The logic to wait_for_stripe is difficult to parse being on so many
lines and with confusing operator precedence. Move it to a helper
function to make it easier to read.
No functional changes intended.
Signed-off-by: Logan Gunthorpe <[email protected]>
---
drivers/md/raid5.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b1cb0be8fa67..e7e02a979670 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -755,6 +755,24 @@ static bool has_failed(struct r5conf *conf)
return degraded > conf->max_degraded;
}
+/*
+ * Block until another thread clears R5_INACTIVE_BLOCKED or
+ * there are fewer than 3/4 the maximum number of active stripes
+ * and there is an inactive stripe available.
+ */
+static bool is_inactive_blocked(struct r5conf *conf, int hash)
+{
+ int active = atomic_read(&conf->active_stripes);
+
+ if (list_empty(conf->inactive_list + hash))
+ return false;
+
+ if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
+ return true;
+
+ return active < (conf->max_nr_stripes * 3 / 4);
+}
+
struct stripe_head *
raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
int previous, int noblock, int noquiesce)
@@ -796,11 +814,7 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
r5l_wake_reclaim(conf->log, 0);
wait_event_lock_irq(conf->wait_for_stripe,
- !list_empty(conf->inactive_list + hash) &&
- (atomic_read(&conf->active_stripes)
- < (conf->max_nr_stripes * 3 / 4)
- || !test_bit(R5_INACTIVE_BLOCKED,
- &conf->cache_state)),
+ is_inactive_blocked(conf, hash),
*(conf->hash_locks + hash));
clear_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
goto retry;
--
2.30.2
On Wed, Jul 27, 2022 at 03:05:57PM -0600, Logan Gunthorpe wrote:
> + int active = atomic_read(&conf->active_stripes);
> +
> + if (list_empty(conf->inactive_list + hash))
> + return false;
> +
> + if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
> + return true;
> +
> + return active < (conf->max_nr_stripes * 3 / 4);
Wy does this reed ->active_stripes without even knowing if that is
needed? In fact I don't see the point of the local active variable
at all.