From 524d280ad09c99bcbf63d789e909afdf7edb5860 Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Fri, 18 Jan 2008 15:33:57 +1100 Subject: [PATCH] merged tdb changes from ctdb (This used to be commit c54c087a19e36e0522eb4546c9425ae446f0628b) --- source4/lib/tdb/common/freelist.c | 85 ++++++++++++++-------------- source4/lib/tdb/common/tdb_private.h | 1 - source4/lib/tdb/common/transaction.c | 22 ++----- 3 files changed, 49 insertions(+), 59 deletions(-) diff --git a/source4/lib/tdb/common/freelist.c b/source4/lib/tdb/common/freelist.c index c086c151fa6..2f2a4c379b0 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 63a6d04e72d..0d3f10582ed 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 0ecfb9b7ff6..ea0e3a93f3d 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; } -- 2.34.1