Commit Graph

46 Commits

Author SHA1 Message Date
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
Paolo Bonzini c25f53b06e raw: Probe required direct I/O alignment
Add a bs->request_alignment field that contains the required
offset/length alignment for I/O requests and fill it in the raw block
drivers. Use ioctls if possible, else see what alignment it takes for
O_DIRECT to succeed.

While at it, also expose the memory alignment requirements, which may be
(and in practice are) different from the disk alignment requirements.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2014-01-24 17:40:02 +01:00
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
Fam Zheng b04b6b6ec3 block: Print its file name if backing file opening failed
If backing file doesn't exist, the error message is confusing and
misleading:

    $ qemu /tmp/a.qcow2
    qemu: could not open disk image /tmp/a.qcow2: Could not open file: No
    such file or directory

But...

    $ ls /tmp/a.qcow2
    /tmp/a.qcow2

    $ qemu-img info /tmp/a.qcow2
    image: /tmp/a.qcow2
    file format: qcow2
    virtual size: 8.0G (8589934592 bytes)
    disk size: 196K
    cluster_size: 65536
    backing file: /tmp/b.qcow2

Because...

    $ ls /tmp/b.qcow2
    ls: cannot access /tmp/b.qcow2: No such file or directory

This is not intuitive. It's better to have the missing file's name in
the error message. With this patch:

    $ qemu-io -c 'read 0 512' /tmp/a.qcow2
    qemu-io: can't open device /tmp/a.qcow2: Could not open backing
    file: Could not open '/stor/vm/arch.raw': No such file or directory
    no file open, try 'help open'

Which is a little bit better.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-11-14 13:09:06 +01:00
Kevin Wolf b94a261057 block: Avoid unecessary drv->bdrv_getlength() calls
The block layer generally keeps the size of an image cached in
bs->total_sectors so that it doesn't have to perform expensive
operations to get the size whenever it needs it.

This doesn't work however when using a backend that can change its size
without qemu being aware of it, i.e. passthrough of removable media like
CD-ROMs or floppy disks. For this reason, the caching is disabled when a
removable device is used.

It is obvious that checking whether the _guest_ device has removable
media isn't the right thing to do when we want to know whether the size
of the host backend can change. To make things worse, non-top-level
BlockDriverStates never have any device attached, which makes qemu
assume they are removable, so drv->bdrv_getlength() is always called on
the protocol layer. In the case of raw-posix, this causes unnecessary
lseek() system calls, which turned out to be rather expensive.

This patch completely changes the logic and disables bs->total_sectors
caching only for certain block driver types, for which a size change is
expected: host_cdrom and host_floppy on POSIX, host_device on win32; also
the raw format in case it sits on top of one of these protocols, but in
the common case the nested bdrv_getlength() call on the protocol driver
will use the cache again and avoid an expensive drv->bdrv_getlength()
call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2013-10-29 13:10:26 +01:00
Max Reitz 45d57f6e71 block/raw-win32: Always use -errno in hdev_open
On one occasion, hdev_open() returned -1 in case of an unknown error
instead of a proper -errno value. Adjust this to match the behavior of
raw_open() (in raw-win32), which is to return -EINVAL in this case.
Also, change the call to error_setg*() to match the one in raw_open() as
well.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-10-17 14:55:46 +02:00
Max Reitz c6252b7cea block/raw-win32: Employ error parameter
Make use of the error parameter in the opening and creating functions in
block/raw-win32.c.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 16:50:00 +02:00
Benoît Canet 030be32184 block: introduce BlockDriver.bdrv_needs_filename to enable some drivers.
Some drivers will have driver specifics options but no filename.
This new bool allow the block layer to treat them correctly.

The .bdrv_needs_filename is set in drivers not having .bdrv_parse_filename and
not having .bdrv_open.

The first exception to this rule will be the quorum driver.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 16:21:28 +02:00
Max Reitz d5124c00d8 bdrv: Use "Error" for creating images
Add an Error ** parameter to BlockDriver.bdrv_create 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
Tal Kain 56e023af80 raw-win32.c: Fix incorrect handling behaviour of small block files
It is a valid case that the read data's size is smaller than the
requested size since there could be files that are smaller than
the minimum block size (For ex. when a VMDK disk descriptor file)

Signed-off-by: Tal Kain <tal.kain@ravellosystems.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12 10:12:46 +02:00
Stefan Weil 68dc036488 w32: Fix access to host devices (regression)
QEMU failed to open host devices like \\.\PhysicalDrive0 (first hard disk)
since some time (commit 8a79380b8ef1b02d2abd705dd026a18863b09020?).

Those devices use hdev_open which did not use the latest API for options.
This resulted in a fatal runtime error:

  Block protocol 'host_device' doesn't support the option 'filename'

Duplicate code from raw_open to fix this.

Cc: qemu-stable@nongnu.org
Reported-by: David Brenner <david.brenner3@gmail.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:08 +02:00
Peter Lieven 3ac216270a block: change default of .has_zero_init to 0
.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>
2013-06-28 13:52:35 +02:00
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 8a79380b8e raw-win32: 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
Stefan Weil ea804cadf8 block: Add options QDict to bdrv_file_open() prototypes (fix MinGW build)
The new parameter is unused yet.

This part was missing in commit 787e4a8500.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-25 09:53:04 +01:00
Stefan Hajnoczi c4d9d19645 threadpool: drop global thread pool
Now that each AioContext has a ThreadPool and the main loop AioContext
can be fetched with bdrv_get_aio_context(), we can eliminate the concept
of a global thread pool from thread-pool.c.

The submit functions must take a ThreadPool* argument.

block/raw-posix.c and block/raw-win32.c use
aio_get_thread_pool(bdrv_get_aio_context(bs)) to fetch the main loop's
ThreadPool.

tests/test-thread-pool.c must be updated to reflect the new
thread_pool_submit() function prototypes.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2013-03-15 16:07:51 +01:00
Stefan Weil fccedc624c block/raw-win32: Fix compiler warnings (wrong format specifiers)
Commit fbcad04d6b added fprintf statements
with wrong format specifiers.

GetLastError() returns a DWORD which is unsigned long, so %lu must be used.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-02 16:08:57 +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 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Fabien Chouteau fbcad04d6b Fix error code checking for SetFilePointer() call
An error has occurred if the return value is invalid_set_file_pointer
and getlasterror doesn't return no_error.

Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-12-11 11:36:57 +01:00
Paolo Bonzini a27365265c raw-win32: implement native asynchronous I/O
With the new support for EventNotifiers in the AIO event loop, we
can hook a completion port to every opened file and use asynchronous
I/O on them.

Wine's support is extremely inefficient, also because it really does
the I/O synchronously on regular files. (!)  But it works, and it is
good to keep the Win32 and POSIX ports as similar as possible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-31 10:38:13 +01:00
Paolo Bonzini fc4edb84bf raw-win32: add emulated AIO support
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-31 10:38:13 +01:00
Jeff Cody 39c9fb9565 block: do not parse BDRV_O_CACHE_WB in block drivers
Block drivers should ignore BDRV_O_CACHE_WB in .bdrv_open flags,
and in the bs->open_flags.

This patch removes the code, leaving the behaviour behind as if
BDRV_O_CACHE_WB was set.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:11 +02:00
Jeff Cody 6a8dc0422e block: move open flag parsing in raw block drivers to helper functions
Code motion, to move parsing of open flags into a helper function.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:11 +02:00
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
Kevin Wolf c68b89acd6 block: Rename bdrv_co_flush to bdrv_co_flush_to_disk
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>
2011-11-11 14:02:59 +01:00
Paolo Bonzini 8b94ff8573 block: change flush to co_flush
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>
2011-10-21 17:34:14 +02:00
Stefan Weil 2c993ec294 w32: Fix qemu_ftruncate64
SetFilePointer returns INVALID_SET_FILE_POINTER when it fails.
In addition, GetLastError must be checked.

The first call of SetFilePointer did not use INVALID_SET_FILE_POINTER,
the second call used wrong error handling.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-22 10:19:00 -05:00
Markus Armbruster 02266d547a block/raw-win32: Drop disabled code for removable host devices
It's been disabled since the start (commit 19cb3738, Aug 2006), and
has been untouched except for spelling fixes and such.  I don't feel
like dragging it along any further.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-08-01 12:10:28 +02:00
Fam Zheng 4a1d5e1fde block: add bdrv_get_allocated_file_size() operation
qemu-img.c wants to count allocated file size of image. Previously it
counts a single bs->file by 'stat' or Window API. As VMDK introduces
multiple file support, the operation becomes format specific with
platform specific meanwhile.

The functions are moved to block/raw-{posix,win32}.c and qemu-img.c calls
bdrv_get_allocated_file_size to count the bs. And also added VMDK code
to count his own extents.

Signed-off-by: Fam Zheng <famcool@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-07-19 15:39:08 +02:00
Christoph Hellwig a659979328 block: clarify the meaning of BDRV_O_NOCACHE
Change BDRV_O_NOCACHE to only imply bypassing the host OS file cache,
but no writeback semantics.  All existing callers are changed to also
specify BDRV_O_CACHE_WB to give them writeback semantics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 10:39:32 +02:00
Kevin Wolf 1b40bbd13a raw-win32: Fix bdrv_flush return value
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-01-31 10:03:00 +01:00
Blue Swirl cfd07e7abb Fix win32 build
Fix a return value change missed by
205ef7961f.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-11-07 15:10:40 +00:00
Kevin Wolf 205ef7961f block: Allow bdrv_flush to return errors
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>
2010-11-04 12:52:16 +01:00
Kevin Wolf 336c1c1255 block: Fix bdrv_has_zero_init
Assuming that any image on a block device is not properly zero-initialized is
actually wrong: Only raw images have this problem. Any other image format
shouldn't care about it, they initialize everything properly themselves.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-08-03 15:57:22 +02:00
Kevin Wolf 66f82ceed6 block: Open the underlying image file in generic code
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>
2010-05-03 10:07:30 +02:00
Christoph Hellwig 84a12e6648 block: separate raw images from the file protocol
We're running into various problems because the "raw" file access, which
is used internally by the various image formats is entangled with the
"raw" image format, which maps the VM view 1:1 to a file system.

This patch renames the raw file backends to the file protocol which
is treated like other protocols (e.g. nbd and http) and adds a new
"raw" image format which is just a wrapper around calls to the underlying
protocol.

The patch is surprisingly simple, besides changing the probing logical
in block.c to only look for image formats when using bdrv_open and
renaming of the old raw protocols to file there's almost nothing in there.

For creating images, a new bdrv_create_file is introduced which guesses the
protocol to use. This allows using qemu-img create -f raw (or just using the
default) for both files and host devices. Converting the other format drivers
to use this function to create their images is left for later patches.

The only issues still open are in the handling of the host devices.
Firstly in current qemu we can specifiy the host* format names
on various command line acceping images, but the new code can't
do that without adding some translation.  Second the layering breaks
the no_zero_init flag in the BlockDriver used by qemu-img.  I'm not
happy how this is done per-driver instead of per-state so I'll
prepare a separate patch to clean this up.

There's some more cleanup opportunity after this patch, e.g. using
separate lists and registration functions for image formats vs
protocols and maybe even host drivers, but this can be done at a
later stage.

Also there's a check for protocol in bdrv_open for the BDRV_O_SNAPSHOT
case that I don't quite understand, but which I fear won't work as
expected - possibly even before this patch.

Note that this patch requires various recent block patches from Kevin
and me, which should all be in his block queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03 10:07:30 +02:00
Christoph Hellwig 9a2d77ad0d block: kill BDRV_O_CREAT
The BDRV_O_CREAT option is unused inside qemu and partially duplicates
the bdrv_create method.  Remove it, and the -C option to qemu-io which
isn't used in qemu-iotests anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 15:42:02 -06:00
Naphtali Sprei f5edb014ed Clean-up a little bit the RW related bits of BDRV_O_FLAGS. BDRV_O_RDONLY gone (and so is BDRV_O_ACCESS). Default value for bdrv_flags (0/zero) is READ-ONLY. Need to explicitly request READ-WRITE.
Instead of using the field 'readonly' of the BlockDriverState struct for passing the request,
pass the request in the flags parameter to the function.

Signed-off-by: Naphtali Sprei <nsprei@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-20 08:25:22 -06:00
Christoph Hellwig 508c7cb3fa block: add bdrv_probe_device method
Add a bdrv_probe_device method to all BlockDriver instances implementing
host devices to move matching of host device types into the actual drivers.
For now we keep exacly the old matching behaviour based on the devices names,
although we really should have better detetion methods based on device
information in the future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2009-06-15 14:04:22 +02:00
Kevin Wolf db08adf526 qemu-img: Print available options with -o ?
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>
2009-06-06 18:38:57 +03:00
Kevin Wolf 0e7e1989f7 Convert all block drivers to new bdrv_create
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>
2009-05-22 10:50:31 -05:00
Anthony Liguori dcc5e4a076 Fix warning on WIN32
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-14 17:03:50 -05:00
Anthony Liguori 019d6b8ff0 Move block drivers into their own directory
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-14 16:13:46 -05:00