From 1db7e98746958564da51eee2a32c7c3f1b56e03d Mon Sep 17 00:00:00 2001
From: delphij <delphij@FreeBSD.org>
Date: Sat, 28 Mar 2009 07:31:02 +0000
Subject: Minor changes from Berkeley DB 1.86 and further improvements from
 OpenBSD. This does not include the new hash routines since they will cause
 problems when reading old hash files.

Since mpool(3) has been changed, provide a compatibility shim for older
binaries.

Obtained from:	OpenBSD
---
 lib/libc/db/mpool/mpool.c | 98 ++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 76 insertions(+), 22 deletions(-)

(limited to 'lib/libc/db/mpool/mpool.c')

diff --git a/lib/libc/db/mpool/mpool.c b/lib/libc/db/mpool/mpool.c
index 5610eb5..09f888b 100644
--- a/lib/libc/db/mpool/mpool.c
+++ b/lib/libc/db/mpool/mpool.c
@@ -110,9 +110,7 @@ mpool_filter(MPOOL *mp, void (*pgin) (void *, pgno_t, void *),
  *	Get a new page of memory.
  */
 void *
-mpool_new(mp, pgnoaddr)
-	MPOOL *mp;
-	pgno_t *pgnoaddr;
+mpool_new(MPOOL *mp, pgno_t *pgnoaddr, u_int flags)
 {
 	struct _hqh *head;
 	BKT *bp;
@@ -131,8 +129,13 @@ mpool_new(mp, pgnoaddr)
 	 */
 	if ((bp = mpool_bkt(mp)) == NULL)
 		return (NULL);
-	*pgnoaddr = bp->pgno = mp->npages++;
-	bp->flags = MPOOL_PINNED;
+	if (flags == MPOOL_PAGE_REQUEST) {
+		mp->npages++;
+		bp->pgno = *pgnoaddr;
+	} else
+		bp->pgno = *pgnoaddr = mp->npages++;
+
+	bp->flags = MPOOL_PINNED | MPOOL_INUSE;
 
 	head = &mp->hqh[HASHKEY(bp->pgno)];
 	TAILQ_INSERT_HEAD(head, bp, hq);
@@ -140,6 +143,32 @@ mpool_new(mp, pgnoaddr)
 	return (bp->page);
 }
 
+int
+mpool_delete(MPOOL *mp, void *page)
+{
+	struct _hqh *head;
+	BKT *bp;
+
+	bp = (BKT *)((char *)page - sizeof(BKT));
+
+#ifdef DEBUG
+	if (!(bp->flags & MPOOL_PINNED)) {
+		(void)fprintf(stderr,
+		    "mpool_delete: page %d not pinned\n", bp->pgno);
+		abort();
+	}
+#endif
+
+	/* Remove from the hash and lru queues. */
+	head = &mp->hqh[HASHKEY(bp->pgno)];
+	TAILQ_REMOVE(head, bp, hq);
+	TAILQ_REMOVE(&mp->lqh, bp, q);
+
+	free(bp);
+	mp->curcache--;
+	return (RET_SUCCESS);
+}	
+	
 /*
  * mpool_get
  *	Get a page.
@@ -154,12 +183,6 @@ mpool_get(MPOOL *mp, pgno_t pgno,
 	off_t off;
 	int nr;
 
-	/* Check for attempt to retrieve a non-existent page. */
-	if (pgno >= mp->npages) {
-		errno = EINVAL;
-		return (NULL);
-	}
-
 #ifdef STATISTICS
 	++mp->pageget;
 #endif
@@ -167,7 +190,7 @@ mpool_get(MPOOL *mp, pgno_t pgno,
 	/* Check for a page that is cached. */
 	if ((bp = mpool_look(mp, pgno)) != NULL) {
 #ifdef DEBUG
-		if (bp->flags & MPOOL_PINNED) {
+		if (!(flags & MPOOL_IGNOREPIN) && bp->flags & MPOOL_PINNED) {
 			(void)fprintf(stderr,
 			    "mpool_get: page %d already pinned\n", bp->pgno);
 			abort();
@@ -193,20 +216,38 @@ mpool_get(MPOOL *mp, pgno_t pgno,
 		return (NULL);
 
 	/* Read in the contents. */
+	off = mp->pagesize * pgno;
+	if ((nr = pread(mp->fd, bp->page, mp->pagesize, off)) != mp->pagesize) {
+		switch (nr) {
+		case -1:
+			/* errno is set for us by pread(). */
+			free(bp);
+			mp->curcache--;
+			return (NULL);
+		case 0:
+			/*
+			 * A zero-length read means you need to create a
+			 * new page.
+			 */
+			memset(bp->page, 0, mp->pagesize);
+			break;
+		default:
+			/* A partial read is definitely bad. */
+			free(bp);
+			mp->curcache--;
+			errno = EINVAL;
+			return (NULL);
+		}
+	}
 #ifdef STATISTICS
 	++mp->pageread;
 #endif
-	off = mp->pagesize * pgno;
-	nr = pread(mp->fd, bp->page, mp->pagesize, off);
-	if (nr != mp->pagesize) {
-		if (nr >= 0)
-			errno = EFTYPE;
-		return (NULL);
-	}
 
 	/* Set the page number, pin the page. */
 	bp->pgno = pgno;
-	bp->flags = MPOOL_PINNED;
+	if (!(flags & MPOOL_IGNOREPIN))
+		bp->flags = MPOOL_PINNED;
+	bp->flags |= MPOOL_INUSE;
 
 	/*
 	 * Add the page to the head of the hash chain and the tail
@@ -245,7 +286,8 @@ mpool_put(MPOOL *mp, void *page, u_int flags)
 	}
 #endif
 	bp->flags &= ~MPOOL_PINNED;
-	bp->flags |= flags & MPOOL_DIRTY;
+	if (flags & MPOOL_DIRTY)
+		bp->flags |= flags & MPOOL_DIRTY;
 	return (RET_SUCCESS);
 }
 
@@ -329,6 +371,7 @@ mpool_bkt(MPOOL *mp)
 				bp->page = spage;
 			}
 #endif
+			bp->flags = 0;
 			return (bp);
 		}
 
@@ -338,6 +381,7 @@ new:	if ((bp = (BKT *)calloc(1, sizeof(BKT) + mp->pagesize)) == NULL)
 	++mp->pagealloc;
 #endif
 	bp->page = (char *)bp + sizeof(BKT);
+	bp->flags = 0;
 	++mp->curcache;
 	return (bp);
 }
@@ -363,6 +407,15 @@ mpool_write(MPOOL *mp, BKT *bp)
 	if (pwrite(mp->fd, bp->page, mp->pagesize, off) != mp->pagesize)
 		return (RET_ERROR);
 
+	/*
+	 * Re-run through the input filter since this page may soon be
+	 * accessed via the cache, and whatever the user's output filter
+	 * did may screw things up if we don't let the input filter
+	 * restore the in-core copy.
+	 */
+	if (mp->pgin)
+		(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
+
 	bp->flags &= ~MPOOL_DIRTY;
 	return (RET_SUCCESS);
 }
@@ -379,7 +432,8 @@ mpool_look(MPOOL *mp, pgno_t pgno)
 
 	head = &mp->hqh[HASHKEY(pgno)];
 	TAILQ_FOREACH(bp, head, hq)
-		if (bp->pgno == pgno) {
+		if ((bp->pgno == pgno) &&
+			((bp->flags & MPOOL_INUSE) == MPOOL_INUSE)) {
 #ifdef STATISTICS
 			++mp->cachehit;
 #endif
-- 
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