use dev+sector keys for buffer cache namespace

8bdfd0b1 · Nickolai Zeldovich · 608991f0 · 8bdfd0b1
--- a/bio.c
+++ b/bio.c
@@ -44,7 +44,7 @@ binit(void)
    b->flags = 0;
    initlock(&b->lock, "bcache-lock");
    initcondvar(&b->cv, "bcache-cv");
-    if (ns_insert(bufns, KI(b->sector), b) < 0)
+    if (ns_insert(bufns, KII(b->dev, b->sector), b) < 0)
      panic("binit ns_insert");
  }
 }
@@ -83,10 +83,10 @@ bget(uint dev, uint sector, int *writer)
  // Try for cached block.
  // XXX ignore dev
  rcu_begin_read();
-  b = ns_lookup(bufns, KI(sector));
+  b = ns_lookup(bufns, KII(dev, sector));
  if (b) {
-    if (b->dev != dev)
-      panic("dev mismatch");
+    if (b->dev != dev || b->sector != sector)
+      panic("block mismatch");
    if (*writer || !(b->flags & B_VALID)) {
      acquire(&b->lock);
      if (b->flags & B_BUSY) {
@@ -113,7 +113,7 @@ bget(uint dev, uint sector, int *writer)
  if (victim == 0)
    panic("bget all busy");
  victim->flags |= B_BUSY;
-  ns_remove(bufns, KI(victim->sector), victim);
+  ns_remove(bufns, KII(victim->dev, victim->sector), victim);
  release(&victim->lock);
  rcu_delayed(victim, kmfree);

@@ -126,7 +126,7 @@ bget(uint dev, uint sector, int *writer)
  initlock(&b->lock, b->lockname+3);
  initcondvar(&b->cv, b->lockname);
  rcu_begin_read();
-  if (ns_insert(bufns, KI(b->sector), b) < 0) {
+  if (ns_insert(bufns, KII(b->dev, b->sector), b) < 0) {
    rcu_delayed(b, kmfree);
    goto loop;
  }