Commit Graph

453 Commits

Author SHA1 Message Date
Zhi Yong Wu
23e9a39e7d qed: adjust the way to get nb_sectors
This patch is only to refactor some lines of codes to get better and more robust codes.

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

In other two functions, if qiov use more than one struct iovec, the existing way will get wrong nb_sectors.
To make the code more robust, it will be nicer to refactor the existing way as below.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:51:34 +01:00
Stefan Hajnoczi
aef4acb661 qcow2: avoid reentrant bdrv_read() in copy_sectors()
A BlockDriverState should not issue requests on itself through the
public block layer interface.  Nested, or reentrant, requests are
problematic because they do I/O throttling and request tracking twice.

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

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

This is also a good opportunity to make copy_sectors() a true
coroutine_fn.  That means calling bdrv_co_writev() instead of
bdrv_write().  Behavior is unchanged but we're being explicit that this
executes in coroutine context.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:49:47 +01:00
Kevin Wolf
1b9f1491f8 qcow2: Unlock during COW
Unlocking during COW allows for more parallelism. One change it requires is
that buffers are dynamically allocated instead of just using a per-image
buffer.

While touching the code, drop the synchronous qcow2_read() function and replace
it by a bdrv_read() call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05 14:49:40 +01:00
Kevin Wolf
5bb1cbac4f vpc: Add missing error handling in alloc_block
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-23 17:04:06 +01:00
Kevin Wolf
6ac5f3881f vdi: Fix memory leak
The block map is allocated in vdi_open, but was never freed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:04:05 +01:00
Kevin Wolf
3397f0cb48 vvfat: Add migration blocker
vvfat caches more or less everything when in writable mode. For migration
to work, it would have to be invalidated. Block migration for now when
in writable mode (default is readonly).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:04:05 +01:00
Kevin Wolf
612ff3d887 vpc: Add migration blocker
vpc caches the BAT. For migration to work, it would have to be
invalidated. Block migration for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:04:04 +01:00
Kevin Wolf
2bc3166c22 vmdk: Add migration blocker
VMDK caches L2 tables. For migration to work, they would have to be
invalidated. Block migration for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:04:03 +01:00
Kevin Wolf
fc9d106c8d vdi: Add migration blocker
vdi caches the block map. For migration to work, it would have to be
invalidated. Block migration for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:04:02 +01:00
Kevin Wolf
fd9f102c3e qcow: Add migration blocker
qcow caches L2 tables. For migration to work, they would have to be
invalidated. Block migration for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-23 17:03:59 +01:00
Dong Xu Wang
c3fecea50d sheepdog: Avoid deadlock in error path
s->lock should be unlocked before leaving add_aio_request.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-22 10:33:43 +01:00
Stefan Weil
2923d34fdc Include zlib.h using #include <>
zlib.h is not a local include file, therefore it should be included
using <> instead of "".

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-21 15:05:59 -06:00
Anthony Liguori
1ed520c66e qed: add migration blocker (v2)
Now when you try to migrate with qed, you get:

(qemu) migrate tcp:localhost:1025
Block format 'qed' used by device 'ide0-hd0' does not support feature 'live migration'
(qemu)

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-21 14:58:48 -06:00
Anthony Liguori
06d9260ffa qcow2: implement bdrv_invalidate_cache (v2)
We don't reopen the actual file, but instead invoke the close and open routines.
We specifically ignore the backing file since it's contents are read-only and
therefore immutable.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-21 14:58:48 -06:00
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
Charles Arnold
78439f6af1 block: Fix vpc initialization of the Dynamic Disk Header
The Data Offset field in the Dynamic Disk Header is an 8 byte field.
Although the specification (2006-10-11) gives an example of initializing
only the first 4 bytes, images generated by Microsoft on Windows initialize
all 8 bytes.

Failure to initialize all 8 bytes results in errors from utilities
like Citrix's vhd-util which checks specifically for the proper Data
Offset field initialization.

Signed-off-by: Charles Arnold <carnold@suse.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:58 +01:00
Kevin Wolf
7704df98b0 vvfat: Fix read-write mode
vvfat used to directly call into the qcow2 block driver instead of using the
block.c wrappers. With the coroutine conversion, this stopped working.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2011-11-11 14:02:57 +01:00
Paolo Bonzini
273e4e03b3 vvfat: reorganize computation of disk geometry
First determine FAT12/16/32, then compute geometry from that for both
FDD and HDD.  For 1.44MB floppies, and 2.88MB floppies using FAT16,
change to 1 sector/cluster.  The default remains 2.88MB with FAT12
and 2 sectors/cluster.  Both DOS and mkdosfs by default format a 2.88MB
floppy as FAT12.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 17:32:23 +01:00
Paolo Bonzini
d71cff42e4 vvfat: do not hardcode sector counts in error message
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 16:36:25 +01:00
Paolo Bonzini
5a742b5557 vvfat: unify and correct computation of sector count
The sector count is stored in the partition and hence must not include the
sectors before its start.  At the same time, remove the useless special
casing for 1.44 MB floppies.  This fixes fsck on VVFAT hard disks,
which otherwise tries to seek past the end of the disk.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 16:27:07 +01:00
Paolo Bonzini
aad37c06dd vvfat: need to use first_sectors_number to distinguish fdd/hdd
This is consistent with what "real" floppies have, so file(1)
now actually recognizes the VVFAT image as a 1.44 MB floppy.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 16:23:25 +01:00
Paolo Bonzini
e654bfe4c1 vvfat: do not fail if the disk has spare sectors
If the number of "faked sectors" + the number of sectors that are
part of a cluster does not sum up to the total number of sectors,
qemu-img convert fails.  Read these spare sectors as all zeros.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 15:55:45 +01:00
Paolo Bonzini
2b6a43a835 vvfat: fix out of bounds array_get usage
When reading the address of the first free entry, you cannot
use array_get without first marking all entries as occupied.

This is visible if you change the sectors per cluster on a
floppy from 2 to 1.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 15:42:44 +01:00
Dong Xu Wang
756f51e408 block/cloop: Use g_free instead of free
Fix mismatching allocation and deallocation: g_free should be used to pair with
g_malloc.

Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed_by: Ray Wang <raywang@linux.vnet.ibm.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 14:24:12 +01:00
Dong Xu Wang
5b47b7c3d3 block/cloop: Fix coding style
Fix coding style in block/cloop.c.

Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed_by: Ray Wang <raywang@linux.vnet.ibm.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-04 14:24:08 +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
Anthony Liguori
3a069ff11b Merge remote-tracking branch 'stefanha/trivial-patches' into staging 2011-10-31 10:23:15 -05:00
Dong Xu Wang
c95de7e2c4 block: fix qcow2_co_flush deadlock
If qcow2_cache_flush failed, s->lock will not be unlock.

Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Kevin Wolf
93897b9fd4 vmdk: Fix possible segfaults
Data we read from the disk isn't necessarily null terminated and may not
contain the string we're looking for. The code needs to be a bit more careful
here.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Kevin Wolf
99f1835d9b vmdk: Improve error handling
Return the right error values in some more places.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Kevin Wolf
bac8d7b45d vmdk: Fix use of uninitialised value
In error cases, cid is never set.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Kevin Wolf
64ebe71aa0 qcow: Fix bdrv_write_compressed error handling
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2011-10-28 19:25:49 +02:00
Eric Sunshine
c794b4e0fd Teach block/vdi about "discarded" (no longer allocated) blocks
An entry in the VDI block map will hold an offset to the actual block if
the block is allocated, or one of two specially-interpreted values if
not allocated. Using VirtualBox terminology, value VDI_IMAGE_BLOCK_FREE
(0xffffffff) represents a never-allocated block (semantically arbitrary
content).  VDI_IMAGE_BLOCK_ZERO (0xfffffffe) represents a "discarded"
block (semantically zero-filled).  block/vdi knows only about
VDI_IMAGE_BLOCK_FREE.  Teach it about VDI_IMAGE_BLOCK_ZERO.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Ronnie Sahlberg
c589b24972 iSCSI block driver
This provides built-in support for iSCSI to QEMU.

This has the advantage that the iSCSI devices need not be made visible to the host, which is useful if you have very many virtual machines and very many iscsi devices.
It also has the benefit that non-root users of QEMU can access iSCSI devices across the network without requiring root privilege on the host.

This driver interfaces with the multiplatform posix library for iscsi initiator/client access to iscsi devices hosted at
    git://github.com/sahlberg/libiscsi.git

The patch adds the driver to interface with the iscsi library.
It also updated the configure script to
* by default, probe is libiscsi is available and if so, build
  qemu against libiscsi.
* --enable-libiscsi
  Force a build against libiscsi. If libiscsi is not available
  the build will fail.
* --disable-libiscsi
  Do not link against libiscsi, even if it is available.

When linked with libiscsi, qemu gains support to access iscsi resources such as disks and cdrom directly, without having to make the devices visible to the host.

You can specify devices using a iscsi url of the form :
iscsi://[<username>[:<password>@]]<host>[:<port]/<target-iqn-name>/<lun>
When using authentication, the password can optionally be set with
LIBISCSI_CHAP_PASSWORD="password" to avoid it showing up in the process list

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:48 +02:00
Pavel Borzenkov
512a2cf8e9 qed: remove unneeded variable assignment
'ret' is unconditionally overwitten by qed_read_l1_table_sync()

Spotted by Clang Analyzer

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-26 13:36:35 +01:00
Pavel Borzenkov
feba23b143 qed: don't pass NULL to memcpy
Spotted by Clang Analyzer

[Note this memcpy call has always been safe because the length will be 0
when the pointer is NULL]

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-26 13:36:35 +01:00
Pavel Borzenkov
8379e46d1f vmdk: vmdk_read_cid returns garbage if p_name is NULL
Spotted by Clang Analyzer

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-26 13:36:35 +01:00
Pavel Borzenkov
c18a1c8805 vmdk: remove unneeded variable assignment
Spotted by Clang Analyzer

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-10-26 13:36:35 +01:00
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
e183ef75cc block: take lock around bdrv_write implementations
This does the first part of the conversion to coroutines, by
wrapping bdrv_write implementations to take the mutex.

Drivers that implement bdrv_write rather than bdrv_co_writev can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.

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
2914caa088 block: take lock around bdrv_read implementations
This does the first part of the conversion to coroutines, by
wrapping bdrv_read implementations to take the mutex.

Drivers that implement bdrv_read rather than bdrv_co_readv can
then benefit from asynchronous operation (at least if the underlying
protocol supports it, which is not the case for raw-win32), even
though they still operate with a bounce buffer.

raw-win32 does not need the lock, because it cannot yield.
nbd also doesn't probably, but better be safe.

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
848c66e8f5 block: add a CoMutex to synchronous read drivers
The big conversion of bdrv_read/write to coroutines caused the two
homonymous callbacks in BlockDriver to become reentrant.  It goes
like this:

1) bdrv_read is now called in a coroutine, and calls bdrv_read or
bdrv_pread.

2) the nested bdrv_read goes through the fast path in bdrv_rw_co_entry;

3) in the common case when the protocol is file, bdrv_co_do_readv calls
bdrv_co_readv_em (and from here goes to bdrv_co_io_em), which yields
until the AIO operation is complete;

4) if bdrv_read had been called from a bottom half, the main loop
is free to iterate again: a device model or another bottom half
can then come and call bdrv_read again.

This applies to all four of read/write/flush/discard.  It would also
apply to is_allocated, but it is not used from within coroutines:
besides qemu-img.c and qemu-io.c, which operate synchronously, the
only user is the monitor.  Copy-on-read will introduce a use in the
block layer, and will require converting it.

The solution is "simply" to convert all drivers to coroutines!  We
just need to add a CoMutex that is taken around affected operations.

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
bae0a0cc38 vmdk: clean up open
Move vmdk_parent_open to vmdk_open.  There's another path how
vmdk_parent_open can be reached:

  vmdk_parse_extents() ->  vmdk_open_sparse() ->  vmdk_open_vmdk4() ->
  vmdk_open_desc_file().

If that can happen, however, the code is bogus.  vmdk_parent_open
reads from bs->file:

    if (bdrv_pread(bs->file, s->desc_offset, desc, DESC_SIZE) != DESC_SIZE) {

but it is always called with s->desc_offset == 0 and with the same
bs->file.  So the data that vmdk_parent_open reads comes always from the
same place, and anyway there is only one place where it can write it,
namely bs->backing_file.

So, if it cannot happen, the patched code is okay.

It is also possible that the recursive call can happen, but only once.  In
that case there would still be a bug in vmdk_open_desc_file setting
s->desc_offset = 0, but the patched code is okay.

Finally, in the case where multiple recursive calls can happen the code
would need to be rewritten anyway.  It is likely that this would anyway
involve adding several parameters to vmdk_parent_open, and calling it from
vmdk_open_vmdk4.

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
588b65a37a vmdk: fix return values of vmdk_parent_open
While vmdk_open_desc_file (touched by the patch) correctly changed -1
to -EINVAL, vmdk_open did not.  Fix it directly in vmdk_parent_open.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:13 +02:00
Kevin Wolf
8f1efd00c4 qcow2: Fix bdrv_write_compressed error handling
If during allocation of compressed clusters the cluster was already allocated
uncompressed, fail and properly release the l2_table (the latter avoids a
failed assertion).

While at it, make it return some real error numbers instead of -1.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
2011-10-21 17:34:13 +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
Stefan Hajnoczi
6f6dc6565e block: drop redundant bdrv_flush implementation
Block drivers now only need to provide either of .bdrv_co_flush,
.bdrv_aio_flush() or for legacy drivers .bdrv_flush().  Remove
the redundant .bdrv_flush() implementations.

[Paolo Bonzini: change raw driver to bdrv_co_flush]

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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
d8716b41b9 sheepdog: add coroutine_fn markers
This makes the following patch easier to review.

Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:12 +02:00