Author: tridge Date: 2007-08-24 02:37:38 +0000 (Fri, 24 Aug 2007) New Revision: 24642
WebSVN: http://websvn.samba.org/cgi-bin/viewcvs.cgi?view=rev&root=samba&rev=24642 Log: prevent recursion with fetch_locked add a note about server_id exists checking Modified: branches/SAMBA_4_0/source/ntvfs/common/brlock_tdb.c Changeset: Modified: branches/SAMBA_4_0/source/ntvfs/common/brlock_tdb.c =================================================================== --- branches/SAMBA_4_0/source/ntvfs/common/brlock_tdb.c 2007-08-24 02:35:46 UTC (rev 24641) +++ branches/SAMBA_4_0/source/ntvfs/common/brlock_tdb.c 2007-08-24 02:37:38 UTC (rev 24642) @@ -135,9 +135,12 @@ /* see if lck1 and lck2 overlap + + lck1 is the existing lock. lck2 is the new lock we are + looking at adding */ static BOOL brl_tdb_overlap(struct lock_struct *lck1, - struct lock_struct *lck2) + struct lock_struct *lck2) { /* this extra check is not redundent - it copes with locks that go beyond the end of 64 bit file space */ @@ -151,6 +154,15 @@ lck2->start >= (lck1->start+lck1->size)) { return False; } + + /* we have a conflict. Now check to see if lck1 really still + * exists, which involves checking if the process still + * exists. We leave this test to last as its the most + * expensive test, especially when we are clustered */ + /* TODO: need to do this via a server_id_exists() call, which + * hasn't been written yet. When clustered this will need to + * call into ctdb */ + return True; } @@ -283,14 +295,6 @@ NTSTATUS status; struct db_record *rec = NULL; - kbuf.dptr = brlh->key.data; - kbuf.dsize = brlh->key.length; - - rec = brl->db->fetch_locked(brl->db, brl, kbuf); - if (rec == NULL) { - return NT_STATUS_INTERNAL_DB_CORRUPTION; - } - /* if this is a pending lock, then with the chainlock held we try to get the real lock. If we succeed then we don't need to make it pending. This prevents a possible race condition @@ -305,11 +309,19 @@ brlh->last_lock = lock; if (NT_STATUS_IS_OK(status)) { - talloc_free(rec); return NT_STATUS_OK; } } + kbuf.dptr = brlh->key.data; + kbuf.dsize = brlh->key.length; + + rec = brl->db->fetch_locked(brl->db, brl, kbuf); + if (rec == NULL) { + return NT_STATUS_INTERNAL_DB_CORRUPTION; + } + + dbuf = rec->value; lock.context.smbpid = smbpid;
