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From: Stefan Hajnoczi <stefanha@redhat.com>
To: qemu-devel@nongnu.org
Cc: Hanna Reitz <hreitz@redhat.com>, Kevin Wolf <kwolf@redhat.com>,
	qemu-block@nongnu.org,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>
Subject: [PATCH v2 0/3] block: protect BlockBackend->queued_requests with a lock
Date: Tue,  7 Mar 2023 16:04:24 -0500	[thread overview]
Message-ID: <20230307210427.269214-1-stefanha@redhat.com> (raw)

v2:
- Use qatomic_fetch_inc/dec() for readability in Patch 1 [Hanna]

QEMU block layer multi-queue support involves running I/O requests from
multiple threads. Shared state must be protected somehow to avoid thread-safety
issues.

The BlockBackend->queued_requests CoQueue is accessed without a lock and will
likely be corrupted when multiple threads queue requests at the same time.

This patch series make BlockBackend->queued_requests thread-safe.

Stefan Hajnoczi (3):
  block: make BlockBackend->quiesce_counter atomic
  block: make BlockBackend->disable_request_queuing atomic
  block: protect BlockBackend->queued_requests with a lock

 block/block-backend.c | 37 ++++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 11 deletions(-)

-- 
2.39.2



             reply	other threads:[~2023-03-07 21:05 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-07 21:04 Stefan Hajnoczi [this message]
2023-03-07 21:04 ` [PATCH v2 1/3] block: make BlockBackend->quiesce_counter atomic Stefan Hajnoczi
2023-03-07 21:10   ` Philippe Mathieu-Daudé
2023-03-07 21:04 ` [PATCH v2 2/3] block: make BlockBackend->disable_request_queuing atomic Stefan Hajnoczi
2023-03-07 21:10   ` Philippe Mathieu-Daudé
2023-03-09  9:07   ` Paolo Bonzini
2023-03-09 12:31     ` Stefan Hajnoczi
2023-03-09 13:37       ` Paolo Bonzini
2023-03-09 11:18   ` Paolo Bonzini
2023-03-09 12:12     ` Stefan Hajnoczi
2023-03-07 21:04 ` [PATCH v2 3/3] block: protect BlockBackend->queued_requests with a lock Stefan Hajnoczi
2023-03-08  9:46 ` [PATCH v2 0/3] " Kevin Wolf

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