Commit Graph

160 Commits

Author SHA1 Message Date
Markus Armbruster
da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Peter Maydell
80c71a241a block: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-20 13:36:23 +01:00
Max Reitz
8b13976d3f block: Add opaque value to the amend CB
Add an opaque value which is to be passed to the bdrv_amend_options()
status callback.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-12-18 14:34:43 +01:00
Kevin Wolf
a99dfb45f2 qcow2: Fix qcow2_get_cluster_offset() for zero clusters
When searching for contiguous zero clusters, we only need to check the
cluster type. Before this patch, an increasing offset (L2E_OFFSET_MASK)
was expected, so that the function never returned more than a single
zero cluster in practice. This patch fixes it to actually return as many
contiguous zero clusters as it can.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1446657384-5907-1-git-send-email-kwolf@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-11-11 16:55:29 +01:00
Kevin Wolf
760e006384 block: Convert bs->backing_hd to BdrvChild
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.

After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-16 15:34:29 +02:00
Kevin Wolf
9a4f4c3156 block: Convert bs->file to BdrvChild
This patch removes the temporary duplication between bs->file and
bs->file_child by converting everything to BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-16 15:34:29 +02:00
Max Reitz
b6d36def6d qcow2: Make size_to_clusters() return uint64_t
Sadly, some images may have more clusters than what can be represented
using a plain int. We should be prepared for that case (in
qcow2_check_refcounts() we actually were trying to catch that case, but
since size_to_clusters() truncated the returned value, that check never
did anything useful).

Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-09-14 16:51:37 +02:00
Kevin Wolf
ff99129ab8 qcow2: Rename BDRVQcowState to BDRVQcow2State
BDRVQcowState is already used by qcow1, and gdb is always confused which
one to use. Rename the qcow2 one so they can be distinguished.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
2015-09-14 16:51:36 +02:00
Daniel P. Berrange
b6af097528 maint: remove / fix many doubled words
Many source files have doubled words (eg "the the", "to to",
and so on). Most of these can simply be removed, but a couple
were actual mis-spellings (eg "to to" instead of "to do").
There was even one triple word score "to to to" :-)

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-09-11 10:21:38 +03:00
Daniel P. Berrange
f6fa64f6d2 block: convert qcow/qcow2 to use generic cipher API
Switch the qcow/qcow2 block driver over to use the generic cipher
API, this allows it to use the pluggable AES implementations,
instead of being hardcoded to use QEMU's built-in impl.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-10-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-08 13:11:01 +02:00
Daniel P. Berrange
8336aafae1 qcow2/qcow: protect against uninitialized encryption key
When a qcow[2] file is opened, if the header reports an
encryption method, this is used to set the 'crypt_method_header'
field on the BDRVQcow[2]State struct, and the 'encrypted' flag
in the BDRVState struct.

When doing I/O operations, the 'crypt_method' field on the
BDRVQcow[2]State struct is checked to determine if encryption
needs to be applied.

The crypt_method_header value is copied into crypt_method when
the bdrv_set_key() method is called.

The QEMU code which opens a block device is expected to always
do a check

   if (bdrv_is_encrypted(bs)) {
       bdrv_set_key(bs, ....key...);
   }

If code forgets to do this, then 'crypt_method' is never set
and so when I/O is performed, QEMU writes plain text data
into a sector which is expected to contain cipher text, or
when reading, will return cipher text instead of plain
text.

Change the qcow[2] code to consult bs->encrypted when deciding
whether encryption is required, and assert(s->crypt_method)
to protect against cases where the caller forgets to set the
encryption key.

Also put an assert in the set_key methods to protect against
the case where the caller sets an encryption key on a block
device that does not have encryption

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-05-22 17:08:01 +02:00
Alberto Garcia
a3f1afb43a qcow2: make qcow2_cache_put() a void function
This function never receives an invalid table pointer, so we can make
it void and remove all the error checking code.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-05-22 17:08:01 +02:00
Alberto Garcia
72e80b8901 qcow2: use one single memory block for the L2/refcount cache tables
The qcow2 L2/refcount cache contains one separate table for each cache
entry. Doing one allocation per table adds unnecessary overhead and it
also requires us to store the address of each table separately.

Since the size of the cache is constant during its lifetime, it's
better to have an array that contains all the tables using one single
allocation.

In my tests measuring freshly created caches with sizes 128MB (L2) and
32MB (refcount) this uses around 10MB of RAM less.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-05-22 17:08:01 +02:00
Max Reitz
0e06528e98 qcow2: Use 64 bits for refcount values
Refcounts may have a width of up to 64 bits, so qemu should use the same
width to represent refcount values internally.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-10 14:02:21 +01:00
Max Reitz
2aabe7c7a1 qcow2: Use unsigned addend for update_refcount()
update_refcount() and qcow2_update_cluster_refcount() currently take a
signed addend. At least one caller passes a value directly derived from
an absolute refcount that should be reached ("l2_refcount - 1" in
expand_zero_clusters_in_l1()). Therefore, the addend should be unsigned
as well; this will be especially important for 64 bit refcounts.

Because update_refcount() then no longer knows whether the refcount
should be increased or decreased, it now requires an additional flag
which specified exactly that. The same applies to
qcow2_update_cluster_refcount().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-10 14:02:21 +01:00
Max Reitz
7324c10f96 qcow2: Only return status from qcow2_get_refcount
Refcounts can theoretically be of type uint64_t; in order to be able to
represent the full range, qcow2_get_refcount() cannot use a single
variable to represent both all refcount values and also keep some values
reserved for errors.

One solution would be to add an Error pointer parameter to
qcow2_get_refcount(); however, no caller could (currently) pass that
error message, so it would have to be emitted immediately and be
passed to the next caller by returning -EIO or something similar.
Therefore, an Error parameter does not offer any advantages here.

The solution applied by this patch is simpler to use. Because no caller
would be able to pass the error message, they would have to print it and
free it, whereas with this patch the caller only needs to pass the
returned integer (which is often a no-op from the code perspective,
because that integer will be stored in a variable "ret" which will be
returned by the fail path of many callers).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-10 14:02:21 +01:00
Max Reitz
8dd93d9339 qcow2: Add two more unalignment checks
This adds checks for unaligned L2 table offsets and unaligned data
cluster offsets (actually the preallocated offsets for zero clusters) to
the zero cluster expansion function.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-23 18:17:05 +01:00
Max Reitz
11c89769dc qcow2: Prevent numerical overflow
In qcow2_alloc_cluster_offset(), *num is limited to
INT_MAX >> BDRV_SECTOR_BITS by all callers. However, since remaining is
of type uint64_t, we might as well cast *num to that type before
performing the shift.

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10 10:31:20 +01:00
Max Reitz
ecf58777c5 block/qcow2: Simplify shared L2 handling in amend
Currently, we have a bitmap for keeping track of which clusters have
been created during the zero cluster expansion process. This was
necessary because we need to properly increase the refcount for shared
L2 tables.

However, now we can simply take the L2 refcount and use it for the
cluster allocated for expansion. This will be the correct refcount and
therefore we don't have to remember that cluster having been allocated
any more.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Message-id: 1414404776-4919-7-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03 11:41:49 +00:00
Max Reitz
4057a2b24a block/qcow2: Implement status CB for amend
The only really time-consuming operation potentially performed by
qcow2_amend_options() is zero cluster expansion when downgrading qcow2
images from compat=1.1 to compat=0.10, so report status of that
operation and that operation only through the status CB.

For this, approximate the progress as the number of L1 entries visited
during the operation.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Message-id: 1414404776-4919-5-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03 11:41:49 +00:00
Max Reitz
808c4b6f30 qcow2: Allow "full" discard
Normally, discarded sectors should read back as zero. However, there are
cases in which a sector (or rather cluster) should be discarded as if
they were never written in the first place, that is, reading them should
fall through to the backing file again.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1414159063-25977-2-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03 11:41:47 +00:00
Max Reitz
a1391444fe qcow2: Do not overflow when writing an L1 sector
While writing an L1 table sector, qcow2_write_l1_entry() copies the
respective range from s->l1_table to the local "buf" array. The size of
s->l1_table does not have to be a multiple of L1_ENTRIES_PER_SECTOR;
thus, limit the index which is used for copying all entries to the L1
size.

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-23 15:34:02 +02:00
Max Reitz
a97c67ee6c qcow2: Check L1/L2/reftable entries for alignment
Offsets taken from the L1, L2 and refcount tables are generally assumed
to be correctly aligned. However, this cannot be guaranteed if the image
has been written to by something different than qemu, thus check all
offsets taken from these tables for correct cluster alignment.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1409926039-29044-5-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-22 11:39:28 +01:00
Markus Armbruster
5839e53bbc block: Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

Patch created with Coccinelle, with two manual changes on top:

* Add const to bdrv_iterate_format() to keep the types straight

* Convert the allocation in bdrv_drop_intermediate(), which Coccinelle
  inexplicably misses

Coccinelle semantic patch:

    @@
    type T;
    @@
    -g_malloc(sizeof(T))
    +g_new(T, 1)
    @@
    type T;
    @@
    -g_try_malloc(sizeof(T))
    +g_try_new(T, 1)
    @@
    type T;
    @@
    -g_malloc0(sizeof(T))
    +g_new0(T, 1)
    @@
    type T;
    @@
    -g_try_malloc0(sizeof(T))
    +g_try_new0(T, 1)
    @@
    type T;
    expression n;
    @@
    -g_malloc(sizeof(T) * (n))
    +g_new(T, n)
    @@
    type T;
    expression n;
    @@
    -g_try_malloc(sizeof(T) * (n))
    +g_try_new(T, n)
    @@
    type T;
    expression n;
    @@
    -g_malloc0(sizeof(T) * (n))
    +g_new0(T, n)
    @@
    type T;
    expression n;
    @@
    -g_try_malloc0(sizeof(T) * (n))
    +g_try_new0(T, n)
    @@
    type T;
    expression p, n;
    @@
    -g_realloc(p, sizeof(T) * (n))
    +g_renew(T, p, n)
    @@
    type T;
    expression p, n;
    @@
    -g_try_realloc(p, sizeof(T) * (n))
    +g_try_renew(T, p, n)

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-20 11:51:28 +02:00
Max Reitz
ff52aab2df qcow2: Catch !*host_offset for data allocation
qcow2_alloc_cluster_offset() uses host_offset == 0 as "no preferred
offset" for the (data) cluster range to be allocated. However, this
offset is actually valid and may be allocated on images with a corrupted
refcount table or first refcount block.

In this case, the corruption prevention should normally catch that
write anyway (because it would overwrite the image header). But since 0
is a special value here, the function assumes that nothing has been
allocated at all which it asserts against.

Because this condition is not qemu's fault but rather that of a broken
image, it shouldn't throw an assertion but rather mark the image corrupt
and show an appropriate message, which this patch does by calling the
corruption check earlier than it would be called normally (before the
assertion).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15 15:07:16 +02:00
Kevin Wolf
de82815db1 qcow2: Handle failure for potentially large allocations
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 qcow2 block driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15 15:07:15 +02:00
Kevin Wolf
bd60436936 qcow2: Fix memory leak in COW error path
This triggers if bs->drv becomes NULL in a concurrent request. This is
currently only the case when corruption prevention kicks in (i.e. at
most once per image, and after that it produces I/O errors).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-28 14:28:46 +02:00
Max Reitz
b93f995081 qcow2: Check min_size in qcow2_grow_l1_table()
First, new_l1_size is an int64_t, whereas min_size is a uint64_t.
Therefore, during the loop which adjusts new_l1_size until it equals or
exceeds min_size, new_l1_size might overflow and become negative. The
comparison in the loop condition however will take it as an unsigned
value (because min_size is unsigned) and therefore recognize it as
exceeding min_size. Therefore, the loop is left with a negative
new_l1_size, which is not correct. This could be fixed by making
new_l1_size uint64_t.

On the other hand, however, by doing this, the while loop may take
forever. If min_size is e.g. UINT64_MAX, it will take new_l1_size
probably multiple overflows to reach the exact same value (if it reaches
it at all). Then, right after the loop, new_l1_size will be recognized
as being too big anyway.

Both problems require a ridiculously high min_size value, which is very
unlikely to occur; but both problems are also simply avoided by checking
whether min_size is sane before calculating new_l1_size (which should
still be checked separately, though).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-30 14:46:17 +02:00
Max Reitz
c883db0df9 qcow2: Fix discard
discard_single_l2() should not implement its own version of
qcow2_get_cluster_type(), but rather rely on this already existing
function. By doing so, it will work for compressed clusters as well
(which it did not so far).

Also, rename "old_offset" to "old_l2_entry", as both are quite different
(and the value is indeed of the latter kind).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-29 16:39:51 +02:00
Kevin Wolf
8885eadedd qcow2: Put cache reference in error case
When qcow2_get_cluster_offset() sees a zero cluster in a version 2
image, it (rightfully) returns an error. But in doing so it shouldn't
leak an L2 table cache reference.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2014-04-04 17:10:08 +02:00
Kevin Wolf
6b7d4c5558 qcow2: Fix copy_sectors() with VM state
bs->total_sectors is not the highest possible sector number that could
be involved in a copy on write operation: VM state is after the end of
the virtual disk. This resulted in wrong values for the number of
sectors to be copied (n).

The code that checks for the end of the image isn't required any more
because the code hasn't been calling the block layer's bdrv_read() for a
long time; instead, it directly calls qcow2_readv(), which doesn't error
out on VM state sector numbers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 15:22:35 +02:00
Kevin Wolf
cab60de930 qcow2: Fix new L1 table size check (CVE-2014-0143)
The size in bytes is assigned to an int later, so check that instead of
the number of entries.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 15:22:35 +02:00
Max Reitz
dba2855572 qcow2: Check bs->drv in copy_sectors()
Before dereferencing bs->drv for a call to its member bdrv_co_readv(),
copy_sectors() should check whether that pointer is indeed valid, since
it may have been set to NULL by e.g. a concurrent write triggering the
corruption prevention mechanism.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13 14:23:27 +01:00
Kevin Wolf
a71835a0cc qcow2: Set zero flag for discarded clusters
Instead of making the backing file contents visible again after a discard
request, set the zero flag if possible (i.e. on version >= 3).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2014-02-21 21:02:21 +01:00
Hu Tao
16f0587e0a qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset()
n_start can be actually calculated from offset. The number of
sectors to be allocated(n_end - n_start) can be passed in in
num. By removing n_start and n_end, we can save two parameters.

The side effect is there is a bug in qcow2.c:preallocate() that
passes incorrect n_start to qcow2_alloc_cluster_offset() is
fixed. The bug can be triggerred by a larger cluster size than
the default value(65536), for example:

./qemu-img create -f qcow2 \
  -o 'cluster_size=131072,preallocation=metadata' file.img 4G

Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-09 09:12:39 +01:00
Hu Tao
ac95acdb8e qcow2: use start_of_cluster() and offset_into_cluster() everywhere
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-06 16:53:50 +01:00
Peter Lieven
aa7bfbfff7 block: add flags to bdrv_*_write_zeroes
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-28 10:30:51 +01:00
Peter Lieven
78a52ad5ac qcow2: fix possible corruption when reading multiple clusters
if multiple sectors spanning multiple clusters are read the
function count_contiguous_clusters should ensure that the
cluster type should not change between the clusters.

Especially the for-loop should break when we have one
or more normal clusters followed by a compressed cluster.

Unfortunately the wrong macro was used in the mask to
compare the flags.

This was discovered while debugging a data corruption
issue when converting a compressed qcow2 image to raw.
qemu-img reads 2MB chunks which span multiple clusters.

CC: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-11-14 13:09:07 +01:00
Peter Maydell
e4ef9f465c bswap.h: Remove cpu_to_be64wu()
Replace the legacy cpu_to_be64wu() with stq_be_p().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 1383669517-25598-9-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@amazon.com>
2013-11-05 19:57:47 -08:00
Max Reitz
231bb26764 qcow2: Use negated overflow check mask
In qcow2_check_metadata_overlap and qcow2_pre_write_overlap_check,
change the parameter signifying the checks to perform from its current
positive form to a negative one, i.e., it will no longer explicitly
specify every check to perform but rather a mask of checks not to
perform.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Max Reitz
e3b21ef9e0 qcow2: Free allocated L2 cluster on error
If an error occurs in l2_allocate, the allocated (but unused) L2 cluster
should be freed.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-10-07 13:23:19 +02:00
Max Reitz
fda74f826b qcow2: Switch L1 table in a single sequence
Switching the L1 table in memory should be an atomic operation, as far
as possible. Calling qcow2_free_clusters on the old L1 table on disk is
not a good idea when the old L1 table is no longer valid and the address
to the new one hasn't yet been written into the corresponding
BDRVQcowState field. To be more specific, this can lead to segfaults due
to qcow2_check_metadata_overlap trying to access the L1 table during the
free operation.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-10-02 15:38:29 +02:00
Kevin Wolf
61653008ad qcow2: Remove useless count_contiguous_clusters() parameter
All callers pass start = 0, and it's doubtful if any other value would
actually do what you expect. Remove the parameter.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
2013-09-27 17:22:43 +02:00
Max Reitz
22f0dd29af qcow2: COMPRESSED on count_contiguous_clusters
Compressed clusters can never be contiguous, therefore the corresponding
flag does not need to be given explicitly to count_contiguous_clusters.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27 17:22:43 +02:00
Max Reitz
15684a4742 qcow2: count_contiguous_clusters and compression
The function is not intended to be used on compressed clusters and will
not work correctly, if used anyway, since L2E_OFFSET_MASK is not the
right mask for determining the offset of compressed clusters. Therefore,
assert that the first cluster is not compressed and always include the
compression flag in the mask of significant flags, i.e., stop the search
as soon as a compressed cluster occurs.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27 17:22:43 +02:00
Max Reitz
320c706666 qcow2: Free only newly allocated clusters on error
In expand_zero_clusters_in_l1, a new cluster is only allocated if it was
not already preallocated. On error, such preallocated clusters should
not be freed, but only the newly allocated ones.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27 17:22:43 +02:00
Max Reitz
be0b742ee3 qcow2: Always use error path in l2_allocate
Just returning -errno in some cases prevents
trace_qcow2_l2_allocate_done from being executed (and, in one case, also
the unused allocated L2 table from being freed). Always going down the
error path fixes this.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27 17:22:43 +02:00
Max Reitz
8585afd813 qcow2: Don't put invalid L2 table into cache
In l2_allocate, the fail path is executed if qcow2_cache_flush fails.
However, the L2 table has not yet been fetched from the L2 table cache.
The qcow2_cache_put in the fail path therefore basically gives an
undefined argument as the L2 table address (in this case).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27 11:31:59 +02:00
Max Reitz
e390cf5a97 qcow2: Correct bitmap size in zero expansion
Since the expanded_clusters bitmap is addressed using host offsets in
the underlying image file, the correct size to use for allocating the
bitmap is not determined by the guest disk image but by the underlying
host image file.

Furthermore, this size may change during the expansion due to cluster
allocations on growable image files. In this case, the bitmap needs to
be resized as well to reflect the growth.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27 11:16:35 +02:00
Max Reitz
c01dbccbad qcow2: Assert against currently impossible overflow
If qcow2_alloc_cluster_link_l2 is called with a QCowL2Meta describing a
request crossing L2 boundaries, a buffer overflow will occur. This is
impossible right now since such requests are never generated (every
request is shortened to L2 boundaries before) and probably also
completely unintended (considering the name "QCowL2Meta"), however, it
is still worth an assertion.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 21:57:44 +02:00