Attachment 9490 Details for Bug 10293 – New lockfix

[patch] New lockfix

lockfix.patch (text/plain), 3.52 KB, created by Alan Hourihane on 2013-11-28 12:08:51 UTC

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Creator: Alan Hourihane

Created: 2013-11-28 12:08:51 UTC

Size: 3.52 KB

patch

obsolete

>--- common/lock.c.old	2013-06-04 15:21:30.000000000 +0100
>+++ common/lock.c	2013-11-28 12:04:04.552298720 +0000
>@@ -552,6 +552,45 @@
> 	return 1;
> }
> 
>+static int tdb_allrecord_newlock(struct tdb_context *tdb,
>+				 int ltype,
>+				 size_t off, size_t len)
>+{
>+	struct tdb_lock_type *new_lck;
>+
>+	new_lck = (struct tdb_lock_type *)realloc(
>+		tdb->allrecord_locks,
>+		sizeof(*tdb->allrecord_locks) * (tdb->num_allrecord_locks+1));
>+	if (new_lck == NULL) {
>+		errno = ENOMEM;
>+		return -1;
>+	}
>+
>+	tdb->allrecord_locks = new_lck;
>+	tdb->allrecord_locks[tdb->num_allrecord_locks].off = off;
>+	tdb->allrecord_locks[tdb->num_allrecord_locks].count = 1;
>+	tdb->allrecord_locks[tdb->num_allrecord_locks].ltype = ltype;
>+	tdb->allrecord_locks[tdb->num_allrecord_locks].len = len;
>+	tdb->num_allrecord_locks++;
>+
>+	return 0;
>+}
>+
>+static int tdb_chainunlock_gradual(struct tdb_context *tdb)
>+{
>+	unsigned i;
>+
>+	for (i = 0; i < tdb->num_allrecord_locks; i++) {
>+		struct tdb_lock_type *lck = &tdb->allrecord_locks[i];
>+		if (tdb_brunlock(tdb, lck->ltype, lck->off, lck->len)) {
>+			TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno)));
>+			return -1;
>+		}
>+	}
>+
>+	return 0;
>+}
>+             
> /* We only need to lock individual bytes, but Linux merges consecutive locks
>  * so we lock in contiguous ranges. */
> static int tdb_chainlock_gradual(struct tdb_context *tdb,
>@@ -563,12 +602,23 @@
> 
> 	if (len <= 4) {
> 		/* Single record.  Just do blocking lock. */
>-		return tdb_brlock(tdb, ltype, off, len, flags);
>+		ret = tdb_brlock(tdb, ltype, off, len, flags);
>+		if (ret == 0) {
>+			if (tdb_allrecord_newlock(tdb, ltype, off, len) == -1) {
>+				tdb_brunlock(tdb, ltype, off, len);
>+				return -1;
>+			}
>+		}
>+		return ret;
> 	}
> 
> 	/* First we try non-blocking. */
> 	ret = tdb_brlock(tdb, ltype, off, len, nb_flags);
> 	if (ret == 0) {
>+		if (tdb_allrecord_newlock(tdb, ltype, off, len) == -1) {
>+			tdb_brunlock(tdb, ltype, off, len);
>+			return -1;
>+		}
> 		return 0;
> 	}
> 
>@@ -583,6 +633,7 @@
> 		tdb_brunlock(tdb, ltype, off, len / 2);
> 		return -1;
> 	}
>+
> 	return 0;
> }
> 
>@@ -606,6 +657,7 @@
> 	 *
> 	 * It is (1) which cause the starvation problem, so we're only
> 	 * gradual for that. */
>+	tdb->num_allrecord_locks = 0;
> 	if (tdb_chainlock_gradual(tdb, ltype, flags, FREELIST_TOP,
> 				  tdb->hash_size * 4) == -1) {
> 		return -1;
>@@ -614,8 +666,7 @@
> 	/* Grab individual record locks. */
> 	if (tdb_brlock(tdb, ltype, lock_offset(tdb->hash_size), 0,
> 		       flags) == -1) {
>-		tdb_brunlock(tdb, ltype, FREELIST_TOP,
>-			     tdb->hash_size * 4);
>+		tdb_chainunlock_gradual(tdb);
> 		return -1;
> 	}
> 
>@@ -671,9 +722,13 @@
> 		return 0;
> 	}
> 
>-	if (!mark_lock && tdb_brunlock(tdb, ltype, FREELIST_TOP, 0)) {
>-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno)));
>-		return -1;
>+	if (!mark_lock) {
>+		tdb_chainunlock_gradual(tdb);
>+
>+		if (tdb_brunlock(tdb, ltype, lock_offset(tdb->hash_size), 0)) {
>+			TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno)));
>+			return -1;
>+		}
> 	}
> 
> 	tdb->allrecord_lock.count = 0;
>--- common/tdb_private.h.old	2013-11-28 12:05:11.401178664 +0000
>+++ common/tdb_private.h	2013-11-28 11:22:39.432877680 +0000
>@@ -195,6 +195,8 @@
> 	int read_only; /* opened read-only */
> 	int traverse_read; /* read-only traversal */
> 	int traverse_write; /* read-write traversal */
>+	int num_allrecord_locks;
>+	struct tdb_lock_type *allrecord_locks;
> 	struct tdb_lock_type allrecord_lock; /* .offset == upgradable */
> 	int num_lockrecs;
> 	struct tdb_lock_type *lockrecs; /* only real locks, all with count>0 */

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Attachments on bug 10293: 9479 | 9481 | 9490