qemu/block
Stefan Hajnoczi cf4fbc3030 block/nvme: fix infinite loop in nvme_free_req_queue_cb()
When the request free list is exhausted the coroutine waits on
q->free_req_queue for the next free request. Whenever a request is
completed a BH is scheduled to invoke nvme_free_req_queue_cb() and wake
up waiting coroutines.

1. nvme_get_free_req() waits for a free request:

    while (q->free_req_head == -1) {
        ...
            trace_nvme_free_req_queue_wait(q->s, q->index);
            qemu_co_queue_wait(&q->free_req_queue, &q->lock);
        ...
    }

2. nvme_free_req_queue_cb() wakes up the coroutine:

    while (qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
       ^--- infinite loop when free_req_head == -1
    }

nvme_free_req_queue_cb() and the coroutine form an infinite loop when
q->free_req_head == -1. Fix this by checking q->free_req_head in
nvme_free_req_queue_cb(). If the free request list is exhausted, don't
wake waiting coroutines. Eventually an in-flight request will complete
and the BH will be scheduled again, guaranteeing forward progress.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20211208152246.244585-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-12-09 09:19:49 +00:00
..
export block/export/fuse.c: fix musl build 2021-11-02 13:02:46 +01:00
monitor block/monitor: Consolidate hmp_handle_error calls to reduce redundant code 2021-09-01 12:57:31 +02:00
accounting.c
aio_task.c block/aio_task: assert max_busy_tasks is greater than 0 2021-10-05 18:56:41 +02:00
amend.c
backup.c jobs: Give Job.force_cancel more meaning 2021-10-07 10:42:34 +02:00
blkdebug.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
blklogwrites.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
blkreplay.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
blkverify.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
block-backend.c block-backend: Silence clang -m32 compiler warning 2021-11-02 13:22:09 +01:00
block-copy.c block/block-copy: block_copy_state_new(): drop extra arguments 2021-09-01 14:38:08 +02:00
block-gen.h
bochs.c block: use int64_t instead of uint64_t in driver read handlers 2021-09-29 13:46:31 -05:00
cloop.c block: use int64_t instead of uint64_t in driver read handlers 2021-09-29 13:46:31 -05:00
commit.c block: use int64_t instead of uint64_t in driver read handlers 2021-09-29 13:46:31 -05:00
copy-before-write.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
copy-before-write.h block/copy-before-write: bdrv_cbw_append(): drop unused compress arg 2021-09-01 14:03:47 +02:00
copy-on-read.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
copy-on-read.h
coroutines.h block-backend: drop blk_prw, use block-coroutine-wrapper 2021-10-15 15:53:24 -05:00
create.c
crypto.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
crypto.h
curl.c block: use int64_t instead of uint64_t in driver read handlers 2021-09-29 13:46:31 -05:00
dirty-bitmap.c iotests: Improve and rename test 291 to qemu-img-bitmap 2021-07-21 14:14:41 -05:00
dmg-bz2.c
dmg-lzfse.c
dmg.c block: use int64_t instead of uint64_t in driver read handlers 2021-09-29 13:46:31 -05:00
dmg.h
file-posix.c file-posix: Fix alignment after reopen changing O_DIRECT 2021-11-16 11:30:29 +01:00
file-win32.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
filter-compress.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
gluster.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
io.c block: introduce max_hw_iov for use in scsi-generic 2021-10-06 10:25:55 +02:00
io_uring.c block/io_uring: resubmit when result is -EAGAIN 2021-07-29 17:14:55 +01:00
iscsi-opts.c
iscsi.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
linux-aio.c linux-aio: add dev_max_batch parameter to laio_io_unplug() 2021-11-02 13:03:35 +01:00
meson.build configure, meson: move libaio check to meson.build 2021-10-14 09:50:57 +02:00
mirror.c mirror: Do not clear .cancelled 2021-10-07 10:42:50 +02:00
nbd.c block/nbd: check that received handle is valid 2021-09-29 13:46:33 -05:00
nfs.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
null.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
nvme.c block/nvme: fix infinite loop in nvme_free_req_queue_cb() 2021-12-09 09:19:49 +00:00
parallels-ext.c
parallels.c
parallels.h
preallocate.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
progress_meter.c
qapi-sysemu.c
qapi.c
qcow.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
qcow2-bitmap.c
qcow2-cache.c
qcow2-cluster.c qcow2: Silence clang -m32 compiler warning 2021-10-15 15:39:38 -05:00
qcow2-refcount.c qcow2-refcount: check_refblocks(): add separate message for reserved 2021-09-15 18:42:38 +02:00
qcow2-snapshot.c
qcow2-threads.c
qcow2.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
qcow2.h qcow2-refcount: check_refblocks(): add separate message for reserved 2021-09-15 18:42:38 +02:00
qed-check.c
qed-cluster.c
qed-l2-cache.c
qed-table.c
qed.c block: use int64_t instead of int in driver write_zeroes handlers 2021-09-29 13:46:32 -05:00
qed.h
quorum.c block: use int64_t instead of int in driver write_zeroes handlers 2021-09-29 13:46:32 -05:00
raw-format.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
rbd.c block/rbd: implement bdrv_co_block_status 2021-11-02 13:02:46 +01:00
replication.c job: @force parameter for job_cancel_sync() 2021-10-07 10:42:09 +02:00
snapshot.c
ssh.c
stream.c stream: Traverse graph after modification 2021-11-16 09:43:23 +01:00
throttle-groups.c
throttle.c block: use int64_t instead of int in driver discard handlers 2021-09-29 13:46:32 -05:00
trace-events block/nvme: Display CQ/SQ pointer in nvme_free_queue_pair() 2021-11-02 15:49:12 +01:00
trace.h
vdi.c block: use int64_t instead of uint64_t in driver write handlers 2021-09-29 13:46:31 -05:00
vhdx-endian.c
vhdx-log.c
vhdx.c
vhdx.h
vmdk.c vmdk: allow specification of tools version 2021-11-02 12:47:51 +01:00
vpc.c block/vpc: Add a sanity check that fixed-size images have the right type 2021-11-02 12:47:51 +01:00
vvfat.c block/vvfat.c fix leak when failure occurs 2021-11-23 15:39:12 +01:00
win32-aio.c
write-threshold.c