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-rw-r--r--source3/tdb/tdb.c103
1 files changed, 58 insertions, 45 deletions
diff --git a/source3/tdb/tdb.c b/source3/tdb/tdb.c
index e0df7ca020..ede38f27f9 100644
--- a/source3/tdb/tdb.c
+++ b/source3/tdb/tdb.c
@@ -21,8 +21,7 @@
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-
-#if STANDALONE
+#ifdef STANDALONE
#if HAVE_CONFIG_H
#include <config.h>
#endif
@@ -52,7 +51,7 @@
#define DEFAULT_HASH_SIZE 131
#define TDB_PAGE_SIZE 0x2000
#define FREELIST_TOP (sizeof(struct tdb_header))
-#define TDB_ALIGN(x,a) (((x) + (a)) & ~((a)-1))
+#define TDB_ALIGN(x,a) (((x) + (a)-1) & ~((a)-1))
#define TDB_BYTEREV(x) (((x<<24)|(x&0xFF00)<<8)|((x>>8)&0xFF00)|(x>>24))
#define TDB_DEAD(r) ((r)->magic == TDB_DEAD_MAGIC)
#define TDB_BAD_MAGIC(r) ((r)->magic != TDB_MAGIC && !TDB_DEAD(r))
@@ -472,10 +471,11 @@ static int tdb_expand(TDB_CONTEXT *tdb, tdb_off size)
0 is returned if the space could not be allocated
*/
-static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length)
+static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length,
+ struct list_struct *rec)
{
- tdb_off rec_ptr, last_ptr;
- struct list_struct rec, newrec;
+ tdb_off rec_ptr, last_ptr, newrec_ptr;
+ struct list_struct newrec;
if (tdb_lock(tdb, -1, F_WRLCK) == -1) return 0;
@@ -490,34 +490,47 @@ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length)
/* keep looking until we find a freelist record big enough */
while (rec_ptr) {
- if (rec_free_read(tdb, rec_ptr, &rec) == -1) goto fail;
+ if (rec_free_read(tdb, rec_ptr, rec) == -1) goto fail;
- if (rec.rec_len >= length) {
+ if (rec->rec_len >= length) {
/* found it - now possibly split it up */
- if (rec.rec_len > length + MIN_REC_SIZE) {
+ if (rec->rec_len > length + MIN_REC_SIZE) {
+ /* Length of left piece */
length = TDB_ALIGN(length, TDB_ALIGNMENT);
- newrec.rec_len = rec.rec_len
- - (sizeof(rec) + length);
- newrec.next = rec.next;
- newrec.magic = TDB_FREE_MAGIC;
+ /* Right piece to go on free list */
+ newrec.rec_len = rec->rec_len
+ - (sizeof(*rec) + length);
+ newrec_ptr = rec_ptr + sizeof(*rec) + length;
- rec.rec_len = length;
- rec.next = rec_ptr + sizeof(rec) + rec.rec_len;
+ /* And left record is shortened */
+ rec->rec_len = length;
+ } else
+ newrec_ptr = 0;
- /* Update split-off record */
- if (rec_write(tdb, rec.next, &newrec) == -1
- || update_tailer(tdb,rec.next,&newrec)==-1)
- goto fail;
- /* Update record we're about to allocate */
- if (rec_write(tdb, rec_ptr, &rec) == -1
- || update_tailer(tdb, rec_ptr, &rec)==-1)
+ /* Remove allocated record from the free list */
+ if (ofs_write(tdb, last_ptr, &rec->next) == -1)
+ goto fail;
+
+ /* 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). */
+ rec->magic = TDB_MAGIC;
+ if (rec_write(tdb, rec_ptr, rec) == -1)
+ goto fail;
+
+ /* Did we create new block? */
+ if (newrec_ptr) {
+ /* Update allocated record tailer (we
+ shortened it). */
+ if (update_tailer(tdb, rec_ptr, rec) == -1)
goto fail;
- }
- /* remove it from the list */
- if (ofs_write(tdb, last_ptr, &rec.next) == -1)
+ /* Free new record */
+ if (tdb_free(tdb, newrec_ptr, &newrec) == -1)
goto fail;
+ }
/* all done - return the new record offset */
tdb_unlock(tdb, -1, F_WRLCK);
@@ -525,11 +538,11 @@ static tdb_off tdb_allocate(TDB_CONTEXT *tdb, tdb_len length)
}
/* move to the next record */
last_ptr = rec_ptr;
- rec_ptr = rec.next;
+ rec_ptr = rec->next;
}
/* we didn't find enough space. See if we can expand the
database and if we can then try again */
- if (tdb_expand(tdb, length + sizeof(rec)) == 0) goto again;
+ if (tdb_expand(tdb, length + sizeof(*rec)) == 0) goto again;
fail:
tdb_unlock(tdb, -1, F_WRLCK);
return 0;
@@ -777,9 +790,9 @@ static int do_delete(TDB_CONTEXT *tdb, tdb_off rec_ptr, struct list_struct*rec)
static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
struct list_struct *rec)
{
- tdb_off next;
+ int want_next = (tlock->off != 0);
- /* No traversal allows sf you've called tdb_lockkeys() */
+ /* No traversal allows if you've called tdb_lockkeys() */
if (tdb->lockedkeys) return TDB_ERRCODE(TDB_ERR_NOLOCK, -1);
/* Lock each chain from the start one. */
@@ -792,21 +805,19 @@ static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
&tlock->off) == -1)
goto fail;
} else {
+ /* Otherwise unlock the previous record. */
+ unlock_record(tdb, tlock->off);
+ }
- /* Get a copy of previous record, to go to next. */
- if (rec_read(tdb, tlock->off, rec) == -1) {
- unlock_record(tdb, tlock->off);
- goto fail;
- }
-
+ if (want_next) {
+ /* We have offset of old record: grab next */
+ if (rec_read(tdb, tlock->off, rec) == -1) goto fail;
tlock->off = rec->next;
-
- /* Now unlock the previous record. */
- unlock_record(tdb, tlock->off);
}
/* Iterate through chain */
- for (; tlock->off; tlock->off = next) {
+ while( tlock->off) {
+ tdb_off current;
if (rec_read(tdb, tlock->off, rec) == -1) goto fail;
if (!TDB_DEAD(rec)) {
/* Woohoo: we found one! */
@@ -814,10 +825,12 @@ static int tdb_next_lock(TDB_CONTEXT *tdb, struct tdb_traverse_lock *tlock,
return tlock->off;
}
/* Try to clean dead ones from old traverses */
- next = rec->next;
- do_delete(tdb, tlock->off, rec);
+ current = tlock->off;
+ tlock->off = rec->next;
+ do_delete(tdb, current, rec);
}
tdb_unlock(tdb, tlock->hash, F_WRLCK);
+ want_next = 0;
}
/* We finished iteration without finding anything */
return TDB_ERRCODE(TDB_SUCCESS, 0);
@@ -968,7 +981,7 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
/* find which hash bucket it is in */
hash = tdb_hash(&key);
if (!tdb_keylocked(tdb, hash)) return -1;
- tdb_lock(tdb, BUCKET(hash), F_WRLCK);
+ if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) return -1;
/* check for it existing, on insert. */
if (flag == TDB_INSERT) {
@@ -993,10 +1006,10 @@ int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag)
/* now we're into insert / modify / replace of a record which
* we know could not be optimised by an in-place store (for
* various reasons). */
- if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize))) goto fail;
+ if (!(rec_ptr = tdb_allocate(tdb, key.dsize + dbuf.dsize, &rec)))
+ goto fail;
- /* read the newly created record, then read hash top into next ptr */
- if (rec_free_read(tdb, rec_ptr, &rec) == -1) goto fail;
+ /* Read hash top into next ptr */
if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) goto fail;
rec.key_len = key.dsize;
generated by cgit (git 2.34.1) at 2024-10-30 19:05:24 +0000