Generalize the code to check for a block appearing on the available or

discard lists if the upper-level engine "owns" it, in other words, if
the upper-level engine is freeing a block or reading a block, it better
not appear on a list of block-manager "owned" blocks.

3 files changed, 60 insertions, 33 deletions

diff --git a/src/block/block_ext.c b/src/block/block_ext.c
index 98915809d66..c2596823951 100644
--- a/src/block/block_ext.c
+++ b/src/block/block_ext.c
@@ -200,12 +200,12 @@ __block_off_insert(
 
 #ifdef HAVE_DIAGNOSTIC
 /*
- * __wt_block_off_match --
+ * __block_off_match --
  *	Return if any part of a specified range appears on a specified extent
  * list.
  */
-int
-__wt_block_off_match(WT_EXTLIST *el, off_t off, off_t size)
+static int
+__block_off_match(WT_EXTLIST *el, off_t off, off_t size)
 {
 	WT_EXT *before, *after;
 
@@ -219,6 +219,39 @@ __wt_block_off_match(WT_EXTLIST *el, off_t off, off_t size)
 		return (1);
 	return (0);
 }
+
+/*
+ * __wt_block_misplaced --
+ *	Complain if a block appears on the available or discard lists.
+ */
+int
+__wt_block_misplaced(WT_SESSION_IMPL *session,
+   WT_BLOCK *block, const char *tag, off_t offset, uint32_t size)
+{
+	const char *name;
+
+	name = NULL;
+
+	/*
+	 * Verify a block the btree engine thinks it "owns" doesn't appear on
+	 * the available or discard lists (it might reasonably be on the alloc
+	 * list, if it was allocated since the last checkpoint).  The engine
+	 * "owns" a block if it's trying to read or free the block, and those
+	 * functions make this check.
+	 */
+	__wt_spin_lock(session, &block->live_lock);
+	if (__block_off_match(&block->live.avail, offset, size))
+		name = "available";
+	else if (__block_off_match(&block->live.discard, offset, size))
+		name = "discard";
+	__wt_spin_unlock(session, &block->live_lock);
+	if (name != NULL)
+		WT_RET_MSG(session, WT_ERROR,
+		    "%s failed: %" PRIuMAX "/%" PRIu32 " is on the %s list",
+		    tag, (uintmax_t)offset, size, name);
+
+	return (0);
+}
 #endif
 
 /*
@@ -458,20 +491,23 @@ __wt_block_free(WT_SESSION_IMPL *session,
     WT_BLOCK *block, const uint8_t *addr, uint32_t addr_size)
 {
 	WT_DECL_RET;
-	off_t off;
+	off_t offset;
 	uint32_t cksum, size;
 
 	WT_UNUSED(addr_size);
 	WT_BSTAT_INCR(session, free);
 
 	/* Crack the cookie. */
-	WT_RET(__wt_block_buffer_to_addr(block, addr, &off, &size, &cksum));
+	WT_RET(__wt_block_buffer_to_addr(block, addr, &offset, &size, &cksum));
 
 	WT_VERBOSE_RET(session, block,
-	    "free %" PRIdMAX "/%" PRIdMAX, (intmax_t)off, (intmax_t)size);
+	    "free %" PRIdMAX "/%" PRIdMAX, (intmax_t)offset, (intmax_t)size);
 
+#ifdef HAVE_DIAGNOSTIC
+	WT_RET(__wt_block_misplaced(session, block, "free", offset, size));
+#endif
 	__wt_spin_lock(session, &block->live_lock);
-	ret = __wt_block_off_free(session, block, off, (off_t)size);
+	ret = __wt_block_off_free(session, block, offset, (off_t)size);
 	__wt_spin_unlock(session, &block->live_lock);
 
 	return (ret);
@@ -483,7 +519,7 @@ __wt_block_free(WT_SESSION_IMPL *session,
  */
 int
 __wt_block_off_free(
-    WT_SESSION_IMPL *session, WT_BLOCK *block, off_t off, off_t size)
+    WT_SESSION_IMPL *session, WT_BLOCK *block, off_t offset, off_t size)
 {
 	WT_DECL_RET;
 
@@ -498,12 +534,12 @@ __wt_block_off_free(
 	 * list.
 	 */
 	if ((ret = __wt_block_off_remove_overlap(
-	    session, &block->live.alloc, off, size)) == 0)
+	    session, &block->live.alloc, offset, size)) == 0)
 		ret = __block_merge(
-		    session, &block->live.avail, off, (off_t)size);
+		    session, &block->live.avail, offset, (off_t)size);
 	else if (ret == WT_NOTFOUND)
 		ret = __block_merge(
-		    session, &block->live.discard, off, (off_t)size);
+		    session, &block->live.discard, offset, (off_t)size);
 	return (ret);
 }
 
diff --git a/src/block/block_read.c b/src/block/block_read.c
index 56df2663fa8..b88d7f5424b 100644
--- a/src/block/block_read.c
+++ b/src/block/block_read.c
@@ -54,27 +54,14 @@ __wt_block_read_off(WT_SESSION_IMPL *session, WT_BLOCK *block,
 #ifdef HAVE_DIAGNOSTIC
 	/*
 	 * In diagnostic mode, verify the block we're about to read isn't on
-	 * either the available or discard lists (it might be on some other
-	 * checkpoint's lists, but this check has proved valuable in finding
-	 * problems).   We don't check during salvage, it's quite possible
-	 * we're trying to read an overflow page that was freed long ago.
+	 * either the available or discard lists.
+	 *
+	 * Don't check during salvage, it's possible we're reading an already
+	 * freed overflow page.
 	 */
-	if (!F_ISSET(session, WT_SESSION_SALVAGE_QUIET_ERR)) {
-		const char *name = NULL;
-		__wt_spin_lock(session, &block->live_lock);
-		if (__wt_block_off_match(&block->live.avail, offset, size))
-			name = "available";
-		else if (
-		    __wt_block_off_match(&block->live.discard, offset, size))
-			name = "discard";
-		__wt_spin_unlock(session, &block->live_lock);
-		if (name != NULL) {
-			WT_RET_MSG(session, WT_ERROR,
-			    "read failed: %" PRIuMAX "/%" PRIu32 " is on "
-			    "the %s list",
-			    (uintmax_t)offset, size, name);
-		}
-	}
+	if (!F_ISSET(session, WT_SESSION_SALVAGE_QUIET_ERR))
+		WT_RET(
+		    __wt_block_misplaced(session, block, "read", offset, size));
 #endif
 
 	/*
diff --git a/src/include/extern.h b/src/include/extern.h
index 802d5360104..ded49ce3632 100644
--- a/src/include/extern.h
+++ b/src/include/extern.h
@@ -57,7 +57,11 @@ extern int __wt_block_compact_page_skip(WT_SESSION_IMPL *session,
     const uint8_t *addr,
     uint32_t addr_size,
     int *skipp);
-extern int __wt_block_off_match(WT_EXTLIST *el, off_t off, off_t size);
+extern int __wt_block_misplaced(WT_SESSION_IMPL *session,
+    WT_BLOCK *block,
+    const char *tag,
+    off_t offset,
+    uint32_t size);
 extern int __wt_block_off_remove_overlap( WT_SESSION_IMPL *session,
     WT_EXTLIST *el,
     off_t off,
@@ -76,7 +80,7 @@ extern int __wt_block_free(WT_SESSION_IMPL *session,
     uint32_t addr_size);
 extern int __wt_block_off_free( WT_SESSION_IMPL *session,
     WT_BLOCK *block,
-    off_t off,
+    off_t offset,
     off_t size);
 extern int __wt_block_extlist_check( WT_SESSION_IMPL *session,
     WT_EXTLIST *al,