/*- * See the file LICENSE for redistribution information. * * Copyright (c) 2001,2008 Oracle. All rights reserved. * * $Id: fop_util.c,v 12.65 2008/05/07 12:27:34 bschmeck Exp $ */ #include "db_config.h" #include "db_int.h" #include "dbinc/db_page.h" #include "dbinc/db_am.h" #include "dbinc/hash.h" #include "dbinc/fop.h" #include "dbinc/lock.h" #include "dbinc/mp.h" #include "dbinc/log.h" #include "dbinc/txn.h" static int __fop_set_pgsize __P((DB *, DB_FH *, const char *)); static int __fop_inmem_create __P((DB *, const char *, DB_TXN *, u_int32_t)); static int __fop_inmem_dummy __P((DB *, DB_TXN *, const char *, u_int8_t *)); static int __fop_inmem_read_meta __P((DB *, DB_TXN *, const char *, u_int32_t)); static int __fop_inmem_swap __P((DB *, DB *, DB_TXN *, const char *, const char *, const char *, DB_LOCKER *)); static int __fop_ondisk_dummy __P((DB *, DB_TXN *, const char *, u_int8_t *, u_int32_t)); static int __fop_ondisk_swap __P((DB *, DB *, DB_TXN *, const char *, const char *, const char *, DB_LOCKER *, u_int32_t)); /* * Acquire the environment meta-data lock. The parameters are the * environment (ENV), the locker id to use in acquiring the lock (ID) * and a pointer to a DB_LOCK. * * !!! * Turn off locking for Critical Path. The application must do its own * synchronization of open/create. Two threads creating and opening a * file at the same time may have unpredictable results. */ #ifdef CRITICALPATH_10266 #define GET_ENVLOCK(ENV, ID, L) (0) #else #define GET_ENVLOCK(ENV, ID, L) do { \ DBT __dbt; \ u_int32_t __lockval; \ \ if (LOCKING_ON((ENV))) { \ __lockval = 1; \ __dbt.data = &__lockval; \ __dbt.size = sizeof(__lockval); \ if ((ret = __lock_get((ENV), (ID), \ 0, &__dbt, DB_LOCK_WRITE, (L))) != 0) \ goto err; \ } \ } while (0) #endif #define RESET_MPF(D, F) do { \ (void)__memp_fclose((D)->mpf, (F)); \ (D)->mpf = NULL; \ F_CLR((D), DB_AM_OPEN_CALLED); \ if ((ret = __memp_fcreate((D)->env, &(D)->mpf)) != 0) \ goto err; \ } while (0) /* * If we open a file handle and our caller is doing fcntl(2) locking, * we can't close the handle because that would discard the caller's * lock. Save it until we close or refresh the DB handle. */ #define CLOSE_HANDLE(D, F) { \ if ((F) != NULL) { \ if (LF_ISSET(DB_FCNTL_LOCKING)) \ (D)->saved_open_fhp = (F); \ else if ((t_ret = \ __os_closehandle((D)->env, (F))) != 0) { \ if (ret == 0) \ ret = t_ret; \ goto err; \ } \ (F) = NULL; \ } \ } /* * __fop_lock_handle -- * * Get the handle lock for a database. If the envlock is specified, do this * as a lock_vec call that releases the environment lock before acquiring the * handle lock. * * PUBLIC: int __fop_lock_handle __P((ENV *, * PUBLIC: DB *, DB_LOCKER *, db_lockmode_t, DB_LOCK *, u_int32_t)); * */ int __fop_lock_handle(env, dbp, locker, mode, elockp, flags) ENV *env; DB *dbp; DB_LOCKER *locker; db_lockmode_t mode; DB_LOCK *elockp; u_int32_t flags; { DBT fileobj; DB_LOCKREQ reqs[2], *ereq; DB_LOCK_ILOCK lock_desc; int ret; if (!LOCKING_ON(env) || F_ISSET(dbp, DB_AM_COMPENSATE | DB_AM_RECOVER)) return (0); /* * If we are in recovery, the only locking we should be * doing is on the global environment. */ if (IS_RECOVERING(env)) return (elockp == NULL ? 0 : __ENV_LPUT(env, *elockp)); memcpy(lock_desc.fileid, dbp->fileid, DB_FILE_ID_LEN); lock_desc.pgno = dbp->meta_pgno; lock_desc.type = DB_HANDLE_LOCK; memset(&fileobj, 0, sizeof(fileobj)); fileobj.data = &lock_desc; fileobj.size = sizeof(lock_desc); DB_TEST_SUBLOCKS(env, flags); if (elockp == NULL) ret = __lock_get(env, locker, flags, &fileobj, mode, &dbp->handle_lock); else { reqs[0].op = DB_LOCK_PUT; reqs[0].lock = *elockp; reqs[1].op = DB_LOCK_GET; reqs[1].mode = mode; reqs[1].obj = &fileobj; reqs[1].timeout = 0; if ((ret = __lock_vec(env, locker, flags, reqs, 2, &ereq)) == 0) { dbp->handle_lock = reqs[1].lock; LOCK_INIT(*elockp); } else if (ereq != reqs) LOCK_INIT(*elockp); } dbp->cur_locker = locker; return (ret); } /* * __fop_file_setup -- * * Perform all the needed checking and locking to open up or create a * file. * * There's a reason we don't push this code down into the buffer cache. * The problem is that there's no information external to the file that * we can use as a unique ID. UNIX has dev/inode pairs, but they are * not necessarily unique after reboot, if the file was mounted via NFS. * Windows has similar problems, as the FAT filesystem doesn't maintain * dev/inode numbers across reboot. So, we must get something from the * file we can use to ensure that, even after a reboot, the file we're * joining in the cache is the right file for us to join. The solution * we use is to maintain a file ID that's stored in the database, and * that's why we have to open and read the file before calling into the * buffer cache or obtaining a lock (we use this unique fileid to lock * as well as to identify like files in the cache). * * There are a couple of idiosyncrasies that this code must support, in * particular, DB_TRUNCATE and DB_FCNTL_LOCKING. First, we disallow * DB_TRUNCATE in the presence of transactions, since opening a file with * O_TRUNC will result in data being lost in an unrecoverable fashion. * We also disallow DB_TRUNCATE if locking is enabled, because even in * the presence of locking, we cannot avoid race conditions, so allowing * DB_TRUNCATE with locking would be misleading. See SR [#7345] for more * details. * * However, if you are running with neither locking nor transactions, then * you can specify DB_TRUNCATE, and if you do so, we will truncate the file * regardless of its contents. * * FCNTL locking introduces another set of complications. First, the only * reason we support the DB_FCNTL_LOCKING flag is for historic compatibility * with programs like Sendmail and Postfix. In these cases, the caller may * already have a lock on the file; we need to make sure that any file handles * we open remain open, because if we were to close them, the lock held by the * caller would go away. Furthermore, Sendmail and/or Postfix need the ability * to create databases in empty files. So, when you're doing FCNTL locking, * it's reasonable that you are trying to create a database into a 0-length * file and we allow it, while under normal conditions, we do not create * databases if the files already exist and are not Berkeley DB files. * * PUBLIC: int __fop_file_setup __P((DB *, DB_THREAD_INFO *ip, * PUBLIC: DB_TXN *, const char *, int, u_int32_t, u_int32_t *)); */ int __fop_file_setup(dbp, ip, txn, name, mode, flags, retidp) DB *dbp; DB_THREAD_INFO *ip; DB_TXN *txn; const char *name; int mode; u_int32_t flags, *retidp; { DBTYPE save_type; DB_FH *fhp; DB_LOCK elock; DB_LOCKER *locker; DB_TXN *stxn; ENV *env; size_t len; u_int32_t dflags, oflags; u_int8_t mbuf[DBMETASIZE]; int created_locker, create_ok, ret, retries, t_ret, tmp_created; int truncating, was_inval; char *real_name, *real_tmpname, *tmpname; *retidp = TXN_INVALID; env = dbp->env; fhp = NULL; LOCK_INIT(elock); stxn = NULL; created_locker = tmp_created = truncating = was_inval = 0; real_name = real_tmpname = tmpname = NULL; dflags = F_ISSET(dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0; ret = 0; retries = 0; save_type = dbp->type; /* * Get a lockerid for this handle. There are paths through queue * rename and remove where this dbp already has a locker, so make * sure we don't clobber it and conflict. */ if (LOCKING_ON(env) && !F_ISSET(dbp, DB_AM_COMPENSATE) && !F_ISSET(dbp, DB_AM_RECOVER) && dbp->locker == DB_LOCK_INVALIDID) { if ((ret = __lock_id(env, NULL, &dbp->locker)) != 0) goto err; created_locker = 1; } LOCK_INIT(dbp->handle_lock); locker = txn == NULL ? dbp->locker : txn->locker; oflags = 0; if (F_ISSET(dbp, DB_AM_INMEM)) real_name = (char *)name; else { /* Get the real backing file name. */ if ((ret = __db_appname(env, DB_APP_DATA, name, 0, NULL, &real_name)) != 0) goto err; /* Fill in the default file mode. */ if (mode == 0) mode = DB_MODE_660; if (LF_ISSET(DB_RDONLY)) oflags |= DB_OSO_RDONLY; if (LF_ISSET(DB_TRUNCATE)) oflags |= DB_OSO_TRUNC; } retries = 0; create_ok = LF_ISSET(DB_CREATE); LF_CLR(DB_CREATE); retry: /* * If we cannot create the file, only retry a few times. We * think we might be in a race with another create, but it could * be that the backup filename exists (that is, is left over from * a previous crash). */ if (++retries > DB_RETRY) { __db_errx(env, "__fop_file_setup: Retry limit (%d) exceeded", DB_RETRY); goto err; } if (!F_ISSET(dbp, DB_AM_COMPENSATE) && !F_ISSET(dbp, DB_AM_RECOVER)) GET_ENVLOCK(env, locker, &elock); if (name == NULL) ret = ENOENT; else if (F_ISSET(dbp, DB_AM_INMEM)) { ret = __env_mpool(dbp, name, flags); /* * We are using __env_open as a check for existence. * However, __env_mpool does an actual open and there * are scenarios where the object exists, but cannot be * opened, because our settings don't match those internally. * We need to check for that explicitly. We'll need the * mpool open to read the meta-data page, so we're going to * have to temporarily turn this dbp into an UNKNOWN one. */ if (ret == EINVAL) { was_inval = 1; save_type = dbp->type; dbp->type = DB_UNKNOWN; ret = __env_mpool(dbp, name, flags); dbp->type = save_type; } } else ret = __os_exists(env, real_name, NULL); if (ret == 0) { /* * If the file exists, there are 5 possible cases: * 1. DB_EXCL was specified so this is an error, unless * this is a file left around after a rename and we * are in the same transaction. This gets decomposed * into several subcases, because we check for various * errors before we know we're in rename. * 2. We are truncating, and it doesn't matter what kind * of file it is, we should open/create it. * 3. It is 0-length, we are not doing transactions (i.e., * we are sendmail), we should open/create into it. * -- on-disk files only! * 4. Is it a Berkeley DB file and we should simply open it. * 5. It is not a BDB file and we should return an error. */ /* Open file (if there is one). */ reopen: if (!F_ISSET(dbp, DB_AM_INMEM) && (ret = __os_open(env, real_name, 0, oflags, 0, &fhp)) != 0) goto err; /* Case 2: DB_TRUNCATE: we must do the creation in place. */ if (LF_ISSET(DB_TRUNCATE)) { if (LF_ISSET(DB_EXCL)) { /* Case 1a: DB_EXCL and DB_TRUNCATE. */ ret = EEXIST; goto err; } tmpname = (char *)name; goto creat2; } /* Cases 1,3-5: we need to read the meta-data page. */ if (F_ISSET(dbp, DB_AM_INMEM)) ret = __fop_inmem_read_meta(dbp, txn, name, flags); else { ret = __fop_read_meta(env, real_name, mbuf, sizeof(mbuf), fhp, LF_ISSET(DB_FCNTL_LOCKING) && txn == NULL ? 1 : 0, &len); /* Case 3: 0-length, no txns. */ if (ret != 0 && len == 0 && txn == NULL) { if (LF_ISSET(DB_EXCL)) { /* * Case 1b: DB_EXCL and * 0-length file exists. */ ret = EEXIST; goto err; } tmpname = (char *)name; goto creat2; } /* Case 4: This is a valid file. */ if (ret == 0) ret = __db_meta_setup(env, dbp, real_name, (DBMETA *)mbuf, flags, 1); } /* Case 5: Invalid file. */ if (ret != 0) goto err; /* Now, get our handle lock. */ if ((ret = __fop_lock_handle(env, dbp, locker, DB_LOCK_READ, NULL, DB_LOCK_NOWAIT)) == 0) { if ((ret = __ENV_LPUT(env, elock)) != 0) goto err; } else if (ret != DB_LOCK_NOTGRANTED || (txn != NULL && F_ISSET(txn, TXN_NOWAIT))) goto err; else { /* * We were unable to acquire the handle lock without * blocking. The fact that we are blocking might mean * that someone else is trying to delete the file. * Since some platforms cannot delete files while they * are open (Windows), we are going to have to close * the file. This would be a problem if we were doing * FCNTL locking, because our closing the handle would * release the FCNTL locks. Fortunately, if we are * doing FCNTL locking, then we should never fail to * acquire our handle lock, so we should never get here. * We assert it here to make sure we aren't destroying * any application level FCNTL semantics. */ DB_ASSERT(env, !LF_ISSET(DB_FCNTL_LOCKING)); if (!F_ISSET(dbp, DB_AM_INMEM)) { if ((ret = __os_closehandle(env, fhp)) != 0) goto err; fhp = NULL; } if ((ret = __fop_lock_handle(env, dbp, locker, DB_LOCK_READ, &elock, 0)) != 0) { if (F_ISSET(dbp, DB_AM_INMEM)) RESET_MPF(dbp, 0); goto err; } /* * It's possible that our DBP was initialized * with a different file last time we opened it. * Therefore, we need to reset the DBP type and then * re-read the meta-data page and reset any other * fields that __db_meta_setup initializes. We * need to shut down this dbp and reopen for in-memory * named databases. Unfortunately __db_refresh is * pretty aggressive at the shutting down, so we need * to do a bunch of restoration. * XXX it would be nice to pull refresh apart into * the stuff you need to do to call __env_mpool * and the stuff you can really throw away. */ if (F_ISSET(dbp, DB_AM_INMEM)) { if ((ret = __db_refresh(dbp, txn, DB_NOSYNC, NULL, 1)) != 0) goto err; ret = __env_mpool(dbp, name, flags); } else ret = __os_open(env, real_name, 0, 0, 0, &fhp); if (ret != 0) { if ((ret = __ENV_LPUT(env, dbp->handle_lock)) != 0) { LOCK_INIT(dbp->handle_lock); goto err; } goto retry; } dbp->type = save_type; if (F_ISSET(dbp, DB_AM_INMEM)) ret = __fop_inmem_read_meta(dbp, txn, name, flags); else if ((ret = __fop_read_meta(env, real_name, mbuf, sizeof(mbuf), fhp, LF_ISSET(DB_FCNTL_LOCKING) && txn == NULL ? 1 : 0, &len)) != 0 || (ret = __db_meta_setup(env, dbp, real_name, (DBMETA *)mbuf, flags, DB_CHK_META)) != 0) goto err; } /* If we got here, then we have the handle lock. */ /* * Check for a file in the midst of a rename. If we find that * the file is in the midst of a rename, it must be the case * that it is in our current transaction (else we would still * be blocking), so we can continue along and create a new file * with the same name. In that case, we have to close the file * handle because we reuse it below. This is a case where * a 'was_inval' above is OK. */ if (F_ISSET(dbp, DB_AM_IN_RENAME)) { was_inval = 0; if (create_ok) { if (F_ISSET(dbp, DB_AM_INMEM)) { RESET_MPF(dbp, DB_MPOOL_DISCARD); } else if ((ret = __os_closehandle(env, fhp)) != 0) goto err; LF_SET(DB_CREATE); goto create; } else { ret = ENOENT; goto err; } } /* If we get here, a was_inval is bad. */ if (was_inval) { ret = EINVAL; goto err; } /* * Now, case 1: check for DB_EXCL, because the file that exists * is not in the middle of a rename, so we have an error. This * is a weird case, but we need to make sure that we don't * continue to hold the handle lock, since technically, we * should not have been allowed to open it. */ if (LF_ISSET(DB_EXCL)) { ret = __ENV_LPUT(env, dbp->handle_lock); LOCK_INIT(dbp->handle_lock); if (ret == 0) ret = EEXIST; goto err; } goto done; } /* File does not exist. */ #ifdef HAVE_VXWORKS /* * VxWorks can return file-system specific error codes if the * file does not exist, not ENOENT. */ if (!create_ok) #else if (!create_ok || ret != ENOENT) #endif goto err; LF_SET(DB_CREATE); ret = 0; /* * We need to create file, which means that we need to set up the file, * the fileid and the locks. Then we need to call the appropriate * routines to create meta-data pages. For in-memory files, we retain * the environment lock, while for on-disk files, we drop the env lock * and create into a temporary. */ if (!F_ISSET(dbp, DB_AM_INMEM) && (ret = __ENV_LPUT(env, elock)) != 0) goto err; create: if (txn != NULL && IS_REP_CLIENT(env) && !F_ISSET(dbp, DB_AM_NOT_DURABLE)) { __db_errx(env, "Transactional create on replication client disallowed"); ret = EINVAL; goto err; } if (F_ISSET(dbp, DB_AM_INMEM)) ret = __fop_inmem_create(dbp, name, txn, flags); else { if ((ret = __db_backup_name(env, name, txn, &tmpname)) != 0) goto err; if (TXN_ON(env) && txn != NULL && (ret = __txn_begin(env, NULL, txn, &stxn, 0)) != 0) goto err; if ((ret = __fop_create(env, stxn, &fhp, tmpname, DB_APP_DATA, mode, dflags)) != 0) { /* * If no transactions, there is a race on creating the * backup file, as the backup file name is the same for * all processes. Wait for the other process to finish * with the name. */ if (!TXN_ON(env) && ret == EEXIST) { __os_free(env, tmpname); tmpname = NULL; __os_yield(env, 1, 0); goto retry; } goto err; } tmp_created = 1; } creat2: if (!F_ISSET(dbp, DB_AM_INMEM)) { if ((ret = __db_appname(env, DB_APP_DATA, tmpname, 0, NULL, &real_tmpname)) != 0) goto err; /* Set the pagesize if it isn't yet set. */ if (dbp->pgsize == 0 && (ret = __fop_set_pgsize(dbp, fhp, real_tmpname)) != 0) goto errmsg; /* Construct a file_id. */ if ((ret = __os_fileid(env, real_tmpname, 1, dbp->fileid)) != 0) goto errmsg; } if ((ret = __db_new_file(dbp, ip, F_ISSET(dbp, DB_AM_INMEM) ? txn : stxn, fhp, tmpname)) != 0) goto err; /* * We need to close the handle here on platforms where remove and * rename fail if a handle is open (including Windows). */ CLOSE_HANDLE(dbp, fhp); /* * Now move the file into place unless we are creating in place (because * we created a database in a file that started out 0-length). If * this is an in-memory file, we may or may not hold the environment * lock depending on how we got here. */ if (!F_ISSET(dbp, DB_AM_COMPENSATE) && !F_ISSET(dbp, DB_AM_RECOVER) && !LOCK_ISSET(elock)) GET_ENVLOCK(env, locker, &elock); if (F_ISSET(dbp, DB_AM_IN_RENAME)) { F_CLR(dbp, DB_AM_IN_RENAME); __txn_remrem(env, txn, real_name); } else if (name == tmpname) { /* We created it in place. */ } else if (!F_ISSET(dbp, DB_AM_INMEM) && __os_exists(env, real_name, NULL) == 0) { /* * Someone managed to create the file; remove our temp * and try to open the file that now exists. */ (void)__fop_remove(env, NULL, dbp->fileid, tmpname, DB_APP_DATA, dflags); (void)__ENV_LPUT(env, dbp->handle_lock); LOCK_INIT(dbp->handle_lock); if (stxn != NULL) { ret = __txn_abort(stxn); stxn = NULL; } if (ret != 0) goto err; goto reopen; } if (name != NULL && (ret = __fop_lock_handle(env, dbp, locker, DB_LOCK_WRITE, &elock, NOWAIT_FLAG(txn))) != 0) goto err; if (tmpname != NULL && tmpname != name && (ret = __fop_rename(env, stxn, tmpname, name, dbp->fileid, DB_APP_DATA, 1, dflags)) != 0) goto err; if (stxn != NULL) { *retidp = stxn->txnid; ret = __txn_commit(stxn, 0); stxn = NULL; } else *retidp = TXN_INVALID; if (ret != 0) goto err; F_SET(dbp, DB_AM_CREATED); if (0) { errmsg: __db_err(env, ret, "%s", name); err: CLOSE_HANDLE(dbp, fhp); if (stxn != NULL) (void)__txn_abort(stxn); if (tmp_created && txn == NULL) (void)__fop_remove(env, NULL, NULL, tmpname, DB_APP_DATA, dflags); if (txn == NULL) (void)__ENV_LPUT(env, dbp->handle_lock); (void)__ENV_LPUT(env, elock); if (created_locker) { (void)__lock_id_free(env, dbp->locker); dbp->locker = NULL; } } done: /* * There are cases where real_name and tmpname take on the * exact same string, so we need to make sure that we do not * free twice. */ if (!truncating && tmpname != NULL && tmpname != name) __os_free(env, tmpname); if (real_name != name && real_name != NULL) __os_free(env, real_name); if (real_tmpname != NULL) __os_free(env, real_tmpname); CLOSE_HANDLE(dbp, fhp); return (ret); } /* * __fop_set_pgsize -- * Set the page size based on file information. */ static int __fop_set_pgsize(dbp, fhp, name) DB *dbp; DB_FH *fhp; const char *name; { ENV *env; u_int32_t iopsize; int ret; env = dbp->env; /* * Use the filesystem's optimum I/O size as the pagesize if a pagesize * not specified. Some filesystems have 64K as their optimum I/O size, * but as that results in fairly large default caches, we limit the * default pagesize to 16K. */ if ((ret = __os_ioinfo(env, name, fhp, NULL, NULL, &iopsize)) != 0) { __db_err(env, ret, "%s", name); return (ret); } if (iopsize < 512) iopsize = 512; if (iopsize > 16 * 1024) iopsize = 16 * 1024; /* * Sheer paranoia, but we don't want anything that's not a power-of-2 * (we rely on that for alignment of various types on the pages), and * we want a multiple of the sector size as well. If the value * we got out of __os_ioinfo looks bad, use a default instead. */ if (!IS_VALID_PAGESIZE(iopsize)) iopsize = DB_DEF_IOSIZE; dbp->pgsize = iopsize; F_SET(dbp, DB_AM_PGDEF); return (0); } /* * __fop_subdb_setup -- * * Subdb setup is significantly simpler than file setup. In terms of * locking, for the duration of the operation/transaction, the locks on * the meta-data page will suffice to protect us from simultaneous operations * on the sub-database. Before we complete the operation though, we'll get a * handle lock on the subdatabase so that on one else can try to remove it * while we've got it open. We use an object that looks like the meta-data * page lock with a different type (DB_HANDLE_LOCK) for the long-term handle. * locks. * * PUBLIC: int __fop_subdb_setup __P((DB *, DB_THREAD_INFO *, DB_TXN *, * PUBLIC: const char *, const char *, int, u_int32_t)); */ int __fop_subdb_setup(dbp, ip, txn, mname, name, mode, flags) DB *dbp; DB_THREAD_INFO *ip; DB_TXN *txn; const char *mname, *name; int mode; u_int32_t flags; { DB *mdbp; ENV *env; db_lockmode_t lkmode; int ret, t_ret; mdbp = NULL; env = dbp->env; if ((ret = __db_master_open(dbp, ip, txn, mname, flags, mode, &mdbp)) != 0) return (ret); /* * If we created this file, then we need to set the DISCARD flag so * that if we fail in the middle of this routine, we discard from the * mpool any pages that we just created. */ if (F_ISSET(mdbp, DB_AM_CREATED)) F_SET(mdbp, DB_AM_DISCARD); /* * We are going to close this instance of the master, so we can * steal its handle instead of reopening a handle on the database. */ if (LF_ISSET(DB_FCNTL_LOCKING)) { dbp->saved_open_fhp = mdbp->saved_open_fhp; mdbp->saved_open_fhp = NULL; } /* Copy the pagesize and set the sub-database flag. */ dbp->pgsize = mdbp->pgsize; F_SET(dbp, DB_AM_SUBDB); if (name != NULL && (ret = __db_master_update(mdbp, dbp, ip, txn, name, dbp->type, MU_OPEN, NULL, flags)) != 0) goto err; /* * Hijack the master's locker ID as well, so that our locks don't * conflict with the master's. Since we're closing the master, * that locker would just have been freed anyway. Once we've gotten * the locker id, we need to acquire the handle lock for this * subdatabase. */ dbp->locker = mdbp->locker; mdbp->locker = NULL; DB_TEST_RECOVERY(dbp, DB_TEST_POSTLOG, ret, mname); /* * We copy our fileid from our master so that we all open * the same file in mpool. We'll use the meta-pgno to lock * so that we end up with different handle locks. */ memcpy(dbp->fileid, mdbp->fileid, DB_FILE_ID_LEN); lkmode = F_ISSET(dbp, DB_AM_CREATED) || LF_ISSET(DB_WRITEOPEN) ? DB_LOCK_WRITE : DB_LOCK_READ; if ((ret = __fop_lock_handle(env, dbp, txn == NULL ? dbp->locker : txn->locker, lkmode, NULL, NOWAIT_FLAG(txn))) != 0) goto err; if ((ret = __db_init_subdb(mdbp, dbp, name, ip, txn)) != 0) { /* * If there was no transaction and we created this database, * then we need to undo the update of the master database. */ if (F_ISSET(dbp, DB_AM_CREATED) && txn == NULL) (void)__db_master_update(mdbp, dbp, ip, txn, name, dbp->type, MU_REMOVE, NULL, 0); F_CLR(dbp, DB_AM_CREATED); goto err; } /* * XXX * This should have been done at the top of this routine. The problem * is that __db_init_subdb() uses "standard" routines to process the * meta-data page and set information in the DB handle based on it. * Those routines have to deal with swapped pages and will normally set * the DB_AM_SWAP flag. However, we use the master's metadata page and * that has already been swapped, so they get the is-swapped test wrong. */ F_CLR(dbp, DB_AM_SWAP); F_SET(dbp, F_ISSET(mdbp, DB_AM_SWAP)); /* * In the file create case, these happen in separate places so we have * two different tests. They end up in the same place for subdbs, but * for compatibility with file testing, we put them both here anyway. */ DB_TEST_RECOVERY(dbp, DB_TEST_POSTLOGMETA, ret, mname); DB_TEST_RECOVERY(dbp, DB_TEST_POSTSYNC, ret, mname); /* * File exists and we have the appropriate locks; we should now * process a normal open. */ if (F_ISSET(mdbp, DB_AM_CREATED)) { F_SET(dbp, DB_AM_CREATED_MSTR); F_CLR(mdbp, DB_AM_DISCARD); } if (0) { err: DB_TEST_RECOVERY_LABEL if (txn == NULL) (void)__ENV_LPUT(env, dbp->handle_lock); } /* * The master's handle lock is under the control of the * subdb (it acquired the master's locker). We want to * keep the master's handle lock so that no one can remove * the file while the subdb is open. If we register the * trade event and then invalidate the copy of the lock * in the master's handle, that will accomplish this. However, * before we register this event, we'd better remove any * events that we've already registered for the master. */ if (!F_ISSET(dbp, DB_AM_RECOVER) && IS_REAL_TXN(txn)) { /* Unregister old master events. */ __txn_remlock(env, txn, &mdbp->handle_lock, DB_LOCK_INVALIDID); /* Now register the new event. */ if ((t_ret = __txn_lockevent(env, txn, dbp, &mdbp->handle_lock, dbp->locker == NULL ? mdbp->locker : dbp->locker)) != 0 && ret == 0) ret = t_ret; } LOCK_INIT(mdbp->handle_lock); /* * If the master was created, we need to sync so that the metadata * page is correct on disk for recovery, since it isn't read through * mpool. If we're opening a subdb in an existing file, we can skip * the sync. */ if (txn == NULL || F_ISSET(txn, TXN_CDSGROUP) || F_ISSET(mdbp, DB_AM_RECOVER)) { if ((t_ret = __db_close(mdbp, txn, F_ISSET(dbp, DB_AM_CREATED_MSTR) ? 0 : DB_NOSYNC)) != 0 && ret == 0) ret = t_ret; } else { if (F_ISSET(dbp, DB_AM_CREATED_MSTR) && (t_ret = __memp_fsync(mdbp->mpf)) != 0 && ret == 0) ret = t_ret; if ((t_ret = __txn_closeevent(env, txn, mdbp)) != 0 && ret == 0) ret = t_ret; } return (ret); } /* * __fop_remove_setup -- * Open handle appropriately and lock for removal of a database file. * * PUBLIC: int __fop_remove_setup __P((DB *, * PUBLIC: DB_TXN *, const char *, u_int32_t)); */ int __fop_remove_setup(dbp, txn, name, flags) DB *dbp; DB_TXN *txn; const char *name; u_int32_t flags; { DB_FH *fhp; DB_LOCK elock; ENV *env; u_int8_t mbuf[DBMETASIZE]; int ret; COMPQUIET(flags, 0); env = dbp->env; LOCK_INIT(elock); fhp = NULL; ret = 0; /* Create locker if necessary. */ retry: if (LOCKING_ON(env)) { if (txn != NULL) dbp->locker = txn->locker; else if (dbp->locker == DB_LOCK_INVALIDID) { if ((ret = __lock_id(env, NULL, &dbp->locker)) != 0) goto err; } } /* * We are about to open a file handle and then possibly close it. * We cannot close handles if we are doing FCNTL locking. However, * there is no way to pass the FCNTL flag into this routine via the * user API. The only way we can get in here and be doing FCNTL * locking is if we are trying to clean up an open that was called * with FCNTL locking. In that case, the save_fhp should already be * set. So, we use that field to tell us if we need to make sure * that we shouldn't close the handle. */ fhp = dbp->saved_open_fhp; DB_ASSERT(env, LF_ISSET(DB_FCNTL_LOCKING) || fhp == NULL); /* * Lock environment to protect file open. That will enable us to * read the meta-data page and get the fileid so that we can lock * the handle. */ GET_ENVLOCK(env, dbp->locker, &elock); /* Open database. */ if (F_ISSET(dbp, DB_AM_INMEM)) { if ((ret = __env_mpool(dbp, name, flags)) == 0) ret = __os_strdup(env, name, &dbp->dname); } else if (fhp == NULL) ret = __os_open(env, name, 0, DB_OSO_RDONLY, 0, &fhp); if (ret != 0) goto err; /* Get meta-data */ if (F_ISSET(dbp, DB_AM_INMEM)) ret = __fop_inmem_read_meta(dbp, txn, name, flags); else if ((ret = __fop_read_meta(env, name, mbuf, sizeof(mbuf), fhp, 0, NULL)) == 0) ret = __db_meta_setup(env, dbp, name, (DBMETA *)mbuf, flags, DB_CHK_META | DB_CHK_NOLSN); if (ret != 0) goto err; /* * Now, get the handle lock. We first try with NOWAIT, because if * we have to wait, we're going to have to close the file and reopen * it, so that if there is someone else removing it, our open doesn't * prevent that. */ if ((ret = __fop_lock_handle(env, dbp, dbp->locker, DB_LOCK_WRITE, NULL, DB_LOCK_NOWAIT)) != 0) { /* * Close the file, block on the lock, clean up the dbp, and * then start all over again. */ if (!F_ISSET(dbp, DB_AM_INMEM) && !LF_ISSET(DB_FCNTL_LOCKING)) { (void)__os_closehandle(env, fhp); fhp = NULL; } if (ret != DB_LOCK_NOTGRANTED || (txn != NULL && F_ISSET(txn, TXN_NOWAIT))) goto err; else if ((ret = __fop_lock_handle(env, dbp, dbp->locker, DB_LOCK_WRITE, &elock, 0)) != 0) goto err; if (F_ISSET(dbp, DB_AM_INMEM)) { (void)__lock_put(env, &dbp->handle_lock); (void)__db_refresh(dbp, txn, DB_NOSYNC, NULL, 1); } else { if (txn != NULL) dbp->locker = NULL; (void)__db_refresh(dbp, txn, DB_NOSYNC, NULL, 0); } goto retry; } else if ((ret = __ENV_LPUT(env, elock)) != 0) goto err; else if (F_ISSET(dbp, DB_AM_IN_RENAME)) ret = ENOENT; if (0) { err: (void)__ENV_LPUT(env, elock); } if (fhp != NULL && !LF_ISSET(DB_FCNTL_LOCKING)) (void)__os_closehandle(env, fhp); /* * If this is a real file and we are going to proceed with the removal, * then we need to make sure that we don't leave any pages around in the * mpool since the file is closed and will be reopened again before * access. However, this might be an in-memory file, in which case * we will handle the discard from the mpool later as it's the "real" * removal of the database. */ if (ret == 0 && !F_ISSET(dbp, DB_AM_INMEM)) F_SET(dbp, DB_AM_DISCARD); return (ret); } /* * __fop_read_meta -- * Read the meta-data page from a file and return it in buf. * * PUBLIC: int __fop_read_meta __P((ENV *, const char *, * PUBLIC: u_int8_t *, size_t, DB_FH *, int, size_t *)); */ int __fop_read_meta(env, name, buf, size, fhp, errok, nbytesp) ENV *env; const char *name; u_int8_t *buf; size_t size; DB_FH *fhp; int errok; size_t *nbytesp; { size_t nr; int ret; /* * Our caller wants to know the number of bytes read, even if we * return an error. */ if (nbytesp != NULL) *nbytesp = 0; nr = 0; ret = __os_read(env, fhp, buf, size, &nr); if (nbytesp != NULL) *nbytesp = nr; if (ret != 0) { if (!errok) __db_err(env, ret, "%s", name); goto err; } if (nr != size) { if (!errok) __db_errx(env, "%s: unexpected file type or format", name); ret = EINVAL; } err: return (ret); } /* * __fop_dummy -- * This implements the creation and name swapping of dummy files that * we use for remove and rename (remove is simply a rename with a delayed * remove). * * PUBLIC: int __fop_dummy __P((DB *, * PUBLIC: DB_TXN *, const char *, const char *, u_int32_t)); */ int __fop_dummy(dbp, txn, old, new, flags) DB *dbp; DB_TXN *txn; const char *old, *new; u_int32_t flags; { DB *tmpdbp; DB_TXN *stxn; ENV *env; char *back; int ret, t_ret; u_int8_t mbuf[DBMETASIZE]; env = dbp->env; back = NULL; stxn = NULL; tmpdbp = NULL; DB_ASSERT(env, txn != NULL); /* * Begin sub transaction to encapsulate the rename. Note that we * expect the inmem_swap calls to complete the sub-transaction, * aborting on error and committing on success. */ if (TXN_ON(env) && (ret = __txn_begin(env, NULL, txn, &stxn, 0)) != 0) goto err; /* We need to create a dummy file as a place holder. */ if ((ret = __db_backup_name(env, new, stxn, &back)) != 0) goto err; /* Create a dummy dbp handle. */ if ((ret = __db_create_internal(&tmpdbp, env, 0)) != 0) goto err; memset(mbuf, 0, sizeof(mbuf)); ret = F_ISSET(dbp, DB_AM_INMEM) ? __fop_inmem_dummy(tmpdbp, stxn, back, mbuf) : __fop_ondisk_dummy(tmpdbp, stxn, back, mbuf, flags); if (ret != 0) goto err; ret = F_ISSET(dbp, DB_AM_INMEM) ? __fop_inmem_swap(dbp, tmpdbp, stxn, old, new, back, txn->locker) : __fop_ondisk_swap(dbp, tmpdbp, stxn, old, new, back, txn->locker, flags); stxn = NULL; if (ret != 0) goto err; err: if (stxn != NULL) (void)__txn_abort(stxn); if (tmpdbp != NULL && (t_ret = __db_close(tmpdbp, NULL, 0)) != 0 && ret == 0) ret = t_ret; if (back != NULL) __os_free(env, back); return (ret); } /* * __fop_dbrename -- * Do the appropriate file locking and file system operations * to effect a dbrename in the absence of transactions (__fop_dummy * and the subsequent calls in __db_rename do the work for the * transactional case). * * PUBLIC: int __fop_dbrename __P((DB *, const char *, const char *)); */ int __fop_dbrename(dbp, old, new) DB *dbp; const char *old, *new; { DB_LOCK elock; ENV *env; char *real_new, *real_old; int ret, t_ret; env = dbp->env; real_new = NULL; real_old = NULL; LOCK_INIT(elock); if (F_ISSET(dbp, DB_AM_INMEM)) { real_new = (char *)new; real_old = (char *)old; } else { /* Get full names. */ if ((ret = __db_appname(env, DB_APP_DATA, new, 0, NULL, &real_new)) != 0) goto err; if ((ret = __db_appname(env, DB_APP_DATA, old, 0, NULL, &real_old)) != 0) goto err; } /* * It is an error to rename a file over one that already exists, * as that wouldn't be transaction-safe. We check explicitly * for ondisk files, but it's done memp_nameop for in-memory ones. */ GET_ENVLOCK(env, dbp->locker, &elock); ret = F_ISSET(dbp, DB_AM_INMEM) ? ENOENT : __os_exists(env, real_new, NULL); if (ret == 0) { ret = EEXIST; __db_errx(env, "rename: file %s exists", real_new); goto err; } ret = __memp_nameop(env, dbp->fileid, new, real_old, real_new, F_ISSET(dbp, DB_AM_INMEM)); err: if ((t_ret = __ENV_LPUT(env, elock)) != 0 && ret == 0) ret = t_ret; if (!F_ISSET(dbp, DB_AM_INMEM) && real_old != NULL) __os_free(env, real_old); if (!F_ISSET(dbp, DB_AM_INMEM) && real_new != NULL) __os_free(env, real_new); return (ret); } static int __fop_inmem_create(dbp, name, txn, flags) DB *dbp; const char *name; DB_TXN *txn; u_int32_t flags; { DBT fid_dbt, name_dbt; DB_LSN lsn; ENV *env; int ret; int32_t lfid; u_int32_t *p32; env = dbp->env; MAKE_INMEM(dbp); /* Set the pagesize if it isn't yet set. */ if (dbp->pgsize == 0) dbp->pgsize = DB_DEF_IOSIZE; /* * Construct a file_id. * * If this file has no name, then we only need a fileid for locking. * If this file has a name, we need the fileid both for locking and * matching in the memory pool. So, with unnamed in-memory databases, * use a lock_id. For named in-memory files, we need to find a value * that we can use to uniquely identify a name/fid pair. We use a * combination of a unique id (__os_unique_id) and a hash of the * original name. */ if (name == NULL) { if (LOCKING_ON(env) && (ret = __lock_id(env, (u_int32_t *)dbp->fileid, NULL)) != 0) goto err; } else { p32 = (u_int32_t *)(&dbp->fileid[0]); __os_unique_id(env, p32); p32++; (void)strncpy( (char *)p32, name, DB_FILE_ID_LEN - sizeof(u_int32_t)); dbp->preserve_fid = 1; if (DBENV_LOGGING(env) && #if !defined(DEBUG_WOP) && !defined(DIAGNOSTIC) txn != NULL && #endif dbp->log_filename != NULL) memcpy(dbp->log_filename->ufid, dbp->fileid, DB_FILE_ID_LEN); } /* Now, set the fileid. */ if ((ret = __memp_set_fileid(dbp->mpf, dbp->fileid)) != 0) goto err; if ((ret = __env_mpool(dbp, name, flags)) != 0) goto err; if (DBENV_LOGGING(env) && #if !defined(DEBUG_WOP) txn != NULL && #endif name != NULL) { DB_INIT_DBT(name_dbt, name, strlen(name) + 1); memset(&fid_dbt, 0, sizeof(fid_dbt)); fid_dbt.data = dbp->fileid; fid_dbt.size = DB_FILE_ID_LEN; lfid = dbp->log_filename == NULL ? DB_LOGFILEID_INVALID : dbp->log_filename->id; if ((ret = __crdel_inmem_create_log(env, txn, &lsn, 0, lfid, &name_dbt, &fid_dbt, dbp->pgsize)) != 0) goto err; } F_SET(dbp, DB_AM_CREATED); err: return (ret); } static int __fop_inmem_read_meta(dbp, txn, name, flags) DB *dbp; DB_TXN *txn; const char *name; u_int32_t flags; { DBMETA *metap; DB_THREAD_INFO *ip; db_pgno_t pgno; int ret, t_ret; if (txn == NULL) ENV_GET_THREAD_INFO(dbp->env, ip); else ip = txn->thread_info; pgno = PGNO_BASE_MD; if ((ret = __memp_fget(dbp->mpf, &pgno, ip, txn, 0, &metap)) != 0) return (ret); ret = __db_meta_setup(dbp->env, dbp, name, metap, flags, 1); if ((t_ret = __memp_fput(dbp->mpf, ip, metap, dbp->priority)) && ret == 0) ret = t_ret; return (ret); } static int __fop_ondisk_dummy(dbp, txn, name, mbuf, flags) DB *dbp; DB_TXN *txn; const char *name; u_int8_t *mbuf; u_int32_t flags; { ENV *env; int ret; char *realname; u_int32_t dflags; realname = NULL; env = dbp->env; dflags = F_ISSET(dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0; if ((ret = __db_appname(env, DB_APP_DATA, name, flags, NULL, &realname)) != 0) goto err; if ((ret = __fop_create(env, txn, NULL, name, DB_APP_DATA, 0, dflags)) != 0) goto err; if ((ret = __os_fileid(env, realname, 1, ((DBMETA *)mbuf)->uid)) != 0) goto err; ((DBMETA *)mbuf)->magic = DB_RENAMEMAGIC; if ((ret = __fop_write(env, txn, name, DB_APP_DATA, NULL, 0, 0, 0, mbuf, DBMETASIZE, 1, dflags)) != 0) goto err; memcpy(dbp->fileid, ((DBMETA *)mbuf)->uid, DB_FILE_ID_LEN); err: if (realname != NULL) __os_free(env, realname); return (ret); } static int __fop_inmem_dummy(dbp, txn, name, mbuf) DB *dbp; DB_TXN *txn; const char *name; u_int8_t *mbuf; { DBMETA *metap; DB_THREAD_INFO *ip; db_pgno_t pgno; int ret, t_ret; if ((ret = __fop_inmem_create(dbp, name, txn, DB_CREATE)) != 0) return (ret); if (txn == NULL) ENV_GET_THREAD_INFO(dbp->env, ip); else ip = txn->thread_info; pgno = PGNO_BASE_MD; if ((ret = __memp_fget(dbp->mpf, &pgno, ip, txn, DB_MPOOL_CREATE | DB_MPOOL_DIRTY, &metap)) != 0) return (ret); /* Check file existed. */ if (metap->magic != 0) ret = EEXIST; else metap->magic = DB_RENAMEMAGIC; /* Copy the fileid onto the meta-data page. */ memcpy(metap->uid, dbp->fileid, DB_FILE_ID_LEN); if ((t_ret = __memp_fput(dbp->mpf, ip, metap, ret == 0 ? dbp->priority : DB_PRIORITY_VERY_LOW)) != 0 && ret == 0) ret = t_ret; if (ret != 0) goto err; ((DBMETA *)mbuf)->magic = DB_RENAMEMAGIC; err: return (ret); } static int __fop_ondisk_swap(dbp, tmpdbp, txn, old, new, back, locker, flags) DB *dbp, *tmpdbp; DB_TXN *txn; const char *old, *new, *back; DB_LOCKER *locker; u_int32_t flags; { DBT fiddbt, namedbt, tmpdbt; DB_FH *fhp; DB_LOCK elock; DB_LSN lsn; DB_TXN *parent; ENV *env; u_int8_t mbuf[DBMETASIZE]; u_int32_t child_txnid, dflags; int ret, t_ret; char *realold, *realnew; env = dbp->env; DB_ASSERT(env, txn != NULL); DB_ASSERT(env, old != NULL); realold = realnew = NULL; LOCK_INIT(elock); fhp = NULL; dflags = F_ISSET(dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0; if ((ret = __db_appname(env, DB_APP_DATA, new, 0, NULL, &realnew)) != 0) goto err; /* Now, lock the name space while we initialize this file. */ retry: GET_ENVLOCK(env, locker, &elock); if (__os_exists(env, realnew, NULL) == 0) { /* * It is possible that the only reason this file exists is * because we've done a previous rename of it and we have * left a placeholder here. We need to check for that case * and allow this rename to succeed if that's the case. */ if ((ret = __os_open(env, realnew, 0, 0, 0, &fhp)) != 0) goto err; if ((ret = __fop_read_meta(env, realnew, mbuf, sizeof(mbuf), fhp, 0, NULL)) != 0 || (ret = __db_meta_setup(env, tmpdbp, realnew, (DBMETA *)mbuf, 0, 1)) != 0) { ret = EEXIST; goto err; } ret = __os_closehandle(env, fhp); fhp = NULL; if (ret != 0) goto err; /* * Now, try to acquire the handle lock. If the handle is locked * by our current, transaction, then we'll get it and life is * good. * * Alternately, it's not locked at all, we'll get the lock, but * we will realize it exists and consider this an error. * * However, if it's held by another transaction, then there * could be two different scenarios: 1) the file is in the * midst of being created or deleted and when that transaction * is over, we might be able to proceed. 2) the file is open * and exists and we should report an error. In order to * distinguish these two cases, we do the following. First, we * try to acquire a READLOCK. If the handle is in the midst of * being created, then we'll block because a writelock is held. * In that case, we should request a blocking write, and when we * get the lock, we should then go back and check to see if the * object exists and start all over again. * * If we got the READLOCK, then either no one is holding the * lock or someone has an open handle and the fact that the file * exists is problematic. So, in this case, we request the * WRITELOCK non-blocking -- if it succeeds, we're golden. If * it fails, then the file exists and we return EEXIST. */ if ((ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_READ, NULL, DB_LOCK_NOWAIT)) != 0) { /* * Someone holds a write-lock. Wait for the write-lock * and after we get it, release it and start over. */ if ((ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_WRITE, &elock, 0)) != 0) goto err; if ((ret = __lock_put(env, &tmpdbp->handle_lock)) != 0) goto err; if ((ret = __db_refresh(tmpdbp, NULL, 0, NULL, 0)) != 0) goto err; goto retry; } /* We got the read lock; try to upgrade it. */ ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_WRITE, NULL, DB_LOCK_UPGRADE | DB_LOCK_NOWAIT); if (ret != 0) { /* * We did not get the writelock, so someone * has the handle open. This is an error. */ (void)__lock_put(env, &tmpdbp->handle_lock); ret = EEXIST; } else if (F_ISSET(tmpdbp, DB_AM_IN_RENAME)) /* We got the lock and are renaming it. */ ret = 0; else { /* We got the lock, but the file exists. */ (void)__lock_put(env, &tmpdbp->handle_lock); ret = EEXIST; } if (ret != 0) goto err; } /* * While we have the namespace locked, do the renames and then * swap for the handle lock. */ if ((ret = __fop_rename(env, txn, old, new, dbp->fileid, DB_APP_DATA, 1, dflags)) != 0) goto err; if ((ret = __fop_rename(env, txn, back, old, tmpdbp->fileid, DB_APP_DATA, 0, dflags)) != 0) goto err; if ((ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_WRITE, &elock, NOWAIT_FLAG(txn))) != 0) goto err; /* * We just acquired a transactional lock on the tmp handle. * We need to null out the tmp handle's lock so that it * doesn't create problems for us in the close path. */ LOCK_INIT(tmpdbp->handle_lock); /* Commit the child. */ child_txnid = txn->txnid; parent = txn->parent; ret = __txn_commit(txn, 0); txn = NULL; /* Now log the child information in the parent. */ memset(&fiddbt, 0, sizeof(fiddbt)); fiddbt.data = dbp->fileid; fiddbt.size = DB_FILE_ID_LEN; memset(&tmpdbt, 0, sizeof(fiddbt)); tmpdbt.data = tmpdbp->fileid; tmpdbt.size = DB_FILE_ID_LEN; DB_INIT_DBT(namedbt, old, strlen(old) + 1); if ((t_ret = __fop_file_remove_log(env, parent, &lsn, 0, &fiddbt, &tmpdbt, &namedbt, (u_int32_t)DB_APP_DATA, child_txnid)) != 0 && ret == 0) ret = t_ret; /* This is a delayed delete of the dummy file. */ if ((ret = __db_appname(env, DB_APP_DATA, old, flags, NULL, &realold)) != 0) goto err; if ((ret = __txn_remevent(env, parent, realold, NULL, 0)) != 0) goto err; err: if (txn != NULL) /* Ret must already be set, so void abort. */ (void)__txn_abort(txn); (void)__ENV_LPUT(env, elock); if (fhp != NULL && (t_ret = __os_closehandle(env, fhp)) != 0 && ret == 0) ret = t_ret; if (realnew != NULL) __os_free(env, realnew); if (realold != NULL) __os_free(env, realold); return (ret); } static int __fop_inmem_swap(olddbp, backdbp, txn, old, new, back, locker) DB *olddbp, *backdbp; DB_TXN *txn; const char *old, *new, *back; DB_LOCKER *locker; { DB *tmpdbp; DBT fid_dbt, n1_dbt, n2_dbt; DB_LOCK elock; DB_LSN lsn; DB_TXN *parent; ENV *env; int ret, t_ret; env = olddbp->env; parent = txn->parent; retry: LOCK_INIT(elock); if ((ret = __db_create_internal(&tmpdbp, env, 0)) != 0) return (ret); MAKE_INMEM(tmpdbp); GET_ENVLOCK(env, locker, &elock); if ((ret = __env_mpool(tmpdbp, new, 0)) == 0) { /* * It is possible that the only reason this database exists is * because we've done a previous rename of it and we have * left a placeholder here. We need to check for that case * and allow this rename to succeed if that's the case. */ if ((ret = __fop_inmem_read_meta(tmpdbp, txn, new, 0)) != 0) { ret = EEXIST; goto err; } /* * Now, try to acquire the handle lock. If it's from our txn, * then we'll get the lock. If it's not, then someone else has * it locked. See the comments in __fop_ondisk_swap for * details. */ if ((ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_READ, NULL, DB_LOCK_NOWAIT)) != 0) { /* * Someone holds a writelock. Try for the WRITELOCK * and after we get it, retry. */ if ((ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_WRITE, &elock, 0)) != 0) goto err; /* We have the write lock; release it and start over. */ (void)__lock_put(env, &tmpdbp->handle_lock); (void)__db_close(tmpdbp, NULL, DB_NOSYNC); (void)__ENV_LPUT(env, elock); goto retry; } else { (void)__lock_put(env, &tmpdbp->handle_lock); if (!F_ISSET(tmpdbp, DB_AM_IN_RENAME)) ret = EEXIST; } if (ret != 0) goto err; } /* Log the renames. */ if (LOGGING_ON(env) #ifndef DEBUG_WOP && txn != NULL #endif ) { /* Rename old to new. */ DB_INIT_DBT(fid_dbt, olddbp->fileid, DB_FILE_ID_LEN); DB_INIT_DBT(n1_dbt, old, strlen(old) + 1); DB_INIT_DBT(n2_dbt, new, strlen(new) + 1); if ((ret = __crdel_inmem_rename_log( env, txn, &lsn, 0, &n1_dbt, &n2_dbt, &fid_dbt)) != 0) goto err; /* Rename back to old */ fid_dbt.data = backdbp->fileid; DB_SET_DBT(n2_dbt, back, strlen(back) + 1); if ((ret = __crdel_inmem_rename_log( env, txn, &lsn, 0, &n2_dbt, &n1_dbt, &fid_dbt)) != 0) goto err; } /* * While we have the namespace locked, do the renames and then * swap for the handle lock. If we ran into a file in the midst * of rename, then we need to delete it first, else nameop is * going to consider it an error. */ if (F_ISSET(tmpdbp, DB_AM_IN_RENAME)) { if ((ret = __memp_nameop(env, tmpdbp->fileid, NULL, new, NULL, 1)) != 0) goto err; __txn_remrem(env, parent, new); } if ((ret = __memp_nameop( env, olddbp->fileid, new, old, new, 1)) != 0) goto err; if ((ret = __memp_nameop( env, backdbp->fileid, old, back, old, 1)) != 0) goto err; if ((ret = __fop_lock_handle(env, tmpdbp, locker, DB_LOCK_WRITE, &elock, 0)) != 0) goto err; /* * We just acquired a transactional lock on the tmp handle. * We need to null out the tmp handle's lock so that it * doesn't create problems for us in the close path. */ LOCK_INIT(tmpdbp->handle_lock); DB_ASSERT(env, txn != NULL); /* Commit the child. */ ret = __txn_commit(txn, 0); txn = NULL; if ((ret = __db_inmem_remove(backdbp, parent, old)) != 0) goto err; err: (void)__ENV_LPUT(env, elock); if (txn != NULL) (void)__txn_abort(txn); if ((t_ret = __db_close(tmpdbp, NULL, 0)) != 0 && ret == 0) ret = t_ret; return (ret); }