Commit Graph

216 Commits

Author SHA1 Message Date
Stefan Hajnoczi
d5ab9490cd Block layer patches
- Cleanup bs->backing and bs->file handling
 - Refactor bdrv_try_set_aio_context using transactions
 - Changes for improved coroutine_fn consistency
 - vhost-user-blk: fix the resize crash
 - io_uring: Use of io_uring_register_ring_fd() led to breakage, revert
 - vvfat: Fix some problems with r/w mode
 - Code cleanup
 - MAINTAINERS: Fold "Block QAPI, monitor, ..." into "Block layer core"
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Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging

Block layer patches

- Cleanup bs->backing and bs->file handling
- Refactor bdrv_try_set_aio_context using transactions
- Changes for improved coroutine_fn consistency
- vhost-user-blk: fix the resize crash
- io_uring: Use of io_uring_register_ring_fd() led to breakage, revert
- vvfat: Fix some problems with r/w mode
- Code cleanup
- MAINTAINERS: Fold "Block QAPI, monitor, ..." into "Block layer core"

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# gpg: Signature made Thu 27 Oct 2022 14:29:38 EDT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
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* tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (58 commits)
  block/block-backend: blk_set_enable_write_cache is IO_CODE
  monitor: switch to *_co_* functions
  vmdk: switch to *_co_* functions
  vhdx: switch to *_co_* functions
  vdi: switch to *_co_* functions
  qed: switch to *_co_* functions
  qcow2: switch to *_co_* functions
  qcow: switch to *_co_* functions
  parallels: switch to *_co_* functions
  mirror: switch to *_co_* functions
  block: switch to *_co_* functions
  commit: switch to *_co_* functions
  vmdk: manually add more coroutine_fn annotations
  qcow2: manually add more coroutine_fn annotations
  qcow: manually add more coroutine_fn annotations
  blkdebug: add missing coroutine_fn annotation for indirect-called functions
  qcow2: add coroutine_fn annotation for indirect-called functions
  block: add missing coroutine_fn annotation to BlockDriverState callbacks
  coroutine-io: add missing coroutine_fn annotation to prototypes
  coroutine-lock: add missing coroutine_fn annotation to prototypes
  ...

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-30 15:15:12 -04:00
Alberto Faria
3aba34adb1 qed: switch to *_co_* functions
Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-21-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Vladimir Sementsov-Ogievskiy
8393078032 block: introduce bdrv_open_file_child() helper
Almost all drivers call bdrv_open_child() similarly. Let's create a
helper for this.

The only not updated drivers that call bdrv_open_child() to set
bs->file are raw-format and snapshot-access:
    raw-format sometimes want to have filtered child but
        don't set drv->is_filter to true.
    snapshot-access wants only DATA | PRIMARY

Possibly we should implement drv->is_filter_func() handler, to consider
raw-format as filter when it works as filter.. But it's another story.

Note also, that we decrease assignments to bs->file in code: it helps
us restrict modifying this field in further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220726201134.924743-3-vsementsov@yandex-team.ru>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-27 20:14:11 +02:00
Stefan Hajnoczi
e8b6535533 block: add BDRV_REQ_REGISTERED_BUF request flag
Block drivers may optimize I/O requests accessing buffers previously
registered with bdrv_register_buf(). Checking whether all elements of a
request's QEMUIOVector are within previously registered buffers is
expensive, so we need a hint from the user to avoid costly checks.

Add a BDRV_REQ_REGISTERED_BUF request flag to indicate that all
QEMUIOVector elements in an I/O request are known to be within
previously registered buffers.

Always pass the flag through to driver read/write functions. There is
little harm in passing the flag to a driver that does not use it.
Passing the flag to drivers avoids changes across many block drivers.
Filter drivers would need to explicitly support the flag and pass
through to their children when the children support it. That's a lot of
code changes and it's hard to remember to do that everywhere, leading to
silent reduced performance when the flag is accidentally dropped.

The only problematic scenario with the approach in this patch is when a
driver passes the flag through to internal I/O requests that don't use
the same I/O buffer. In that case the hint may be set when it should
actually be clear. This is a rare case though so the risk is low.

Some drivers have assert(!flags), which no longer works when
BDRV_REQ_REGISTERED_BUF is passed in. These assertions aren't very
useful anyway since the functions are called almost exclusively by
bdrv_driver_preadv/pwritev() so if we get flags handling right there
then the assertion is not needed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20221013185908.1297568-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-10-26 14:56:42 -04:00
Paolo Bonzini
b383ae60a2 qed: add missing coroutine_fn annotations
Callers of coroutine_fn must be coroutine_fn themselves, or the call
must be within "if (qemu_in_coroutine())".  Apply coroutine_fn to
functions where this holds.

Reviewed-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220922084924.201610-18-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-10-07 12:11:41 +02:00
Hanna Reitz
dc70638ff6 block/qed: Keep auto_backing_file if possible
Just like qcow2, qed invokes its open function in its
.bdrv_co_invalidate_cache() implementation.  Therefore, just like done
for qcow2 in HEAD^, update auto_backing_file only if the backing file
string in the image header differs from the one we have read before.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220803144446.20723-3-hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-09-30 18:43:44 +02:00
Alberto Faria
a9262f551e block: Change blk_{pread,pwrite}() param order
Swap 'buf' and 'bytes' around for consistency with
blk_co_{pread,pwrite}(), and in preparation to implement these functions
using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression blk, offset, buf, bytes, flags; @@
    - blk_pread(blk, offset, buf, bytes, flags)
    + blk_pread(blk, offset, bytes, buf, flags)

    @@ expression blk, offset, buf, bytes, flags; @@
    - blk_pwrite(blk, offset, buf, bytes, flags)
    + blk_pwrite(blk, offset, bytes, buf, flags)

It had no effect on hw/block/nand.c, presumably due to the #if, so that
file was updated manually.

Overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-4-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12 12:14:56 +02:00
Alberto Faria
353a5d84b2 block: Make bdrv_{pread,pwrite}() return 0 on success
They currently return the value of their 'bytes' parameter on success.

Make them return 0 instead, for consistency with other I/O functions and
in preparation to implement them using generated_co_wrapper. This also
makes it clear that short reads/writes are not possible.

The few callers that rely on the previous behavior are adjusted
accordingly by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220609152744.3891847-4-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12 12:14:55 +02:00
Alberto Faria
32cc71def9 block: Change bdrv_{pread,pwrite,pwrite_sync}() param order
Swap 'buf' and 'bytes' around for consistency with
bdrv_co_{pread,pwrite}(), and in preparation to implement these
functions using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression child, offset, buf, bytes, flags; @@
    - bdrv_pread(child, offset, buf, bytes, flags)
    + bdrv_pread(child, offset, bytes, buf, flags)

    @@ expression child, offset, buf, bytes, flags; @@
    - bdrv_pwrite(child, offset, buf, bytes, flags)
    + bdrv_pwrite(child, offset, bytes, buf, flags)

    @@ expression child, offset, buf, bytes, flags; @@
    - bdrv_pwrite_sync(child, offset, buf, bytes, flags)
    + bdrv_pwrite_sync(child, offset, bytes, buf, flags)

Resulting overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220609152744.3891847-3-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12 12:14:55 +02:00
Alberto Faria
53fb7844f0 block: Add a 'flags' param to bdrv_{pread,pwrite,pwrite_sync}()
For consistency with other I/O functions, and in preparation to
implement them using generated_co_wrapper.

Callers were updated using this Coccinelle script:

    @@ expression child, offset, buf, bytes; @@
    - bdrv_pread(child, offset, buf, bytes)
    + bdrv_pread(child, offset, buf, bytes, 0)

    @@ expression child, offset, buf, bytes; @@
    - bdrv_pwrite(child, offset, buf, bytes)
    + bdrv_pwrite(child, offset, buf, bytes, 0)

    @@ expression child, offset, buf, bytes; @@
    - bdrv_pwrite_sync(child, offset, buf, bytes)
    + bdrv_pwrite_sync(child, offset, buf, bytes, 0)

Resulting overly-long lines were then fixed by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220609152744.3891847-2-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2022-07-12 12:14:55 +02:00
Peter Maydell
5df022cf2e osdep: Move memalign-related functions to their own header
Move the various memalign-related functions out of osdep.h and into
their own header, which we include only where they are used.
While we're doing this, add some brief documentation comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20220226180723.1706285-10-peter.maydell@linaro.org
2022-03-07 13:16:49 +00:00
Vladimir Sementsov-Ogievskiy
f34b2bcf8c block: use int64_t instead of int in driver write_zeroes handlers
We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver write_zeroes handlers bytes parameter to int64_t.

The only caller of all updated function is bdrv_co_do_pwrite_zeroes().

bdrv_co_do_pwrite_zeroes() itself is of course OK with widening of
callee parameter type. Also, bdrv_co_do_pwrite_zeroes()'s
max_write_zeroes is limited to INT_MAX. So, updated functions all are
safe, they will not get "bytes" larger than before.

Still, let's look through all updated functions, and add assertions to
the ones which are actually unprepared to values larger than INT_MAX.
For these drivers also set explicit max_pwrite_zeroes limit.

Let's go:

blkdebug: calculations can't overflow, thanks to
  bdrv_check_qiov_request() in generic layer. rule_check() and
  bdrv_co_pwrite_zeroes() both have 64bit argument.

blklogwrites: pass to blk_log_writes_co_log() with 64bit argument.

blkreplay, copy-on-read, filter-compress: pass to
  bdrv_co_pwrite_zeroes() which is OK

copy-before-write: Calls cbw_do_copy_before_write() and
  bdrv_co_pwrite_zeroes, both have 64bit argument.

file-posix: both handler calls raw_do_pwrite_zeroes, which is updated.
  In raw_do_pwrite_zeroes() calculations are OK due to
  bdrv_check_qiov_request(), bytes go to RawPosixAIOData::aio_nbytes
  which is uint64_t.
  Check also where that uint64_t gets handed:
  handle_aiocb_write_zeroes_block() passes a uint64_t[2] to
  ioctl(BLKZEROOUT), handle_aiocb_write_zeroes() calls do_fallocate()
  which takes off_t (and we compile to always have 64-bit off_t), as
  does handle_aiocb_write_zeroes_unmap. All look safe.

gluster: bytes go to GlusterAIOCB::size which is int64_t and to
  glfs_zerofill_async works with off_t.

iscsi: Aha, here we deal with iscsi_writesame16_task() that has
  uint32_t num_blocks argument and iscsi_writesame16_task() has
  uint16_t argument. Make comments, add assertions and clarify
  max_pwrite_zeroes calculation.
  iscsi_allocmap_() functions already has int64_t argument
  is_byte_request_lun_aligned is simple to update, do it.

mirror_top: pass to bdrv_mirror_top_do_write which has uint64_t
  argument

nbd: Aha, here we have protocol limitation, and NBDRequest::len is
  uint32_t. max_pwrite_zeroes is cleanly set to 32bit value, so we are
  OK for now.

nvme: Again, protocol limitation. And no inherent limit for
  write-zeroes at all. But from code that calculates cdw12 it's obvious
  that we do have limit and alignment. Let's clarify it. Also,
  obviously the code is not prepared to handle bytes=0. Let's handle
  this case too.
  trace events already 64bit

preallocate: pass to handle_write() and bdrv_co_pwrite_zeroes(), both
  64bit.

rbd: pass to qemu_rbd_start_co() which is 64bit.

qcow2: offset + bytes and alignment still works good (thanks to
  bdrv_check_qiov_request()), so tail calculation is OK
  qcow2_subcluster_zeroize() has 64bit argument, should be OK
  trace events updated

qed: qed_co_request wants int nb_sectors. Also in code we have size_t
  used for request length which may be 32bit. So, let's just keep
  INT_MAX as a limit (aligning it down to pwrite_zeroes_alignment) and
  don't care.

raw-format: Is OK. raw_adjust_offset and bdrv_co_pwrite_zeroes are both
  64bit.

throttle: Both throttle_group_co_io_limits_intercept() and
  bdrv_co_pwrite_zeroes() are 64bit.

vmdk: pass to vmdk_pwritev which is 64bit

quorum: pass to quorum_co_pwritev() which is 64bit

Hooray!

At this point all block drivers are prepared to support 64bit
write-zero requests, or have explicitly set max_pwrite_zeroes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210903102807.27127-8-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: use <= rather than < in assertions relying on max_pwrite_zeroes]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-09-29 13:46:32 -05:00
Vladimir Sementsov-Ogievskiy
15ce94a68c block/qed: bdrv_qed_do_open: deal with errp
Always set errp on failure. The generic bdrv_open_driver supports
driver functions which can return a negative value but forget to set
errp.  That's a strange thing. Let's improve bdrv_qed_do_open to not
behave this way. This allows the simplification of code in
bdrv_qed_co_invalidate_cache().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210202124956.63146-14-vsementsov@virtuozzo.com>
[eblake: commit message grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-03-08 16:03:32 -06:00
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
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
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
Max Reitz
69dca43d6b block: Use bdrv_default_perms()
bdrv_default_perms() can decide which permission profile to use based on
the BdrvChildRole, so block drivers do not need to select it explicitly.

The blkverify driver now no longer shares the WRITE permission for the
image to verify.  We thus have to adjust two places in
test-block-iothread not to take it.  (Note that in theory, blkverify
should behave like quorum in this regard and share neither WRITE nor
RESIZE for both of its children.  In practice, it does not really
matter, because blkverify is used only for debugging, so we might as
well keep its permissions rather liberal.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-30-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Max Reitz
8b1869daad block: Make format drivers use child_of_bds
Commonly, they need to pass the BDRV_CHILD_IMAGE set as the
BdrvChildRole; but there are exceptions for drivers with external data
files (qcow2 and vmdk).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-26-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Max Reitz
258b776515 block: Add BdrvChildRole to BdrvChild
For now, it is always set to 0.  Later patches in this series will
ensure that all callers pass an appropriate combination of flags.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200513110544.176672-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Max Reitz
d67066d8bc block: Add BlockDriver.is_format
We want to unify child_format and child_file at some point.  One of the
important things that set format drivers apart from other drivers is
that they do not expect other format nodes under them (except in the
backing chain), i.e. we must not probe formats inside of formats.  That
means we need something on which to distinguish format drivers from
others, and hence this flag.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200513110544.176672-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-18 19:05:25 +02:00
Eric Blake
47e0b38a13 block: Drop unused .bdrv_has_zero_init_truncate
Now that there are no clients of bdrv_has_zero_init_truncate, none of
the drivers need to worry about providing it.

What's more, this eliminates a source of some confusion: a literal
reading of the documentation as written in ceaca56f and implemented in
commit 1dcaf527 claims that a driver which returns 0 for
bdrv_has_zero_init_truncate() must not return 1 for
bdrv_has_zero_init(); this condition was violated for parallels, qcow,
and sometimes for vdi, although in practice it did not matter since
those drivers also lacked .bdrv_co_truncate.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200428202905.770727-10-eblake@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-05-08 13:26:35 +02:00
Eric Blake
a3aeeab557 block: Add blk_new_with_bs() helper
There are several callers that need to create a new block backend from
an existing BDS; make the task slightly easier with a common helper
routine.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424190903.522087-2-eblake@redhat.com>
[mreitz: Set @ret only in error paths, see
 https://lists.nongnu.org/archive/html/qemu-block/2020-04/msg01216.html]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200428192648.749066-2-eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-05-05 13:17:36 +02:00
Kevin Wolf
8c6242b6f3 block-backend: Add flags to blk_truncate()
Now that node level interface bdrv_truncate() supports passing request
flags to the block driver, expose this on the BlockBackend level, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-4-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30 17:51:07 +02:00
Kevin Wolf
92b92799dc block: Add flags to BlockDriver.bdrv_co_truncate()
This adds a new BdrvRequestFlags parameter to the .bdrv_co_truncate()
driver callbacks, and a supported_truncate_flags field in
BlockDriverState that allows drivers to advertise support for request
flags in the context of truncate.

For now, we always pass 0 and no drivers declare support for any flag.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-2-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-04-30 17:51:07 +02:00
Maxim Levitsky
b92902dfea block: pass BlockDriver reference to the .bdrv_co_create
This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26 14:44:33 +01:00
Max Reitz
e8d04f9237 block: Pass truncate exact=true where reasonable
This is a change in behavior, so all instances need a good
justification.  The comments added here should explain my reasoning.

qed already had a comment that suggests it always expected
bdrv_truncate()/blk_truncate() to behave as if exact=true were passed
(c743849bee came eight months before 55b949c847), so it was simply
broken until now.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-8-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
[mreitz: Changed comment in qed.c to explain why a new QED file must be
         empty, as requested and suggested by Maxim]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:08:45 +01:00
Max Reitz
c80d8b06cf block: Add @exact parameter to bdrv_co_truncate()
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk.  Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.

This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around.  All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior.  Future patches take care
of that.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:00:07 +01:00
Max Reitz
1dcaf52760 block: Implement .bdrv_has_zero_init_truncate()
We need to implement .bdrv_has_zero_init_truncate() for every block
driver that supports truncation and has a .bdrv_has_zero_init()
implementation.

Implement it the same way each driver implements .bdrv_has_zero_init().
This is at least not any more unsafe than what we had before.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19 17:13:26 +02:00
Markus Armbruster
db72581598 Include qemu/main-loop.h less
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).  It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.

Include qemu/main-loop.h only where it's needed.  Touching it now
recompiles only some 1700 objects.  For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800.  For the
others, they shrink only slightly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Kevin Wolf
d861ab3acf block: Add BlockBackend.ctx
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).

The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:22 +02:00
Vladimir Sementsov-Ogievskiy
54277a2aab block/qed: add missed coroutine_fn markers
qed_read_table and qed_write_table use coroutine-only interfaces but
are not marked coroutine_fn. Happily, they are called only from
coroutine context, so we only need to add missed markers.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30 15:29:00 +02:00
Vladimir Sementsov-Ogievskiy
696e8cb292 block/qed: use buffer-based io
Move to _co_ versions of io functions qed_read_table() and
qed_write_table(), as we use qemu_co_mutex_unlock()
anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30 15:29:00 +02:00
Peter Maydell
adf2e451f3 Block layer patches:
- Block graph change fixes (avoid loops, cope with non-tree graphs)
 - bdrv_set_aio_context() related fixes
 - HMP snapshot commands: Use only tag, not the ID to identify snapshots
 - qmeu-img, commit: Error path fixes
 - block/nvme: Build fix for gcc 9
 - MAINTAINERS updates
 - Fix various issues with bdrv_refresh_filename()
 - Fix various iotests
 - Include LUKS overhead in qemu-img measure for qcow2
 - A fix for vmdk's image creation interface
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- Block graph change fixes (avoid loops, cope with non-tree graphs)
- bdrv_set_aio_context() related fixes
- HMP snapshot commands: Use only tag, not the ID to identify snapshots
- qmeu-img, commit: Error path fixes
- block/nvme: Build fix for gcc 9
- MAINTAINERS updates
- Fix various issues with bdrv_refresh_filename()
- Fix various iotests
- Include LUKS overhead in qemu-img measure for qcow2
- A fix for vmdk's image creation interface

# gpg: Signature made Mon 25 Feb 2019 14:18:15 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# 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: (71 commits)
  iotests: Skip 211 on insufficient memory
  vmdk: false positive of compat6 with hwversion not set
  iotests: add LUKS payload overhead to 178 qemu-img measure test
  qcow2: include LUKS payload overhead in qemu-img measure
  iotests.py: s/_/-/g on keys in qmp_log()
  iotests: Let 045 be run concurrently
  iotests: Filter SSH paths
  iotests.py: Filter filename in any string value
  iotests.py: Add is_str()
  iotests: Fix 207 to use QMP filters for qmp_log
  iotests: Fix 232 for LUKS
  iotests: Remove superfluous rm from 232
  iotests: Fix 237 for Python 2.x
  iotests: Re-add filename filters
  iotests: Test json:{} filenames of internal BDSs
  block: BDS options may lack the "driver" option
  block/null: Generate filename even with latency-ns
  block/curl: Implement bdrv_refresh_filename()
  block/curl: Harmonize option defaults
  block/nvme: Fix bdrv_refresh_filename()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-02-26 19:04:47 +00:00
Max Reitz
998c201923 block: Add BDS.auto_backing_file
If the backing file is overridden, this most probably does change the
guest-visible data of a BDS.  Therefore, we will need to consider this
in bdrv_refresh_filename().

To see whether it has been overridden, we might want to compare
bs->backing_file and bs->backing->bs->filename.  However,
bs->backing_file is changed by bdrv_set_backing_hd() (which is just used
to change the backing child at runtime, without modifying the image
header), so bs->backing_file most of the time simply contains a copy of
bs->backing->bs->filename anyway, so it is useless for such a
comparison.

This patch adds an auto_backing_file BDS field which contains the
backing file path as indicated by the image header, which is not changed
by bdrv_set_backing_hd().

Because of bdrv_refresh_filename() magic, however, a BDS's filename may
differ from what has been specified during bdrv_open().  Then, the
comparison between bs->auto_backing_file and bs->backing->bs->filename
may fail even though bs->backing was opened from bs->auto_backing_file.
To mitigate this, we can copy the real BDS's filename (after the whole
bdrv_open() and bdrv_refresh_filename() process) into
bs->auto_backing_file, if we know the former has been opened based on
the latter.  This is only possible if no options modifying the backing
file's behavior have been specified, though.  To simplify things, this
patch only copies the filename from the backing file if no options have
been specified for it at all.

Furthermore, there are cases where an overlay is created by qemu which
already contains a BDS's filename (e.g. in blockdev-snapshot-sync).  We
do not need to worry about updating the overlay's bs->auto_backing_file
there, because we actually wrote a post-bdrv_refresh_filename() filename
into the image header.

So all in all, there will be false negatives where (as of a future
patch) bdrv_refresh_filename() will assume that the backing file differs
from what was specified in the image header, even though it really does
not.  However, these cases should be limited to where (1) the user
actually did override something in the backing chain (e.g. by specifying
options for the backing file), or (2) the user executed a QMP command to
change some node's backing file (e.g. change-backing-file or
block-commit with @backing-file given) where the given filename does not
happen to coincide with qemu's idea of the backing BDS's filename.

Then again, (1) really is limited to -drive.  With -blockdev or
blockdev-add, you have to adhere to the schema, so a user cannot give
partial "unimportant" options (e.g. by just setting backing.node-name
and leaving the rest to the image header).  Therefore, trying to fix
this would mean trying to fix something for -drive only.

To improve on (2), we would need a full infrastructure to "canonicalize"
an arbitrary filename (+ options), so it can be compared against
another.  That seems a bit over the top, considering that filenames
nowadays are there mostly for the user's entertainment.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-5-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:25 +01:00
Vladimir Sementsov-Ogievskiy
342544f98b block/qed: use qemu_iovec_init_buf
Use new qemu_iovec_init_buf() instead of
qemu_iovec_init_external( ... , 1), which simplifies the code.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190218140926.333779-11-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-11-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-22 09:42:13 +00:00
Kevin Wolf
4720cbeea1 block: Fix hangs in synchronous APIs with iothreads
In the block layer, synchronous APIs are often implemented by creating a
coroutine that calls the asynchronous coroutine-based implementation and
then waiting for completion with BDRV_POLL_WHILE().

For this to work with iothreads (more specifically, when the synchronous
API is called in a thread that is not the home thread of the block
device, so that the coroutine will run in a different thread), we must
make sure to call aio_wait_kick() at the end of the operation. Many
places are missing this, so that BDRV_POLL_WHILE() keeps hanging even if
the condition has long become false.

Note that bdrv_dec_in_flight() involves an aio_wait_kick() call. This
corresponds to the BDRV_POLL_WHILE() in the drain functions, but it is
generally not enough for most other operations because they haven't set
the return value in the coroutine entry stub yet. To avoid race
conditions there, we need to kick after setting the return value.

The race window is small enough that the problem doesn't usually surface
in the common path. However, it does surface and causes easily
reproducible hangs if the operation can return early before even calling
bdrv_inc/dec_in_flight, which many of them do (trivial error or no-op
success paths).

The bug in bdrv_truncate(), bdrv_check() and bdrv_invalidate_cache() is
slightly different: These functions even neglected to schedule the
coroutine in the home thread of the node. This avoids the hang, but is
obviously wrong, too. Fix those to schedule the coroutine in the right
AioContext in addition to adding aio_wait_kick() calls.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-01 13:46:44 +01:00
Markus Armbruster
4b5766488f error: Fix use of error_prepend() with &error_fatal, &error_abort
From include/qapi/error.h:

  * Pass an existing error to the caller with the message modified:
  *     error_propagate(errp, err);
  *     error_prepend(errp, "Could not frobnicate '%s': ", name);

Fei Li pointed out that doing error_propagate() first doesn't work
well when @errp is &error_fatal or &error_abort: the error_prepend()
is never reached.

Since I doubt fixing the documentation will stop people from getting
it wrong, introduce error_propagate_prepend(), in the hope that it
lures people away from using its constituents in the wrong order.
Update the instructions in error.h accordingly.

Convert existing error_prepend() next to error_propagate to
error_propagate_prepend().  If any of these get reached with
&error_fatal or &error_abort, the error messages improve.  I didn't
check whether that's the case anywhere.

Cc: Fei Li <fli@suse.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181017082702.5581-2-armbru@redhat.com>
2018-10-19 14:51:34 +02:00
Kevin Wolf
061ca8a368 block: Convert .bdrv_truncate callback to coroutine_fn
bdrv_truncate() is an operation that can block (even for a quite long
time, depending on the PreallocMode) in I/O paths that shouldn't block.
Convert it to a coroutine_fn so that we have the infrastructure for
drivers to make their .bdrv_co_truncate implementation asynchronous.

This change could potentially introduce new race conditions because
bdrv_truncate() isn't necessarily executed atomically any more. Whether
this is a problem needs to be evaluated for each block driver that
supports truncate:

* file-posix/win32, gluster, iscsi, nfs, rbd, ssh, sheepdog: The
  protocol drivers are trivially safe because they don't actually yield
  yet, so there is no change in behaviour.

* copy-on-read, crypto, raw-format: Essentially just filter drivers that
  pass the request to a child node, no problem.

* qcow2: The implementation modifies metadata, so it needs to hold
  s->lock to be safe with concurrent I/O requests. In order to avoid
  double locking, this requires pulling the locking out into
  preallocate_co() and using qcow2_write_caches() instead of
  bdrv_flush().

* qed: Does a single header update, this is fine without locking.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-29 14:20:56 +02:00
Markus Armbruster
af91062ee1 block: Factor out qobject_input_visitor_new_flat_confused()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Markus Armbruster
92adf9dbcd block: Clean up a misuse of qobject_to() in .bdrv_co_create_opts()
The following pattern occurs in the .bdrv_co_create_opts() methods of
parallels, qcow, qcow2, qed, vhdx and vpc:

    qobj = qdict_crumple_for_keyval_qiv(qdict, errp);
    qobject_unref(qdict);
    qdict = qobject_to(QDict, qobj);
    if (qdict == NULL) {
         ret = -EINVAL;
         goto done;
    }

    v = qobject_input_visitor_new_keyval(QOBJECT(qdict));
    [...]
    ret = 0;
done:
    qobject_unref(qdict);
    [...]
    return ret;

If qobject_to() fails, we return failure without setting errp.  That's
wrong.  As far as I can tell, it cannot fail here.  Clean it up
anyway, by removing the useless conversion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Markus Armbruster
e5af0da1dc block: Fix -blockdev for certain non-string scalars
Configuration flows through the block subsystem in a rather peculiar
way.  Configuration made with -drive enters it as QemuOpts.
Configuration made with -blockdev / blockdev-add enters it as QAPI
type BlockdevOptions.  The block subsystem uses QDict, QemuOpts and
QAPI types internally.  The precise flow is next to impossible to
explain (I tried for this commit message, but gave up after wasting
several hours).  What I can explain is a flaw in the BlockDriver
interface that leads to this bug:

    $ qemu-system-x86_64 -blockdev node-name=n1,driver=nfs,server.type=inet,server.host=localhost,path=/foo/bar,user=1234
    qemu-system-x86_64: -blockdev node-name=n1,driver=nfs,server.type=inet,server.host=localhost,path=/foo/bar,user=1234: Internal error: parameter user invalid

QMP blockdev-add is broken the same way.

Here's what happens.  The block layer passes configuration represented
as flat QDict (with dotted keys) to BlockDriver methods
.bdrv_file_open().  The QDict's members are typed according to the
QAPI schema.

nfs_file_open() converts it to QAPI type BlockdevOptionsNfs, with
qdict_crumple() and a qobject input visitor.

This visitor comes in two flavors.  The plain flavor requires scalars
to be typed according to the QAPI schema.  That's the case here.  The
keyval flavor requires string scalars.  That's not the case here.
nfs_file_open() uses the latter, and promptly falls apart for members
@user, @group, @tcp-syn-count, @readahead-size, @page-cache-size,
@debug.

Switching to the plain flavor would fix -blockdev, but break -drive,
because there the scalars arrive in nfs_file_open() as strings.

The proper fix would be to replace the QDict by QAPI type
BlockdevOptions in the BlockDriver interface.  Sadly, that's beyond my
reach right now.

Next best would be to fix the block layer to always pass correctly
typed QDicts to the BlockDriver methods.  Also beyond my reach.

What I can do is throw another hack onto the pile: have
nfs_file_open() convert all members to string, so use of the keyval
flavor actually works, by replacing qdict_crumple() by new function
qdict_crumple_for_keyval_qiv().

The pattern "pass result of qdict_crumple() to
qobject_input_visitor_new_keyval()" occurs several times more:

* qemu_rbd_open()

  Same issue as nfs_file_open(), but since BlockdevOptionsRbd has only
  string members, its only a latent bug.  Fix it anyway.

* parallels_co_create_opts(), qcow_co_create_opts(),
  qcow2_co_create_opts(), bdrv_qed_co_create_opts(),
  sd_co_create_opts(), vhdx_co_create_opts(), vpc_co_create_opts()

  These work, because they create the QDict with
  qemu_opts_to_qdict_filtered(), which creates only string scalars.
  The function sports a TODO comment asking for better typing; that's
  going to be fun.  Use qdict_crumple_for_keyval_qiv() to be safe.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Max Reitz
609f45ea95 block: Add block-specific QDict header
There are numerous QDict functions that have been introduced for and are
used only by the block layer.  Move their declarations into an own
header file to reflect that.

While qdict_extract_subqdict() is in fact used outside of the block
layer (in util/qemu-config.c), it is still a function related very
closely to how the block layer works with nested QDicts, namely by
sometimes flattening them.  Therefore, its declaration is put into this
header as well and util/qemu-config.c includes it with a comment stating
exactly which function it needs.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20180509165530.29561-7-mreitz@redhat.com>
[Copyright note tweaked, superfluous includes dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Eric Blake
e18a58b4e3 block: Merge .bdrv_co_writev{,_flags} in drivers
We have too many driver callback interfaces; simplify the mess
somewhat by merging the flags parameter of .bdrv_co_writev_flags()
into .bdrv_co_writev().  Note that as long as a driver doesn't set
.supported_write_flags, the flags argument will be 0 and behavior is
identical.  Also note that the public function bdrv_co_writev() still
lacks a flags argument; so the driver signature is thus intentionally
slightly different.  But that's not the end of the world, nor the first
time that the driver interface differs slightly from the public
interface.

Ideally, we should be rewriting all of these drivers to use modern
byte-based interfaces.  But that's a more invasive patch to write
and audit, compared to the simplification done here.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-15 16:11:41 +02:00
Marc-André Lureau
cb3e7f08ae qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF
Now that we can safely call QOBJECT() on QObject * as well as its
subtypes, we can have macros qobject_ref() / qobject_unref() that work
everywhere instead of having to use QINCREF() / QDECREF() for QObject
and qobject_incref() / qobject_decref() for its subtypes.

The replacement is mechanical, except I broke a long line, and added a
cast in monitor_qmp_cleanup_req_queue_locked().  Unlike
qobject_decref(), qobject_unref() doesn't accept void *.

Note that the new macros evaluate their argument exactly once, thus no
need to shout them.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180419150145.24795-4-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Rebased, semantic conflict resolved, commit message improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-05-04 08:27:53 +02:00
Max Reitz
7dc847ebba qapi: Replace qobject_to_X(o) by qobject_to(X, o)
This patch was generated using the following Coccinelle script:

@@
expression Obj;
@@
(
- qobject_to_qnum(Obj)
+ qobject_to(QNum, Obj)
|
- qobject_to_qstring(Obj)
+ qobject_to(QString, Obj)
|
- qobject_to_qdict(Obj)
+ qobject_to(QDict, Obj)
|
- qobject_to_qlist(Obj)
+ qobject_to(QList, Obj)
|
- qobject_to_qbool(Obj)
+ qobject_to(QBool, Obj)
)

and a bit of manual fix-up for overly long lines and three places in
tests/check-qjson.c that Coccinelle did not find.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-4-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: swap order from qobject_to(o, X), rebase to master, also a fix
to latent false-positive compiler complaint about hw/i386/acpi-build.c]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-19 14:58:36 -05:00
Kevin Wolf
959355a476 qed: Support .bdrv_co_create
This adds the .bdrv_co_create driver callback to qed, which
enables image creation over QMP.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-03-19 12:01:39 +01:00
Paolo Bonzini
2fd6163884 block: convert bdrv_check callback to coroutine_fn
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-8-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Paolo Bonzini
2b148f392b block: convert bdrv_invalidate_cache callback to coroutine_fn
QED's bdrv_invalidate_cache implementation would like to reuse functions
that acquire/release the metadata locks.  Call it from coroutine context
to simplify the logic.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-6-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00