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authorAndrew Tridgell <tridge@samba.org>2008-01-18 15:33:57 +1100
committerAndrew Tridgell <tridge@samba.org>2008-01-18 15:33:57 +1100
commit524d280ad09c99bcbf63d789e909afdf7edb5860 (patch)
tree06aee6a02dae7c6d86ad3a9d74b85df80f7e74c9
parent55ad09a01b31f2d2c9503f744b519e089f9f936b (diff)
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merged tdb changes from ctdb
(This used to be commit c54c087a19e36e0522eb4546c9425ae446f0628b)
-rw-r--r--source4/lib/tdb/common/freelist.c85
-rw-r--r--source4/lib/tdb/common/tdb_private.h1
-rw-r--r--source4/lib/tdb/common/transaction.c22
3 files changed, 49 insertions, 59 deletions
diff --git a/source4/lib/tdb/common/freelist.c b/source4/lib/tdb/common/freelist.c
index c086c151fa..2f2a4c379b 100644
--- a/source4/lib/tdb/common/freelist.c
+++ b/source4/lib/tdb/common/freelist.c
@@ -208,62 +208,61 @@ update:
}
+
/*
the core of tdb_allocate - called when we have decided which
free list entry to use
+
+ Note that we try to allocate by grabbing data from the end of an existing record,
+ not the beginning. This is so the left merge in a free is more likely to be
+ able to free up the record without fragmentation
*/
-static tdb_off_t tdb_allocate_ofs(struct tdb_context *tdb, tdb_len_t length, tdb_off_t rec_ptr,
- struct list_struct *rec, tdb_off_t last_ptr)
+static tdb_off_t tdb_allocate_ofs(struct tdb_context *tdb,
+ tdb_len_t length, tdb_off_t rec_ptr,
+ struct list_struct *rec, tdb_off_t last_ptr)
{
- struct list_struct newrec;
- tdb_off_t newrec_ptr;
+#define MIN_REC_SIZE (sizeof(struct list_struct) + sizeof(tdb_off_t) + 8)
- memset(&newrec, '\0', sizeof(newrec));
+ if (rec->rec_len < length + MIN_REC_SIZE) {
+ /* we have to grab the whole record */
- /* found it - now possibly split it up */
- if (rec->rec_len > length + MIN_REC_SIZE) {
- /* Length of left piece */
- length = TDB_ALIGN(length, TDB_ALIGNMENT);
-
- /* Right piece to go on free list */
- newrec.rec_len = rec->rec_len - (sizeof(*rec) + length);
- newrec_ptr = rec_ptr + sizeof(*rec) + length;
-
- /* And left record is shortened */
- rec->rec_len = length;
- } else {
- newrec_ptr = 0;
+ /* unlink it from the previous record */
+ if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) {
+ return 0;
+ }
+
+ /* mark it not free */
+ rec->magic = TDB_MAGIC;
+ if (tdb_rec_write(tdb, rec_ptr, rec) == -1) {
+ return 0;
+ }
+ return rec_ptr;
+ }
+
+ /* we're going to just shorten the existing record */
+ rec->rec_len -= (length + sizeof(*rec));
+ if (tdb_rec_write(tdb, rec_ptr, rec) == -1) {
+ return 0;
}
-
- /* Remove allocated record from the free list */
- if (tdb_ofs_write(tdb, last_ptr, &rec->next) == -1) {
+ if (update_tailer(tdb, rec_ptr, rec) == -1) {
return 0;
}
-
- /* Update header: do this before we drop alloc
- lock, otherwise tdb_free() might try to
- merge with us, thinking we're free.
- (Thanks Jeremy Allison). */
+
+ /* and setup the new record */
+ rec_ptr += sizeof(*rec) + rec->rec_len;
+
+ memset(rec, '\0', sizeof(*rec));
+ rec->rec_len = length;
rec->magic = TDB_MAGIC;
+
if (tdb_rec_write(tdb, rec_ptr, rec) == -1) {
return 0;
}
-
- /* Did we create new block? */
- if (newrec_ptr) {
- /* Update allocated record tailer (we
- shortened it). */
- if (update_tailer(tdb, rec_ptr, rec) == -1) {
- return 0;
- }
-
- /* Free new record */
- if (tdb_free(tdb, newrec_ptr, &newrec) == -1) {
- return 0;
- }
+
+ if (update_tailer(tdb, rec_ptr, rec) == -1) {
+ return 0;
}
-
- /* all done - return the new record offset */
+
return rec_ptr;
}
@@ -287,6 +286,7 @@ tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_st
/* Extra bytes required for tailer */
length += sizeof(tdb_off_t);
+ length = TDB_ALIGN(length, TDB_ALIGNMENT);
again:
last_ptr = FREELIST_TOP;
@@ -343,7 +343,8 @@ tdb_off_t tdb_allocate(struct tdb_context *tdb, tdb_len_t length, struct list_st
goto fail;
}
- newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr, rec, bestfit.last_ptr);
+ newrec_ptr = tdb_allocate_ofs(tdb, length, bestfit.rec_ptr,
+ rec, bestfit.last_ptr);
tdb_unlock(tdb, -1, F_WRLCK);
return newrec_ptr;
}
diff --git a/source4/lib/tdb/common/tdb_private.h b/source4/lib/tdb/common/tdb_private.h
index 63a6d04e72..0d3f10582e 100644
--- a/source4/lib/tdb/common/tdb_private.h
+++ b/source4/lib/tdb/common/tdb_private.h
@@ -49,7 +49,6 @@ typedef uint32_t tdb_off_t;
#define TDB_DEAD_MAGIC (0xFEE1DEAD)
#define TDB_RECOVERY_MAGIC (0xf53bc0e7U)
#define TDB_ALIGNMENT 4
-#define MIN_REC_SIZE (2*sizeof(struct list_struct) + TDB_ALIGNMENT)
#define DEFAULT_HASH_SIZE 131
#define FREELIST_TOP (sizeof(struct tdb_header))
#define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
diff --git a/source4/lib/tdb/common/transaction.c b/source4/lib/tdb/common/transaction.c
index 0ecfb9b7ff..ea0e3a93f3 100644
--- a/source4/lib/tdb/common/transaction.c
+++ b/source4/lib/tdb/common/transaction.c
@@ -316,25 +316,15 @@ static int transaction_write_existing(struct tdb_context *tdb, tdb_off_t off,
return 0;
}
- /* overwrite part of an existing block */
- if (buf == NULL) {
- memset(tdb->transaction->blocks[blk] + off, 0, len);
- } else {
- memcpy(tdb->transaction->blocks[blk] + off, buf, len);
- }
- if (blk == tdb->transaction->num_blocks-1) {
- if (len + off > tdb->transaction->last_block_size) {
- tdb->transaction->last_block_size = len + off;
- }
+ if (blk == tdb->transaction->num_blocks-1 &&
+ off + len > tdb->transaction->last_block_size) {
+ len = tdb->transaction->last_block_size - off;
}
- return 0;
+ /* overwrite part of an existing block */
+ memcpy(tdb->transaction->blocks[blk] + off, buf, len);
-fail:
- TDB_LOG((tdb, TDB_DEBUG_FATAL, "transaction_write: failed at off=%d len=%d\n",
- (blk*tdb->transaction->block_size) + off, len));
- tdb->transaction->transaction_error = 1;
- return -1;
+ return 0;
}