This patch converts all block layer close calls, that correspond
to qemu_open calls, to qemu_close.
Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch converts all block layer open calls to qemu_open.
Note that this adds the O_CLOEXEC flag to the changed open paths
when the O_CLOEXEC macro is defined.
Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* kwolf/for-anthony:
qemu-iotests: skip 039 with ./check -nocache
block: add BLOCK_O_CHECK for qemu-img check
qcow2: mark image clean after repair succeeds
qed: mark image clean after repair succeeds
blockdev: flip default cache mode from writethrough to writeback
virtio-blk: disable write cache if not negotiated
virtio-blk: support VIRTIO_BLK_F_CONFIG_WCE
qemu-iotests: Save some sed processes
ahci: Fix sglist memleak in ahci_dma_rw_buf()
ahci: Fix ahci cdrom read corruptions for reads > 128k
virtio-blk: fix use-after-free while handling scsi commands
* bonzini/scsi-next:
scsi-disk: add support for the UNMAP command
scsi-disk: improve out-of-range LBA detection for WRITE SAME
scsi-disk: more assertions and resets for aiocb
virtio-scsi: do not compare 32-bit QEMU tags against 64-bit virtio-scsi tags
iscsi: Pick default initiator-name based on the name of the VM
iscsi: reorganize code for parse_initiator_name
iscsi: do not leak initiator_name
Image formats with a dirty bit, like qed and qcow2, repair dirty image
files upon open with BDRV_O_RDWR. Performing automatic repair when
qemu-img check runs is not ideal because the bdrv_open() call repairs
the image before the actual bdrv_check() call from qemu-img.c.
Fix this "double repair" since it leads to confusing output from
qemu-img check. Tell the block driver that this image is being opened
just for bdrv_check(). This skips automatic repair and qemu-img.c can
invoke it manually with bdrv_check().
Update the golden output for qemu-iotests 039 to reflect the new
qemu-img check output.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The dirty bit is cleared after image repair succeeds in qcow2_open().
Move this into qcow2_check() so that all callers benefit from this
behavior when fix mode is enabled.
This is necessary so qemu-img check can call .bdrv_check() and mark the
image clean.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The dirty bit is cleared after image repair succeeds in qed_open().
Move this into qed_check() so that all callers benefit from this
behavior when fix=true.
This is necessary so qemu-img check can call .bdrv_check() and mark the
image clean.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch updates the iscsi layer to automatically pick a 'unique'
initiator-name based on the name of the vm in case the user has not set
an explicit iqn-name to use.
Create a new function qemu_get_vm_name() that returns the name of the VM,
if specified.
This way we can thus create default names to use as the initiator name
based on the guest session.
If the VM is not named via the '-name' command line argument, the iscsi
initiator-name used wiull simply be
iqn.2008-11.org.linux-kvm
If a name for the VM was specified with the '-name' option, iscsi will
use a default initiatorname of
iqn.2008-11.org.linux-kvm:<name>
These names are just the default iscsi initiator name that qemu will
generate/use only when the user has not set an explicit initiator name
via the commandlines or config files.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
The argument of iscsi_create_context is never freed by libiscsi,
which in fact calls strdup on it. Avoid a leak.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Lazy refcounts is a performance optimization for qcow2 that postpones
refcount metadata updates and instead marks the image dirty. In the
case of crash or power failure the image will be left in a dirty state
and repaired next time it is opened.
Reducing metadata I/O is important for cache=writethrough and
cache=directsync because these modes guarantee that data is on disk
after each write (hence we cannot take advantage of caching updates in
RAM). Refcount metadata is not needed for guest->file block address
translation and therefore does not need to be on-disk at the time of
write completion - this is the motivation behind the lazy refcount
optimization.
The lazy refcount optimization must be enabled at image creation time:
qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=on a.qcow2 10G
qemu-system-x86_64 -drive if=virtio,file=a.qcow2,cache=writethrough
Update qemu-iotests 031 and 036 since the extension header size changes
when we add feature bit table entries.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch adds an incompatible feature bit to mark images that have not
been closed cleanly. When a dirty image file is opened a consistency
check and repair is performed.
Update qemu-iotests 031 and 036 since the extension header size changes
when we add feature bit table entries.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
vvfat creates a virtual VFAT filesystem with a certain logical
geometry that depends on its options. It sets the "geometry hint" to
this geometry. It is the only block driver to do this.
The geometry hint is about about *physical* geometry, and used only by
certain hard disk device models.
vvfat's hint is normally invisible for device models, because
bdrv_open() puts a raw format on top of vvfat's fat protocol. That
raw format is where drive_init() puts the user's geometry (if any),
and where the device model gets it from.
Nobody complained, because the default physical geometry is the same
as vvfat's logical geometry:
opts LCHS def. PCHS
1024,16,63 same
:32: 1024,16,63 same
:16: 1024,16,63 same
:12: 64,16,63 same
Except when you specify :floppy:
opts LCHS def. PCHS
:floppy: 80, 2,36 5,16,63
:32:floppy: 80, 2,36 5,16,63
:16:floppy: 80, 2,36 5,16,63
:12:floppy: 80, 2,18 2,16,63
Silly thing to do for use with a hard disk.
However, the "raw" format can be suppressed by adding an
redundant-looking "format=vvfat" to "file=fat:FOO". Then, vvfat's
hint clobbers the user's geometry, i.e. -drive options cyls, heads,
secs get silently ignored. Don't do that.
No change without format=vvfat. With it, the user's hard disk
geometry (-drive options cyls, heads, secs) is now obeyed, and the
default hard disk geometry with :floppy: now matches the one without
format=vvfat.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Unless parameter ":floppy:" is given, vvfat creates a virtual image
with DOS MBR defining a single partition which holds the FAT file
system. The size of the virtual image depends on the width of the
FAT: 32 MiB (CHS 64, 16, 63) for 12 bit FAT, 504 MiB (CHS 1024, 16,
63) for 16 and 32 bit FAT, leaving (64*16-1)*63 = 64449 and
(1024*16-1)*64 = 1032129 sectors for the partition.
However, it screws up the end of the partition in the MBR:
FAT width param. start CHS end CHS start LBA size
:32: 0,1,1 1023,14,63 63 1032065
:16: 0,1,1 1023,14,55 63 1032057
:12: 0,1,1 63,14,55 63 64377
The actual FAT file system nevertheless assumes the partition has
1032129 or 64449 sectors. Oops.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Only buffers that map to unallocated blocks need to be zeroed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* 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>
* kwolf/for-anthony: (24 commits)
block: Factor bdrv_read_unthrottled() out of guess_disk_lchs()
qtest: Tidy up temporary files properly
fdc: Drop broken code for user-defined floppy geometry
fdc_test: introduce test_sense_interrupt
fdc_test: update media_change test
fdc: fix interrupt handling
fdc: rewrite seek and DSKCHG bit handling
block: introduce bdrv_swap, implement bdrv_append on top of it
block: copy over job and dirty bitmap fields in bdrv_append
raw: hook into blkdebug
blkdebug: optionally tie errors to a specific sector
blkdebug: store list of active rules
blkdebug: pass getlength to underlying file
blkdebug: tiny cleanup
blkdebug: remove sync i/o events
sheepdog: traverse pending_list from the first for each time
sheepdog: split outstanding list into inflight and pending
sheepdog: make sure we don't free aiocb before sending all requests
sheepdog: use coroutine based socket functions in coroutine context
sheepdog: restart I/O when socket becomes ready in do_co_req()
...
This makes blkdebug scripts more powerful, and independent of the
exact sequence of operations performed by streaming.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This prepares for the next patch, where some active rules may actually
not trigger depending on input to readv/writev. Store the active rules
in a SIMPLEQ (so that it can be emptied easily with QSIMPLEQ_INIT), and
fetch the errno/once/immediately arguments from there.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is required when using blkdebug with raw format. Unlike qcow2/QED,
raw asks blkdebug for the length of the file, it doesn't get it from
a header.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These are unused, except (by mistake more or less) in QED.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The pending list can be modified in other coroutine context
sd_co_rw_vector, so we need to traverse the list from the first again
after we send the pending request.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
outstanding_list_head is used for both pending and inflight requests.
This patch splits it and improves readability.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch increments the pending counter before sending requests, and
make sures that aiocb is not freed while sending them.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This removes blocking network I/Os in coroutine context.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Currently, no one reenters the yielded coroutine. This fixes it.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This fixes warnings about dprintf format in debug mode.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When qcow2_alloc_clusters() error handling code was introduced in commit
5d757b563d, the value of free_byte_offset
was clobbered in the error case. This patch keeps free_byte_offset at 0
so we will try to allocate clusters again next time this function is
called.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The DEBUG_ALLOC qcow2.h macro enables additional consistency checks
throughout the code. This makes it easier to spot corruptions that are
introduced during development. Since consistency check is an expensive
operation the DEBUG_ALLOC macro is used to compile checks out in normal
builds and qcow2_check_refcounts() calls missed the addition of a new
function argument.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the device we open is a SMC or SSC device, then force the use of sg. We
dont have any medium changer or tape emulation so only passthrough via
real sg or scsi-generic via iscsi would work anyway.
Forcing sg also makes qemu skip trying to read from the device to guess
the image format by reading from the device (find_image_format()).
SMC devices do not implement READ6/10/12/16 so it is not possible to
read from them (SSC have different CDBs).
With this patch I can successfully manage a SMC device wiht iscsi in
passthrough mode.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
[Added TYPE_TAPE handling - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Update iscsi to allow passthrough of SG_IO scsi commands when the iscsi
device is forced to be scsi-generic.
Implement both bdrv_ioctl() and bdrv_aio_ioctl() in the iscsi backend,
emulate the SG_IO ioctl and pass the SCSI commands across to the
iscsi target.
This allows end-to-end passthrough of SCSI all the way from the guest,
to qemu, via scsi-generic, then libiscsi all the way to the iscsi target.
To activate this you need to specify that the iscsi lun should be treated
as a scsi-generic device.
Example:
-device lsi -device scsi-generic,drive=MyISCSI \
-drive file=iscsi://10.1.1.125/iqn.ronnie.test/1,if=none,id=MyISCSI
Note, you can currently not boot a qemu guest from a scsi device.
Note,
This only works when the host is linux, since the emulation relies on
definitions of SG_IO from the scsi-generic implementation in the
linux kernel.
It should be fairly easy to re-implement some structures similar enough
for non-linux hosts to do the same style of passthrough via a fake
scsi generic layer and libiscsi if need be.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the declaration of s into the #ifdef sections that actually make
use of it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The autoclear feature bits can be used for qcow2 file format features
that are safe to "drop" by old programs that do not understand the
feature. Upon opening the image file unknown autoclear feature bits are
cleared and the image file header is rewritten, but this was happening
too early in the code when critical header fields were not yet loaded.
Process autoclear feature bits after all necessary header information
has been loaded.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
avail_sectors should really be the number of sectors from the start of
the allocation, not from the start of the write request.
We're lucky enough that this mistake didn't cause any real bug.
avail_sectors is only used in the intialiser of QCowL2Meta:
.nb_available = MIN(requested_sectors, avail_sectors),
m->nb_available in turn is only used for COW at the end of the
allocation. A COW occurs only if the request wasn't cluster aligned,
which in turn would imply that requested_sectors was less than
avail_sectors (both in the original and in the fixed version). In this
case avail_sectors is ignored and therefore the mistake doesn't cause
any misbehaviour.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
copy_sectors() always uses the sum (cluster_offset + n_start) or
(start_sect + n_start), so if some value is added to both cluster_offset
and start_sect, and subtracted from n_start, it's cancelled out anyway.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Writethrough does not need special-casing anymore in the qcow2 caches.
The block layer adds flushes after every guest-initiated data write,
and these will also flush the qcow2 caches to the OS.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Writeback caching was added in Ceph 0.46, and writethrough will be in
0.47. These are controlled by general config options, so there's no
need to check for librbd version.
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When any inconsistencies have been fixed, print the statistics and run
another check to make sure everything is correct now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
is_allocated_base has complex semantics that are not really usable
outside streaming. Split the check in two parts, where the allocated
state for the top bs is moved to the caller. The resulting function
is more generally useful.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Either FIEMAP, or SEEK_DATA+SEEK_HOLE can be used to implement the
is_allocated callback for raw files. On Linux ext4, btrfs and XFS
all support it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.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>
Commit 3948d1d4 removed the pointer argument we filled in with l2_offset
but forgot to remove the unnecessary l2_offset assignment.
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>
Some gcc versions seem not to be able to figure out that the switch
statement covers all possible values and that c is therefore always
initialised. Add a default branch for them.
Reported-by: malc <av1474@comtv.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: malc <av1474@comtv.ru>
The same as for non-coroutine versions in previous
patches: rename arguments to be more obvious, change
type of arguments from int to size_t where appropriate,
and use common code for send and receive paths (with
one extra argument) since these are exactly the same.
Use common iov_send_recv() directly.
qemu_co_sendv(), qemu_co_recvv(), and qemu_co_recv()
are now trivial #define's merely adding one extra arg.
qemu_co_sendv() and qemu_co_recvv() callers are
converted to different argument order and extra
`iov_cnt' argument.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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>
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>
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>
This patch combines two functions into one, and replaces
the implementation with already existing iov_memset() from
iov.c.
The new prototype of qemu_iovec_memset():
size_t qemu_iovec_memset(qiov, size_t offset, int fillc, size_t bytes)
It is different from former qemu_iovec_memset_skip(), and
I want to make other functions to be consistent with it
too: first how much to skip, second what, and 3rd how many
of it. It also returns actual number of bytes filled in,
which may be less than the requested `bytes' if qiov is
smaller than offset+bytes, in the same way iov_memset()
does.
While at it, use utility function iov_memset() from
iov.h in posix-aio-compat.c, where qiov was used.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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
Signed-off-by: Jim Meyering <meyering@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_save_vmstate and bdrv_load_vmstate should return the vmstate size
on success, and -errno on error.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* kwolf/for-anthony:
fdc-test: introduced qtest no_media_on_start and cmos qtest for floppy
fdc: fix media detection
fdc: floppy drive should be visible after start without media
qemu-iotests: mark 035 qcow2-only
qcow2: Check qcow2_alloc_clusters_at() return value
sheepdog: use heap instead of stack for BDRVSheepdogState
sheepdog: return -errno on error
sheepdog: mark image as snapshot when tag is specified
qemu-img: Explain how rebase operation can be used to perform a 'diff' operation.
qcow2: don't leak buffer for unexpected qcow_version in header
This allows using LUNs bigger than 2TB. Keep using READ10 for other
device types such as MMC.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
This is needed to avoid READ CAPACITY(16) for MMC devices.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Call qemu_notify_event() after updating events. Otherwise, If we add
an event for -is-writeable but the socket is already writeable there
may be a delay before the event callback is actually triggered.
Those delays would in particular hurt performance during BIOS boot and
when the GRUB bootloader reads the kernel and initrd.
But first call out to the socket write functions directly, and only set up
the write event if the socket is full. This will happen very rarely and
this improves performance.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
When using qcow2_alloc_clusters_at(), the cluster allocation code
checked the wrong variable for an error code.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_create() is called in coroutine context now, so we cannot use
more stack than 1 MB in the function if we use ucontext coroutine.
This patch allocates BDRVSheepdogState, whose size is 4 MB, on the
heap in sd_create().
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
On error, BlockDriver APIs should return -errno instead of -1.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When a snapshot tag is specified in the filename, the opened image is
a snapshot.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Unallocated sectors should really never be accessed by the guest,
so there's no need to copy them during the streaming process.
If they are read by the guest during streaming, guest-initiated
copy-on-read will copy them (we're in the base == NULL case, which
enables copy on read). If they are read after we disconnect the
image from the base, they will read as zeroes anyway.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This fixes inability to make progress in streaming if the quota is set
to less than the amount of data that an I/O operation has to write.
In this case, limit->dispatched + n will always be above the quota and,
due to the "goto retry" to recheck cancellation and allocation, streaming
will livelock.
This can be reproduced with "block_job_set_speed ide0-hd0 1b". Of course,
with this patch the requested limit will not be obeyed. That could be
done with another patch that caps is_allocated's n argument by the slice
quota.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When an image is modified to point to the new backing file, the backing
file format is set to NULL, which means auto-probe. This is wrong, in
fact it is a small security problem.
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
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>
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>
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>
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>
* kwolf/for-anthony:
fdc: simplify media change handling
qcow2: lock on prealloc
block: make bdrv_create adopt coroutine
qcow2: Limit COW to where it's needed
sheepdog: switch to writethrough mode if cluster doesn't support flush
preallocate() will be locked. This is required because
qcow2_alloc_cluster_link_l2() assumes that it runs under a lock that it
can drop while COW is being performed.
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This fixes a regression introduced in commit 250196f1. The bug leads to
data corruption, found during an Autotest run with a Fedora 8 guest.
Consider a write request whose first part is covered by an already
allocated cluster, but additional clusters need to be newly allocated.
When counting the number of clusters to allocate, the qcow2 code would
decide to do COW for all remaining clusters of the write request, even
if some of them are already allocated.
If during this COW operation another write request is issued that touches
the same cluster, it will still refer to the old cluster. When the COW
completes, the first request will update the L2 table and the second
write request will be lost. Note that the requests need not overlap, it's
enough for them to touch the same cluster.
This patch ensures that only clusters that really require COW are
considered for allocation. In this case any other request writing to the
same cluster will be an allocating write and gets serialised.
Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is necessary for qemu to work with the older version of Sheepdog
which doesn't support SD_OP_FLUSH_VDI.
Signed-off-by: MORITA Kazutaka <morita.kazutaka@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Update the configure test for libiscsi support to detect version 1.3
or later. Version 1.3 of libiscsi provides both READCAPACITY16 as well
as UNMAP commands.
Update the iscsi block layer to use READCAPACITY16 to detect the size of
the LUN instead of READCAPACITY10. This allows support for LUNs larger
than 2TB.
Update to implement bdrv_aio_discard() using the UNMAP command.
This allows us to use thin-provisioned LUNs from TGTD and other iSCSI
targets that support thin-provisioning.
Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
[squashed in subsequent patch from Ronnie to fix off-by-one in LBA count]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Change the write flag to an operation type in RBDAIOCB, and make the
buffer optional since discard doesn't use it.
Discard is first included in librbd 0.1.2 (which is in Ceph 0.46).
If librbd is too old, leave out qemu_rbd_aio_discard entirely,
so the old behavior is preserved.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.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>
If cache references are held while the coroutine has yielded, the cache
may get used up and abort() when it can't find a free entry.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Use __APPLE__ and __MACH__ macros instead of CONFIG_COCOA to detect Mac
OS X host. The patch is based on Ben Leslie's patch:
http://patchwork.ozlabs.org/patch/97859/
Signed-off-by: Ben Leslie <benno@benno.id.au>
Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Andreas Färber <andreas.faerber@web.de>
* qmp/queue/qmp:
qapi: fix qmp_balloon() conversion
qemu-iotests: add block-stream speed value test case
block: add 'speed' optional parameter to block-stream
block: change block-job-set-speed argument from 'value' to 'speed'
block: use Error mechanism instead of -errno for block_job_set_speed()
block: use Error mechanism instead of -errno for block_job_create()
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>
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>
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>
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>
s->sock is assigned only afterwards, so we're really registering an
aio_fd_handler for file descriptor 0 here. Not exactly what we intended.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* kwolf/for-anthony: (38 commits)
qemu-iotests: Fix test 031 for qcow2 v3 support
qemu-iotests: Add -o and make v3 the default for qcow2
qcow2: Zero write support
qemu-iotests: Test backing file COW with zero clusters
qemu-iotests: add a simple test for write_zeroes
qcow2: Support for feature table header extension
qcow2: Support reading zero clusters
qcow2: Version 3 images
qcow2: Ignore reserved bits in check_refcounts
qcow2: Ignore reserved bits in refcount table entries
qcow2: Simplify count_cow_clusters
qcow2: Refactor qcow2_free_any_clusters
qcow2: Ignore reserved bits in L1/L2 entries
qcow2: Fail write_compressed when overwriting data
qcow2: Ignore reserved bits in count_contiguous_clusters()
qcow2: Ignore reserved bits in get_cluster_offset
qcow2: Save disk size in snapshot header
Specification for qcow2 version 3
qcow2: Fix refcount block allocation during qcow2_alloc_cluster_at()
iotests: Resolve test failures caused by hostname
...
Instead of printing an ugly bitmask, qemu can now print a more helpful
string even for yet unknown features.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds the basic infrastructure to qcow2 to handle version 3 images.
It includes code to create v3 images, allow header updates for v3 images
and checks feature bits.
It still misses support for zero clusters, so this is not a fully
compliant implementation of v3 yet.
The default for creating new images stays at v2 for now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Also don't infer the cluster type directly from the L2 entries, but use
qcow2_get_cluster_type() to keep everything in a single place.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
count_cow_clusters() tries to reuse existing functions, and all it
achieves is to make things much more complicated than they really are:
Everything needs COW, unless it's a normal cluster with refcount 1.
This patch implements the obvious way of doing this, and by using
qcow2_get_cluster_type() it gets rid of all flag magic.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Zero clusters will add another cluster type. Refactor the open-coded
cluster type detection into a switch of QCOW2_CLUSTER_* options so that
the detection is in a single place. This makes it easier to add new
cluster types.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This changes the still existing places that assume that the only flags
are QCOW_OFLAG_COPIED and QCOW_OFLAG_COMPRESSED to properly mask out
reserved bits.
It does not convert bdrv_check yet.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
qcow2_alloc_compressed_cluster_offset() already fails if the copied flag
is set, because qcow2_write_compressed() doesn't perform COW as it would
have to do to allow this.
However, what we really want to check here is whether the cluster is
allocated or not. With internal snapshots the copied flag may not be set
on allocated clusters. Check the cluster offset instead.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Until now, count_contiguous_clusters() has an argument that allowed to
specify flags that should be ignored in the comparison, i.e. that are
allowed to change between contiguous clusters.
This patch changes the function so that it ignores all flags by default
now and you need to pass the flags on which it should stop.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
With this change, reading from a qcow2 image ignores all reserved bits
that are set in an L1 or L2 table entry.
Now get_cluster_offset() assigns *cluster_offset only the offset without
any other flags. The cluster type is not longer encoded in the offset,
but a positive return value in case of success.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This allows that different snapshots of an image can have different
sizes, which is a requirement for enabling image resizing even with
images that have internal snapshots.
We don't do the actual support for it now, but make sure that the
additional field is present and not completely ignored in all version 3
images. When trying to load a snapshot of different size, it returns
an error.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Refcount block allocation and refcount table growth rely on
s->free_cluster_index pointing to somewhere after the current
allocation. Change qcow2_alloc_cluster_at() to fulfill this
assumption.
Without this change it could happen that a newly allocated refcount
block and the allocated data block point to the same area in the image
file, causing data corruption in the long run.
This fixes a bug that became first visible after commit 250196f1.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Right now, nbd_wr_sync will hang if no data at all is available on the
socket and the other side is not going to provide any. Relax this by
making it loop only for writes or partial reads. This fixes a race
where one thread is executing qemu_aio_wait() and another is executing
main_loop_wait(). Then, the select() call in main_loop_wait() can return
stale data and call the "readable" callback with no data in the socket.
Reported-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In the next patch we need to look at the return code of nbd_wr_sync.
To avoid percolating the socket_error() ugliness all around, let's
handle errors by returning negative errno values.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Someone forgot something in commit 29c1a730... Documenting the right
return value is not enough, you also need to actually return it in the
code.
This bug sometimes causes error return values even when everything has
succeeded: The new offset of the refcount block is truncated to 32 bits
and interpreted as signed. At least with small cluster sizes it's easy
to get a negative return value this way.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
If do_alloc_cluster_offset() fails, the error handling code tried to
remove the request from the in-flight queue, to which it wasn't added
yet, resulting in a NULL pointer dereference.
m->nb_clusters really only becomes != 0 when the request is in the list.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* kwolf/for-anthony: (46 commits)
qed: remove incoming live migration blocker
qed: honor BDRV_O_INCOMING for incoming live migration
migration: clear BDRV_O_INCOMING flags on end of incoming live migration
qed: add bdrv_invalidate_cache to be called after incoming live migration
blockdev: open images with BDRV_O_INCOMING on incoming live migration
block: add a function to clear incoming live migration flags
block: Add new BDRV_O_INCOMING flag to notice incoming live migration
block stream: close unused files and update ->backing_hd
qemu-iotests: Fix call syntax for qemu-io
qemu-iotests: Fix call syntax for qemu-img
qemu-iotests: Test unknown qcow2 header extensions
qemu-iotests: qcow2.py
sheepdog: fix send req helpers
sheepdog: implement SD_OP_FLUSH_VDI operation
block: bdrv_append() fixes
qed: track dirty flag status
qemu-img: add dirty flag status
qed: image fragmentation statistics
qemu-img: add image fragmentation statistics
block: document job API
...
From original commit with Patchwork-id: 31108 by
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
"The QED image format includes a file header bit to mark images dirty.
QED normally checks dirty images on open and fixes inconsistent
metadata. This is undesirable during live migration since the dirty bit
may be set if the source host is modifying the image file. The check
should be postponed until migration completes.
Skip operations that modify the image file if the BDRV_O_INCOMING flag
is set."
Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The QED image is reopened to flush metadata and check consistency.
Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Close the now unused images that were part of the previous backing file
chain and adjust ->backing_hd, backing_filename and backing_format
properly.
Fixes https://bugzilla.redhat.com/show_bug.cgi?id=801449
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We should return if reading of the header fails.
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Acked-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Flush operation is supposed to flush the write-back cache of
sheepdog cluster.
By issuing flush operation, we can assure the Guest of data
reaching the sheepdog cluster storage.
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
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>
Finally reindent all code and change goto statements to a loop.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reads and writes to the underlying file can also occur with the simple
non-vectored I/O interfaces.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
vdi.c really works as if it implemented bdrv_read and bdrv_write. However,
because only vector I/O is supported by the asynchronous callbacks, it
went through extra pain to bounce-buffer the I/O. This can be handled
by the block layer now that the format is coroutine-based.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Most of the AIOCB really holds local variables that need to persist
across callback invocation. It can go away now.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now inline the former AIO callbacks into vdi_co_readv and vdi_co_writev.
While many cleanups are possible, the code now really looks synchronous.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The next step is to take code that only triggers after the first operation,
and move it at the end of vdi_aio_read_cb and vdi_aio_write_cb.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Even a basic conversion changing the bdrv_aio_readv/bdrv_aio_writev calls
to bdrv_co_readv/bdrv_co_writev, and callbacks to goto statements can
eliminate a lot of code. This is because error handling is simplified
and indirections through bottom halves can go away.
After this patch, I/O to the underlying file already happens via
coroutines, but the code still looks a lot like if asynchronous I/O was
being used.
Acked-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
After validation check, the 'checksum' is not written back
to footer, which leave it with zero.
This results in errors while loadding it under Microsoft's
Hyper-V environment, and also errors from utilities like
Citrix's vhd-util.
Signed-off-by: Zhang Shengju <sean_zhang@trendmicro.com.cn>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Since everything goes through the cache, callers don't use the L2 table
offset any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
The function usleep is not available for all supported platforms:
at least some versions of MinGW don't support it.
usleep was also declared obsolete by POSIX.1-2001.
The function g_usleep is part of glib2.0, so it is available for
all supported platforms.
Using nanosleep would also be possible but needs more code.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
If the first part of a write request is allocated, but the second isn't
and it can be allocated so that the resulting area is contiguous, handle
it at once. This is a common case for sequential writes.
After this patch, alloc_cluster_offset() only checks if the clusters are
already allocated or how many new clusters can be allocated contigouosly.
The actual cluster allocation is split off into a new function
do_alloc_cluster_offset().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This function allows to allocate clusters at a given offset in the image
file. This is useful if you want to allocate the second part of an area
that must be contiguous.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
qemu-img resize has some limitations with qcow2, but the user is only
told that "this image format does not support resize". Quite confusing,
so add some more detailed error_report() calls and change "this image
format" into "this image".
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
The L2 table cache reduces QED metadata reads that would be required
when translating LBAs to offsets into the image file. Since requests
execute in parallel it is possible to share an L2 table between multiple
requests.
There is a potential data corruption issue when an in-use L2 table is
evicted from the cache because the following situation occurs:
1. An allocating write performs an update to L2 table "A".
2. Another request needs L2 table "B" and causes table "A" to be
evicted.
3. A new read request needs L2 table "A" but it is not cached.
As a result the L2 update from #1 can overlap with the L2 fetch from #3.
We must avoid doing overlapping I/O requests here since the worst case
outcome is that the L2 fetch completes before the L2 update and yields
stale data. In that case we would effectively discard the L2 update and
lose data clusters!
Thanks to Benoît Canet <benoit.canet@gmail.com> for extensive testing
and debugging which lead to discovery of this bug.
Reported-by: Benoît Canet <benoit.canet@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Tested-by: Benoît Canet <benoit.canet@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
