Throttle groups consist of members sharing one throttling state
(including bps/iops limits). Round-robin scheduling is used to ensure
fairness. If a group member already has a timer pending then other
groups members do not schedule their own timers. The next group member
will have its turn when the existing timer expires.
A hang may occur when a group member leaves while it had a timer
scheduled. Although the code carefully removes the group member from
the round-robin list, it does not schedule the next member. Therefore
remaining members continue to wait for the removed member's timer to
expire.
This patch schedules the next request if a timer is pending.
Unfortunately the actual bug is a race condition that I've been unable
to capture in a test case.
Sometimes drive2 hangs when drive1 is removed from the throttling group:
$ qemu ... -drive if=none,id=drive1,cache=none,format=qcow2,file=data1.qcow2,iops=100,group=foo \
-device virtio-blk-pci,id=virtio-blk-pci0,drive=drive1 \
-drive if=none,id=drive2,cache=none,format=qcow2,file=data2.qcow2,iops=10,group=foo \
-device virtio-blk-pci,id=virtio-blk-pci1,drive=drive2
(guest-console1)# fio -filename /dev/vda 4k-seq-read.job
(guest-console2)# fio -filename /dev/vdb 4k-seq-read.job
(qmp) {"execute": "block_set_io_throttle", "arguments": {"device": "drive1","bps": 0,"bps_rd": 0,"bps_wr": 0,"iops": 0,"iops_rd": 0,"iops_wr": 0}}
Reported-by: Nini Gu <ngu@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180704145410.794-1-stefanha@redhat.com
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1535914
Cc: Alberto Garcia <berto@igalia.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Adjust each caller of raw_open_common to specify if they are expecting
host and character devices or not. Tighten expectations of file types upon
open in the common code and refuse types that are not expected.
This has two effects:
(1) Character and block devices are now considered deprecated for the
'file' driver, which expects only S_IFREG, and
(2) no file-posix driver (file, host_cdrom, or host_device) can open
directories now.
I don't think there's a legitimate reason to open directories as if
they were files. This prevents QEMU from opening and attempting to probe
a directory inode, which can break in exciting ways. One of those ways
is lseek on ext4/xfs, which will return 0x7fffffffffffffff as the file
size instead of EISDIR. This can coax QEMU into responding with a
confusing "file too big" instead of "Hey, that's not a file".
See: https://bugs.launchpad.net/qemu/+bug/1739304/
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Truncation is the last to convert from open coded req handling to
reusing helpers. This time the permission check in prepare has to adapt
to the new caller: it checks a different permission bit, and doesn't
trigger the before write notifier.
Also, truncation should always trigger a bs->total_sectors update and in
turn call parent resize_cb. Update the condition in finish helper, too.
It's intended to do a duplicated bs->read_only check before calling
bdrv_co_write_req_prepare() so that we can be more informative with the
error message, as bdrv_co_write_req_prepare() doesn't have Error
parameter.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If we are growing the image and potentially using preallocation for the
new area, we need to make sure that no write requests are made to the
"preallocated" area which is [@old_size, @offset), not
[@offset, offset * 2 - @old_size).
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This brings the request handling logic inline with write and discard,
fixing write_gen, resize_cb, dirty bitmaps and image size refreshing.
The last of these issues broke iotest case 222, which is now fixed.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reuse the new bdrv_co_write_req_prepare/finish helpers. The variation
here is that discard requests don't affect bs->wr_highest_offset, and it
cannot extend the image.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Two problems exist when a write request that enlarges the image (i.e.
write beyond EOF) finishes:
1) parent is not notified about size change;
2) dirty bitmap is not resized although we try to set the dirty bits;
Fix them just like how bdrv_co_truncate works.
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
As a mechanical refactoring patch, this is the first step towards
unified and more correct write code paths. This is helpful because
multiple BlockDriverState fields need to be updated after modifying
image data, and it's hard to maintain in multiple places such as copy
offload, discard and truncate.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This matches the types used for bytes in the rest parts of block layer.
In the case of bdrv_co_truncate, new_bytes can be the image size which
probably doesn't fit in a 32 bit int.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Other I/O functions are already using a BdrvChild pointer in the API, so
make discard do the same. It makes it possible to initiate the same
permission checks before doing I/O, and much easier to share the
helper functions for this, which will be added and used by write,
truncate and copy range paths.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
A few trace points that can help reveal what is happening in a copy
offloading I/O path.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
With in one module, trace points usually have a common prefix named
after the module name. paio_submit and paio_submit_co are the only two
trace points so far in the two file protocol drivers. As we are adding
more, having a common prefix here is better so that trace points can be
enabled with a glob. Rename them.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This reverts commit b008326744.
Hold off removing this for one more QEMU release (current libvirt
release still uses it.)
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The sector size needs to be large enough to accommodate the data
structures for the log super block and log write entries. This was
previously not properly checked, which made it possible to cause
QEMU to badly misbehave.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Fleecing scheme works as follows: we want a kind of temporary snapshot
of active drive A. We create temporary image B, with B->backing = A.
Then we start backup(sync=none) from A to B. From this point, B reads
as point-in-time snapshot of A (A continues to be active drive,
accepting guest IO).
This scheme needs some additional synchronization between reads from B
and backup COW operations, otherwise, the following situation is
theoretically possible:
(assume B is qcow2, client is NBD client, reading from B)
1. client starts reading and take qcow2 mutex in qcow2_co_preadv, and
goes up to l2 table loading (assume cache miss)
2) guest write => backup COW => qcow2 write =>
try to take qcow2 mutex => waiting
3. l2 table loaded, we see that cluster is UNALLOCATED, go to
"case QCOW2_CLUSTER_UNALLOCATED" and unlock mutex before
bdrv_co_preadv(bs->backing, ...)
4) aha, mutex unlocked, backup COW continues, and we finally finish
guest write and change cluster in our active disk A
5. actually, do bdrv_co_preadv(bs->backing, ...) and read
_new updated_ data.
To avoid this, let's make backup writes serializing, to not intersect
with reads from B.
Note: we expand range of handled cases from (sync=none and
B->backing = A) to just (A in backing chain of B), to finally allow
safe reading from B during backup for all cases when A in backing chain
of B, i.e. B formally looks like point-in-time snapshot of A.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Serialized writes should be used in copy-on-write of backup(sync=none)
for image fleecing scheme.
We need to change an assert in bdrv_aligned_pwritev, added in
28de2dcd88. The assert may fail now, because call to
wait_serialising_requests here may become first call to it for this
request with serializing flag set. It occurs if the request is aligned
(otherwise, we should already set serializing flag before calling
bdrv_aligned_pwritev and correspondingly waited for all intersecting
requests). However, for aligned requests, we should not care about
outdating of previously read data, as there no such data. Therefore,
let's just update an assert to not care about aligned requests.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Pass read flags and write flags separately. This is needed to handle
coming BDRV_REQ_NO_SERIALISING clearly in following patches.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Here two things are fixed:
1. Architecture
On each recursion step, we go to the child of src or dst, only for one
of them. So, it's wrong to create tracked requests for both on each
step. It leads to tracked requests duplication.
2. Wait for serializing requests on write path independently of
BDRV_REQ_NO_SERIALISING
Before commit 9ded4a0114 "backup: Use copy offloading",
BDRV_REQ_NO_SERIALISING was used for only one case: read in
copy-on-write operation during backup. Also, the flag was handled only
on read path (in bdrv_co_preadv and bdrv_aligned_preadv).
After 9ded4a0114, flag is used for not waiting serializing operations
on backup target (in same case of copy-on-write operation). This
behavior change is unsubstantiated and potentially dangerous, let's
drop it and add additional asserts and documentation.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If the virtual disk size isn't aligned to full clusters,
bdrv_co_do_copy_on_readv() may get pnum == 0 before having the full
cluster completed, which will let it run into an assertion failure:
qemu-io: block/io.c:1203: bdrv_co_do_copy_on_readv: Assertion `skip_bytes < pnum' failed.
Check for EOF, assert that we read at least as much as the read request
originally wanted to have (which is true at EOF because otherwise
bdrv_check_byte_request() would already have returned an error) and
return success early even though we couldn't copy the full cluster.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit dcf94a23b1 ('block: Don't poll in parent drain callbacks')
removed polling in bdrv_child_cb_drained_begin() on the grounds that the
original bdrv_drain() already will poll and BdrvChildRole.drained_begin
calls must not cause graph changes (and therefore must not call
aio_poll() or the recursion through the graph will break.
This reasoning is correct for calls through bdrv_do_drained_begin().
However, BdrvChildRole.drained_begin is also called when a node that is
already in a drained section (i.e. bdrv_do_drained_begin() has already
returned and therefore can't poll any more) is attached to a new parent.
In this case, we must explicitly poll to have all requests completed
before the drained new child can be attached to the parent.
In bdrv_replace_child_noperm(), we know that we're not inside the
recursion of bdrv_do_drained_begin() because graph changes are not
allowed there, and bdrv_replace_child_noperm() is a graph change. The
call of BdrvChildRole.drained_begin() must therefore be followed by a
BDRV_POLL_WHILE() that waits for the completion of requests.
Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
VMDK performs a probing check in vmdk_co_create_opts() to prevent the
user from assigning non-VMDK files as a backing file, because it only
supports VMDK backing files. However, with the @backing runtime option,
it is possible to assign arbitrary nodes as backing nodes, regardless of
what the image header says. Therefore, VMDK may not just access backing
nodes assuming they are VMDK nodes -- which it does, because it needs to
compare the backing file's CID with the overlay's parentCID value, and
naturally the backing file only has a CID when it's a VMDK file.
Instead, it should report the CID of non-VMDK backing files not to match
the overlay because clearly a non-present CID does not match.
Without this change, vmdk_read_cid() reads from the backing file's
bs->file, which may be NULL (in which case we get a segfault). Also, it
interprets bs->opaque as a BDRVVmdkState and then reads from the
.desc_offset field, which usually will just return some arbitrary value
which then results in either garbage to be read, or bdrv_pread() to
return an error, both of which result in a non-matching CID to be
reported.
(In a very unlikely case, we could read something that looks like a
VMDK descriptor, and then get a CID which might actually match. But
that is highly unlikely, and the only result would be that VMDK accepts
the backing file which is not too bad (albeit unintentional).)
((And in theory, the seek to .desc_offset might leak data from another
block driver's opaque object. But then again, the user should realize
very quickly that a non-VMDK backing file does not work (because the
read will very likely fail, due to the reasons given above), so this
should not be exploitable.))
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180702210721.4847-2-mreitz@redhat.com
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
One of them is a typo. But update both to be more readable.
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180702025836.20957-3-famz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
- qcow2: Use worker threads for compression to improve performance of
'qemu-img convert -W' and compressed backup jobs
- blklogwrites: New filter driver to log write requests to an image in
the dm-log-writes format
- file-posix: Fix image locking during image creation
- crypto: Fix memory leak in error path
- Error out instead of silently truncating node names
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
Block layer patches:
- qcow2: Use worker threads for compression to improve performance of
'qemu-img convert -W' and compressed backup jobs
- blklogwrites: New filter driver to log write requests to an image in
the dm-log-writes format
- file-posix: Fix image locking during image creation
- crypto: Fix memory leak in error path
- Error out instead of silently truncating node names
# gpg: Signature made Thu 05 Jul 2018 11:24:33 BST
# gpg: using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6
* remotes/kevin/tags/for-upstream:
file-posix: Unlock FD after creation
file-posix: Fix creation locking
block/blklogwrites: Add an option for the update interval of the log superblock
block/blklogwrites: Add an option for appending to an old log
block/blklogwrites: Change log_sector_size from int64_t to uint64_t
block/crypto: Fix memory leak in create error path
block: Don't silently truncate node names
block: Add blklogwrites
block: Move two block permission constants to the relevant enum
qcow2: add compress threads
qcow2: refactor data compression
qemu-img: allow compressed not-in-order writes
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Closing the FD does not necessarily mean that it is unlocked. Fix this
by relinquishing all permission locks before qemu_close().
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
raw_apply_lock_bytes() takes a bit mask of "permissions that are NOT
shared".
Also, make the "perm" and "shared" variables uint64_t, because I do not
particularly like using ~ on signed integers (and other permission masks
are usually uint64_t, too).
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is a way to ensure that the log superblock is periodically
updated. Before, this was only done on flush requests, which may
not be enough if the VM exits abnormally, omitting the final flush.
The default interval is 4096 write requests.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Suggested by Kevin Wolf. May be useful when testing multiple batches
of writes or doing long-term testing involving restarts of the VM.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This was a simple oversight when working on intermediate versions
of the original patch which introduced blklogwrites.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Implements a block device write logging system, similar to Linux kernel
device mapper dm-log-writes. The write operations that are performed
on a block device are logged to a file or another block device. The
write log format is identical to the dm-log-writes format. Currently,
log markers are not supported.
This functionality can be used for crash consistency and fs consistency
testing. By implementing it in qemu, tests utilizing write logs can be
be used to test non-Linux drivers and older kernels.
The driver accepts an optional parameter to set the sector size used
for logging. This makes the driver require all requests to be aligned
to this sector size and also makes offsets and sizes of writes in the
log metadata to be expressed in terms of this value (the log format has
a granularity of one sector for offsets and sizes). This allows
accurate logging of writes to guest block devices that have unusual
sector sizes.
The implementation is based on the blkverify and blkdebug block
drivers.
Signed-off-by: Aapo Vienamo <aapo@tuxera.com>
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Do data compression in separate threads. This significantly improve
performance for qemu-img convert with -W (allow async writes) and -c
(compressed) options.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Make a separate function for compression to be parallelized later.
- use .avail_out field instead of .next_out to calculate size of
compressed data. It looks more natural and it allows to keep dest to
be void pointer
- set avail_out to be at least one byte less than input, to be sure
avoid inefficient compression earlier
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Bitmap lock/unlock were added to bdrv_enable_dirty_bitmap in
8b1402ce80, but some places were not updated correspondingly, which
leads to trying to take this lock twice, which is dead-lock. Fix this.
Actually, iotest 199 (about dirty bitmap postcopy migration) is broken
now, and this fixes it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180625165745.25259-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Add _locked version of bdrv_enable_dirty_bitmap, to fix dirty bitmap
migration in the following patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180625165745.25259-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Bug fixes and iotest exposure of fleecing via NBD (serving a
read-only point-in-time view via blockdev-backup sync:none,
as well as serving dirty bitmaps over NBD), including a new
x-dirty-bitmap parameter when opening NBD clients as the
counterpart to x-nbd-server-add-bitmap. Also a random fix
for iscsi block_status spotted by Coverity that missed other
miscellaneous trees.
- Eric Blake: nbd/server: Fix dirty bitmap logic regression
- Eric Blake: iscsi: Avoid potential for get_status overflow
- John Snow/Vladimir Sementsov-Ogievskiy: 0/2 block: formalize and test fleecing
- Eric Blake: 0/2 test NBD bitmap export
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Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2018-07-02' into staging
nbd patches for 2018-07-02
Bug fixes and iotest exposure of fleecing via NBD (serving a
read-only point-in-time view via blockdev-backup sync:none,
as well as serving dirty bitmaps over NBD), including a new
x-dirty-bitmap parameter when opening NBD clients as the
counterpart to x-nbd-server-add-bitmap. Also a random fix
for iscsi block_status spotted by Coverity that missed other
miscellaneous trees.
- Eric Blake: nbd/server: Fix dirty bitmap logic regression
- Eric Blake: iscsi: Avoid potential for get_status overflow
- John Snow/Vladimir Sementsov-Ogievskiy: 0/2 block: formalize and test fleecing
- Eric Blake: 0/2 test NBD bitmap export
# gpg: Signature made Tue 03 Jul 2018 02:33:03 BST
# gpg: using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg: aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg: aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2 F3AA A7A1 6B4A 2527 436A
* remotes/ericb/tags/pull-nbd-2018-07-02:
iotests: New test 223 for exporting dirty bitmap over NBD
nbd/client: Add x-dirty-bitmap to query bitmap from server
iotests: add 222 to test basic fleecing
blockdev: enable non-root nodes for backup source
iscsi: Avoid potential for get_status overflow
nbd/server: Fix dirty bitmap logic regression
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The implementation is similar to the 'qemu-img convert'. In the
beginning of the job, offloaded copy is attempted. If it fails, further
I/O will go through the existing bounce buffer code path.
Then, as Kevin pointed out, both this and qemu-img convert can benefit
from a local check if one request fails because of, for example, the
offset is beyond EOF, but another may well be accepted by the protocol
layer. This will be implemented separately.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-4-famz@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
This semantics is needed by drive-backup so implement it before using
this API there.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-3-famz@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
src may be NULL if BDRV_REQ_ZERO_WRITE flag is set, in this case only
check dst and dst->bs. This bug was introduced when moving in the
request tracking code from bdrv_co_copy_range, in 37aec7d75e.
This especially fixes the possible segfault when initializing src_bs
with a NULL src.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-2-famz@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
In order to test that the NBD server is properly advertising
dirty bitmaps, we need a bare minimum client that can request
and read the context. Since feature freeze for 3.0 is imminent,
this is the smallest workable patch, which replaces the qemu
block status report with the results of the NBD server's dirty
bitmap (making it very easy to use 'qemu-img map --output=json'
to learn where the dirty portions are). Note that the NBD
protocol defines a dirty section with the same bit but opposite
sense that normal "base:allocation" uses to report an allocated
section; so in qemu-img map output, "data":true corresponds to
clean, "data":false corresponds to dirty.
A more complete solution that allows dirty bitmaps to be queried
at the same time as normal block status will be required before
this addition can lose the x- prefix. Until then, the fact that
this replaces normal status with dirty status means actions
like 'qemu-img convert' will likely misbehave due to treating
dirty regions of the file as if they are unallocated.
The next patch adds an iotest to exercise this new code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180702191458.28741-2-eblake@redhat.com>
Detected by Coverity: Multiplying two 32-bit int and assigning
the result to a 64-bit number is a risk of overflow. Prior to
the conversion to byte-based interfaces, the block layer took
care of ensuring that a status request never exceeded 2G in
the driver; but after that conversion, the block layer expects
drivers to deal with any size request (the driver can always
truncate the request size back down, as long as it makes
progress). So, in the off-chance that someone makes a large
request, we are at the mercy of whether iscsi_get_lba_status_task()
will cap things to at most INT_MAX / iscsilun->block_size when
it populates lbasd->num_blocks; since I could not easily audit
that, it's better to be safe than sorry by just forcing a 64-bit
multiply.
Fixes: 92809c36
CC: qemu-stable@nongnu.org
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180508212718.1482663-1-eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20180625124238.25339-3-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Now that all callers of vectored I/O have been converted
to use our preferred byte-based bdrv_co_p{read,write}v(), we can
delete the unused bdrv_co_{read,write}v().
Furthermore, this gets rid of the signature difference between the
public bdrv_co_writev() and the callback .bdrv_co_writev (the
latter still exists, because some drivers still need more work
before they are fully byte-based).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Make the change for the last few sector-based calls
into the block layer from the vhdx driver.
Ideally, the vhdx driver should switch to doing everything
byte-based, but that's a more invasive change that requires a
bit more auditing.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Make the change for the last few sector-based calls
into the block layer from the replication driver.
Ideally, the replication driver should switch to doing everything
byte-based, but that's a more invasive change that requires a
bit more auditing.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
