .bdrv_co_flush()
    .bdrv_co_is_allocated()

The new .bdrv_co_is_allocated() interface is useful because it can be
used when a VM is running, whereas .bdrv_is_allocated() is a synchronous
interface that does not cope with parallel requests.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

There is no need for bdrv_commit() to use the BlockDriver
.bdrv_is_allocated() interface directly.  Converting to the public
interface gives us the freedom to drop .bdrv_is_allocated() entirely in
favor of a new .bdrv_co_is_allocated() in the future.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

First the snapshot must be deleted and only then the refcounts can be
decreased.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan 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: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Looks better when reviewing these source files.
Signed-off-by: NDong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Since common file operation functions lack of error detection,
so change them to bdrv series functions.
Signed-off-by: NLi Zhi Hui <zhihuili@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Xen_disk.c has support for using synchronous I/O instead of asynchronous,
but it is compiled out by default.  Remove it.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch is only to refactor some lines of codes to get better and more robust codes.

As you have seen, in qed_read_table_cb() it's nice to
use qiov->size because that function doesn't obviously use a single
struct iovec.

In other two functions, if qiov use more than one struct iovec, the existing way will get wrong nb_sectors.
To make the code more robust, it will be nicer to refactor the existing way as below.
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Acked-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

A BlockDriverState should not issue requests on itself through the
public block layer interface.  Nested, or reentrant, requests are
problematic because they do I/O throttling and request tracking twice.

Features like block layer copy-on-read use request tracking to avoid
race conditions between concurrent requests.  The reentrant request will
have to "wait" for its parent request to complete.  But the parent is
waiting for the reentrant request to make progress so we have reached
deadlock.

The solution is for block drivers to avoid the public block layer
interfaces for reentrant requests.   Instead they should call their own
internal functions if they wish to perform reentrant requests.

This is also a good opportunity to make copy_sectors() a true
coroutine_fn.  That means calling bdrv_co_writev() instead of
bdrv_write().  Behavior is unchanged but we're being explicit that this
executes in coroutine context.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Unlocking during COW allows for more parallelism. One change it requires is
that buffers are dynamically allocated instead of just using a per-image
buffer.

While touching the code, drop the synchronous qcow2_read() function and replace
it by a bdrv_read() call.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Generally $(BUILD_DIR) == $(CURDIR), but that isn't necessarilly the
case, so use $(BUILD_DIR)/qapi-generated for generated files to
avoid potentionally sticking generating files in odd places outside
the build's include paths.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Fix a bug in handling dotted paths, and exclude directory prefixes
from generated guardnames to avoid odd/pseudo-random guardnames in
generated headers.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

ATR size exceeding the limit is diagnosed, but then we merrily use it
anyway, overrunning card->atr[].

The message is read from a character device.  Obvious security
implications unless the other end of the character device is trusted.

Spotted by Coverity.  CVE-2011-4111.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This reverts commit be85c90b.

This patch is incorrect and breaks the build with a freshly cloned git tree.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

--*dir) option pattern precede --{en,dis}able-usb-redir) patterns in the
option analysis switch, making the latter options have no effect.

There were some --*dir that are supported by Autoconf and not by QEMU configure.
The aim was to let QEMU packagers use the rpm (or similar) macro that overrides
directories for their distribution.

Replace --*dir with exact option names.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

strtosz() & friends require the size to be at the end of the string,
or be followed by whitespace or ','.  I find this surprising, because
the name suggests it works like strtol().

The check simplifies callers that accept exactly that follow set
slightly.  No such callers exist.

The check is redundant for callers that accept a smaller follow set,
and thus need to check themselves anyway.  Right now, this is the case
for all but one caller.  All of them neglected to check, or checked
incorrectly, but the previous few commits fixed them up.

Finally, the check is problematic for callers that accept a larger
follow set.  This is the case in monitor_parse_command().
Fortunately, the problems there are relatively harmless.

monitor_parse_command() uses strtosz() for argument type 'o'.  When
the last argument is of type 'o', a trailing ',' is diagnosed
differently than other trailing junk:

    (qemu) migrate_set_speed 1x
    invalid size
    (qemu) migrate_set_speed 1,
    migrate_set_speed: extraneous characters at the end of line

A related inconsistency exists with non-last arguments.  No such
command exists, but let's use memsave to explore the inconsistency.

The monitor permits, but does not require whitespace between
arguments.  For instance, "memsave (1-1)1024foo" is parsed as command
memsave with three arguments 0, 1024 and "foo".  Yes, this is daft,
but at least it's consistently daft.

If I change memsave's second argument from 'i' to 'o', then "memsave
(1-1)1foo" is rejected, because the size is followed by an 'f'.  But
"memsave (1-1)1," is still accepted, and duly saves to file ",".

We don't have any users of strtosz that profit from the check.  In the
users we have, it appears to encourage sloppy error checking, or gets
in the way.  Drop the bothersome check.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

strtosz_suffix() fails unless the size is followed by 0, whitespace or
','.  Useless here, because we need to fail for any junk following the
size, even if it starts with whitespace or ','.  Check manually.
Things like "qemu-img create xxx 1024," and "qemu-img convert -S '1024
junk'" are now caught.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

cpu_x86_find_by_name() uses strtosz_suffix_unit(), but screws up the
error checking.  It detects some failures, but not all.  Undetected
failures result in a zero tsc_khz value (error value -1 divided by
1000), which means "no tsc_freq set".

To reproduce, try "-cpu qemu64,tsc_freq=9999999T".
strtosz_suffix_unit() fails, because the value overflows int64_t,
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

strtosz_suffix() fails unless the size is followed by 0, whitespace or
','.  Useless here, because we need to fail for any junk following the
size, even if it starts with whitespace or ','.  Check manually.
Things like "-m 1024," are now caught.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

strtosz_suffix() fails unless the size is followed by 0, whitespace or
','.  Useless here, because we need to fail for any junk following the
size, even if it starts with whitespace or ','.  Check manually.

Things like

    -smp 4 -numa "node,mem=1024,cpus=0-1" -numa "node,mem=1024 cpus=2-3"

are now caught.  Before, the second -numa's argument was silently
interpreted as just "node,mem=1024".
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Commit 9f9b17a4's strtosz() defaults a missing suffix to 'M', except
it rejects fractions then (switch case 0).

When commit d8427002 introduced strtosz_suffix(), that changed:
fractions are no longer rejected, because we go to switch case 'M' on
missing suffix now.  Not mentioned in commit message, probably
unintentional.  Not worth changing back now.

Because case 0 is still around, you can get the old behavior by
passing a zero default_suffix to strtosz_suffix() or
strtosz_suffix_unit().  Undocumented and not used.  Drop.

Commit d8427002 also neglected to update the function comment.  Fix it
up.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>