diff options
Diffstat (limited to 'source4/lib/tdb/common/traverse.c')
| -rw-r--r-- | source4/lib/tdb/common/traverse.c | 70 |
1 files changed, 55 insertions, 15 deletions
diff --git a/source4/lib/tdb/common/traverse.c b/source4/lib/tdb/common/traverse.c index 7d1e99cbe8..335dce4152 100644 --- a/source4/lib/tdb/common/traverse.c +++ b/source4/lib/tdb/common/traverse.c @@ -71,7 +71,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc } } - if (tdb_lock(tdb, tlock->hash, F_WRLCK) == -1) + if (tdb_lock(tdb, tlock->hash, tlock->lock_rw) == -1) return -1; /* No previous record? Start at top of chain. */ @@ -118,7 +118,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc tdb_do_delete(tdb, current, rec) != 0) goto fail; } - tdb_unlock(tdb, tlock->hash, F_WRLCK); + tdb_unlock(tdb, tlock->hash, tlock->lock_rw); want_next = 0; } /* We finished iteration without finding anything */ @@ -126,7 +126,7 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc fail: tlock->off = 0; - if (tdb_unlock(tdb, tlock->hash, F_WRLCK) != 0) + if (tdb_unlock(tdb, tlock->hash, tlock->lock_rw) != 0) TDB_LOG((tdb, 0, "tdb_next_lock: On error unlock failed!\n")); return -1; } @@ -136,32 +136,33 @@ static int tdb_next_lock(struct tdb_context *tdb, struct tdb_traverse_lock *tloc if fn is NULL then it is not called a non-zero return value from fn() indicates that the traversal should stop */ -int tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *private) +static int tdb_traverse_internal(struct tdb_context *tdb, + tdb_traverse_func fn, void *private, + struct tdb_traverse_lock *tl) { TDB_DATA key, dbuf; struct list_struct rec; - struct tdb_traverse_lock tl = { NULL, 0, 0 }; int ret, count = 0; /* This was in the initializaton, above, but the IRIX compiler * did not like it. crh */ - tl.next = tdb->travlocks.next; + tl->next = tdb->travlocks.next; /* fcntl locks don't stack: beware traverse inside traverse */ - tdb->travlocks.next = &tl; + tdb->travlocks.next = tl; /* tdb_next_lock places locks on the record returned, and its chain */ - while ((ret = tdb_next_lock(tdb, &tl, &rec)) > 0) { + while ((ret = tdb_next_lock(tdb, tl, &rec)) > 0) { count++; /* now read the full record */ - key.dptr = tdb_alloc_read(tdb, tl.off + sizeof(rec), + key.dptr = tdb_alloc_read(tdb, tl->off + sizeof(rec), rec.key_len + rec.data_len); if (!key.dptr) { ret = -1; - if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) + if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) goto out; - if (tdb_unlock_record(tdb, tl.off) != 0) + if (tdb_unlock_record(tdb, tl->off) != 0) TDB_LOG((tdb, 0, "tdb_traverse: key.dptr == NULL and unlock_record failed!\n")); goto out; } @@ -170,31 +171,70 @@ int tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *private) dbuf.dsize = rec.data_len; /* Drop chain lock, call out */ - if (tdb_unlock(tdb, tl.hash, F_WRLCK) != 0) { + if (tdb_unlock(tdb, tl->hash, tl->lock_rw) != 0) { ret = -1; goto out; } if (fn && fn(tdb, key, dbuf, private)) { /* They want us to terminate traversal */ ret = count; - if (tdb_unlock_record(tdb, tl.off) != 0) { + if (tdb_unlock_record(tdb, tl->off) != 0) { TDB_LOG((tdb, 0, "tdb_traverse: unlock_record failed!\n"));; ret = -1; } - tdb->travlocks.next = tl.next; + tdb->travlocks.next = tl->next; SAFE_FREE(key.dptr); return count; } SAFE_FREE(key.dptr); } out: - tdb->travlocks.next = tl.next; + tdb->travlocks.next = tl->next; if (ret < 0) return -1; else return count; } + +/* + a write style traverse - temporarily marks the db read only +*/ +int tdb_traverse_read(struct tdb_context *tdb, + tdb_traverse_func fn, void *private) +{ + struct tdb_traverse_lock tl = { NULL, 0, 0, F_RDLCK }; + int ret, read_only = tdb->read_only; + tdb->read_only = 1; + ret = tdb_traverse_internal(tdb, fn, private, &tl); + tdb->read_only = read_only; + return ret; +} + +/* + a write style traverse - needs to get the transaction lock to + prevent deadlocks +*/ +int tdb_traverse(struct tdb_context *tdb, + tdb_traverse_func fn, void *private) +{ + struct tdb_traverse_lock tl = { NULL, 0, 0, F_WRLCK }; + int ret; + + if (tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_WRLCK, F_SETLKW, 0) == -1) { + TDB_LOG((tdb, 0, "tdb_traverse: failed to get transaction lock\n")); + tdb->ecode = TDB_ERR_LOCK; + return -1; + } + + ret = tdb_traverse_internal(tdb, fn, private, &tl); + + tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0); + + return ret; +} + + /* find the first entry in the database and return its key */ TDB_DATA tdb_firstkey(struct tdb_context *tdb) { |