Christian Brauner brauner@kernel.org wrote:
From: Lukas Schauer lukas@schauer.dev
Commit c73be61cede5 ("pipe: Add general notification queue support") a regression was introduced that would lock up resized pipes under certain conditions. See the reproducer in [1].
The commit resizing the pipe ring size was moved to a different function, doing that moved the wakeup for pipe->wr_wait before actually raising pipe->max_usage. If a pipe was full before the resize occured it would result in the wakeup never actually triggering pipe_write.
Set @max_usage and @nr_accounted before waking writers if this isn't a watch queue.
Fixes: c73be61cede5 ("pipe: Add general notification queue support") Link: https://bugzilla.kernel.org/show_bug.cgi?id=212295 [1] Cc: stable@vger.kernel.org [Christian Brauner brauner@kernel.org: rewrite to account for watch queues] Signed-off-by: Christian Brauner brauner@kernel.org
Reviewed-by: David Howells dhowells@redhat.com