qemu/block
Stefan Hajnoczi 195332c1d9 block/export: rewrite vduse-blk drain code
vduse_blk_detach_ctx() waits for in-flight requests using
AIO_WAIT_WHILE(). This is not allowed according to a comment in
bdrv_set_aio_context_commit():

  /*
   * Take the old AioContex when detaching it from bs.
   * At this point, new_context lock is already acquired, and we are now
   * also taking old_context. This is safe as long as bdrv_detach_aio_context
   * does not call AIO_POLL_WHILE().
   */

Use this opportunity to rewrite the drain code in vduse-blk:

- Use the BlockExport refcount so that vduse_blk_exp_delete() is only
  called when there are no more requests in flight.

- Implement .drained_poll() so in-flight request coroutines are stopped
  by the time .bdrv_detach_aio_context() is called.

- Remove AIO_WAIT_WHILE() from vduse_blk_detach_ctx() to solve the
  .bdrv_detach_aio_context() constraint violation. It's no longer
  needed due to the previous changes.

- Always handle the VDUSE file descriptor, even in drained sections. The
  VDUSE file descriptor doesn't submit I/O, so it's safe to handle it in
  drained sections. This ensures that the VDUSE kernel code gets a fast
  response.

- Suspend virtqueue fd handlers in .drained_begin() and resume them in
  .drained_end(). This eliminates the need for the
  aio_set_fd_handler(is_external=true) flag, which is being removed from
  QEMU.

This is a long list but splitting it into individual commits would
probably lead to git bisect failures - the changes are all related.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230516190238.8401-14-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30 17:32:02 +02:00
..
export block/export: rewrite vduse-blk drain code 2023-05-30 17:32:02 +02:00
monitor block/monitor: Fix crash when executing HMP commit 2023-04-25 15:11:57 +02:00
accounting.c block: add missed block_acct_setup with new block device init procedure 2022-09-30 18:42:34 +02:00
aio_task.c block/aio_task: assert max_busy_tasks is greater than 0 2021-10-05 18:56:41 +02:00
amend.c block: Mark BlockDriver callbacks for amend job GRAPH_RDLOCK 2023-05-10 14:16:54 +02:00
backup.c Block layer patches 2023-02-24 15:09:39 +00:00
blkdebug.c blkdebug: add missing coroutine_fn annotation 2023-04-25 13:17:28 +02:00
blkio.c block: Convert bdrv_get_info() to co_wrapper_mixed 2023-02-01 16:52:32 +01:00
blklogwrites.c block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK 2023-02-23 19:49:33 +01:00
blkreplay.c block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK 2023-02-23 19:49:33 +01:00
blkverify.c block: Mark bdrv_recurse_can_replace() and callers GRAPH_RDLOCK 2023-05-10 14:16:54 +02:00
block-backend.c block: add blk_in_drain() API 2023-05-30 17:32:02 +02:00
block-copy.c block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK 2023-02-23 19:49:14 +01:00
block-gen.h block-coroutine-wrapper.py: support also basic return types 2022-12-15 16:07:43 +01:00
block-ram-registrar.c block: add BlockRAMRegistrar 2022-10-26 14:56:42 -04:00
bochs.c block: Mark public read/write functions GRAPH_RDLOCK 2023-02-23 19:49:17 +01:00
cloop.c include/block: Untangle inclusion loops 2023-01-20 07:24:28 +01:00
commit.c blockjob: Adhere to rate limit even when reentered early 2023-05-19 19:12:12 +02:00
copy-before-write.c copy-before-write: Fix open with child in iothread 2023-05-30 17:29:35 +02:00
copy-before-write.h block/copy-before-write.h: global state API + assertions 2022-03-04 18:18:25 +01:00
copy-on-read.c block: remove has_variable_length from filters 2023-04-11 16:38:56 +02:00
copy-on-read.h Clean up ill-advised or unusual header guards 2022-05-11 16:50:01 +02:00
coroutines.h nbd: Mark nbd_co_do_establish_connection() and callers GRAPH_RDLOCK 2023-05-10 14:16:53 +02:00
create.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
crypto.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
crypto.h nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
curl.c block: Handle curl 7.55.0, 7.85.0 version changes 2023-02-17 14:33:52 +01:00
dirty-bitmap.c block: Mark bdrv_*_dirty_bitmap() and callers GRAPH_RDLOCK 2023-02-23 19:49:32 +01:00
dmg-bz2.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
dmg-lzfse.c block/dmg: Ignore C99 prototype declaration mismatch from <lzfse.h> 2023-03-30 15:03:36 +02:00
dmg.c block/dmg: Declare a type definition for DMG uncompress function 2023-04-24 13:53:44 -04:00
dmg.h block/dmg: Declare a type definition for DMG uncompress function 2023-04-24 13:53:44 -04:00
file-posix.c block: add some trace events for zone append 2023-05-15 08:18:10 -04:00
file-win32.c thread-pool: avoid passing the pool parameter every time 2023-04-25 13:17:28 +02:00
filter-compress.c block: remove has_variable_length from filters 2023-04-11 16:38:56 +02:00
gluster.c block: Convert bdrv_get_allocated_file_size() to co_wrapper 2023-02-01 16:52:32 +01:00
graph-lock.c graph-lock: Disable locking for now 2023-05-19 19:16:53 +02:00
io_uring.c block: introduce zone append write for zoned devices 2023-05-15 08:18:10 -04:00
io.c block: drain from main loop thread in bdrv_co_yield_to_drain() 2023-05-30 17:32:02 +02:00
iscsi-opts.c modules: add block module annotations 2021-07-09 18:20:27 +02:00
iscsi.c block: Mark bdrv_co_copy_range() GRAPH_RDLOCK 2023-02-23 19:49:20 +01:00
linux-aio.c block: introduce zone append write for zoned devices 2023-05-15 08:18:10 -04:00
meson.build block/meson.build: prefer positive condition for replication 2023-05-10 18:48:11 +02:00
mirror.c mirror: Hold main AioContext lock for calling bdrv_open_backing_file() 2023-05-30 17:21:23 +02:00
nbd.c nbd: Mark nbd_co_do_establish_connection() and callers GRAPH_RDLOCK 2023-05-10 14:16:53 +02:00
nfs.c block/nfs: do not poll within a coroutine 2023-04-12 18:26:51 +02:00
null.c block: Convert bdrv_get_allocated_file_size() to co_wrapper 2023-02-01 16:52:32 +01:00
nvme.c block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed 2023-02-01 16:52:32 +01:00
parallels-ext.c include/block: Untangle inclusion loops 2023-01-20 07:24:28 +01:00
parallels.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
parallels.h parallels: support bitmap extension for read-only mode 2021-03-08 14:56:55 +01:00
preallocate.c block: remove has_variable_length from filters 2023-04-11 16:38:56 +02:00
progress_meter.c coroutine: Clean up superfluous inclusion of qemu/lockable.h 2023-01-19 10:18:28 +01:00
qapi-sysemu.c block: Take main AioContext lock when calling bdrv_open() 2023-05-30 17:21:23 +02:00
qapi.c block: add accounting for zone append operation 2023-05-15 08:18:10 -04:00
qcow2-bitmap.c qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK 2023-04-25 13:17:28 +02:00
qcow2-cache.c include/block: Untangle inclusion loops 2023-01-20 07:24:28 +01:00
qcow2-cluster.c qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK 2023-04-25 13:17:28 +02:00
qcow2-refcount.c qcow2: Don't call bdrv_getlength() in coroutine_fns 2023-05-10 14:16:53 +02:00
qcow2-snapshot.c qcow2: mark various functions as coroutine_fn and GRAPH_RDLOCK 2023-04-25 13:17:28 +02:00
qcow2-threads.c thread-pool: avoid passing the pool parameter every time 2023-04-25 13:17:28 +02:00
qcow2.c qcow2: Fix open with 'file' in iothread 2023-05-30 17:21:23 +02:00
qcow2.h qcow2: Don't call bdrv_getlength() in coroutine_fns 2023-05-10 14:16:53 +02:00
qcow.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
qed-check.c block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK 2023-02-23 19:49:12 +01:00
qed-cluster.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-l2-cache.c osdep: Move memalign-related functions to their own header 2022-03-07 13:16:49 +00:00
qed-table.c block: Mark public read/write functions GRAPH_RDLOCK 2023-02-23 19:49:17 +01:00
qed.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
qed.h block: Mark public read/write functions GRAPH_RDLOCK 2023-02-23 19:49:17 +01:00
quorum.c block: Mark bdrv_recurse_can_replace() and callers GRAPH_RDLOCK 2023-05-10 14:16:54 +02:00
raw-format.c raw-format: Fix open with 'file' in iothread 2023-05-30 17:21:23 +02:00
rbd.c block/rbd: Add support for layered encryption 2023-02-23 19:49:35 +01:00
replication.c block: remove has_variable_length from filters 2023-04-11 16:38:56 +02:00
reqlist.c block/reqlist: add reqlist_wait_all() 2022-03-07 09:33:30 +01:00
snapshot-access.c block: Mark preadv_snapshot/snapshot_block_status GRAPH_RDLOCK 2023-02-23 19:49:21 +01:00
snapshot.c block/snapshot: drop indirection around bdrv_snapshot_fallback_ptr 2022-10-27 20:14:11 +02:00
ssh.c block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed 2023-02-01 16:52:32 +01:00
stream.c blockjob: Adhere to rate limit even when reentered early 2023-05-19 19:12:12 +02:00
throttle-groups.c block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes 2021-02-03 08:14:00 -06:00
throttle.c block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK 2023-02-23 19:49:33 +01:00
trace-events block: add some trace events for zone append 2023-05-15 08:18:10 -04:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
vdi.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
vhdx-endian.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vhdx-log.c block/vhdx: fix dynamic VHDX BAT corruption 2023-04-11 13:53:03 +02:00
vhdx.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
vhdx.h block/vhdx: Use IEC binary prefixes for size constants 2019-04-30 15:29:00 +02:00
vmdk.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
vpc.c block: Call .bdrv_co_create(_opts) unlocked 2023-05-19 19:12:12 +02:00
vvfat.c vvfat: mark various functions as coroutine_fn 2023-04-25 13:17:28 +02:00
win32-aio.c include/block: Untangle inclusion loops 2023-01-20 07:24:28 +01:00
write-threshold.c include/block: Untangle inclusion loops 2023-01-20 07:24:28 +01:00