Changeset 38e3c0a7 in mainline

Timestamp:

2024-12-22T15:35:54Z (5 months ago)

Author:

Miroslav Cimerman <mc@…>

Children:

83c8bb2

Parents:

f725787

Message:

hr: range locks

Location:

uspace/srv/bd/hr

Files:

• util.c (modified) (4 diffs)
• util.h (modified) (1 diff)
• var.h (modified) (3 diffs)

uspace/srv/bd/hr/util.c

@@ -34 +34 @@
  */
 
+#include <adt/list.h>
 #include <block.h>
 #include <errno.h>
+#include <fibril_synch.h>
 #include <hr.h>
 #include <io/log.h>
@@ -46 +48 @@
 #include "var.h"
 
+#define HR_RL_LIST_LOCK(vol) (fibril_mutex_lock(&vol->range_lock_list_lock))
+#define HR_RL_LIST_UNLOCK(vol) \
+    (fibril_mutex_unlock(&vol->range_lock_list_lock))
+
+static bool hr_range_lock_overlap(hr_range_lock_t *, hr_range_lock_t *);
+
 extern loc_srv_t *hr_srv;
 
@@ -128 +136 @@
 
         vol->svc_id = new_id;
-
 error:
         free(fullname);
@@ -258 +265 @@
 {
         size_t count = 0;
-        for (size_t i = 0; i < vol->extent_no; i++) {
+        for (size_t i = 0; i < vol->extent_no; i++)
                 if (vol->extents[i].status == status)
                         count++;
-        }
 
         return count;
 }
 
+hr_range_lock_t *hr_range_lock_acquire(hr_volume_t *vol, uint64_t ba,
+    uint64_t cnt)
+{
+        hr_range_lock_t *rl = malloc(sizeof(hr_range_lock_t));
+        if (rl == NULL)
+                return NULL;
+
+        rl->vol = vol;
+        rl->off = ba;
+        rl->len = cnt;
+
+        rl->pending = 1;
+        rl->ignore = false;
+
+        link_initialize(&rl->link);
+        fibril_mutex_initialize(&rl->lock);
+
+        fibril_mutex_lock(&rl->lock);
+
+again:
+        HR_RL_LIST_LOCK(vol);
+        list_foreach(vol->range_lock_list, link, hr_range_lock_t, rlp) {
+                if (rlp->ignore)
+                        continue;
+                if (hr_range_lock_overlap(rlp, rl)) {
+                        rlp->pending++;
+
+                        HR_RL_LIST_UNLOCK(vol);
+
+                        fibril_mutex_lock(&rlp->lock);
+
+                        HR_RL_LIST_LOCK(vol);
+
+                        rlp->pending--;
+
+                        /*
+                         * when ignore is set, after HR_RL_LIST_UNLOCK(),
+                         * noone new is going to be able to start sleeping
+                         * on the ignored range lock, only already waiting
+                         * IOs will come through here
+                         */
+                        rlp->ignore = true;
+
+                        fibril_mutex_unlock(&rlp->lock);
+
+                        if (rlp->pending == 0) {
+                                list_remove(&rlp->link);
+                                free(rlp);
+                        }
+
+                        HR_RL_LIST_UNLOCK(vol);
+                        goto again;
+                }
+        }
+
+        list_append(&rl->link, &vol->range_lock_list);
+
+        HR_RL_LIST_UNLOCK(vol);
+        return rl;
+}
+
+void hr_range_lock_release(hr_range_lock_t *rl)
+{
+        HR_RL_LIST_LOCK(rl->vol);
+
+        rl->pending--;
+
+        fibril_mutex_unlock(&rl->lock);
+
+        if (rl->pending == 0) {
+                list_remove(&rl->link);
+                free(rl);
+        }
+
+        HR_RL_LIST_UNLOCK(rl->vol);
+}
+
+static bool hr_range_lock_overlap(hr_range_lock_t *rl1, hr_range_lock_t *rl2)
+{
+        uint64_t rl1_start = rl1->off;
+        uint64_t rl1_end = rl1->off + rl1->len - 1;
+        uint64_t rl2_start = rl2->off;
+        uint64_t rl2_end = rl2->off + rl2->len - 1;
+
+        /* one ends before the other starts */
+        if (rl1_end < rl2_start || rl2_end < rl1_start)
+                return false;
+
+        return true;
+}
+
 /** @}
  */

uspace/srv/bd/hr/util.h

@@ -61 +61 @@
 extern void hr_sync_all_extents(hr_volume_t *);
 extern size_t hr_count_extents(hr_volume_t *, hr_ext_status_t);
+extern hr_range_lock_t *hr_range_lock_acquire(hr_volume_t *, uint64_t,
+    uint64_t);
+extern void hr_range_lock_release(hr_range_lock_t *rl);
 
 #endif

uspace/srv/bd/hr/var.h

@@ -37 +37 @@
 #define _HR_VAR_H
 
+#include <adt/list.h>
 #include <bd_srv.h>
 #include <errno.h>
+#include <fibril_synch.h>
 #include <hr.h>
 
@@ -60 +62 @@
         link_t lvolumes;
         fibril_mutex_t lock;
+
+        list_t range_lock_list;
+        fibril_mutex_t range_lock_list_lock;
 
         size_t extent_no;
@@ -90 +95 @@
 } hr_bd_op_type_t;
 
+typedef struct hr_range_lock {
+        fibril_mutex_t lock;
+        link_t link;
+        hr_volume_t *vol;
+        uint64_t off;
+        uint64_t len;
+        size_t pending; /* protected by vol->range_lock_list_lock */
+        bool ignore; /* protected by vol->range_lock_list_lock */
+} hr_range_lock_t;
+
 extern errno_t hr_init_devs(hr_volume_t *);
 extern void hr_fini_devs(hr_volume_t *);