[SCM] Samba Shared Repository - branch master updated

Rusty Russell rusty at samba.org
Tue Dec 20 22:26:03 MST 2011


The branch, master has been updated
       via  5767224 tdb: don't free old recovery area when expanding if already at EOF.
       via  3a2a755 tdb: use same expansion factor logic when expanding for new recovery area.
      from  c23f1ee Allow an object to be deleted from a directory if the caller has DELETE_CHILD access even if we don't have access to read the ACL on the object. Fixes bug #8673 - NT ACL issue. Different fix needed for 3.6.x.

http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master


- Log -----------------------------------------------------------------
commit 5767224b7f4703c3195aa69eef4352d80980f95e
Author: Rusty Russell <rusty at rustcorp.com.au>
Date:   Wed Dec 21 14:17:25 2011 +1030

    tdb: don't free old recovery area when expanding if already at EOF.
    
    We allocate a new recovery area by expanding the file.  But if the
    recovery area is already at the end of file (as shown in at least one
    client case), we can simply expand the record, rather than freeing it
    and creating a new one.
    
    Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
    
    Autobuild-User: Rusty Russell <rusty at rustcorp.com.au>
    Autobuild-Date: Wed Dec 21 06:25:40 CET 2011 on sn-devel-104

commit 3a2a755e3380a8f81374009d463cd06161352507
Author: Rusty Russell <rusty at rustcorp.com.au>
Date:   Wed Dec 21 14:17:16 2011 +1030

    tdb: use same expansion factor logic when expanding for new recovery area.
    
    If we're expanding because the current recovery area is too small, we
    expand only the amount we need.  This can quickly lead to exponential
    growth when we have a slowly-expanding record (hence a
    slowly-expanding transaction size).
    
    Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>

-----------------------------------------------------------------------

Summary of changes:
 lib/tdb/common/io.c          |   48 ++++++++++++++++++++++---------------
 lib/tdb/common/tdb_private.h |    1 +
 lib/tdb/common/transaction.c |   53 +++++++++++++++++++++++++++--------------
 3 files changed, 64 insertions(+), 38 deletions(-)


Changeset truncated at 500 lines:

diff --git a/lib/tdb/common/io.c b/lib/tdb/common/io.c
index a2db3bf..ac21e3f 100644
--- a/lib/tdb/common/io.c
+++ b/lib/tdb/common/io.c
@@ -313,41 +313,49 @@ static int tdb_expand_file(struct tdb_context *tdb, tdb_off_t size, tdb_off_t ad
 }
 
 
-/* expand the database at least size bytes by expanding the underlying
-   file and doing the mmap again if necessary */
-int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
+/* You need 'size', this tells you how much you should expand by. */
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size)
 {
-	struct tdb_record rec;
-	tdb_off_t offset, new_size, top_size, map_size;
-
-	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
-		TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
-		return -1;
-	}
-
-	/* must know about any previous expansions by another process */
-	tdb->methods->tdb_oob(tdb, tdb->map_size, 1, 1);
+	tdb_off_t new_size, top_size;
 
 	/* limit size in order to avoid using up huge amounts of memory for
 	 * in memory tdbs if an oddball huge record creeps in */
 	if (size > 100 * 1024) {
-		top_size = tdb->map_size + size * 2;
+		top_size = map_size + size * 2;
 	} else {
-		top_size = tdb->map_size + size * 100;
+		top_size = map_size + size * 100;
 	}
 
 	/* always make room for at least top_size more records, and at
 	   least 25% more space. if the DB is smaller than 100MiB,
 	   otherwise grow it by 10% only. */
-	if (tdb->map_size > 100 * 1024 * 1024) {
-		map_size = tdb->map_size * 1.10;
+	if (map_size > 100 * 1024 * 1024) {
+		new_size = map_size * 1.10;
 	} else {
-		map_size = tdb->map_size * 1.25;
+		new_size = map_size * 1.25;
 	}
 
 	/* Round the database up to a multiple of the page size */
-	new_size = MAX(top_size, map_size);
-	size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size;
+	new_size = MAX(top_size, new_size);
+	return TDB_ALIGN(new_size, page_size) - map_size;
+}
+
+/* expand the database at least size bytes by expanding the underlying
+   file and doing the mmap again if necessary */
+int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
+{
+	struct tdb_record rec;
+	tdb_off_t offset;
+
+	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
+		TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
+		return -1;
+	}
+
+	/* must know about any previous expansions by another process */
+	tdb->methods->tdb_oob(tdb, tdb->map_size, 1, 1);
+
+	size = tdb_expand_adjust(tdb->map_size, size, tdb->page_size);
 
 	if (!(tdb->flags & TDB_INTERNAL))
 		tdb_munmap(tdb);
diff --git a/lib/tdb/common/tdb_private.h b/lib/tdb/common/tdb_private.h
index 3c6aabf..4fc7381 100644
--- a/lib/tdb/common/tdb_private.h
+++ b/lib/tdb/common/tdb_private.h
@@ -271,6 +271,7 @@ tdb_off_t tdb_find_lock_hash(struct tdb_context *tdb, TDB_DATA key, uint32_t has
 			   struct tdb_record *rec);
 void tdb_io_init(struct tdb_context *tdb);
 int tdb_expand(struct tdb_context *tdb, tdb_off_t size);
+tdb_off_t tdb_expand_adjust(tdb_off_t map_size, tdb_off_t size, int page_size);
 int tdb_rec_free_read(struct tdb_context *tdb, tdb_off_t off,
 		      struct tdb_record *rec);
 bool tdb_write_all(int fd, const void *buf, size_t count);
diff --git a/lib/tdb/common/transaction.c b/lib/tdb/common/transaction.c
index 66ecbfd..c3477eb 100644
--- a/lib/tdb/common/transaction.c
+++ b/lib/tdb/common/transaction.c
@@ -698,7 +698,7 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 {
 	struct tdb_record rec;
 	const struct tdb_methods *methods = tdb->transaction->io_methods;
-	tdb_off_t recovery_head;
+	tdb_off_t recovery_head, new_end;
 
 	if (tdb_recovery_area(tdb, methods, &recovery_head, &rec) == -1) {
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to read recovery head\n"));
@@ -707,6 +707,7 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 
 	*recovery_size = tdb_recovery_size(tdb);
 
+	/* Existing recovery area? */
 	if (recovery_head != 0 && *recovery_size <= rec.rec_len) {
 		/* it fits in the existing area */
 		*recovery_max_size = rec.rec_len;
@@ -714,29 +715,45 @@ static int tdb_recovery_allocate(struct tdb_context *tdb,
 		return 0;
 	}
 
-	/* we need to free up the old recovery area, then allocate a
-	   new one at the end of the file. Note that we cannot use
-	   tdb_allocate() to allocate the new one as that might return
-	   us an area that is being currently used (as of the start of
-	   the transaction) */
-	if (recovery_head != 0) {
-		if (tdb_free(tdb, recovery_head, &rec) == -1) {
-			TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to free previous recovery area\n"));
-			return -1;
+	/* If recovery area in middle of file, we need a new one. */
+	if (recovery_head == 0
+	    || recovery_head + sizeof(rec) + rec.rec_len != tdb->map_size) {
+		/* we need to free up the old recovery area, then allocate a
+		   new one at the end of the file. Note that we cannot use
+		   tdb_allocate() to allocate the new one as that might return
+		   us an area that is being currently used (as of the start of
+		   the transaction) */
+		if (recovery_head) {
+			if (tdb_free(tdb, recovery_head, &rec) == -1) {
+				TDB_LOG((tdb, TDB_DEBUG_FATAL,
+					 "tdb_recovery_allocate: failed to"
+					 " free previous recovery area\n"));
+				return -1;
+			}
+
+			/* the tdb_free() call might have increased
+			 * the recovery size */
+			*recovery_size = tdb_recovery_size(tdb);
 		}
+
+		/* New head will be at end of file. */
+		recovery_head = tdb->map_size;
 	}
 
-	/* the tdb_free() call might have increased the recovery size */
-	*recovery_size = tdb_recovery_size(tdb);
+	/* Now we know where it will be. */
+	*recovery_offset = recovery_head;
+
+	/* Expand by more than we need, so we don't do it often. */
+	*recovery_max_size = tdb_expand_adjust(tdb->map_size,
+					       *recovery_size,
+					       tdb->page_size)
+		- sizeof(rec);
 
-	/* round up to a multiple of page size */
-	*recovery_max_size = TDB_ALIGN(sizeof(rec) + *recovery_size, tdb->page_size) - sizeof(rec);
-	*recovery_offset = tdb->map_size;
-	recovery_head = *recovery_offset;
+	new_end = recovery_head + sizeof(rec) + *recovery_max_size;
 
 	if (methods->tdb_expand_file(tdb, tdb->transaction->old_map_size, 
-				     (tdb->map_size - tdb->transaction->old_map_size) +
-				     sizeof(rec) + *recovery_max_size) == -1) {
+				     new_end - tdb->transaction->old_map_size)
+	    == -1) {
 		TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_recovery_allocate: failed to create recovery area\n"));
 		return -1;
 	}


-- 
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