qemu/block/meson.build
Emanuele Giuseppe Esposito c86422c554 block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed
BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01 16:52:32 +01:00

158 lines
4.2 KiB
Meson

block_ss.add(genh)
block_ss.add(files(
'accounting.c',
'aio_task.c',
'amend.c',
'backup.c',
'copy-before-write.c',
'blkdebug.c',
'blklogwrites.c',
'blkverify.c',
'block-backend.c',
'block-copy.c',
'graph-lock.c',
'commit.c',
'copy-on-read.c',
'preallocate.c',
'progress_meter.c',
'create.c',
'crypto.c',
'dirty-bitmap.c',
'filter-compress.c',
'io.c',
'mirror.c',
'nbd.c',
'null.c',
'qapi.c',
'qcow2-bitmap.c',
'qcow2-cache.c',
'qcow2-cluster.c',
'qcow2-refcount.c',
'qcow2-snapshot.c',
'qcow2-threads.c',
'qcow2.c',
'quorum.c',
'raw-format.c',
'reqlist.c',
'snapshot.c',
'snapshot-access.c',
'throttle-groups.c',
'throttle.c',
'vhdx-endian.c',
'vhdx-log.c',
'vhdx.c',
'vmdk.c',
'vpc.c',
'write-threshold.c',
), zstd, zlib, gnutls)
softmmu_ss.add(when: 'CONFIG_TCG', if_true: files('blkreplay.c'))
softmmu_ss.add(files('block-ram-registrar.c'))
if get_option('qcow1').allowed()
block_ss.add(files('qcow.c'))
endif
if get_option('vdi').allowed()
block_ss.add(files('vdi.c'))
endif
if get_option('cloop').allowed()
block_ss.add(files('cloop.c'))
endif
if get_option('bochs').allowed()
block_ss.add(files('bochs.c'))
endif
if get_option('vvfat').allowed()
block_ss.add(files('vvfat.c'))
endif
if get_option('dmg').allowed()
block_ss.add(files('dmg.c'))
endif
if get_option('qed').allowed()
block_ss.add(files(
'qed-check.c',
'qed-cluster.c',
'qed-l2-cache.c',
'qed-table.c',
'qed.c',
))
endif
if get_option('parallels').allowed()
block_ss.add(files('parallels.c', 'parallels-ext.c'))
endif
block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c'))
block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
block_ss.add(when: libiscsi, if_true: files('iscsi-opts.c'))
block_ss.add(when: 'CONFIG_LINUX', if_true: files('nvme.c'))
if not get_option('replication').disabled()
block_ss.add(files('replication.c'))
endif
block_ss.add(when: libaio, if_true: files('linux-aio.c'))
block_ss.add(when: linux_io_uring, if_true: files('io_uring.c'))
block_modules = {}
modsrc = []
foreach m : [
[blkio, 'blkio', files('blkio.c')],
[curl, 'curl', files('curl.c')],
[glusterfs, 'gluster', files('gluster.c')],
[libiscsi, 'iscsi', [files('iscsi.c'), libm]],
[libnfs, 'nfs', files('nfs.c')],
[libssh, 'ssh', files('ssh.c')],
[rbd, 'rbd', files('rbd.c')],
]
if m[0].found()
module_ss = ss.source_set()
module_ss.add(when: m[0], if_true: m[2])
if enable_modules
modsrc += module_ss.all_sources()
endif
block_modules += {m[1] : module_ss}
endif
endforeach
# those are not exactly regular block modules, so treat them apart
if get_option('dmg').allowed()
foreach m : [
[liblzfse, 'dmg-lzfse', liblzfse, 'dmg-lzfse.c'],
[libbzip2, 'dmg-bz2', [glib, libbzip2], 'dmg-bz2.c']
]
if m[0].found()
module_ss = ss.source_set()
module_ss.add(when: m[2], if_true: files(m[3]))
block_modules += {m[1] : module_ss}
endif
endforeach
endif
module_block_py = find_program('../scripts/modules/module_block.py')
module_block_h = custom_target('module_block.h',
output: 'module_block.h',
input: modsrc,
command: [module_block_py, '@OUTPUT0@', modsrc])
block_ss.add(module_block_h)
wrapper_py = find_program('../scripts/block-coroutine-wrapper.py')
block_gen_c = custom_target('block-gen.c',
output: 'block-gen.c',
input: files(
'../include/block/block-io.h',
'../include/block/dirty-bitmap.h',
'../include/block/block_int-io.h',
'../include/block/block-global-state.h',
'../include/sysemu/block-backend-io.h',
'coroutines.h'
),
command: [wrapper_py, '@OUTPUT@', '@INPUT@'])
block_ss.add(block_gen_c)
block_ss.add(files('stream.c'))
softmmu_ss.add(files('qapi-sysemu.c'))
subdir('export')
subdir('monitor')
modules += {'block': block_modules}