From 71b5267ed33f9e60bc98acbabcbed62f01a96ff4 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 30 Mar 2020 11:19:23 +0100 Subject: [PATCH 3/4] Revert "mirror: Don't let an operation wait for itself" RH-Author: Kevin Wolf Message-id: <20200330111924.22938-2-kwolf@redhat.com> Patchwork-id: 94464 O-Subject: [RHEL-AV-8.2.0 qemu-kvm PATCH 1/2] Revert "mirror: Don't let an operation wait for itself" Bugzilla: 1794692 RH-Acked-by: Maxim Levitsky RH-Acked-by: Danilo de Paula RH-Acked-by: Max Reitz This reverts commit 7e6c4ff792734e196c8ca82564c56b5e7c6288ca. The fix was incomplete as it only protected against requests waiting for themselves, but not against requests waiting for each other. We need a different solution. Signed-off-by: Kevin Wolf Message-Id: <20200326153628.4869-2-kwolf@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf (cherry picked from commit 9178f4fe5f083064f5c91f04d98c815ce5a5af1c) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- block/mirror.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index cacbc70..8959e42 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -283,14 +283,11 @@ static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset, } static inline void coroutine_fn -mirror_wait_for_any_operation(MirrorBlockJob *s, MirrorOp *self, bool active) +mirror_wait_for_any_operation(MirrorBlockJob *s, bool active) { MirrorOp *op; QTAILQ_FOREACH(op, &s->ops_in_flight, next) { - if (self == op) { - continue; - } /* Do not wait on pseudo ops, because it may in turn wait on * some other operation to start, which may in fact be the * caller of this function. Since there is only one pseudo op @@ -305,10 +302,10 @@ mirror_wait_for_any_operation(MirrorBlockJob *s, MirrorOp *self, bool active) } static inline void coroutine_fn -mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s, MirrorOp *self) +mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s) { /* Only non-active operations use up in-flight slots */ - mirror_wait_for_any_operation(s, self, false); + mirror_wait_for_any_operation(s, false); } /* Perform a mirror copy operation. @@ -351,7 +348,7 @@ static void coroutine_fn mirror_co_read(void *opaque) while (s->buf_free_count < nb_chunks) { trace_mirror_yield_in_flight(s, op->offset, s->in_flight); - mirror_wait_for_free_in_flight_slot(s, op); + mirror_wait_for_free_in_flight_slot(s); } /* Now make a QEMUIOVector taking enough granularity-sized chunks @@ -558,7 +555,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) while (s->in_flight >= MAX_IN_FLIGHT) { trace_mirror_yield_in_flight(s, offset, s->in_flight); - mirror_wait_for_free_in_flight_slot(s, pseudo_op); + mirror_wait_for_free_in_flight_slot(s); } if (s->ret < 0) { @@ -612,7 +609,7 @@ static void mirror_free_init(MirrorBlockJob *s) static void coroutine_fn mirror_wait_for_all_io(MirrorBlockJob *s) { while (s->in_flight > 0) { - mirror_wait_for_free_in_flight_slot(s, NULL); + mirror_wait_for_free_in_flight_slot(s); } } @@ -797,7 +794,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s) if (s->in_flight >= MAX_IN_FLIGHT) { trace_mirror_yield(s, UINT64_MAX, s->buf_free_count, s->in_flight); - mirror_wait_for_free_in_flight_slot(s, NULL); + mirror_wait_for_free_in_flight_slot(s); continue; } @@ -950,7 +947,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) /* Do not start passive operations while there are active * writes in progress */ while (s->in_active_write_counter) { - mirror_wait_for_any_operation(s, NULL, true); + mirror_wait_for_any_operation(s, true); } if (s->ret < 0) { @@ -976,7 +973,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 || (cnt == 0 && s->in_flight > 0)) { trace_mirror_yield(s, cnt, s->buf_free_count, s->in_flight); - mirror_wait_for_free_in_flight_slot(s, NULL); + mirror_wait_for_free_in_flight_slot(s); continue; } else if (cnt != 0) { delay_ns = mirror_iteration(s); -- 1.8.3.1