Changeset 401b9e42 in mainline for uspace/srv/bd/hr/raid1.c

Timestamp:

2025-01-12T21:53:55Z (5 months ago)

Author:

Miroslav Cimerman <mc@…>

Children:

dec4150

Parents:

e2b417f

git-author:

Miroslav Cimerman <mc@…> (2025-01-12 19:18:08)

git-committer:

Miroslav Cimerman <mc@…> (2025-01-12 21:53:55)

Message:

hr: state_changed and peding_invalidation atomic flags

These flags are used to check whether there was a state
change, or if there is a pending invalidation, so that
we can avoid the slow code paths in a lockless fashion.

File:

• uspace/srv/bd/hr/raid1.c (modified) (5 diffs)

uspace/srv/bd/hr/raid1.c

@@ -103 +103 @@
         new_volume->hr_bds.sarg = new_volume;
 
+        /* force volume state update */
+        atomic_store(&new_volume->state_changed, true);
         hr_raid1_update_vol_status(new_volume);
         if (new_volume->status == HR_VOL_FAULTY)
@@ -275 +277 @@
 static void hr_raid1_update_vol_status(hr_volume_t *vol)
 {
-        fibril_mutex_lock(&vol->deferred_list_lock);
-
-        if (list_count(&vol->deferred_invalidations_list) > 0)
+        bool exp = true;
+
+        if (!atomic_compare_exchange_strong(&vol->state_changed, &exp, false))
+                return;
+
+        if (atomic_compare_exchange_strong(&vol->pending_invalidation, &exp,
+            false)) {
+                fibril_mutex_lock(&vol->deferred_list_lock);
                 process_deferred_invalidations(vol);
-
-        fibril_mutex_unlock(&vol->deferred_list_lock);
+                fibril_mutex_unlock(&vol->deferred_list_lock);
+        }
 
         fibril_rwlock_read_lock(&vol->extents_lock);
@@ -344 +351 @@
                                 assert(vol->extents[extent].status ==
                                     HR_EXT_INVALID);
-                                goto done;
+                                goto deferring_end;
                         }
                 }
@@ -358 +365 @@
                 list_append(&vol->deferred_inval[i].link,
                     &vol->deferred_invalidations_list);
-        done:
+
+                atomic_store(&vol->pending_invalidation, true);
+        deferring_end:
+
                 fibril_mutex_unlock(&vol->deferred_list_lock);
                 break;
@@ -367 +377 @@
                 hr_update_ext_status(vol, extent, HR_EXT_FAILED);
         }
+
+        atomic_store(&vol->state_changed, true);
 
         fibril_rwlock_write_unlock(&vol->states_lock);