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Revert "mirror: Don't let an operation wait for itself"

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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 <kwolf@redhat.com>
Message-Id: <20200326153628.4869-2-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2020-03-26 16:36:27 +01:00
parent 6fcc859fc2
commit 9178f4fe5f
1 changed files with 9 additions and 12 deletions
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21
block/mirror.c
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@ -283,14 +283,11 @@ static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset,
} }
static inline void coroutine_fn 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; MirrorOp *op;
QTAILQ_FOREACH(op, &s->ops_in_flight, next) { 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 /* Do not wait on pseudo ops, because it may in turn wait on
* some other operation to start, which may in fact be the * some other operation to start, which may in fact be the
* caller of this function. Since there is only one pseudo op * 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 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 */ /* 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. /* 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) { while (s->buf_free_count < nb_chunks) {
trace_mirror_yield_in_flight(s, op->offset, s->in_flight); 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 /* 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) { while (s->in_flight >= MAX_IN_FLIGHT) {
trace_mirror_yield_in_flight(s, offset, s->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) { 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) static void coroutine_fn mirror_wait_for_all_io(MirrorBlockJob *s)
{ {
while (s->in_flight > 0) { while (s->in_flight > 0) {
mirror_wait_for_free_in_flight_slot(s, NULL); mirror_wait_for_free_in_flight_slot(s);
} }
} }
@ -810,7 +807,7 @@ static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
if (s->in_flight >= MAX_IN_FLIGHT) { if (s->in_flight >= MAX_IN_FLIGHT) {
trace_mirror_yield(s, UINT64_MAX, s->buf_free_count, trace_mirror_yield(s, UINT64_MAX, s->buf_free_count,
s->in_flight); s->in_flight);
mirror_wait_for_free_in_flight_slot(s, NULL); mirror_wait_for_free_in_flight_slot(s);
continue; continue;
} }
@ -963,7 +960,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
/* Do not start passive operations while there are active /* Do not start passive operations while there are active
* writes in progress */ * writes in progress */
while (s->in_active_write_counter) { 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) { if (s->ret < 0) {
@ -989,7 +986,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp)
if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 || if (s->in_flight >= MAX_IN_FLIGHT || s->buf_free_count == 0 ||
(cnt == 0 && s->in_flight > 0)) { (cnt == 0 && s->in_flight > 0)) {
trace_mirror_yield(s, cnt, s->buf_free_count, s->in_flight); 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; continue;
} else if (cnt != 0) { } else if (cnt != 0) {
delay_ns = mirror_iteration(s); delay_ns = mirror_iteration(s);