Commit Graph

625 Commits

Author SHA1 Message Date
Kevin Wolf
707ff8282b block: Pass bdrv_file_open() options to block drivers
Specify -drive file.option=... on the command line to pass the option to
the protocol instead of the format driver.

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
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
Peter Lieven
5c916681ae Revert "block: complete all IOs before .bdrv_truncate"
brdv_truncate() is also called from readv/writev commands on self-
growing file based storage. this will result in requests waiting
for theirselves to complete.

This reverts commit 9a665b2b86.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-22 17:51:31 +01:00
Stefan Hajnoczi
4d70655bcb block: fix BDRV_O_SNAPSHOT protocol detection
realpath(3) is used to get an absolute path to the image file when
creating a -drive snapshot=on temporary qcow2.  This does not work for
protocols since their filenames ("proto:foo:...") do not correspond to
file system paths.

Commit 7c96d46ec2 ("Let snapshot work with
protocols") skipped realpath(3) for protocols.  Later on the "raw"
format was introduced and broke the check.

Use path_has_protocol(filename) to decide if this image uses a protocol
or a filename.

Reported-by: Richard Jones <rjones@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-03-19 11:48:37 +01:00
Stefan Hajnoczi
85d126f3ee block: add bdrv_get_aio_context()
For now bdrv_get_aio_context() is just a stub that calls
qemu_aio_get_context() since the block layer is currently tied to the
main loop AioContext.

Add the stub now so that the block layer can begin accessing its
AioContext.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2013-03-15 16:07:51 +01:00
Kevin Wolf
b6ad491a49 block: Add options QDict to bdrv_open_common()
The options are passed down to the block drivers, which are supposed to
remove all options they have processed. Anything that is left over in
the end is an unknown option and results in an error.

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
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
Kevin Wolf
1a86938f04 block: Add options QDict to .bdrv_open()
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
Jeff Cody
272d2d8e12 block: for HMP commit() operations on 'all', skip non-COW drives
During a commit of 'all' using the HMP non-live commit, the operation
is aborted and returns error on the first error enountered.  When
non-COW drives are in use (e.g. ejected floppy, cdrom, or drives without
a backing parent), that means a commit all will return an error of either
-ENOMEDIUM or -ENOTSUP.  This is not desirable, so for the 'all' commit
case, only attempt the commit if both bs->drv and bs->backing_hd are
present.

More succinctly: 'commit all' now means a commit on all COW drives.

This means an individual commit to a specific non-COW drive will still
return the appropriate error (-ENOMEDIUM if eject / not present, -ENOTSUP
if no backing file).

Reported-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-04 09:54:17 +01:00
Paolo Bonzini
9e8f1835ea block: implement BDRV_O_UNMAP
It is better to present homogeneous hardware independent of the storage
technology that is chosen on the host, hence we make discard a host
parameter; the user can choose whether to pass it down to the image
format and protocol, or to ignore it.

Using DISCARD with filesystems can cause very severe fragmentation, so it
is left default-off for now.  This can change later when we implement the
"anchor" operation for efficient management of preallocated files.

There is still one choice to make: whether DISCARD has an effect on the
dirty bitmap or not.  I chose yes, though there is a disadvantage: if
the guest is buggy and issues discards for data that is in use, there
will be no way to migrate storage for that guest without downgrading
the machine type to an older one.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-02-22 21:29:42 +01:00
Peter Lieven
9a665b2b86 block: complete all IOs before .bdrv_truncate
bdrv_truncate() invalidates the bdrv_check_request() result for
in-flight requests, so there should better be none.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Reported-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-02-22 21:21:10 +01:00
Miroslav Rezanina
f382d43a91 qemu-img: Add "Quiet mode" option
There can be a need to turn output to stdout off. This patch adds a -q option
that enable "Quiet mode". In Quiet mode, only errors are printed out.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:09 +01:00
Miroslav Rezanina
b35b2bba5b block: Add synchronous wrapper for bdrv_co_is_allocated_above
There's no synchronous wrapper for bdrv_co_is_allocated_above function
so it's not possible to check for sector allocation in an image with
a backing file.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-22 21:21:09 +01:00
Vishvananda Ishaya
63ba17d39f block: Fix is_allocated_above with resized files
In an image chain, if the base image is smaller than the current
image, we need to make sure to use the current images count of
unallocated blocks once we get to the end of the base image. Without
this change the code will return 0 blocks when it gets to the end
of the base image and mirror_run will fail its assertion.

Signed-off-by: Vishvananda Ishaya <vishvananda@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-01 14:58:28 +01:00
Paolo Bonzini
50717e941b block: allow customizing the granularity of the dirty bitmap
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:34 +01:00
Paolo Bonzini
acc906c6c5 block: return count of dirty sectors, not chunks
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:33 +01:00
Paolo Bonzini
343bded4ec block: make round_to_clusters public
This is needed in the following patch.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:33 +01:00
Paolo Bonzini
8f0720ecbc block: implement dirty bitmap using HBitmap
This actually uses the dirty bitmap in the block layer, and converts
mirroring to use an HBitmapIter.

Reviewed-by: Laszlo Ersek <lersek@redhat.com> (except block/mirror.c parts)
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-25 18:18:33 +01:00
Paolo Bonzini
df702c9b4c block: clear dirty bitmap when discarding
Note that resetting bits in the dirty bitmap is done _before_ actually
processing the request.  Writes, instead, set bits after the request
is completed.

This way, when there are concurrent write and discard requests, the
outcome will always be that the blocks are marked dirty.  This scenario
should never happen, but it is safer to do it this way.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-15 10:03:48 +01:00
Peter Lieven
029d091e49 block: fix initialization in bdrv_io_limits_enable()
bdrv_io_limits_enable() starts a new slice, but does not set io_base
correctly for that slice.

Here is how io_base is used:

    bytes_base  = bs->nr_bytes[is_write] - bs->io_base.bytes[is_write];
    bytes_res   = (unsigned) nb_sectors * BDRV_SECTOR_SIZE;

    if (bytes_base + bytes_res <= bytes_limit) {
        /* no wait */
    } else {
        /* operation needs to be throttled */
    }

As a result, any I/O operations that are triggered between now and
bs->slice_end are incorrectly limited.  If 10 MB of data has been
written since the VM was started, QEMU thinks that 10 MB of data has
been written in this slice. This leads to a I/O lockup in the guest.

We fix this by delaying the start of a new slice to the next
call of bdrv_exceed_io_limits().

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-15 09:24:38 +01:00
Stefan Hajnoczi
c53b1c5114 block: make qiov_is_aligned() public
The qiov_is_aligned() function checks whether a QEMUIOVector meets a
BlockDriverState's alignment requirements.  This is needed by
virtio-blk-data-plane so:

1. Move the function from block/raw-posix.c to block/block.c.
2. Make it public in block/block.h.
3. Rename to bdrv_qiov_is_aligned().
4. Change return type from int to bool.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-14 10:06:56 +01:00
Paolo Bonzini
8e895599a1 block: do not probe zero-sized disks
A blank CD or DVD is visible as a zero-sized disks.  Probing such
disks will lead to an EIO and a failure to start the VM.  Treating
them as raw is a better solution.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-01-14 10:06:56 +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
9c17d615a6 softmmu: move include files to include/sysemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:45 +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
83c9089e73 monitor: move include files to include/monitor/
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
Paolo Bonzini
7b1b5d1913 qapi: move include files to include/qobject/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Kevin Wolf
41c695c749 qemu-io: Add AIO debugging commands
This makes the blkdebug suspend/resume functionality available in
qemu-io. Use it like this:

  $ ./qemu-io blkdebug::/tmp/test.qcow2
  qemu-io> break write_aio req_a
  qemu-io> aio_write 0 4k
  qemu-io> blkdebug: Suspended request 'req_a'
  qemu-io> resume req_a
  blkdebug: Resuming request 'req_a'
  qemu-io> wrote 4096/4096 bytes at offset 0
  4 KiB, 1 ops; 0:00:30.71 (133.359788 bytes/sec and 0.0326 ops/sec)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-12 12:33:48 +01:00
Luiz Capitulino
d92ada2202 block: bdrv_img_create(): drop unused error handling code
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:05:10 +01:00
Luiz Capitulino
71c79813d8 block: bdrv_img_create(): add Error ** argument
This commit adds an Error ** argument to bdrv_img_create() and set it
appropriately on error.

Callers of bdrv_img_create() pass NULL for the new argument and still
rely on bdrv_img_create()'s return value. Next commits will change
callers to use the Error object instead.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:05:10 +01:00
Kevin Wolf
f500a6d3c2 block: Avoid second open for format probing
This fixes problems that are caused by the additional open/close cycle
of the existing format probing, for example related to qemu-nbd without
-t option or file descriptor passing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:04:25 +01:00
Kevin Wolf
7b27245239 block: Factor out bdrv_open_flags
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:04:25 +01:00
Kevin Wolf
d318aea932 block: Improve bdrv_aio_co_cancel_em
Instead of waiting for all requests to complete, wait just for the
specific request that should be cancelled.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:04:25 +01:00
Stefan Weil
89c9bc3d14 block: Fix regression for MinGW (assertion caused by short string)
The local string tmp_filename is passed to function get_tmp_filename
which expects a string with minimum size MAX_PATH for w32 hosts.

MAX_PATH is 260 and PATH_MAX is 259, so tmp_filename was too short.

Commit eba25057b9 introduced this
regression.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-11-24 19:54:43 +00:00
Stefan Hajnoczi
d7331bed11 aio: rename AIOPool to AIOCBInfo
Now that AIOPool no longer keeps a freelist, it isn't really a "pool"
anymore.  Rename it to AIOCBInfo and make it const since it no longer
needs to be modified.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-11-14 18:19:21 +01:00
Stefan Hajnoczi
d37c975fb1 aio: use g_slice_alloc() for AIOCB pooling
AIO control blocks are frequently acquired and released because each aio
request involves at least one AIOCB.  Therefore, we pool them to avoid
heap allocation overhead.

The problem with the freelist approach in AIOPool is thread-safety.  If
we want BlockDriverStates to associate with AioContexts that execute in
multiple threads, then a global freelist becomes a problem.

This patch drops the freelist and instead uses g_slice_alloc() which is
tuned for per-thread fixed-size object pools.  qemu_aio_get() and
qemu_aio_release() are now thread-safe.

Note that the change from g_malloc0() to g_slice_alloc() should be safe
since the freelist reuse case doesn't zero the AIOCB either.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-11-14 18:19:21 +01:00
Anthony Liguori
90c45b3031 Merge remote-tracking branch 'kwolf/for-anthony' into staging
* kwolf/for-anthony: (32 commits)
  osdep: Less restrictive F_SEFL in qemu_dup_flags()
  qemu-iotests: add testcases for mirroring on-source-error/on-target-error
  qmp: add pull_event function
  mirror: add support for on-source-error/on-target-error
  iostatus: forward block_job_iostatus_reset to block job
  qemu-iotests: add mirroring test case
  mirror: implement completion
  qmp: add drive-mirror command
  mirror: introduce mirror job
  block: introduce BLOCK_JOB_READY event
  block: add block-job-complete
  block: rename block_job_complete to block_job_completed
  block: export dirty bitmap information in query-block
  block: introduce new dirty bitmap functionality
  block: add bdrv_open_backing_file
  block: add bdrv_query_stats
  block: add bdrv_query_info
  qemu-config: Add new -add-fd command line option
  monitor: Prevent removing fd from set during init
  monitor: Enable adding an inherited fd to an fd set
  ...

Conflicts:
	vl.c

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-10-29 10:34:05 -05:00
Paolo Bonzini
3bd293c3fd iostatus: forward block_job_iostatus_reset to block job
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:22 +02:00
Paolo Bonzini
b9a9b3a462 block: export dirty bitmap information in query-block
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Paolo Bonzini
1755da16e3 block: introduce new dirty bitmap functionality
Assert that write_compressed is never used with the dirty bitmap.
Setting the bits early is wrong, because a coroutine might concurrently
examine them and copy incomplete data from the source.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Paolo Bonzini
9156df12a4 block: add bdrv_open_backing_file
Mirroring runs without the backing file so that it can be copied outside
QEMU.  However, we need to add it at the time the job is completed and
QEMU switches to the target.  Factor out the common bits of opening an
image and completing a mirroring operation.

The new function does not assume that the file is closed immediately after
it returns failure, so it keeps the BDRV_O_NO_BACKING flag up-to-date.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Paolo Bonzini
9887b61661 block: add bdrv_query_stats
qmp_query_blockstat cannot have errors, remove the Error argument and
create a new public function bdrv_query_stats out of it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Paolo Bonzini
ac84adac48 block: add bdrv_query_info
Extract it out of the implementation of "info block".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Luiz Capitulino
80168bff43 block: bdrv_create(): don't leak cco.filename on error
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:19 +02:00
Jeff Cody
b1b1d783ea block: make bdrv_find_backing_image compare canonical filenames
Currently, bdrv_find_backing_image compares bs->backing_file with
what is passed in as a backing_file name.  Mismatches may occur,
however, when bs->backing_file and backing_file are not both
absolute or relative.

Use path_combine() to make sure any relative backing filenames are
relative to the current image filename being searched, and then use
realpath() to make all comparisons based on absolute filenames.

If either backing_file or bs->backing_file is determine to be a
protocol, then no filename normalization is performed.

This also changes bdrv_find_backing_image to no longer be recursive,
but iterative.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24 10:26:18 +02:00
Paolo Bonzini
d7d512f609 block: add close notifiers
The first user of close notifiers will be the embedded NBD server.
It would be possible to use them to do some of the ad hoc processing
(e.g. for block jobs and I/O limits) that is currently done by
bdrv_close.

Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-23 22:39:32 +02:00
Paolo Bonzini
3cbc002c34 block: prepare code for adding block notifiers
There is no reason in principle to skip job cancellation and draining
of pending I/O when there is no medium in the disk.  Do these unconditionally,
which also prepares the code for the next patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-23 22:39:32 +02:00
Jim Meyering
c2cba3d931 block: avoid buffer overrun by using pstrcpy, not strncpy
Also, use PATH_MAX, rather than the arbitrary 1024.
Using PATH_MAX is more consistent with other filename-related
variables in this file, like backing_filename and tmp_filename.

Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-10-05 07:58:36 -05:00
Paolo Bonzini
32c81a4a6e block: introduce block job error
The following behaviors are possible:

'report': The behavior is the same as in 1.1.  An I/O error,
respectively during a read or a write, will complete the job immediately
with an error code.

'ignore': An I/O error, respectively during a read or a write, will be
ignored.  For streaming, the job will complete with an error and the
backing file will be left in place.  For mirroring, the sector will be
marked again as dirty and re-examined later.

'stop': The job will be paused and the job iostatus will be set to
failed or nospace, while the VM will keep running.  This can only be
specified if the block device has rerror=stop and werror=stop or enospc.

'enospc': Behaves as 'stop' for ENOSPC errors, 'report' for others.

In all cases, even for 'report', the I/O error is reported as a QMP
event BLOCK_JOB_ERROR, with the same arguments as BLOCK_IO_ERROR.

It is possible that while stopping the VM a BLOCK_IO_ERROR event will be
reported and will clobber the event from BLOCK_JOB_ERROR, or vice versa.
This is not really avoidable since stopping the VM completes all pending
I/O requests.  In fact, it is already possible now that a series of
BLOCK_IO_ERROR events are reported with rerror=stop, because vm_stop
calls bdrv_drain_all and this can generate further errors.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:56 +02:00
Paolo Bonzini
3e1caa5f76 iostatus: reorganize io error code
Move the common part of IDE/SCSI/virtio error handling to the block
layer.  The new function bdrv_error_action subsumes all three of
bdrv_emit_qmp_error_event, vm_stop, bdrv_iostatus_set_err.

The same scheme will be used for errors in block jobs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:56 +02:00
Paolo Bonzini
1ceee0d5cc iostatus: change is_read to a bool
Do this while we are touching this part of the code, before introducing
more uses of "int is_read".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:56 +02:00
Paolo Bonzini
92aa5c6d77 iostatus: move BlockdevOnError declaration to QAPI
This will let block-stream reuse the enum.  Places that used the enums
are renamed accordingly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:40:26 +02:00
Paolo Bonzini
ff06f5f351 iostatus: rename BlockErrorAction, BlockQMPEventAction
We want to remove knowledge of BLOCK_ERR_STOP_ENOSPC from drivers;
drivers should only be told whether to stop/report/ignore the error.
On the other hand, we want to keep using the nicer BlockErrorAction
name in the drivers.  So rename the enums, while leaving aside the
names of the enum values for now.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:14:32 +02:00
Paolo Bonzini
2f0c9fe64c block: move job APIs to separate files
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 19:14:26 +02:00
Jeff Cody
79fac5680d block: helper function, to find the base image of a chain
This is a simple helper function, that will return the base image
of a given image chain.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 18:23:44 +02:00
Jeff Cody
6ebdcee2d8 block: add support functions for live commit, to find and delete images.
Add bdrv_find_overlay(), and bdrv_drop_intermediate().

bdrv_find_overlay():  given 'bs' and the active (topmost) BDS of an image chain,
                    find the image that is the immediate top of 'bs'

bdrv_drop_intermediate():
                    Given 3 BDS (active, top, base), drop images above
                    base up to and including top, and set base to be the
                    backing file of top's overlay node.

                    E.g., this converts:

                    bottom <- base <- intermediate <- top <- active

                    to

                    bottom <- base <- active

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28 18:22:44 +02:00
Jeff Cody
dc1c13d969 block: remove keep_read_only flag from BlockDriverState struct
The keep_read_only flag is no longer used, in favor of the bdrv
flag BDRV_O_ALLOW_RDWR.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:13 +02:00
Jeff Cody
0bce597d6e block: convert bdrv_commit() to use bdrv_reopen()
Currently, bdrv_commit() reopens images r/w itself, via risky
_delete() and _open() calls. Use the new safe method for drive reopen.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:12 +02:00
Jeff Cody
e971aa1273 block: Framework for reopening files safely
This is based on Supriya Kannery's bdrv_reopen() patch series.

This provides a transactional method to reopen multiple
images files safely.

Image files are queue for reopen via bdrv_reopen_queue(), and the
reopen occurs when bdrv_reopen_multiple() is called.  Changes are
staged in bdrv_reopen_prepare() and in the equivalent driver level
functions.  If any of the staged images fails a prepare, then all
of the images left untouched, and the staged changes for each image
abandoned.

Block drivers are passed a reopen state structure, that contains:
    * BDS to reopen
    * flags for the reopen
    * opaque pointer for any driver-specific data that needs to be
      persistent from _prepare to _commit/_abort
    * reopen queue pointer, if the driver needs to queue additional
      BDS for a reopen

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
55b110f24e block: make bdrv_set_enable_write_cache() modify open_flags
bdrv_set_enable_write_cache() sets the bs->enable_write_cache flag,
but without the flag recorded in bs->open_flags, then next time
a reopen() is performed the enable_write_cache setting may be
inadvertently lost.

This will set the flag in open_flags, so it is preserved across
reopens.

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
be028adced block: correctly set the keep_read_only flag
I believe the bs->keep_read_only flag is supposed to reflect
the initial open state of the device. If the device is initially
opened R/O, then commit operations, or reopen operations changing
to R/W, are prohibited.

Currently, the keep_read_only flag is only accurate for the active
layer, and its backing file. Subsequent images end up always having
the keep_read_only flag set.

For instance, what happens now:

[  base  ]  kro = 1, ro = 1
    |
    v
[ snap-1 ]  kro = 1, ro = 1
    |
    v
[ snap-2 ]  kro = 0, ro = 1
    |
    v
[ active ]  kro = 0, ro = 0

What we want:

[  base  ]  kro = 0, ro = 1
    |
    v
[ snap-1 ]  kro = 0, ro = 1
    |
    v
[ snap-2 ]  kro = 0, ro = 1
    |
    v
[ active ]  kro = 0, ro = 0

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:11 +02:00
Dunrong Huang
fe235a06e1 block: Don't forget to delete temporary file
The caller would not delete temporary file after failed get_tmp_filename().

Signed-off-by: Dunrong Huang <riegamaths@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-12 15:50:09 +02:00
Pavel Hrdina
9ca111544c block: fix block tray status
The tray status should change also if you eject empty block device.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-12 15:50:09 +02:00
Kevin Wolf
d4c8232923 block: Flush parent to OS with cache=unsafe
Commit 29cdb251 already added a comment that no unnecessary flushes to
disk will occur, this patch makes the code even get to the point of the
comment. This is mostly theoretical because in practice we only stack
one format on top of one protocol, the former implementing flush_to_os
and the latter only flush_to_disk. It starts to matter when drivers that
are not on top implement flush_to_os.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-15 15:14:43 +02:00
Luiz Capitulino
c75a1a8a5a qmp: query-block: add 'encryption_key_missing' field
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2012-08-13 13:20:06 -03:00
Benoît Canet
2e3e331710 block: Use bdrv_get_backing_file_depth()
Use the dedicated counting function in qmp_query_block in order to
propagate the backing file depth to HMP and add backing_file_depth
to qmp-commands.hx

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-08-03 10:10:51 -03:00
Benoît Canet
f198fd1c9a block: create bdrv_get_backing_file_depth()
Create bdrv_get_backing_file_depth() in order to be able to show
in QMP and HMP how many ancestors backing an image a block device
have.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-08-03 10:10:38 -03:00
Blue Swirl
0ed8b6f67f Avoid returning void
It's silly and non-conforming to standards to return void,
don't do it.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-07-28 09:23:11 +00:00
Markus Armbruster
2b584959ed block: Geometry and translation hints are now useless, purge them
There are two producers of these hints: drive_init() on behalf of
-drive, and hd_geometry_guess().

The only consumer of the hint is hd_geometry_guess().

The callers of hd_geometry_guess() call it only when drive_init()
didn't set the hints.  Therefore, drive_init()'s hints are never used.

Thus, hd_geometry_guess() only ever sees hints it produced itself in a
prior call.  Only the first call computes something, subsequent calls
just repeat the first call's results.  However, hd_geometry_guess() is
never called more than once: the device models don't, and the block
device is destroyed on unplug.  Thus, dropping the repeat feature
doesn't break anything now.

If a block device wasn't destroyed on unplug and could be reused with
a new device, then repeating old results would be wrong.  Thus,
dropping the repeat feature prevents future breakage.

This renders the hints unused.  Purge them from the block layer.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-17 16:48:31 +02:00
Markus Armbruster
9db1c0f7a9 hd-geometry: Move disk geometry guessing back from block.c
Commit f3d54fc4 factored it out of hw/ide.c for reuse.  Sensible,
except it was put into block.c.  Device-specific functionality should
be kept in device code, not the block layer.  Move it to
hw/hd-geometry.c, and make stylistic changes required to keep
checkpatch.pl happy.

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
61a8d649ff fdc: Move floppy geometry guessing back from block.c
Commit 5bbdbb46 moved it to block.c because "other geometry guessing
functions already reside in block.c".  Device-specific functionality
should be kept in device code, not the block layer.  Move it back.

Disk geometry guessing is still in block.c.  To be moved out in a
later patch series.

Bonus: the floppy type used in pc_cmos_init() now obviously matches
the one in the FDrive.  Before, we relied on
bdrv_get_floppy_geometry_hint() picking the same type both in
fd_revalidate() and in pc_cmos_init().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-17 16:48:29 +02:00
Anthony Liguori
23797df3d9 Merge remote-tracking branch 'mjt/mjt-iov2' into staging
* mjt/mjt-iov2:
  rewrite iov_send_recv() and move it to iov.c
  cleanup qemu_co_sendv(), qemu_co_recvv() and friends
  export iov_send_recv() and use it in iov_send() and iov_recv()
  rename qemu_sendv to iov_send, change proto and move declarations to iov.h
  change qemu_iovec_to_buf() to match other to,from_buf functions
  consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent
  allow qemu_iovec_from_buffer() to specify offset from which to start copying
  consolidate qemu_iovec_memset{,_skip}() into single function and use existing iov_memset()
  rewrite iov_* functions
  change iov_* function prototypes to be more appropriate
  virtio-serial-bus: use correct lengths in control_out() message

Conflicts:
	tests/Makefile

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-07-09 12:35:06 -05:00
Markus Armbruster
07d27a442e block: Factor bdrv_read_unthrottled() out of guess_disk_lchs()
To prepare move of guess_disk_lchs() into hw/, where it poking
BlockDriverState member io_limits_enabled directly would be unclean.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-09 17:21:02 +02:00
Markus Armbruster
1f69c2b022 fdc: Drop broken code for user-defined floppy geometry
bdrv_get_floppy_geometry_hint() fails to store through its parameter
drive when bs has a geometry hint.  Makes fd_revalidate() assign
random crap to drv->drive.

Has been broken that way for ages.  Harmless, because:

* The only way to set a geometry hint is -drive if=none,cyls=...
  Since commit c219331e, probably unintentional.

* The only use of drv->drive is as argument to another
  bdrv_get_floppy_geometry_hint().  Which doesn't use it, since the
  geometry hint is still there.

Drop the broken code, ignore -drive parameter cyls, heads and secs for
floppies even with if=none, just like before commit c219331e.  Matches
-help, which explains cyls, heads, secs as "hard disk physical
geometry".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-09 15:53:03 +02:00
Paolo Bonzini
4ddc07cac2 block: introduce bdrv_swap, implement bdrv_append on top of it
The new function can be made a bit nicer than bdrv_append.  It swaps the
whole contents, and then swaps back (using the usual t=a;a=b;b=t idiom)
the fields that need to stay on top.  Thus, it does not need explicit
bdrv_detach_dev, bdrv_iostatus_disable, etc.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-09 15:53:02 +02:00
Paolo Bonzini
a9fc4408e3 block: copy over job and dirty bitmap fields in bdrv_append
While these should not be in use at the time a transaction is started,
a command in the prepare phase of a transaction might have added them,
so they need to be brought over.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-09 15:53:02 +02:00
Markus Armbruster
f8d6bba1c1 block: Replace bdrv_get_format() by bdrv_get_format_name()
So callers don't need to know anything about maximum name length.
Returning a pointer is safe, because the name string lives as long as
the block driver it names, and block drivers don't die.

Requested by Peter Maydell.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Paolo Bonzini
e1e9b0aca0 block: always open drivers in writeback mode
Formats are entirely in charge of flushes for metadata writes.  For
guest-initiated writes, a writethrough cache is faked in the block layer.
So we can always open in writeback mode.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Paolo Bonzini
425b01487a block: add bdrv_set_enable_write_cache
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Paolo Bonzini
c4a248a138 block: copy enable_write_cache in bdrv_append
Because the guest will be able to flip enable_write_cache, the actual
state may not match what is used to open the new snapshot.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Paolo Bonzini
f05fa4ad03 block: flush in writethrough mode after writes
We want to make the formats handle their own flushes
autonomously, while keeping for guests the ability to use a writethrough
cache.  Since formats will write metadata via bs->file, bdrv_co_do_writev
is the only place where we need to add a flush.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Markus Armbruster
c843328783 block: New bdrv_get_flags()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:43 +02:00
Kevin Wolf
4534ff5426 qemu-img check -r for repairing images
The QED block driver already provides the functionality to not only
detect inconsistencies in images, but also fix them. However, this
functionality cannot be manually invoked with qemu-img, but the
check happens only automatically during bdrv_open().

This adds a -r switch to qemu-img check that allows manual invocation
of an image repair.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:42 +02:00
Paolo Bonzini
188a7bbf94 stream: move is_allocated_above to block.c
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:42 +02:00
Michael Tokarev
d5e6b1619c change qemu_iovec_to_buf() to match other to,from_buf functions
It now allows specifying offset within qiov to start from and
amount of bytes to copy.  Actual implementation is just a call
to iov_to_buf().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Michael Tokarev
1b093c480a consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent
qemu_iovec_concat() is currently a wrapper for
qemu_iovec_copy(), use the former (with extra
"0" arg) in a few places where it is used.

Change skip argument of qemu_iovec_copy() from
uint64_t to size_t, since size of qiov itself
is size_t, so there's no way to skip larger
sizes.  Rename it to soffset, to make it clear
that the offset is applied to src.

Also change the only usage of uint64_t in
hw/9pfs/virtio-9p.c, in v9fs_init_qiov_from_pdu() -
all callers of it actually uses size_t too,
not uint64_t.

One added restriction: as for all other iovec-related
functions, soffset must point inside src.

Order of argumens is already good:
 qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
                   int c, size_t bytes)
vs:
 qemu_iovec_concat(QEMUIOVector *dst,
                   QEMUIOVector *src,
                   size_t soffset, size_t sbytes)
(note soffset is after _src_ not dst, since it applies to src;
for memset it applies to qiov).

Note that in many places where this function is used,
the previous call is qemu_iovec_reset(), which means
many callers actually want copy (replacing dst content),
not concat.  So we may want to add a wrapper like
qemu_iovec_copy() with the same arguments but which
calls qemu_iovec_reset() before _concat().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Michael Tokarev
03396148bc allow qemu_iovec_from_buffer() to specify offset from which to start copying
Similar to
 qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
                   int c, size_t bytes);
the new prototype is:
 qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
                     const void *buf, size_t bytes);

The processing starts at offset bytes within qiov.

This way, we may copy a bounce buffer directly to
a middle of qiov.

This is exactly the same function as iov_from_buf() from
iov.c, so use the existing implementation and rename it
to qemu_iovec_from_buf() to be shorter and to match the
utility function.

As with utility implementation, we now assert that the
offset is inside actual iovec.  Nothing changed for
current callers, because `offset' parameter is new.

While at it, stop using "bounce-qiov" in block/qcow2.c
and copy decrypted data directly from cluster_data
instead of recreating a temp qiov for doing that.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
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
dc5a137125 qemu-img: make "info" backing file output correct and easier to use
qemu-img info should use the same logic as qemu when printing the
backing file path, or debugging becomes quite tricky.  We can also
simplify the output in case the backing file has an absolute path
or a protocol.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
6405875cdd block: move field reset from bdrv_open_common to bdrv_close
bdrv_close should leave fields in the same state as bdrv_new.  It is
not up to bdrv_open_common to fix the mess.

Also, backing_format was not being re-initialized.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
947995c09e block: protect path_has_protocol from filenames with colons
path_has_protocol will erroneously return "true" if the colon is part
of a filename.  These names are common with stable device names produced
by udev.  We cannot fully protect against this in case the filename
does not have a path component (e.g. if the current directory is
/dev/disk/by-path), but in the common case there will be a slash before
and path_has_protocol can easily detect that and return false.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
f53f4da9c6 block: simplify path_is_absolute
On Windows, all the logic is already in is_windows_drive and
is_windows_drive_prefix.  On POSIX, there is no need to look
out for colons.

The win32 code changes the behaviour in some cases, we could have
something like "d:foo.img". The old code would treat it as relative
path, the new one as absolute. Now the path is absolute, because to
go from c:/program files/blah to d:foo.img you cannot say c:/program
files/blah/d:foo.img.  You have to say d:foo.img.  But you could also
say it's relative because (I think, at least it was like that in DOS
15 years ago) d:foo.img is relative to the current path of drive D.
Considering how path_is_absolute is used by path_combine, I think it's
better to treat it as absolute.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
fa4478d5c8 block: wait for job callback in block_job_cancel_sync
The limitation on not having I/O after cancellation cannot really be
kept.  Even streaming has a very small race window where you could
cancel a job and have it report completion.  If this window is hit,
bdrv_change_backing_file() will yield and possibly cause accesses to
dangling pointers etc.

So, let's just assume that we cannot know exactly what will happen
after the coroutine has set busy to false.  We can set a very lax
condition:

- if we cancel the job, the coroutine won't set it to false again
(and hence will not call co_sleep_ns again).

- block_job_cancel_sync will wait for the coroutine to exit, which
pretty much ensures no race.

Instead, we track the coroutine that executes the job and put very
strict conditions on what to do while it is quiescent (busy = false).
First of all, the coroutine must never set busy = false while the job
has been cancelled.  Second, the coroutine can be reentered arbitrarily
while it is quiescent, so you cannot really do anything but co_sleep_ns at
that time.  This condition is obeyed by the block_job_sleep_ns function.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
4513eafe92 block: add block_job_sleep_ns
This function abstracts the pretty complex semantics of the "busy"
member of BlockJob.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
0ac9377d04 block: fully delete bs->file when closing
We are reusing bs->file across close/open, which may not cause any
known bugs but is a recipe for trouble.  Prefer bdrv_delete, and
enjoy the new invariant in the implementation of bdrv_delete.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
a275fa42fa block: do not reuse the backing file across bdrv_close/bdrv_open
This is another bug caused by not doing a full cleanup of the BDS
across close/open.  This was found with mirroring by Shaolong Hu,
but it can probably be reproduced also with eject or change.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
Paolo Bonzini
3a389e7926 block: another bdrv_append fix
bdrv_append must also copy open_flags to the top, because the snapshot
has BDRV_O_NO_BACKING set.  This causes interesting results if you
later use drive-reopen (not upstream) to reopen the image, and lose
the backing file in the process.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:12 +02:00
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
Paolo Bonzini
71df14fcbe block: fix allocation size for dirty bitmap
Also reuse elsewhere the new constant for sizeof(unsigned long) * 8.

The dirty bitmap is allocated in bits but declared as unsigned long.
Thus, its memory block is accessed beyond its end unless the image
is a multiple of 64 chunks (i.e. a multiple of 64 MB).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:11 +02:00
Paolo Bonzini
63090dac3a block: open backing file as read-only when probing for size
bdrv_img_create will temporarily open the backing file to probe its size.
However, this could be done with a read-write open if the wrong flags are
passed to bdrv_img_create.  Since there is really no documentation on
what flags can be passed, assume that bdrv_img_create receives the flags
with which the new image will be opened; sanitize them when opening
the backing file.

Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:11 +02:00
Paolo Bonzini
469ef350e1 block: update in-memory backing file and format
These are needed to print "info block" output correctly.  QCOW2 does this
because it needs it to write the header, but QED does not, and common code
is the right place to do it.

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 10:32:11 +02:00
Paolo Bonzini
5f3777945d block: push bdrv_change_backing_file error checking up from drivers
This check applies to all drivers, but QED lacks it.

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 10:32:11 +02:00
Zhi Yong Wu
4c355d53c6 block: add the support to drain throttled requests
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
[ Iterate until all block devices have processed all requests,
  add comments. - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10 10:32:11 +02:00
Zhi Yong Wu
5b7e1542cf block: make bdrv_create adopt coroutine
The current qemu.git introduces failure with preallocation and some
sizes:

qemu-img create -f qcow2 new.img 976563K -o preallocation=metadata
qemu-img: qemu-coroutine-lock.c:111: qemu_co_mutex_unlock: Assertion
`mutex->locked == 1' failed.

And lock needs to work in coroutine context. So to fix this issue, we
need to make bdrv_create adopt coroutine at first.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-07 19:33:18 +02:00
Stefan Hajnoczi
c83c66c3b5 block: add 'speed' optional parameter to block-stream
Allow streaming operations to be started with an initial speed limit.
This eliminates the window of time between starting streaming and
issuing block-job-set-speed.  Users should use the new optional 'speed'
parameter instead so that speed limits are in effect immediately when
the job starts.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27 11:44:50 -03:00
Stefan Hajnoczi
882ec7ce53 block: change block-job-set-speed argument from 'value' to 'speed'
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27 11:44:50 -03:00
Stefan Hajnoczi
9e6636c72d block: use Error mechanism instead of -errno for block_job_set_speed()
There are at least two different errors that can occur in
block_job_set_speed(): the job might not support setting speeds or the
value might be invalid.

Use the Error mechanism to report the error where it occurs.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27 11:44:50 -03:00
Stefan Hajnoczi
fd7f8c6537 block: use Error mechanism instead of -errno for block_job_create()
The block job API uses -errno return values internally and we convert
these to Error in the QMP functions.  This is ugly because the Error
should be created at the point where we still have all the relevant
information.  More importantly, it is hard to add new error cases to
this case since we quickly run out of -errno values without losing
information.

Go ahead and use Error directly and don't convert later.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27 11:44:50 -03:00
Kevin Wolf
621f058940 qcow2: Zero write support
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:30 +02:00
Liu Yuan
80ccf93b88 qemu-img: let 'qemu-img convert' flush data
The 'qemu-img convert -h' advertise that the default cache mode is
'writeback', while in fact it is 'unsafe'.

This patch 1) fix the help manual and 2) let bdrv_close() call bdrv_flush()

2) is needed because some backend storage doesn't have a self-flush
mechanism(for e.g., sheepdog), so we need to call bdrv_flush() to make
sure the image is really writen to the storage instead of hanging around
writeback cache forever.

Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 11:42:41 +02:00
Kevin Wolf
7094f12f86 block: Drain requests in bdrv_close
If an AIO request is in flight that refers to a BlockDriverState that
has been closed and possibly even freed, more or less anything could
happen. I have seen segfaults, -EBADF return values and qcow2 sometimes
actually catches the situation in bdrv_close() and abort()s.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2012-04-19 15:48:52 +02:00
Benoît Canet
077892696b block: add a function to clear incoming live migration flags
This function will clear all BDRV_O_INCOMING flags.

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 16:27:56 +02:00
Jeff Cody
f6801b83d0 block: bdrv_append() fixes
A few fixups for bdrv_append():

The new bs (bs_new) passed into bdrv_append() should be anonymous.  Rather
than call bdrv_make_anon() to enforce this, use an assert to catch when a caller
is passing in a bs_new that is not anonymous.

Also, the new top layer should have its backing_format reflect the original
top's format.

And last, after the swap of bs contents, the device_name will have been copied
down. This needs to be cleared to reflect the anonymity of the bs that was
pushed down.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:41 +02:00
Paolo Bonzini
9f25eccc1c block: set job->speed in block_set_speed
There is no need to do this in every implementation of set_speed
(even though there is only one right now).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
3e914655f2 block: fix streaming/closing race
Streaming can issue I/O while qcow2_close is running.  This causes the
L2 caches to become very confused or, alternatively, could cause a
segfault when the streaming coroutine is reentered after closing its
block device.  The fix is to cancel streaming jobs when closing their
underlying device.

The cancellation must be synchronous, on the other hand qemu_aio_wait
will not restart a coroutine that is sleeping in co_sleep.  So add
a flag saying whether streaming has in-flight I/O.  If the busy flag
is false, the coroutine is quiescent and, when cancelled, will not
issue any new I/O.

This protects streaming against closing, but not against deleting.
We have a reference count protecting us against concurrent deletion,
but I still added an assertion to ensure nothing bad happens.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Zhi Yong Wu
498e386c58 block: disable I/O throttling on sync api
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:40 +02:00
Paolo Bonzini
29cdb2513c block: push recursive flushing up from drivers
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05 14:54:39 +02:00
Stefan Hajnoczi
e88774971c block: handle -EBUSY in bdrv_commit_all()
Monitor operations that manipulate image files must not execute while a
background job (like image streaming) is in progress.  This prevents
corruptions from happening when two pieces of code are manipulating the
image file without knowledge of each other.

The monitor "commit" command raises QERR_DEVICE_IN_USE when
bdrv_commit() returns -EBUSY but "commit all" has no error handling.
This is easy to fix, although note that we do not deliver a detailed
error about which device was busy in the "commit all" case.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-03-12 15:14:06 +01:00
Jeff Cody
8802d1fdd4 qapi: Introduce blockdev-group-snapshot-sync command
This is a QAPI/QMP only command to take a snapshot of a group of
devices. This is similar to the blockdev-snapshot-sync command, except
blockdev-group-snapshot-sync accepts a list devices, filenames, and
formats.

It is attempted to keep the snapshot of the group atomic; if the
creation or open of any of the new snapshots fails, then all of
the new snapshots are abandoned, and the name of the snapshot image
that failed is returned.  The failure case should not interrupt
any operations.

Rather than use bdrv_close() along with a subsequent bdrv_open() to
perform the pivot, the original image is never closed and the new
image is placed 'in front' of the original image via manipulation
of the BlockDriverState fields.  Thus, once the new snapshot image
has been successfully created, there are no more failure points
before pivoting to the new snapshot.

This allows the group of disks to remain consistent with each other,
even across snapshot failures.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-29 15:48:33 +01:00
Paolo Bonzini
b6a127a156 block: drop aio_multiwrite in BlockDriver
These were never used.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-29 12:48:47 +01:00
Hervé Poussineau
f8d3d12857 block: add a transfer rate for floppy types
Floppies must be read at a specific transfer rate, depending of its own format.
Update floppy description table to include required transfer rate.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-29 12:48:46 +01:00
Luiz Capitulino
6f382ed226 qmp: add DEVICE_TRAY_MOVED event
It's emitted whenever the tray is moved by the guest or by HMP/QMP
commands.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2012-02-22 17:23:50 -02:00
Luiz Capitulino
f36f394952 block: bdrv_eject(): Make eject_flag a real bool
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2012-02-22 17:23:05 -02:00
Luiz Capitulino
329c0a48a9 block: Rename bdrv_mon_event() & BlockMonEventAction
They are QMP events, not monitor events. Rename them accordingly.

Also, move bdrv_emit_qmp_error_event() up in the file. A new event will
be added soon and it's good to have them next each other.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
2012-02-22 17:22:35 -02:00
Stefan Hajnoczi
79c053bde9 block: perform zero-detection during copy-on-read
Copy-on-Read populates the image file with data read from a backing
image.  In order to avoid bloating the image file when all zeroes are
read we should scan the buffer and perform an optimized zero write
operation.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09 16:17:50 +01:00
Stefan Hajnoczi
f08f2ddae0 block: add .bdrv_co_write_zeroes() interface
The ability to zero regions of an image file is a useful primitive for
higher-level features such as image streaming or zero write detection.

Image formats may support an optimized metadata representation instead
of writing zeroes into the image file.  This allows zero writes to be
potentially faster than regular write operations and also preserve
sparseness of the image file.

The .bdrv_co_write_zeroes() interface should be implemented by block
drivers that wish to provide efficient zeroing.

Note that this operation is different from the discard operation, which
may leave the contents of the region indeterminate.  That means
discarded blocks are not guaranteed to contain zeroes and may contain
junk data instead.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09 16:17:50 +01:00
Marcelo Tosatti
e8a6bb9caa block: add bdrv_find_backing_image
Add bdrv_find_backing_image: given a BlockDriverState pointer, and an id,
traverse the backing image chain to locate the id.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26 14:49:18 +01:00
Stefan Hajnoczi
eeec61f291 block: add BlockJob interface for long-running operations
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26 11:45:26 +01:00
Stefan Hajnoczi
470c05047a block: make copy-on-read a per-request flag
Previously copy-on-read could only be enabled for all requests to a
block device.  This means requests coming from the guest as well as
QEMU's internal requests would perform copy-on-read when enabled.

For image streaming we want to support finer-grained behavior than just
populating the image file from its backing image.  Image streaming
supports partial streaming where a common backing image is preserved.
In this case guest requests should not perform copy-on-read because they
would indiscriminately copy data which should be left in a backing image
from the backing chain.

Introduce a per-request flag for copy-on-read so that a block device can
process both regular and copy-on-read requests.  Overlapping reads and
writes still need to be serialized for correctness when copy-on-read is
happening, so add an in-flight reference count to track this.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26 11:45:26 +01:00
Stefan Hajnoczi
2d3735d3bf block: check bdrv_in_use() before blockdev operations
Long-running block operations like block migration and image streaming
must have continual access to their block device.  It is not safe to
perform operations like hotplug, eject, change, resize, commit, or
external snapshot while a long-running operation is in progress.

This patch adds the missing bdrv_in_use() checks so that block migration
and image streaming never have the rug pulled out from underneath them.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26 11:45:26 +01:00
Paolo Bonzini
3f3aace830 block: avoid useless checks on acb->bh
Coverity is confused by this "if" and reports leaks on acb->bh.
The bottom half is always deleted before releasing the AIOCB,
in either bdrv_aio_cancel_em or bdrv_aio_bh_cb.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:08 +01:00
Paolo Bonzini
df9309fb43 block: simplify failure handling for bdrv_aio_multiwrite
Now that early failure of bdrv_aio_writev is not possible anymore,
mcb->num_requests can be set before the loop starts.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:07 +01:00
Paolo Bonzini
ad54ae80c7 block: bdrv_aio_* do not return NULL
Initially done with the following semantic patch:

@ rule1 @
expression E;
statement S;
@@
  E =
(
   bdrv_aio_readv
|  bdrv_aio_writev
|  bdrv_aio_flush
|  bdrv_aio_discard
|  bdrv_aio_ioctl
)
     (...);
(
- if (E == NULL) { ... }
|
- if (E)
    { <... S ...> }
)

which however missed the occurrence in block/blkverify.c
(as it should have done), and left behind some unused
variables.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:07 +01:00
Stefan Hajnoczi
922453bca6 block: convert qemu_aio_flush() calls to bdrv_drain_all()
Many places in QEMU call qemu_aio_flush() to complete all pending
asynchronous I/O.  Most of these places actually want to drain all block
requests but there is no block layer API to do so.

This patch introduces the bdrv_drain_all() API to wait for requests
across all BlockDriverStates to complete.  As a bonus we perform checks
after qemu_aio_wait() to ensure that requests really have finished.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:56:06 +01:00
Stefan Hajnoczi
5f8b6491f2 block: wait_for_overlapping_requests() deadlock detection
Debugging a reentrant request deadlock was fun but in the future we need
a quick and obvious way of detecting such bugs.  Add an assert that
checks we are not about to deadlock when waiting for another request.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:52:34 +01:00
Stefan Hajnoczi
bd9533e36e block: implement bdrv_co_is_allocated() boundary cases
Cases beyond the end of the disk image are only implemented for block
drivers that do not provide .bdrv_co_is_allocated().  It's worth making
these cases generic so that block drivers that do implement
.bdrv_co_is_allocated() also get them for free.

Suggested-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:39 +01:00
Stefan Hajnoczi
ab1859218a block: core copy-on-read logic
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:38 +01:00
Stefan Hajnoczi
d83947ac6d block: request overlap detection
Detect overlapping requests and remember to align to cluster boundaries
if the image format uses them.  This assumes that allocating I/O is
performed in cluster granularity - which is true for qcow2, qed, etc.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:38 +01:00
Stefan Hajnoczi
f4658285f9 block: wait for overlapping requests
When copy-on-read is enabled it is necessary to wait for overlapping
requests before issuing new requests.  This prevents races between the
copy-on-read and a write request.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:38 +01:00
Stefan Hajnoczi
53fec9d3fd block: add interface to toggle copy-on-read
The bdrv_enable_copy_on_read()/bdrv_disable_copy_on_read() functions can
be used to programmatically enable or disable copy-on-read for a block
device.  Later patches add the actual copy-on-read logic.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:38 +01:00
Stefan Hajnoczi
dbffbdcfff block: add request tracking
The block layer does not know about pending requests.  This information
is necessary for copy-on-read since overlapping requests must be
serialized to prevent races that corrupt the image.

The BlockDriverState gets a new tracked_request list field which
contains all pending requests.  Each request is a BdrvTrackedRequest
record with sector_num, nb_sectors, and is_write fields.

Note that request tracking is always enabled but hopefully this extra
work is so small that it doesn't justify adding an enable/disable flag.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:38 +01:00
Stefan Hajnoczi
060f51c9de block: add bdrv_co_is_allocated() interface
This patch introduces the public bdrv_co_is_allocated() interface which
can be used to query image allocation status while the VM is running.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:37 +01:00
Stefan Hajnoczi
6aebab140d block: drop .bdrv_is_allocated() interface
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: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:37 +01:00
Stefan Hajnoczi
376ae3f1cb block: add .bdrv_co_is_allocated()
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: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:36 +01:00
Stefan Hajnoczi
05c4af54c6 block: use public bdrv_is_allocated() interface
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: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:36 +01:00
Zhi Yong Wu
727f005e6a hmp/qmp: add block_set_io_throttle
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:35 +01:00
Zhi Yong Wu
98f90dba5e block: add I/O throttling algorithm
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:35 +01:00
Zhi Yong Wu
0563e19151 block: add the blockio limits command line support
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:35 +01:00
Anthony Liguori
0f15423c32 block: allow migration to work with image files (v3)
Image files have two types of data: immutable data that describes things like
image size, backing files, etc. and mutable data that includes offset and
reference count tables.

Today, image formats aggressively cache mutable data to improve performance.  In
some cases, this happens before a guest even starts.  When dealing with live
migration, since a file is open on two machines, the caching of meta data can
lead to data corruption.

This patch addresses this by introducing a mechanism to invalidate any cached
mutable data a block driver may have which is then used by the live migration
code.

NB, this still requires coherent shared storage.  Addressing migration without
coherent shared storage (i.e. NFS) requires additional work.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-21 14:58:48 -06:00
Kevin Wolf
ca716364f0 block: Make cache=unsafe flush to the OS
cache=unsafe completely ignored bdrv_flush, because flushing the host disk
costs a lot of performance. However, this means that qcow2 images (and
potentially any other format) can lose data even after the guest has issued a
flush if the qemu process crashes/is killed. In case of a host crash, data loss
is certainly expected with cache=unsafe, but if just the qemu process dies this
is a bit too unsafe.

Now that we have two separate flush functions, we can choose to flush
everythign to the OS, but don't enforce that it's physically written to the
disk.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:59 +01:00
Kevin Wolf
eb489bb1ec block: Introduce bdrv_co_flush_to_os
qcow2 has a writeback metadata cache, so flushing a qcow2 image actually
consists of writing back that cache to the protocol and only then flushes the
protocol in order to get everything stable on disk.

This introduces a separate bdrv_co_flush_to_os to reflect the split.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:59 +01:00
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
025ccaa7f9 block: add eject request callback
Recent versions of udev always keep the tray locked so that the kernel
can observe "eject request" events (aka tray button presses) even on
discs that aren't mounted.  Add support for these events in the ATAPI
and SCSI cd drive device models.

To let management cope with the behavior of udev, an event should also
be added for "tray opened/closed".  This way, after issuing an "eject"
command, management can poll until the guests actually reacts to the
command.  They can then issue the "change" command after the tray has been
opened, or try with "eject -f" after a (configurable?) timeout.  However,
with this patch and the corresponding support in the device models,
at least it is possible to do a manual two-step eject+change sequence.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:57 +01:00
Anthony Liguori
8494a397b6 Merge remote-tracking branch 'kwolf/for-anthony' into staging
Conflicts:
	block/vmdk.c
2011-10-31 11:09:00 -05:00
Stefan Hajnoczi
03f541bd6e block: reinitialize across bdrv_close()/bdrv_open()
Several BlockDriverState fields are not being reinitialized across
bdrv_close()/bdrv_open().  Make sure they are reset to their default
values.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:50 +02:00
Stefan Hajnoczi
e7c637967e block: set bs->read_only before .bdrv_open()
Several block drivers set bs->read_only in .bdrv_open() but
block.c:bdrv_open_common() clobbers its value.  Additionally, QED uses
bdrv_is_read_only() in .bdrv_open() to decide whether to perform
consistency checks.

The correct ordering is to initialize bs->read_only from the open flags
before calling .bdrv_open().  This way block drivers can override it if
necessary and can use bdrv_is_read_only() in .bdrv_open().

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Kevin Wolf
2b5728164f block: Fix bdrv_open use after free
tmp_filename was used outside the block it was defined in, i.e. after it went
out of scope. Move its declaration to the top level.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Kevin Wolf
3574c60819 block: Remove dead code
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Luiz Capitulino
f795e743bd Drop qemu-objects.h from modules that don't require it
Previous commits dropped most qobjects usage from qemu modules
(now they are a low level interface used by the QAPI). However,
some modules still include the qemu-objects.h header file.

This commit drops qemu-objects.h from some of those modules
and includes qjson.h instead, which is what they actually need.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27 11:48:47 -02:00
Luiz Capitulino
f11f57e405 qapi: Convert query-blockstats
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27 11:48:47 -02:00
Luiz Capitulino
b202381800 qapi: Convert query-block
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27 11:48:47 -02:00
Luiz Capitulino
58e21ef5ab block: Rename the BlockIOStatus enum values
The biggest change is to rename its prefix from BDRV_IOS to
BLOCK_DEVICE_IO_STATUS.

Next commit will convert the query-block command to the QAPI
and that's how the enumeration is going to be generated.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27 11:48:47 -02:00
Luiz Capitulino
d6bf279e7a block: iostatus: Drop BDRV_IOS_INVAL
A future commit will convert bdrv_info() to the QAPI and it won't
provide IOS_INVAL.

Luckily all we have to do is to add a new 'iostatus_enabled'
member to BlockDriverState and use it instead.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-10-27 11:48:47 -02:00
Paolo Bonzini
6db39ae2e2 block: change discard to co_discard
Since coroutine operation is now mandatory, convert both bdrv_discard
implementations to coroutines.  For qcow2, this means taking the lock
around the operation.  raw-posix remains synchronous.

The bdrv_discard callback is then unused and can be eliminated.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
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
Paolo Bonzini
4265d620c5 block: add bdrv_co_discard and bdrv_aio_discard support
This similarly adds support for coroutine and asynchronous discard.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:13 +02:00
Paolo Bonzini
07f0761574 block: unify flush implementations
Add coroutine support for flush and apply the same emulation that
we already do for read/write.  bdrv_aio_flush is simplified to always
go through a coroutine.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:13 +02:00
Paolo Bonzini
35246a6825 block: rename bdrv_co_rw_bh
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:12 +02:00
Stefan Hajnoczi
09f085d59d block: drop bdrv_has_async_rw()
Commit cd74d83345e0e3b708330ab8c4cd9111bb82cda6 ("block: switch
bdrv_read()/bdrv_write() to coroutines") removed the bdrv_has_async_rw()
callers.  This patch removes bdrv_has_async_rw() since it is no longer
used.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-14 17:31:22 +02:00
Stefan Hajnoczi
f8c35c1d59 block: drop .bdrv_read()/.bdrv_write() emulation
There is no need to emulate .bdrv_read()/.bdrv_write() since these
interfaces are only called if aio and coroutine interfaces are not
present.  All valid BlockDrivers must implement either sync, aio, or
coroutine interfaces.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-14 17:31:22 +02:00
Stefan Hajnoczi
8c5873d697 block: drop emulation functions that use coroutines
Block drivers that implement coroutine functions used to get sync and
aio wrappers.  This is no longer necessary since all request processing
now happens in a coroutine.  If a block driver implements the coroutine
interface then none of the other interfaces will be invoked.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-14 17:31:22 +02:00
Stefan Hajnoczi
1a6e115b19 block: switch bdrv_aio_writev() to coroutines
More sync, aio, and coroutine unification.  Make bdrv_aio_writev() go
through coroutine request processing.

Remove the dirty block callback mechanism which was needed only for aio
processing and can be done more naturally in coroutine context.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:54 +02:00
Stefan Hajnoczi
6b7cb2479b block: mark blocks dirty on coroutine write completion
The aio write operation marks blocks dirty when the write operation
completes.  The coroutine write operation marks blocks dirty before
issuing the write operation.

It seems safest to mark the block dirty when the operation completes so
that anything tracking dirty blocks will not act before the change has
been made to the image file.

Make the coroutine write operation dirty blocks on write completion.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:54 +02:00
Stefan Hajnoczi
b2a6137166 block: switch bdrv_aio_readv() to coroutines
More sync, aio, and coroutine unification.  Make bdrv_aio_readv() go
through coroutine request processing.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:54 +02:00
Stefan Hajnoczi
1c9805a398 block: switch bdrv_read()/bdrv_write() to coroutines
The bdrv_read()/bdrv_write() functions call .bdrv_read()/.bdrv_write().
They should go through bdrv_co_do_readv() and bdrv_co_do_writev()
instead in order to unify request processing code across sync, aio, and
coroutine interfaces.  This is also an important step towards removing
BlockDriverState .bdrv_read()/.bdrv_write() in the future.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:53 +02:00
Stefan Hajnoczi
c5fbe57111 block: split out bdrv_co_do_readv() and bdrv_co_do_writev()
The public interface for I/O in coroutine context is bdrv_co_readv() and
bdrv_co_writev().  Split out the request processing code into
bdrv_co_do_readv() and bdrv_co_writev() so that it can be called
internally when we refactor all request processing to use coroutines.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:53 +02:00
Stefan Hajnoczi
1ed20acf2f block: directly invoke .bdrv_* from emulation functions
The emulation functions which supply default BlockDriver .bdrv_*()
functions given another implemented .bdrv_*() function should not use
public bdrv_*() interfaces.  This patch ensures they invoke .bdrv_*()
directly to avoid adding an extra layer of coroutine request processing
and possibly entering an infinite loop.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:53 +02:00
Stefan Hajnoczi
a652d16025 block: directly invoke .bdrv_aio_*() in bdrv_co_io_em()
We will unify block layer request processing across sync, aio, and
coroutines and this means a .bdrv_co_*() emulation function should not
call back into the public interface.  There's no need here, just call
.bdrv_aio_*() directly.

The gory details: bdrv_co_io_em() cannot call back into the public
bdrv_aio_*() interface since that will be handled using coroutines,
which causes us to call into bdrv_co_io_em() again in an infinite loop
:).

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-13 15:02:27 +02:00
Luiz Capitulino
d2078cc238 HMP: Print 'io-status' information
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-11 09:42:45 +02:00
Luiz Capitulino
f04ef60100 QMP: query-status: Add 'io-status' key
Contains the I/O status for the given device. The key is only present
if the device supports it and the VM is configured to stop on errors.

Please, check the documentation being added in this commit for more
information.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-11 09:42:45 +02:00
Luiz Capitulino
28a7282a5d block: Keep track of devices' I/O status
This commit adds support to the BlockDriverState type to keep track
of devices' I/O status.

There are three possible status: BDRV_IOS_OK (no error), BDRV_IOS_ENOSPC
(no space error) and BDRV_IOS_FAILED (any other error). The distinction
between no space and other errors is important because a management
application may want to watch for no space in order to extend the
space assigned to the VM and put it to run again.

Qemu devices supporting the I/O status feature have to enable it
explicitly by calling bdrv_iostatus_enable() _and_ have to be
configured to stop the VM on errors (ie. werror=stop|enospc or
rerror=stop).

In case of multiple errors being triggered in sequence only the first
one is stored. The I/O status is always reset to BDRV_IOS_OK when the
'cont' command is issued.

Next commits will add support to some devices and extend the
query-block/info block commands to return the I/O status information.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-11 09:41:47 +02:00
Stefan Hajnoczi
59370aaa56 trace: add arguments to bdrv_co_io_em() trace event
It is useful to know the BlockDriverState as well as the
sector_num/nb_sectors of an emulated .bdrv_co_*() request.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-03 10:56:27 +01:00
Stefan Hajnoczi
28dcee10c5 trace: trace bdrv_open_common()
bdrv_open_common() is a useful point to trace since it reveals the
filename and block driver for a given BlockDriverState.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-03 10:55:50 +01:00
Markus Armbruster
7d4b4ba5c2 block: New change_media_cb() parameter load
To let device models distinguish between eject and load.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:22 +02:00
Markus Armbruster
29e05f2022 block: Reset buffer alignment on detach
BlockDriverState member buffer_alignment is initially 512.  The device
model may set them, with bdrv_set_buffer_alignment().  If the device
model gets detached (hot unplug), the device's alignment is left
behind.  Only okay because device hot unplug automatically destroys
the BlockDriverState.  But that's a questionable feature, best not to
rely on it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:22 +02:00
Markus Armbruster
7b6f9300d5 block: New bdrv_set_buffer_alignment()
Device models should be able to set it without an unclean include of
block_int.h.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:22 +02:00
Markus Armbruster
e4def80b36 block: Show whether the virtual tray is open in info block
Need to ask the device, so this requires new BlockDevOps member
is_tray_open().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:21 +02:00
Markus Armbruster
9e6a4c9177 block: Drop BlockDriverState member removable
It's a confused mess (see previous commit).  No users remain.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:21 +02:00
Markus Armbruster
2c6942fa7b block: Clean up remaining users of "removable"
BlockDriverState member removable is a confused mess.  It is true when
an ide-cd, scsi-cd or floppy qdev is attached, or when the
BlockDriverState was created with -drive if={floppy,sd} or -drive
if={ide,scsi,xen,none},media=cdrom ("created removable"), except when
an ide-hd, scsi-hd, scsi-generic or virtio-blk qdev is attached.

Three users remain:

1. eject_device(), via bdrv_is_removable() uses it to determine
   whether a block device can eject media.

2. bdrv_info() is monitor command "info block".  QMP documentation
   says "true if the device is removable, false otherwise".  From the
   monitor user's point of view, the only sensible interpretation of
   "is removable" is "can eject media with monitor commands eject and
   change".

A block device can eject media unless a device is attached that
doesn't support it.  Switch the two users over to new
bdrv_dev_has_removable_media() that returns exactly that.

3. bdrv_getlength() uses to suppress its length cache when media can
   change (see commit 46a4e4e6).  Media change is either monitor
   command change (updates the length cache), monitor command eject
   (doesn't update the length cache, easily fixable), or physical
   media change (invalidates length cache, not so easily fixable).

I'm refraining from improving anything here, because this series is
long enough already.  Instead, I simply switch it over to
bdrv_dev_has_removable_media() as well.

This changes the behavior of the length cache and of monitor commands
eject and change in two cases:

a. drive not created removable, no device attached

   The commit makes the drive removable, and defeats the length cache.

   Example: -drive if=none

b. drive created removable, but the attached drive is non-removable,
   and doesn't call bdrv_set_removable(..., 0) (most devices don't)

   The commit makes the drive non-removable, and enables the length
   cache.

   Example: -drive if=xen,media=cdrom -M xenpv

   The other non-removable devices that don't call
   bdrv_set_removable() can't currently use a drive created removable,
   either because they aren't qdevified, or because they lack a drive
   property.  Won't stay that way.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:21 +02:00
Markus Armbruster
025e849a50 block: Rename bdrv_set_locked() to bdrv_lock_medium()
While there, make the locked parameter bool.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:20 +02:00
Markus Armbruster
f107639a6f block: Drop medium lock tracking, ask device models instead
Requires new BlockDevOps member is_medium_locked().  Implement for IDE
and SCSI CD-ROMs.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:20 +02:00
Markus Armbruster
fdec4404dd block: Leave enforcing tray lock to device models
The device model knows best when to accept the guest's eject command.
No need to detour through the block layer.

bdrv_eject() can't fail anymore.  Make it void.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:20 +02:00
Markus Armbruster
22cf56c4d8 block: Drop tray status tracking, no longer used
Commit 4be9762a is now completely redone.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:20 +02:00
Markus Armbruster
a1aff5bf67 block: Revert entanglement of bdrv_is_inserted() with tray status
Commit 4be9762a changed bdrv_is_inserted() to fail when the tray is
open.  Unfortunately, there are two different kinds of users, with
conflicting needs.

1. Device models using bdrv_eject(), currently ide-cd and scsi-cd.
They expect bdrv_is_inserted() to reflect the tray status.  Commit
4be9762a makes them happy.

2. Code that wants to know whether a BlockDriverState has media, such
as find_image_format(), bdrv_flush_all().  Commit 4be9762a makes them
unhappy.  In particular, it breaks flush on VM stop for media ejected
by the guest.

Revert the change to bdrv_is_inserted().  Check the tray status in the
device models instead.

Note on IDE: Since only ATAPI devices have a tray, and they don't
accept ATA commands since the recent commit "ide: Reject ATA commands
specific to drive kinds", checking in atapi.c suffices.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:20 +02:00
Markus Armbruster
07b70bfbb3 savevm: Include writable devices with removable media
savevm and loadvm silently ignore block devices with removable media,
such as floppies and SD cards.  Rolling back a VM to a previous
checkpoint will *not* roll back writes to block devices with removable
media.

Moreover, bdrv_is_removable() is a confused mess, and wrong in at
least one case: it considers "-drive if=xen,media=cdrom -M xenpv"
removable.  It'll be cleaned up later in this series.

Read-only block devices are also ignored, but that's okay.

Fix by ignoring only read-only block devices and empty block devices.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:24:07 +02:00
Markus Armbruster
c602a489f9 block: Clean up bdrv_flush_all()
Change (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)) to just
bdrv_is_inserted().  Rationale:

    The value of bdrv_is_removable(bs) matters only when
    bdrv_is_inserted(bs) is false.

    bdrv_is_inserted(bs) is true when bs is open (bs->drv != NULL) and
    not an empty host drive (CD-ROM or floppy).

    Therefore, bdrv_is_removable(bs) matters only when:

    1. bs is not open
       old: may call bdrv_flush(bs), which does nothing
       new: won't call

    2. bs is an empty host drive
       old: may call bdrv_flush(bs), which calls driver method
            raw_flush(), which calls fdatasync() or equivalent, which
            can't do anything useful while the drive is empty
       new: won't call

Result is bs->drv && !bdrv_is_read_only(bs) && bdrv_is_inserted(bs).
bdrv_is_inserted(bs) implies bs->drv.  Drop the redundant test.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:24:07 +02:00
Markus Armbruster
8e49ca4624 block: Leave tracking media change to device models
hw/fdc.c is the only one that cares.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:24:06 +02:00
Markus Armbruster
145feb176f block: Split change_cb() into change_media_cb(), resize_cb()
Multiplexing callbacks complicates matters needlessly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:23:51 +02:00
Markus Armbruster
0e49de5232 block: Generalize change_cb() to BlockDevOps
So we can more easily add device model callbacks.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06 11:23:51 +02:00