Add more annotations to functions, describing valid and invalid
calls from coroutine to non-coroutine context.
When applied to a function, no_coroutine_fn advertises that it should
not be called from coroutine_fn functions. This can be because the
function blocks or, in the case of generated_co_wrapper, to enforce
that coroutine_fn functions directly call the coroutine_fn that backs
the generated_co_wrapper.
coroutine_mixed_fn instead is for function that can be called in
both coroutine and non-coroutine context, but will suspend when
called in coroutine context. Annotating them is a first step
towards enforcing that non-annotated functions are absolutely
not going to suspend.
These can be used for example with the vrc tool:
# find functions that *really* cannot be called from no_coroutine_fn
(vrc) load --loader clang libblock.fa.p/meson-generated_.._block_block-gen.c.o
(vrc) paths [no_coroutine_fn,!coroutine_mixed_fn]
bdrv_remove_persistent_dirty_bitmap
bdrv_create
bdrv_can_store_new_dirty_bitmap
# find how coroutine_fns end up calling a mixed function
(vrc) load --loader clang --force libblock.fa.p/*.c.o
(vrc) paths [coroutine_fn] [!no_coroutine_fn]* [coroutine_mixed_fn]
...
bdrv_pread <- vhdx_log_write <- vhdx_log_write_and_flush <- vhdx_co_writev
...
Signed-off-by: Alberto Faria <afaria@redhat.com>
[Rebase, add coroutine_mixed_fn. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221216110758.559947-3-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Clang has a generic __annotate__ attribute that can be used by
static analyzers to understand properties of functions and
analyze the control flow. Furthermore, unlike TSA annotations, the
__annotate__ attribute applies to function pointers as well.
As a first step towards static analysis of coroutine_fn markers,
attach the attribute to the marker when compiling with clang.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221216110758.559947-2-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Setting it to true can cause the device size to be queried from libblkio
in otherwise fast paths, degrading performance. Set it to false and
require users to refresh the device size explicitly instead.
Fixes: 4c8f4fda05 ("block/blkio: Tolerate device size changes")
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20221108144433.1334074-1-afaria@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The nvme-io_uring driver expects a character special file such as
/dev/ng0n1. Follow the convention of having a "filename" option when a
regular file is expected, and a "path" option otherwise.
This makes io_uring the only libblkio-based driver with a "filename"
option, as it accepts a regular file (even though it can also take a
block special file).
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-id: 20221028233854.839933-1-afaria@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Some libblkio drivers may be able to work with regular files (e.g.,
io_uring) or otherwise resizable devices. Conservatively set
BlockDriver::has_variable_length to true to ensure bdrv_nb_sectors()
always gives up-to-date results.
Also implement BlockDriver::bdrv_co_truncate for the case where no
preallocation is needed and the device already has a size compatible
with what was requested.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-id: 20221029122031.975273-1-afaria@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Keep generated_co_wrapper and coroutine_fn pairs together. This should
make it clear that each I/O function has these two versions.
Also move blk_co_{pread,pwrite}()'s implementations out of the header
file for consistency.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220705161527.1054072-18-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
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>
For consistency with other I/O functions, and in preparation to
implement it using generated_co_wrapper.
Callers were updated using this Coccinelle script:
@@ expression blk, offset, buf, bytes; @@
- blk_pread(blk, offset, buf, bytes)
+ blk_pread(blk, offset, buf, bytes, 0)
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: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-3-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
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.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20220705161527.1054072-2-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
bdrv_{pread,pwrite}() now return -EIO instead of -EINVAL when 'bytes' is
negative, making them consistent with bdrv_{preadv,pwritev}() and
bdrv_co_{pread,pwrite,preadv,pwritev}().
bdrv_pwrite_zeroes() now also calls trace_bdrv_co_pwrite_zeroes() and
clears the BDRV_REQ_MAY_UNMAP flag when appropriate, which it didn't
previously.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20220609152744.3891847-8-afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
For consistency with other I/O functions, and in preparation to
implement bdrv_{pread,pwrite}() using generated_co_wrapper.
unsigned int fits in int64_t, so all callers remain correct.
bdrv_check_request32() is called further down the stack and causes -EIO
to be returned if 'bytes' is negative or greater than
BDRV_REQUEST_MAX_BYTES, which in turns never exceeds SIZE_MAX.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20220609152744.3891847-7-afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
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>
Alberto Faria