Commit Graph

4814 Commits

Author SHA1 Message Date
Peter Maydell
b50dab9eca QOM patches for 2020-07-21
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Merge remote-tracking branch 'remotes/armbru/tags/pull-qom-2020-07-21' into staging

QOM patches for 2020-07-21

# gpg: Signature made Tue 21 Jul 2020 16:40:27 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qom-2020-07-21:
  qom: Make info qom-tree sort children more efficiently
  qom: Document object_get_canonical_path() returns malloced string
  qom: Change object_get_canonical_path_component() not to malloc

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-21 18:31:52 +01:00
Markus Armbruster
7a309cc95b qom: Change object_get_canonical_path_component() not to malloc
object_get_canonical_path_component() returns a malloced copy of a
property name on success, null on failure.

19 of its 25 callers immediately free the returned copy.

Change object_get_canonical_path_component() to return the property
name directly.  Since modifying the name would be wrong, adjust the
return type to const char *.

Drop the free from the 19 callers become simpler, add the g_strdup()
to the other six.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-4-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
2020-07-21 16:23:43 +02:00
Stefan Hajnoczi
1d719ddc35 block: fix bdrv_aio_cancel() for ENOMEDIUM requests
bdrv_aio_cancel() calls aio_poll() on the AioContext for the given I/O
request until it has completed. ENOMEDIUM requests are special because
there is no BlockDriverState when the drive has no medium!

Define a .get_aio_context() function for BlkAioEmAIOCB requests so that
bdrv_aio_cancel() can find the AioContext where the completion BH is
pending. Without this function bdrv_aio_cancel() aborts on ENOMEDIUM
requests!

libFuzzer triggered the following assertion:

  cat << EOF | qemu-system-i386 -M pc-q35-5.0 \
    -nographic -monitor none -serial none \
    -qtest stdio -trace ide\*
  outl 0xcf8 0x8000fa24
  outl 0xcfc 0xe106c000
  outl 0xcf8 0x8000fa04
  outw 0xcfc 0x7
  outl 0xcf8 0x8000fb20
  write 0x0 0x3 0x2780e7
  write 0xe106c22c 0xd 0x1130c218021130c218021130c2
  write 0xe106c218 0x15 0x110010110010110010110010110010110010110010
  EOF
  ide_exec_cmd IDE exec cmd: bus 0x56170a77a2b8; state 0x56170a77a340; cmd 0xe7
  ide_reset IDEstate 0x56170a77a340
  Aborted (core dumped)

  (gdb) bt
  #1  0x00007ffff4f93895 in abort () at /lib64/libc.so.6
  #2  0x0000555555dc6c00 in bdrv_aio_cancel (acb=0x555556765550) at block/io.c:2745
  #3  0x0000555555dac202 in blk_aio_cancel (acb=0x555556765550) at block/block-backend.c:1546
  #4  0x0000555555b1bd74 in ide_reset (s=0x555557213340) at hw/ide/core.c:1318
  #5  0x0000555555b1e3a1 in ide_bus_reset (bus=0x5555572132b8) at hw/ide/core.c:2422
  #6  0x0000555555b2aa27 in ahci_reset_port (s=0x55555720eb50, port=2) at hw/ide/ahci.c:650
  #7  0x0000555555b29fd7 in ahci_port_write (s=0x55555720eb50, port=2, offset=44, val=16) at hw/ide/ahci.c:360
  #8  0x0000555555b2a564 in ahci_mem_write (opaque=0x55555720eb50, addr=556, val=16, size=1) at hw/ide/ahci.c:513
  #9  0x000055555598415b in memory_region_write_accessor (mr=0x55555720eb80, addr=556, value=0x7fffffffb838, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:483

Looking at bdrv_aio_cancel:

2728 /* async I/Os */
2729
2730 void bdrv_aio_cancel(BlockAIOCB *acb)
2731 {
2732     qemu_aio_ref(acb);
2733     bdrv_aio_cancel_async(acb);
2734     while (acb->refcnt > 1) {
2735         if (acb->aiocb_info->get_aio_context) {
2736             aio_poll(acb->aiocb_info->get_aio_context(acb), true);
2737         } else if (acb->bs) {
2738             /* qemu_aio_ref and qemu_aio_unref are not thread-safe, so
2739              * assert that we're not using an I/O thread.  Thread-safe
2740              * code should use bdrv_aio_cancel_async exclusively.
2741              */
2742             assert(bdrv_get_aio_context(acb->bs) == qemu_get_aio_context());
2743             aio_poll(bdrv_get_aio_context(acb->bs), true);
2744         } else {
2745             abort();     <===============
2746         }
2747     }
2748     qemu_aio_unref(acb);
2749 }

Fixes: 02c50efe08 ("block: Add bdrv_aio_cancel_async")
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Buglink: https://bugs.launchpad.net/qemu/+bug/1878255
Originally-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200720100141.129739-1-stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-21 12:00:38 +02:00
Maxim Levitsky
662d0c5392 block/crypto: disallow write sharing by default
My commit 'block/crypto: implement the encryption key management'
accidently allowed raw luks images to be shared between different
qemu processes without share-rw=on explicit override.
Fix that.

Fixes: bbfdae91fb ("block/crypto: implement the encryption key management")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1857490

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200719122059.59843-2-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-21 10:49:02 +02:00
Kevin Wolf
a8c5cf27c9 file-posix: Fix leaked fd in raw_open_common() error path
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200717105426.51134-4-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf
bca5283bd4 file-posix: Fix check_hdev_writable() with auto-read-only
For Linux block devices, being able to open the device read-write
doesn't necessarily mean that the device is actually writable (one
example is a read-only LV, as you get with lvchange -pr <device>). We
have check_hdev_writable() to check this condition and fail opening the
image read-write if it's not actually writable.

However, this check doesn't take auto-read-only into account, but
results in a hard failure instead of downgrading to read-only where
possible.

Fix this and do the writable check not based on BDRV_O_RDWR, but only
when this actually results in opening the file read-write. A second
check is inserted in raw_reconfigure_getfd() to have the same check when
dynamic auto-read-only upgrades an image file from read-only to
read-write.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200717105426.51134-3-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf
20eaf1bf6e file-posix: Move check_hdev_writable() up
We'll need to call it in raw_open_common(), so move the function to
avoid a forward declaration.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200717105426.51134-2-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Kevin Wolf
5edc85571e file-posix: Allow byte-aligned O_DIRECT with NFS
Since commit a6b257a08e ('file-posix: Handle undetectable alignment'),
we assume that if we open a file with O_DIRECT and alignment probing
returns 1, we just couldn't find out the real alignment requirement
because some filesystems make the requirement only for allocated blocks.
In this case, a safe default of 4k is used.

This is too strict for NFS, which does actually allow byte-aligned
requests even with O_DIRECT. Because we can't distinguish both cases
with generic code, let's just look at the file system magic and disable
s->needs_alignment for NFS. This way, O_DIRECT can still be used on NFS
for images that are not aligned to 4k.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200716142601.111237-3-kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Marc-André Lureau
a08464521c Remove VXHS block device
The vxhs code doesn't compile since v2.12.0. There's no point in fixing
and then adding CI for a config that our users have demonstrated that
they do not use; better to just remove it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200711065926.2204721-1-marcandre.lureau@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-17 14:20:57 +02:00
Peter Maydell
d2628b1eb7 Block layer patches:
- file-posix: Mitigate file fragmentation with extent size hints
 - Tighten qemu-img rules on missing backing format
 - qemu-img map: Don't limit block status request size
 - Fix crash with virtio-scsi and iothreads
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- file-posix: Mitigate file fragmentation with extent size hints
- Tighten qemu-img rules on missing backing format
- qemu-img map: Don't limit block status request size
- Fix crash with virtio-scsi and iothreads

# gpg: Signature made Tue 14 Jul 2020 14:24:19 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block: Avoid stale pointer dereference in blk_get_aio_context()
  qemu-img: Deprecate use of -b without -F
  block: Add support to warn on backing file change without format
  iotests: Specify explicit backing format where sensible
  qcow2: Deprecate use of qemu-img amend to change backing file
  block: Error if backing file fails during creation without -u
  qcow: Tolerate backing_fmt=
  vmdk: Add trivial backing_fmt support
  sheepdog: Add trivial backing_fmt support
  block: Finish deprecation of 'qemu-img convert -n -o'
  qemu-img: Flush stdout before before potential stderr messages
  file-posix: Mitigate file fragmentation with extent size hints
  iotests/059: Filter out disk size with more standard filter
  qemu-img map: Don't limit block status request size
  iotests: Simplify _filter_img_create() a bit

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-07-14 19:39:52 +01:00
Greg Kurz
e6cada9231 block: Avoid stale pointer dereference in blk_get_aio_context()
It is possible for blk_remove_bs() to race with blk_drain_all(), causing
the latter to dereference a stale blk->root pointer:

  blk_remove_bs(blk)
   bdrv_root_unref_child(blk->root)
    child_bs = blk->root->bs
    bdrv_detach_child(blk->root)
     ...
     g_free(blk->root) <============== blk->root becomes stale
    bdrv_unref(child_bs) <============ yield at some point

A blk_drain_all() can be triggered by some guest action in the
meantime, eg. on POWER, SLOF might disable bus mastering on
a virtio-scsi-pci device:

  virtio_write_config()
   virtio_pci_stop_ioeventfd()
    virtio_bus_stop_ioeventfd()
     virtio_scsi_dataplane_stop()
      blk_drain_all()
       blk_get_aio_context()
       bs = blk->root ? blk->root->bs : NULL
            ^^^^^^^^^
              stale

Then, depending on one's luck, QEMU either crashes with SEGV or
hits the assertion in blk_get_aio_context().

blk->root is set by blk_insert_bs() which calls bdrv_root_attach_child()
first. The blk_remove_bs() function should rollback the changes made
by blk_insert_bs() in the opposite order (or it should be documented
somewhere why this isn't the case). Clear blk->root before calling
bdrv_root_unref_child() in blk_remove_bs().

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159430264541.389456.11925072456012783045.stgit@bahia.lan>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:24:15 +02:00
Eric Blake
e54ee1b385 block: Add support to warn on backing file change without format
For now, this is a mechanical addition; all callers pass false. But
the next patch will use it to improve 'qemu-img rebase -u' when
selecting a backing file with no format.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Message-Id: <20200706203954.341758-10-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
bc5ee6da71 qcow2: Deprecate use of qemu-img amend to change backing file
The use of 'qemu-img amend' to change qcow2 backing files is not
tested very well.  In particular, our implementation has a bug where
if a new backing file is provided without a format, then the prior
format is blindly reused, even if this results in data corruption, but
this is not caught by iotests.

There are also situations where amending other options needs access to
the original backing file (for example, on a downgrade to a v2 image,
knowing whether a v3 zero cluster must be allocated or may be left
unallocated depends on knowing whether the backing file already reads
as zero), but the command line does not have a nice way to tell us
both the backing file to use for opening the image as well as the
backing file to install after the operation is complete.

Even if we do allow changing the backing file, it is redundant with
the existing ability to change backing files via 'qemu-img rebase -u'.
It is time to deprecate this support (leaving the existing behavior
intact, even if it is buggy), and at a point in the future, require
the use of only 'qemu-img rebase' for adjusting backing chain
relations, saving 'qemu-img amend' for changes unrelated to the
backing chain.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-8-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
344acbd62f qcow: Tolerate backing_fmt=
qcow has no space in the metadata to store a backing format, and there
are existing qcow images backed both by raw or by other formats
(usually qcow) images, reliant on probing to tell the difference.  On
the bright side, because we probe every time, raw files are marked as
probed and we thus forbid a commit action into the backing file where
guest-controlled contents could change the result of the probe next
time around (the iotest added here proves that).

Still, allowing the user to specify the backing format during
creation, even if we can't record it, is a good thing.  This patch
blindly allows any value that resolves to a known driver, even if the
user's request is a mismatch from what probing finds; then the next
patch will further enhance things to verify that the user's request
matches what we actually probe.  With this and the next patch in
place, we will finally be ready to deprecate the creation of images
where a backing format was not explicitly specified by the user.

Note that this is only for QemuOpts usage; there is no change to the
QAPI to allow a format through -blockdev.

Add a new iotest 301 just for qcow, to demonstrate the latest
behavior, and to make it easier to show the improvements made in the
next patch.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-6-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
d51a814cf4 vmdk: Add trivial backing_fmt support
vmdk already requires that if backing_file is present, that it be
another vmdk image (see vmdk_co_do_create).  Meanwhile, we want to
move towards always being explicit about the backing format for other
drivers where it matters.  So for convenience, make qemu-img create -F
vmdk work, while rejecting all other explicit formats (note that this
is only for QemuOpts usage; there is no change to the QAPI to allow a
format through -blockdev).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-5-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
80fa43e7df sheepdog: Add trivial backing_fmt support
Sheepdog already requires that if backing_file is present, that it be
another sheepdog image (see sd_co_create).  Meanwhile, we want to move
towards always being explicit about the backing format for other
drivers where it matters.  So for convenience, make qemu-img create -F
sheepdog work, while rejecting all other explicit formats (note that
this is only for QemuOpts usage; there is no change to the QAPI to
allow a format through -blockdev).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-4-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Kevin Wolf
ffa244c84a file-posix: Mitigate file fragmentation with extent size hints
Especially when O_DIRECT is used with image files so that the page cache
indirection can't cause a merge of allocating requests, the file will
fragment on the file system layer, with a potentially very small
fragment size (this depends on the requests the guest sent).

On Linux, fragmentation can be reduced by setting an extent size hint
when creating the file (at least on XFS, it can't be set any more after
the first extent has been allocated), basically giving raw files a
"cluster size" for allocation.

This adds a create option to set the extent size hint, and changes the
default from not setting a hint to setting it to 1 MB. The main reason
why qcow2 defaults to smaller cluster sizes is that COW becomes more
expensive, which is not an issue with raw files, so we can choose a
larger size. The tradeoff here is only potentially wasted disk space.

For qcow2 (or other image formats) over file-posix, the advantage should
even be greater because they grow sequentially without leaving holes, so
there won't be wasted space. Setting even larger extent size hints for
such images may make sense. This can be done with the new option, but
let's keep the default conservative for now.

The effect is very visible with a test that intentionally creates a
badly fragmented file with qemu-img bench (the time difference while
creating the file is already remarkable) and then looks at the number of
extents and the time a simple "qemu-img map" takes.

Without an extent size hint:

    $ ./qemu-img create -f raw -o extent_size_hint=0 ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=0
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 25.848 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 19.616 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 2000000 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m1,279s
    user    0m0,043s
    sys     0m1,226s

With the new default extent size hint of 1 MB:

    $ ./qemu-img create -f raw -o extent_size_hint=1M ~/tmp/test.raw 10G
    Formatting '/home/kwolf/tmp/test.raw', fmt=raw size=10737418240 extent_size_hint=1048576
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 0
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 0, step size 8192)
    Run completed in 11.833 seconds.
    $ ./qemu-img bench -f raw -t none -n -w ~/tmp/test.raw -c 1000000 -S 8192 -o 4096
    Sending 1000000 write requests, 4096 bytes each, 64 in parallel (starting at offset 4096, step size 8192)
    Run completed in 10.155 seconds.
    $ filefrag ~/tmp/test.raw
    /home/kwolf/tmp/test.raw: 178 extents found
    $ time ./qemu-img map ~/tmp/test.raw
    Offset          Length          Mapped to       File
    0               0x1e8480000     0               /home/kwolf/tmp/test.raw

    real    0m0,061s
    user    0m0,040s
    sys     0m0,014s

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200707142329.48303-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00
Eric Blake
00d69986da nbd: Avoid off-by-one in long export name truncation
When snprintf returns the same value as the buffer size, the final
byte was truncated to ensure a NUL terminator.  Fortunately, such long
export names are unusual enough, with no real impact other than what
is displayed to the user.

Fixes: 5c86bdf120
Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200622210355.414941-1-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-07-13 09:01:01 -05:00
Xie Yongji
c58daf76a6 iscsi: return -EIO when sense fields are meaningless
When an I/O request failed, now we only return correct
value on scsi check condition. We should also have a
default errno such as -EIO in other case.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20200701105444.3226-2-xieyongji@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:23 -04:00
Xie Yongji
dd3b00202a iscsi: handle check condition status in retry loop
The handling of check condition was incorrect because
we would only do it after retries exceed maximum.

Fixes: 8c460269aa ("iscsi: base all handling of check condition on scsi_sense_to_errno")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Message-Id: <20200701105444.3226-1-xieyongji@bytedance.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:23 -04:00
Vladimir Sementsov-Ogievskiy
795d946d07 nbd: Use ERRP_GUARD()
If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix several such cases, e.g. in nbd_read().

This commit is generated by command

    sed -n '/^Network Block Device (NBD)$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-8-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]
2020-07-10 15:18:09 +02:00
Markus Armbruster
386f6c07d2 error: Avoid error_propagate() after migrate_add_blocker()
When migrate_add_blocker(blocker, &errp) is followed by
error_propagate(errp, err), we can often just as well do
migrate_add_blocker(..., errp).

Do that with this Coccinelle script:

    @@
    expression blocker, err, errp;
    expression ret;
    @@
    -    ret = migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    ret = migrate_add_blocker(blocker, errp);
    +    if (ret < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

    @@
    expression blocker, err, errp;
    @@
    -    migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    if (migrate_add_blocker(blocker, errp) < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

Double-check @err is not used afterwards.  Dereferencing it would be
use after free, but checking whether it's null would be legitimate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-43-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
b11a093c60 qapi: Smooth another visitor error checking pattern
Convert

    visit_type_FOO(v, ..., &ptr, &err);
    ...
    if (err) {
        ...
    }

to

    visit_type_FOO(v, ..., &ptr, errp);
    ...
    if (!ptr) {
        ...
    }

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
4bc6d7ee0e block/parallels: Simplify parallels_open() after previous commit
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-39-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
a5f9b9df25 error: Reduce unnecessary error propagation
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away, even when we need to keep error_propagate() for other
error paths.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-38-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
992861fb1e error: Eliminate error_propagate() manually
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous two commits did that for sufficiently simple
cases with Coccinelle.  Do it for several more manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-37-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
af175e85f9 error: Eliminate error_propagate() with Coccinelle, part 2
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
dcfe480544 error: Avoid unnecessary error_propagate() after error_setg()
Replace

    error_setg(&err, ...);
    error_propagate(errp, err);

by

    error_setg(errp, ...);

Related pattern:

    if (...) {
        error_setg(&err, ...);
        goto out;
    }
    ...
 out:
    error_propagate(errp, err);
    return;

When all paths to label out are that way, replace by

    if (...) {
        error_setg(errp, ...);
        return;
    }

and delete the label along with the error_propagate().

When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.

    foo(..., &err);
    if (err) {
        goto out;
    }
    ...
    bar(..., &err);
 out:
    error_propagate(errp, err);
    return;

move the error_propagate() to where it's needed, like

    if (...) {
        foo(..., &err);
        error_propagate(errp, err);
        return;
    }
    ...
    bar(..., errp);
    return;

and transform the error_setg() as above.

In some places, the transformation results in obviously unnecessary
error_propagate().  The next few commits will eliminate them.

Bonus: the elimination of gotos will make later patches in this series
easier to review.

Candidates for conversion tracked down with this Coccinelle script:

    @@
    identifier err, errp;
    expression list args;
    @@
    -    error_setg(&err, args);
    +    error_setg(errp, args);
         ... when != err
         error_propagate(errp, err);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
14217038bc qapi: Use returned bool to check for failure, manual part
The previous commit used Coccinelle to convert from checking the Error
object to checking the return value.  Convert a few more manually.
Also tweak control flow in places to conform to the conventional "if
error bail out" pattern.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-20-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
62a35aaa31 qapi: Use returned bool to check for failure, Coccinelle part
The previous commit enables conversion of

    visit_foo(..., &err);
    if (err) {
        ...
    }

to

    if (!visit_foo(..., errp)) {
        ...
    }

for visitor functions that now return true / false on success / error.
Coccinelle script:

    @@
    identifier fun =~ "check_list|input_type_enum|lv_start_struct|lv_type_bool|lv_type_int64|lv_type_str|lv_type_uint64|output_type_enum|parse_type_bool|parse_type_int64|parse_type_null|parse_type_number|parse_type_size|parse_type_str|parse_type_uint64|print_type_bool|print_type_int64|print_type_null|print_type_number|print_type_size|print_type_str|print_type_uint64|qapi_clone_start_alternate|qapi_clone_start_list|qapi_clone_start_struct|qapi_clone_type_bool|qapi_clone_type_int64|qapi_clone_type_null|qapi_clone_type_number|qapi_clone_type_str|qapi_clone_type_uint64|qapi_dealloc_start_list|qapi_dealloc_start_struct|qapi_dealloc_type_anything|qapi_dealloc_type_bool|qapi_dealloc_type_int64|qapi_dealloc_type_null|qapi_dealloc_type_number|qapi_dealloc_type_str|qapi_dealloc_type_uint64|qobject_input_check_list|qobject_input_check_struct|qobject_input_start_alternate|qobject_input_start_list|qobject_input_start_struct|qobject_input_type_any|qobject_input_type_bool|qobject_input_type_bool_keyval|qobject_input_type_int64|qobject_input_type_int64_keyval|qobject_input_type_null|qobject_input_type_number|qobject_input_type_number_keyval|qobject_input_type_size_keyval|qobject_input_type_str|qobject_input_type_str_keyval|qobject_input_type_uint64|qobject_input_type_uint64_keyval|qobject_output_start_list|qobject_output_start_struct|qobject_output_type_any|qobject_output_type_bool|qobject_output_type_int64|qobject_output_type_null|qobject_output_type_number|qobject_output_type_str|qobject_output_type_uint64|start_list|visit_check_list|visit_check_struct|visit_start_alternate|visit_start_list|visit_start_struct|visit_type_.*";
    expression list args;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err);
    -    if (err)
    +    if (!fun(args, &err))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-19-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster
235e59cf03 qemu-option: Use returned bool to check for failure
The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for QemuOpts functions that now return true / false on success /
error.  Coccinelle script:

    @@
    identifier fun = {
        opts_do_parse, parse_option_bool, parse_option_number,
        parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
        qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
        qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
        qemu_opts_validate
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]
2020-07-10 15:17:35 +02:00
Markus Armbruster
c6ecec43b2 qemu-option: Check return value instead of @err where convenient
Convert uses like

    opts = qemu_opts_create(..., &err);
    if (err) {
        ...
    }

to

    opts = qemu_opts_create(..., errp);
    if (!opts) {
        ...
    }

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Note that we can't drop parallels_open()'s error_propagate() here.  We
continue to execute it even in the converted case.  It's a no-op then:
local_err is null.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-8-armbru@redhat.com>
2020-07-10 15:01:06 +02:00
Eric Blake
365fed5111 qed: Simplify backing reads
The other four drivers that support backing files (qcow, qcow2,
parallels, vmdk) all rely on the block layer to populate zeroes when
reading beyond EOF of a short backing file.  We can simplify the qed
code by doing likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200528094405.145708-11-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
a2adbbf603 block: drop unallocated_blocks_are_zero
Currently this field only set by qed and qcow2. But in fact, all
backing-supporting formats (parallels, qcow, qcow2, qed, vmdk) share
these semantics: on unallocated blocks, if there is no backing file they
just memset the buffer with zeroes.

So, document this behavior for .supports_backing and drop
.unallocated_blocks_are_zero

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-10-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
cdf9ebf18f block/vhdx: drop unallocated_blocks_are_zero
vhdx doesn't have .bdrv_co_block_status handler, so DATA|ALLOCATED is
always assumed for it in bdrv_co_block_status().
unallocated_blocks_are_zero is useless (it doesn't affect the only user
of the field: bdrv_co_block_status()), drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-9-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
ac9185603e block/file-posix: drop unallocated_blocks_are_zero
raw_co_block_status() in block/file-posix.c never returns 0, so
unallocated_blocks_are_zero is useless (it doesn't affect the only user
of the field: bdrv_co_block_status()). Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-8-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
32d293c8c6 block/iscsi: drop unallocated_blocks_are_zero
We set bdi->unallocated_blocks_are_zero = iscsilun->lbprz, but
iscsi_co_block_status doesn't return 0 in case of iscsilun->lbprz, it
returns ZERO when appropriate. So actually unallocated_blocks_are_zero
is useless (it doesn't affect the only user of the field:
bdrv_co_block_status()). Drop it now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-7-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
74036395ea block/crypto: drop unallocated_blocks_are_zero
It's false by default, no needs to set it. We are going to drop this
variable at all, so drop it now here, it doesn't hurt.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-6-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:34:14 +02:00
Vladimir Sementsov-Ogievskiy
2c060c0f50 block/vpc: return ZERO block-status when appropriate
In case when get_image_offset() returns -1, we do zero out the
corresponding chunk of qiov. So, this should be reported as ZERO.

Note that this changes visible output of "qemu-img map --output=json"
and "qemu-io -c map" commands. For qemu-img map, the change is obvious:
we just mark as zero what is really zero. For qemu-io it's less
obvious: what was unallocated now is allocated.

There is an inconsistency in understanding of unallocated regions in
Qemu: backing-supporting format-drivers return 0 block-status to report
go-to-backing logic for this area. Some protocol-drivers (iscsi) return
0 to report fs-unallocated-non-zero status (i.e., don't occupy space on
disk, read result is undefined).

BDRV_BLOCK_ALLOCATED is defined as something more close to
go-to-backing logic. Still it is calculated as ZERO | DATA, so 0 from
iscsi is treated as unallocated. It doesn't influence backing-chain
behavior, as iscsi can't have backing file. But it does influence
"qemu-io -c map".

We should solve this inconsistency at some future point. Now, let's
just make backing-not-supporting format drivers (vdi in the previous
patch and vpc now) to behave more like backing-supporting drivers
and not report 0 block-status. More over, returning ZERO status is
absolutely valid thing, and again, corresponds to how the other
format-drivers (backing-supporting) work.

After block-status update, it never reports 0, so setting
unallocated_blocks_are_zero doesn't make sense (as the only user of it
is bdrv_co_block_status and it checks unallocated_blocks_are_zero only
for unallocated areas). Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-5-vsementsov@virtuozzo.com>
[mreitz: qemu-io -c map as used by iotest 146 now reports everything as
         allocated; in order to make the test do something useful, we
         use qemu-img map --output=json now]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 10:32:38 +02:00
Vladimir Sementsov-Ogievskiy
2ea0332f42 block/vdi: return ZERO block-status when appropriate
In case of !VDI_IS_ALLOCATED[], we do zero out the corresponding chunk
of qiov. So, this should be reported as ZERO.

Note that this changes visible output of "qemu-img map --output=json"
and "qemu-io -c map" commands. For qemu-img map, the change is obvious:
we just mark as zero what is really zero. For qemu-io it's less
obvious: what was unallocated now is allocated.

There is an inconsistency in understanding of unallocated regions in
Qemu: backing-supporting format-drivers return 0 block-status to report
go-to-backing logic for this area. Some protocol-drivers (iscsi) return
0 to report fs-unallocated-non-zero status (i.e., don't occupy space on
disk, read result is undefined).

BDRV_BLOCK_ALLOCATED is defined as something more close to
go-to-backing logic. Still it is calculated as ZERO | DATA, so 0 from
iscsi is treated as unallocated. It doesn't influence backing-chain
behavior, as iscsi can't have backing file. But it does influence
"qemu-io -c map".

We should solve this inconsistency at some future point. Now, let's
just make backing-not-supporting format drivers (vdi at this patch and
vpc with the following) to behave more like backing-supporting drivers
and not report 0 block-status. More over, returning ZERO status is
absolutely valid thing, and again, corresponds to how the other
format-drivers (backing-supporting) work.

After block-status update, it never reports 0, so setting
unallocated_blocks_are_zero doesn't make sense (as the only user of it
is bdrv_co_block_status and it checks unallocated_blocks_are_zero only
for unallocated areas). Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-4-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Vladimir Sementsov-Ogievskiy
7b1efe996c block: inline bdrv_unallocated_blocks_are_zero()
The function has only one user: bdrv_co_block_status(). Inline it to
simplify reviewing of the following patches, which will finally drop
unallocated_blocks_are_zero field too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200528094405.145708-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
8ea1613d91 block/qcow2: implement blockdev-amend
Currently the implementation only supports amending the encryption
options, unlike the qemu-img version

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-14-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
30da9dd88a block/crypto: implement blockdev-amend
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-13-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
ced914d0ab block/core: add generic infrastructure for x-blockdev-amend qmp command
blockdev-amend will be used similiar to blockdev-create
to allow on the fly changes of the structure of the format based block devices.

Current plan is to first support encryption keyslot management for luks
based formats (raw and embedded in qcow2)

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200608094030.670121-12-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
90766d9db9 block/qcow2: extend qemu-img amend interface with crypto options
Now that we have all the infrastructure in place,
wire it in the qcow2 driver and expose this to the user.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-9-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
bbfdae91fb block/crypto: implement the encryption key management
This implements the encryption key management using the generic code in
qcrypto layer and exposes it to the user via qemu-img

This code adds another 'write_func' because the initialization
write_func works directly on the underlying file, and amend
works on instance of luks device.

This commit also adds a 'hack/workaround' I and Kevin Wolf (thanks)
made to make the driver both support write sharing (to avoid breaking the users),
and be safe against concurrent  metadata update (the keyslots)

Eventually the write sharing for luks driver will be deprecated
and removed together with this hack.

The hack is that we ask (as a format driver) for BLK_PERM_CONSISTENT_READ
and then when we want to update the keys, we unshare that permission.
So if someone else has the image open, even readonly, encryption
key update will fail gracefully.

Also thanks to Daniel Berrange for the idea of
unsharing read, rather that write permission which allows
to avoid cases when the other user had opened the image read-only.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-8-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
e0d0ddc591 block/crypto: rename two functions
rename the write_func to create_write_func, and init_func to create_init_func.
This is preparation for other write_func that will be used to update the encryption keys.

No functional changes

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200608094030.670121-7-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
0b6786a9c1 block/amend: refactor qcow2 amend options
Some qcow2 create options can't be used for amend.
Remove them from the qcow2 create options and add generic logic to detect
such options in qemu-img

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[mreitz: Dropped some iotests reference output hunks that became
         unnecessary thanks to
         "iotests: Make _filter_img_create more active"]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200625125548.870061-12-mreitz@redhat.com>
2020-07-06 08:49:28 +02:00
Maxim Levitsky
df373fb0a3 block/amend: separate amend and create options for qemu-img
Some options are only useful for creation
(or hard to be amended, like cluster size for qcow2), while some other
options are only useful for amend, like upcoming keyslot management
options for luks

Since currently only qcow2 supports amend, move all its options
to a common macro and then include it in each action option list.

In future it might be useful to remove some options which are
not supported anyway from amend list, which currently
cause an error message if amended.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200608094030.670121-5-mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-07-06 08:49:28 +02:00