Commit Graph

91 Commits

Author SHA1 Message Date
Alberto Garcia
81e5f78a9f block: use bdrv_get_device_or_node_name() in error messages
There are several error messages that identify a BlockDriverState by
its device name. However those errors can be produced in nodes that
don't have a device name associated.

In those cases we should use bdrv_get_device_or_node_name() to fall
back to the node name and produce a more meaningful message. The
messages are also updated to use the more generic term 'node' instead
of 'device'.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 9823a1f0514fdb0692e92868661c38a9e00a12d6.1428485266.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-04-28 15:36:09 +02:00
Markus Armbruster
f43e47dbf6 QemuOpts: Drop qemu_opt_set(), rename qemu_opt_set_err(), fix use
qemu_opt_set() is a wrapper around qemu_opt_set() that reports the
error with qerror_report_err().

Most of its users assume the function can't fail.  Make them use
qemu_opt_set_err() with &error_abort, so that should the assumption
ever break, it'll break noisily.

Just two users remain, in util/qemu-config.c.  Switch them to
qemu_opt_set_err() as well, then rename qemu_opt_set_err() to
qemu_opt_set().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-26 14:49:31 +01:00
Markus Armbruster
39101f2511 QemuOpts: Convert qemu_opt_set_number() to Error, fix its use
Return the Error object instead of reporting it with
qerror_report_err().

Change callers that assume the function can't fail to pass
&error_abort, so that should the assumption ever break, it'll break
noisily.

Turns out all callers outside its unit test assume that.  We could
drop the Error ** argument, but that would make the interface less
regular, so don't.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-26 14:47:32 +01:00
Jeff Cody
9a29e18f7d block: update string sizes for filename,backing_file,exact_filename
The string field entries 'filename', 'backing_file', and
'exact_filename' in the BlockDriverState struct are defined as 1024
bytes.

However, many places that use these values accept a maximum of PATH_MAX
bytes, so we have a mixture of 1024 byte and PATH_MAX byte allocations.
This patch makes the BlockDriverStruct field string sizes match usage.

This patch also does a few fixes related to the size that needs to
happen now:

    * the block qapi driver is updated to use PATH_MAX bytes
    * the qcow and qcow2 drivers have an additional safety check
    * the block vvfat driver is updated to use PATH_MAX bytes
      for the size of backing_file, for systems where PATH_MAX is < 1024
      bytes.
    * qemu-img uses PATH_MAX rather than 1024.  These instances were not
      changed to be dynamically allocated, however, as the extra
      temporary 3K in stack usage for qemu-img does not seem worrisome.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-23 18:17:06 +01:00
Max Reitz
1bcb15cf77 block/vvfat: qcow driver may not be found
Although virtually impossible right now, bdrv_find_format("qcow") may
fail. The vvfat block driver should heed that case.

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 10:31:19 +01:00
Markus Armbruster
bfb197e0d9 block: Eliminate BlockDriverState member device_name[]
device_name[] can become non-empty only in bdrv_new_root() and
bdrv_move_feature_fields().  The latter is used only to undo damage
done by bdrv_swap().  The former is called only by blk_new_with_bs().
Therefore, when a BlockDriverState's device_name[] is non-empty, then
it's been created with a BlockBackend, and vice versa.  Furthermore,
blk_new_with_bs() keeps the two names equal.

Therefore, device_name[] is redundant.  Eliminate it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20 13:41:26 +02:00
Markus Armbruster
e4e9986b1c block: Split bdrv_new_root() off bdrv_new()
Creating an anonymous BDS can't fail.  Make that obvious.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20 13:41:26 +02:00
Michael Tokarev
13b552c2f4 block/vvfat.c: remove debugging code to reinit stderr if NULL
Just log to stderr unconditionally, like other similar code does.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-21 10:36:29 +02:00
Markus Armbruster
d4df3dbc02 block: Drop some superfluous casts from void *
They clutter the code.  Unfortunately, I can't figure out how to make
Coccinelle drop all of them, so I have to settle for common special
cases:

    @@
    type T;
    T *pt;
    void *pv;
    @@
    - pt = (T *)pv;
    + pt = pv;
    @@
    type T;
    @@
    - (T *)
      (\(g_malloc\|g_malloc0\|g_realloc\|g_new\|g_new0\|g_renew\|
	 g_try_malloc\|g_try_malloc0\|g_try_realloc\|
	 g_try_new\|g_try_new0\|g_try_renew\)(...))

Topped off with minor manual style cleanups.

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
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
Chunyan Liu
c282e1fdf7 cleanup QEMUOptionParameter
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>
2014-06-16 17:23:21 +08:00
Chunyan Liu
facdbb0272 vvfat.c: handle cross_driver's create_options and create_opts
vvfat shares create options of qcow driver. To avoid vvfat breaking when
qcow driver changes from QEMUOptionParameter to QemuOpts, let it able
to handle both cases.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-16 17:23:20 +08:00
Chunyan Liu
83d0521a1e change block layer to support both QemuOpts and QEMUOptionParamter
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>
2014-06-16 17:23:20 +08:00
Markus Armbruster
b122c3b6d0 block/vvfat: Plug memory leak in read_directory()
Has always been leaky.  Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-30 14:26:54 +02:00
Markus Armbruster
6262bbd363 block/vvfat: Plug memory leak in check_directory_consistency()
On error path.  Introduced in commit a046433a.  Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-30 14:26:54 +02:00
Markus Armbruster
75e347d66a block/vvfat: Plug memory leak in enable_write_target()
I figure the leak originated in bdrv_create2(), and was duplicated
into callers when commit 91a073a dropped that function.  Looks like
the other places have since been fixed.

Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-30 14:26:54 +02:00
Markus Armbruster
d11c8917b2 block/vvfat: Propagate errors through init_directories()
Completes the conversion of the open method to Error started in commit
015a103.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-28 14:28:47 +02:00
Markus Armbruster
68c70af16d block/vvfat: Propagate errors through enable_write_target()
Continues the conversion of the open method to Error started in commit
015a103.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-28 14:28:47 +02:00
Fam Zheng
920beae103 block: Use bdrv_set_backing_hd everywhere
We need to handle the coming backing_blocker properly, so don't open
code the assignment, instead, call bdrv_set_backing_hd to change
backing_hd.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-28 14:28:46 +02:00
Kevin Wolf
98522f63f4 block: Add errp to bdrv_new()
This patch adds an errp parameter to bdrv_new() and updates all its
callers. The next patches will make use of this in order to check for
duplicate IDs. Most of the callers know that their ID is fine, so they
can simply assert that there is no error.

Behaviour doesn't change with this patch yet as bdrv_new() doesn't
actually assign errors to errp.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2014-04-22 12:00:20 +02:00
Markus Armbruster
4c7096607d vvfat: Fix :floppy: option to suppress partition table
Regressed in commit 7ad9be6, v1.5.0.

Reported-by: Kiyokazu SUTO <suto@ks-and-ks.ne.jp>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01 13:49:53 +02:00
Paolo Bonzini
c0f92b526d vvfat: correctly propagate errors
Before:
    $ ./qemu-io-old
    qemu-io-old> open -r -o driver=vvfat,fat-type=24,dir=i386-softmmu
    Valid FAT types are only 12, 16 and 32
    qemu-io-old: can't open device (null): Could not open image: Invalid argument

After:
    $ ./qemu-io
    qemu-io> open -r -o driver=vvfat,fat-type=24,dir=i386-softmmu
    qemu-io: can't open device (null): Valid FAT types are only 12, 16 and 32

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-21 21:02:23 +01:00
Max Reitz
ddf5636dc9 block: Add reference parameter to bdrv_open()
Allow bdrv_open() to handle references to existing block devices just as
bdrv_file_open() is already capable of.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-21 21:02:22 +01:00
Max Reitz
f67503e5bd block: Change BDS parameter of bdrv_open() to **
Make bdrv_open() take a pointer to a BDS pointer, similarly to
bdrv_file_open(). If a pointer to a NULL pointer is given, bdrv_open()
will create a new BDS with an empty name; if the BDS pointer is not
NULL, that existing BDS will be reused (in the same way as bdrv_open()
already did).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-02-21 21:02:21 +01:00
Markus Armbruster
84d18f065f Use error_is_set() only when necessary
error_is_set(&var) is the same as var != NULL, but it takes
whole-program analysis to figure that out.  Unnecessarily hard for
optimizers, static checkers, and human readers.  Dumb it down to
obvious.

Gets rid of several dozen Coverity false positives.

Note that the obvious form is already used in many places.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-02-17 11:57:23 -05:00
Peter Crosthwaite
87ea75d5e1 qemu-option: Remove qemu_opts_create_nofail
This is a boiler-plate _nofail variant of qemu_opts_create. Remove and
use error_abort in call sites.

null/0 arguments needs to be added for the id and fail_if_exists fields
in affected callsites due to argument inconsistency between the normal and
no_fail variants.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 15:02:30 -05:00
Stefan Weil
f671d173c7 block/vvfat: Fix compiler warnings for OpenBSD
The buildbot shows these compiler warnings:

block/vvfat.c: In function 'create_short_and_long_name':
block/vvfat.c:620: warning: array size (8) smaller than bound length (11)
block/vvfat.c:620: warning: array size (8) smaller than bound length (11)
block/vvfat.c:635: warning: array size (8) smaller than bound length (11)
block/vvfat.c:635: warning: array size (8) smaller than bound length (11)

They are caused by tricky code where 8 characters for the name are followed
by 3 characters for the extension, and some operations touch both name and
extension.

Using an 11 character name which includes the extension fixes the compiler
warning, satisfies cppcheck, valgrind and maybe other static and dynamic
code checkers, and even simplifies some parts of the code.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-12-13 14:49:50 +01:00
Max Reitz
cc84d90ff5 block: Error parameter for create functions
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>
2013-09-12 10:12:48 +02:00
Max Reitz
34b5d2c68e block: Error parameter for open functions
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>
2013-09-12 10:12:48 +02:00
Max Reitz
015a1036a7 bdrv: Use "Error" for opening images
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>
2013-09-12 10:12:47 +02:00
Paolo Bonzini
4bc74be997 block: return get_block_status data and flags for formats
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
Paolo Bonzini
b6b8a33354 block: introduce bdrv_get_block_status API
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>
2013-09-06 15:25:09 +02:00
Fam Zheng
4f6fd3491c block: make bdrv_delete() static
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>
2013-09-06 15:25:08 +02:00
Fam Zheng
3d34c6cd99 vvfat: use bdrv_new() to allocate BlockDriverState
we need bdrv_new() to properly initialize BDS, don't allocate memory
manually.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:08 +02:00
Fam Zheng
78f27bd02c block: fix vvfat error path for enable_write_target
s->qcow and s->qcow_filename are allocated but not freed on error. Fix the
possible leaks, remove unnecessary check for bdrv_new(), propagate ret code of
bdrv_create() and also the one of enable_write_target().

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-07-19 12:29:21 +08:00
Kevin Wolf
56d1b4d21d block: Remove filename parameter from .bdrv_file_open()
It is unused now in all block drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22 11:34:35 +02:00
Kevin Wolf
7ad9be64e8 vvfat: Use bdrv_open options instead of filename
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22 10:27:59 +02:00
Kevin Wolf
787e4a8500 block: Add options QDict to bdrv_file_open() prototypes
The new parameter is unused yet.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-03-22 17:51:31 +01:00
Kevin Wolf
de9c0cec6c block: Add options QDict to bdrv_open() prototype
It doesn't do anything yet except storing the options QDict in the
BlockDriverState.

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>
2013-03-15 16:07:49 +01:00
Stefan Weil
eb7ff6fb0b Replace remaining gmtime, localtime by gmtime_r, localtime_r
This allows removing of MinGW specific code and improves
reentrancy for POSIX hosts.

[Removed unused ret variable in qemu_get_timedate() to fix warning:
vl.c: In function ‘qemu_get_timedate’:
vl.c:451:16: error: variable ‘ret’ set but not used [-Werror=unused-but-set-variable]
-- Stefan Hajnoczi]

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-11 09:44:37 +01:00
Paolo Bonzini
1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini
caf71f86a3 migration: move include files to include/migration/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:32 +01:00
Paolo Bonzini
737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Corey Bryant
2e1e79dae7 block: Convert close calls to qemu_close
This patch converts all block layer close calls, that correspond
to qemu_open calls, to qemu_close.

Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-15 10:48:57 +02:00
Corey Bryant
6165f4d85d block: Convert open calls to qemu_open
This patch converts all block layer open calls to qemu_open.

Note that this adds the O_CLOEXEC flag to the changed open paths
when the O_CLOEXEC macro is defined.

Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-15 10:48:57 +02:00
Markus Armbruster
4480e0f924 vvfat: Do not clobber the user's geometry
vvfat creates a virtual VFAT filesystem with a certain logical
geometry that depends on its options.  It sets the "geometry hint" to
this geometry.  It is the only block driver to do this.

The geometry hint is about about *physical* geometry, and used only by
certain hard disk device models.

vvfat's hint is normally invisible for device models, because
bdrv_open() puts a raw format on top of vvfat's fat protocol.  That
raw format is where drive_init() puts the user's geometry (if any),
and where the device model gets it from.

Nobody complained, because the default physical geometry is the same
as vvfat's logical geometry:

    opts        LCHS        def. PCHS
                1024,16,63  same
    :32:        1024,16,63  same
    :16:        1024,16,63  same
    :12:          64,16,63  same

Except when you specify :floppy:

    opts        LCHS        def. PCHS
       :floppy:   80, 2,36  5,16,63
    :32:floppy:   80, 2,36  5,16,63
    :16:floppy:   80, 2,36  5,16,63
    :12:floppy:   80, 2,18  2,16,63

Silly thing to do for use with a hard disk.

However, the "raw" format can be suppressed by adding an
redundant-looking "format=vvfat" to "file=fat:FOO".  Then, vvfat's
hint clobbers the user's geometry, i.e. -drive options cyls, heads,
secs get silently ignored.  Don't do that.

No change without format=vvfat.  With it, the user's hard disk
geometry (-drive options cyls, heads, secs) is now obeyed, and the
default hard disk geometry with :floppy: now matches the one without
format=vvfat.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-17 16:48:30 +02:00
Markus Armbruster
f91cbefe2d vvfat: Fix partition table
Unless parameter ":floppy:" is given, vvfat creates a virtual image
with DOS MBR defining a single partition which holds the FAT file
system.  The size of the virtual image depends on the width of the
FAT: 32 MiB (CHS 64, 16, 63) for 12 bit FAT, 504 MiB (CHS 1024, 16,
63) for 16 and 32 bit FAT, leaving (64*16-1)*63 = 64449 and
(1024*16-1)*64 = 1032129 sectors for the partition.

However, it screws up the end of the partition in the MBR:

    FAT width param.  start CHS  end CHS     start LBA  size
        :32:          0,1,1      1023,14,63       63    1032065
        :16:          0,1,1      1023,14,55       63    1032057
        :12:          0,1,1        63,14,55       63      64377

The actual FAT file system nevertheless assumes the partition has
1032129 or 64449 sectors.  Oops.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-17 16:48:30 +02:00
Jim Meyering
eba25057b9 block: prevent snapshot mode $TMPDIR symlink attack
In snapshot mode, bdrv_open creates an empty temporary file without
checking for mkstemp or close failure, and ignoring the possibility
of a buffer overrun given a surprisingly long $TMPDIR.
Change the get_tmp_filename function to return int (not void),
so that it can inform its two callers of those failures.
Also avoid the risk of buffer overrun and do not ignore mkstemp
or close failure.
Update both callers (in block.c and vvfat.c) to propagate
temp-file-creation failure to their callers.

get_tmp_filename creates and closes an empty file, while its
callers later open that presumed-existing file with O_CREAT.
The problem was that a malicious user could provoke mkstemp failure
and race to create a symlink with the selected temporary file name,
thus causing the qemu process (usually root owned) to open through
the symlink, overwriting an attacker-chosen file.

This addresses CVE-2012-2652.
http://bugzilla.redhat.com/CVE-2012-2652

Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-30 14:48:40 +08:00
Paolo Bonzini
e023b2e244 block: fix snapshot on QED
QED's opaque data includes a pointer back to the BlockDriverState.
This breaks when bdrv_append shuffles data between bs_new and bs_top.
To avoid this, add a "rebind" function that tells the driver about
the new relationship between the BlockDriverState and its opaque.

The patch also adds rebind to VVFAT for completeness, even though
it is not used with live snapshots.

Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Stefan Hajnoczi
8d98734651 vvfat: avoid leaking file descriptor in commit_one_file()
Reported-by: Dr David Alan Gilbert <davidagilbert@uk.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-01-13 10:36:59 +00:00