fop_util.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:24k
- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 2001-2002
- * Sleepycat Software. All rights reserved.
- */
- #include "db_config.h"
- #ifndef lint
- static const char revid[] = "$Id: fop_util.c,v 1.52 2002/09/10 02:41:42 bostic Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #include <stddef.h>
- #include <stdlib.h>
- #include <string.h>
- #endif
- #include "db_int.h"
- #include "dbinc/db_page.h"
- #include "dbinc/db_shash.h"
- #include "dbinc/db_am.h"
- #include "dbinc/fop.h"
- #include "dbinc/lock.h"
- #include "dbinc/log.h"
- #include "dbinc/txn.h"
- static int __fop_set_pgsize __P((DB *, DB_FH *, const char *));
- /*
- * 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.
- */
- #define GET_ENVLOCK(ENV, ID, L) do {
- DBT __dbt;
- u_int32_t __lockval;
-
- if (LOCKING_ON((ENV))) {
- __lockval = 0;
- __dbt.data = &__lockval;
- __dbt.size = sizeof(__lockval);
- if ((ret = (ENV)->lock_get((ENV), (ID),
- 0, &__dbt, DB_LOCK_WRITE, (L))) != 0)
- goto err;
- }
- } while (0)
- #define REL_ENVLOCK(ENV, L)
- (!LOCK_ISSET(*(L)) ? 0 : (ENV)->lock_put((ENV), (L)))
- /*
- * If our caller is doing fcntl(2) locking, then we can't close it
- * because that would discard the caller's lock. Otherwise, close
- * the handle.
- */
- #define CLOSE_HANDLE(D, F) {
- if (F_ISSET((F), DB_FH_VALID)) {
- if (LF_ISSET(DB_FCNTL_LOCKING))
- (D)->saved_open_fhp = (F);
- else if ((ret = __os_closehandle((D)->dbenv,(F))) != 0)
- goto err;
- }
- }
- /*
- * __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 enviroment lock before
- * acquiring the handle lock.
- *
- * PUBLIC: int __fop_lock_handle __P((DB_ENV *,
- * PUBLIC: DB *, u_int32_t, db_lockmode_t, DB_LOCK *, u_int32_t));
- *
- */
- int
- __fop_lock_handle(dbenv, dbp, locker, mode, elock, flags)
- DB_ENV *dbenv;
- DB *dbp;
- u_int32_t locker;
- db_lockmode_t mode;
- DB_LOCK *elock;
- u_int32_t flags;
- {
- DBT fileobj;
- DB_LOCKREQ reqs[2], *ereq;
- DB_LOCK_ILOCK lock_desc;
- int ret;
- if (!LOCKING_ON(dbenv) || F_ISSET(dbp, DB_AM_COMPENSATE))
- return (0);
- /*
- * If we are in recovery, the only locking we should be
- * doing is on the global environment.
- */
- if (IS_RECOVERING(dbenv)) {
- if (elock != NULL)
- REL_ENVLOCK(dbenv, elock);
- return (0);
- }
- 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(dbenv, flags);
- if (elock == NULL)
- ret = dbenv->lock_get(dbenv, locker,
- flags, &fileobj, mode, &dbp->handle_lock);
- else {
- reqs[0].op = DB_LOCK_PUT;
- reqs[0].lock = *elock;
- reqs[1].op = DB_LOCK_GET;
- reqs[1].mode = mode;
- reqs[1].obj = &fileobj;
- reqs[1].timeout = 0;
- if ((ret = __lock_vec(dbenv,
- locker, flags, reqs, 2, &ereq)) == 0) {
- dbp->handle_lock = reqs[1].lock;
- LOCK_INIT(*elock);
- } else if (ereq != reqs)
- LOCK_INIT(*elock);
- }
- dbp->cur_lid = 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).
- *
- * PUBLIC: int __fop_file_setup __P((DB *,
- * PUBLIC: DB_TXN *, const char *, int, u_int32_t, u_int32_t *));
- */
- int
- __fop_file_setup(dbp, txn, name, mode, flags, retidp)
- DB *dbp;
- DB_TXN *txn;
- const char *name;
- int mode;
- u_int32_t flags, *retidp;
- {
- DB_ENV *dbenv;
- DB_FH fh, *fhp;
- DB_LOCK elock, tmp_lock;
- DB_TXN *stxn;
- db_lockmode_t lmode;
- u_int32_t locker, oflags;
- u_int8_t mbuf[DBMETASIZE];
- int created_fhp, created_locker, ret, tmp_created, truncating;
- char *real_name, *real_tmpname, *tmpname;
- DB_ASSERT(name != NULL);
- *retidp = TXN_INVALID;
- dbenv = dbp->dbenv;
- LOCK_INIT(elock);
- LOCK_INIT(tmp_lock);
- stxn = NULL;
- created_fhp = created_locker = 0;
- real_name = real_tmpname = tmpname = NULL;
- tmp_created = truncating = 0;
- /*
- * If we open a file handle and our caller is doing fcntl(2) locking,
- * we can't close it because that would discard the caller's lock.
- * Save it until we close the DB handle.
- */
- if (LF_ISSET(DB_FCNTL_LOCKING)) {
- if ((ret = __os_malloc(dbenv, sizeof(*fhp), &fhp)) != 0)
- return (ret);
- created_fhp = 1;
- } else
- fhp = &fh;
- memset(fhp, 0, sizeof(*fhp));
- /*
- * 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(dbenv) &&
- !F_ISSET(dbp, DB_AM_COMPENSATE) && dbp->lid == DB_LOCK_INVALIDID) {
- if ((ret = __lock_id(dbenv, &dbp->lid)) != 0)
- goto err;
- created_locker = 1;
- }
- locker = txn == NULL ? dbp->lid : txn->txnid;
- /* Get the real backing file name. */
- if ((ret = __db_appname(dbenv,
- DB_APP_DATA, name, 0, NULL, &real_name)) != 0)
- goto err;
- /* Fill in the default file mode. */
- if (mode == 0)
- mode = __db_omode("rwrw--");
- oflags = 0;
- if (LF_ISSET(DB_RDONLY))
- oflags |= DB_OSO_RDONLY;
- retry: if (!F_ISSET(dbp, DB_AM_COMPENSATE))
- GET_ENVLOCK(dbenv, locker, &elock);
- if ((ret = __os_exists(real_name, NULL)) == 0) {
- if (LF_ISSET(DB_EXCL)) {
- ret = EEXIST;
- goto err;
- }
- reopen: if ((ret = __fop_read_meta(dbenv, real_name,
- mbuf, sizeof(mbuf), fhp, 0, oflags)) != 0)
- goto err;
- if ((ret = __db_meta_setup(dbenv,
- dbp, real_name, (DBMETA *)mbuf, flags, 1)) != 0)
- goto err;
- /* Now, get our handle lock. */
- lmode = LF_ISSET(DB_TRUNCATE) ? DB_LOCK_WRITE : DB_LOCK_READ;
- if ((ret = __fop_lock_handle(dbenv,
- dbp, locker, lmode, NULL, DB_LOCK_NOWAIT)) == 0) {
- if ((ret = REL_ENVLOCK(dbenv, &elock)) != 0)
- goto err;
- } else {
- /* Someone else has file locked; need to wait. */
- if ((ret = __os_closehandle(dbenv, fhp)) != 0)
- goto err;
- ret = __fop_lock_handle(dbenv,
- dbp, locker, lmode, &elock, 0);
- if (ret == DB_LOCK_NOTEXIST)
- goto retry;
- if (ret != 0)
- goto err;
- /*
- * XXX I need to convince myself that I don't need
- * to re-read the metadata page here.
- * XXX If you do need to re-read it you'd better
- * decrypt it too...
- */
- if ((ret = __os_open(dbenv, real_name, 0, 0, fhp)) != 0)
- goto err;
- }
- /*
- * Check for a truncate which needs to leap over to the
- * create case.
- */
- if (LF_ISSET(DB_TRUNCATE)) {
- /*
- * Sadly, we need to close and reopen the handle
- * in order to do the actual truncate. We couldn't
- * do the truncate on the initial open because we
- * needed to read the old file-id in order to lock.
- */
- if ((ret = __os_closehandle(dbenv, fhp)) != 0)
- goto err;
- if ((ret = __os_open(dbenv,
- real_name, DB_OSO_TRUNC, 0, fhp)) != 0)
- goto err;
- /*
- * This is not-transactional, so we'll do the
- * open/create in-place.
- */
- tmp_lock = dbp->handle_lock;
- truncating = 1;
- tmpname = (char *)name;
- goto creat2;
- }
- /*
- * Check for a file in the midst of a rename
- */
- if (F_ISSET(dbp, DB_AM_IN_RENAME)) {
- if (LF_ISSET(DB_CREATE)) {
- F_CLR(dbp, DB_AM_IN_RENAME);
- goto create;
- } else {
- ret = ENOENT;
- goto err;
- }
- }
- CLOSE_HANDLE(dbp, fhp);
- goto done;
- }
- /* File does not exist. */
- if (!LF_ISSET(DB_CREATE))
- goto err;
- ret = 0;
- /*
- * Need to create file; 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.
- */
- if ((ret = REL_ENVLOCK(dbenv, &elock)) != 0)
- goto err;
- create: if ((ret = __db_backup_name(dbenv, name, txn, &tmpname)) != 0)
- goto err;
- if (TXN_ON(dbenv) && txn != NULL &&
- (ret = dbenv->txn_begin(dbenv, txn, &stxn, 0)) != 0)
- goto err;
- if ((ret = __fop_create(dbenv,
- stxn, fhp, tmpname, DB_APP_DATA, mode)) != 0)
- goto err;
- tmp_created = 1;
- creat2: if ((ret = __db_appname(dbenv,
- 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(dbenv, real_tmpname, 1, dbp->fileid)) != 0)
- goto errmsg;
- if ((ret = __db_new_file(dbp, stxn, fhp, tmpname)) != 0)
- goto err;
- CLOSE_HANDLE(dbp, fhp);
- /* Now move the file into place. */
- if (!F_ISSET(dbp, DB_AM_COMPENSATE))
- GET_ENVLOCK(dbenv, locker, &elock);
- if (!truncating && __os_exists(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(dbenv,
- NULL, dbp->fileid, tmpname, DB_APP_DATA);
- if (LOCKING_ON(dbenv))
- dbenv->lock_put(dbenv, &dbp->handle_lock);
- LOCK_INIT(dbp->handle_lock);
- /* If we have a saved handle; close it. */
- if (LF_ISSET(DB_FCNTL_LOCKING))
- (void)__os_closehandle(dbenv, fhp);
- if (stxn != NULL) {
- ret = stxn->abort(stxn);
- stxn = NULL;
- }
- if (ret != 0)
- goto err;
- goto reopen;
- }
- /* We've successfully created, move the file into place. */
- if ((ret = __fop_lock_handle(dbenv,
- dbp, locker, DB_LOCK_WRITE, &elock, 0)) != 0)
- goto err;
- if (!truncating && (ret = __fop_rename(dbenv,
- stxn, tmpname, name, dbp->fileid, DB_APP_DATA)) != 0)
- goto err;
- /* If this was a truncate; release lock on the old file. */
- if (LOCK_ISSET(tmp_lock) && (ret = __lock_put(dbenv, &tmp_lock)) != 0)
- goto err;
- if (stxn != NULL) {
- *retidp = stxn->txnid;
- ret = stxn->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(dbenv, "%s: %s", name, db_strerror(ret));
- err: if (stxn != NULL)
- (void)stxn->abort(stxn);
- if (tmp_created && txn == NULL)
- (void)__fop_remove(dbenv,
- NULL, NULL, tmpname, DB_APP_DATA);
- if (F_ISSET(fhp, DB_FH_VALID))
- (void)__os_closehandle(dbenv, fhp);
- if (LOCK_ISSET(tmp_lock))
- __lock_put(dbenv, &tmp_lock);
- if (LOCK_ISSET(dbp->handle_lock) && txn == NULL)
- __lock_put(dbenv, &dbp->handle_lock);
- if (LOCK_ISSET(elock))
- (void)REL_ENVLOCK(dbenv, &elock);
- if (created_locker) {
- (void)__lock_id_free(dbenv, dbp->lid);
- dbp->lid = DB_LOCK_INVALIDID;
- }
- if (created_fhp)
- __os_free(dbenv, fhp);
- }
- done: if (!truncating && tmpname != NULL)
- __os_free(dbenv, tmpname);
- if (real_name != NULL)
- __os_free(dbenv, real_name);
- if (real_tmpname != NULL)
- __os_free(dbenv, real_tmpname);
- 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;
- {
- DB_ENV *dbenv;
- u_int32_t iopsize;
- int ret;
- dbenv = dbp->dbenv;
- /*
- * 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(dbenv, name, fhp, NULL, NULL, &iopsize)) != 0) {
- __db_err(dbenv, "%s: %s", name, db_strerror(ret));
- 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_TXN *,
- * PUBLIC: const char *, const char *, int, u_int32_t));
- */
- int
- __fop_subdb_setup(dbp, txn, mname, name, mode, flags)
- DB *dbp;
- DB_TXN *txn;
- const char *mname, *name;
- int mode;
- u_int32_t flags;
- {
- DB *mdbp;
- DB_ENV *dbenv;
- int do_remove, ret;
- mdbp = NULL;
- dbenv = dbp->dbenv;
- if ((ret = __db_master_open(dbp, txn, mname, flags, mode, &mdbp)) != 0)
- return (ret);
- /*
- * 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;
- }
- /* Now copy the pagesize. */
- dbp->pgsize = mdbp->pgsize;
- F_SET(dbp, DB_AM_SUBDB);
- if (name != NULL && (ret = __db_master_update(mdbp, dbp, 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 lid would just have been freed anyway. Once we've gotten
- * the locker id, we need to acquire the handle lock for this
- * subdatabase.
- */
- dbp->lid = mdbp->lid;
- mdbp->lid = DB_LOCK_INVALIDID;
- 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);
- if ((ret = __fop_lock_handle(dbenv, dbp,
- txn == NULL ? dbp->lid : txn->txnid,
- F_ISSET(dbp, DB_AM_CREATED) || LF_ISSET(DB_WRITEOPEN) ?
- DB_LOCK_WRITE : DB_LOCK_READ, NULL, 0)) != 0)
- goto err;
- if ((ret = __db_init_subdb(mdbp, dbp, name, txn)) != 0)
- goto err;
- /*
- * 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);
- }
- /*
- * 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) && txn != NULL) {
- /* Unregister old master events. */
- __txn_remlock(dbenv,
- txn, &mdbp->handle_lock, DB_LOCK_INVALIDID);
- /* Now register the new event. */
- if ((ret = __txn_lockevent(dbenv,
- txn, dbp, &mdbp->handle_lock, dbp->lid)) != 0)
- goto err;
- }
- LOCK_INIT(mdbp->handle_lock);
- return (__db_close_i(mdbp, txn, 0));
- err:
- DB_TEST_RECOVERY_LABEL
- if (LOCK_ISSET(dbp->handle_lock) && txn == NULL)
- __lock_put(dbenv, &dbp->handle_lock);
- /* If we created the master file then we need to remove it. */
- if (mdbp != NULL) {
- do_remove = F_ISSET(mdbp, DB_AM_CREATED) ? 1 : 0;
- if (do_remove)
- F_SET(mdbp, DB_AM_DISCARD);
- (void)__db_close_i(mdbp, txn, 0);
- if (do_remove) {
- (void)db_create(&mdbp, dbp->dbenv, 0);
- (void)__db_remove_i(mdbp, txn, mname, NULL);
- }
- }
- 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_ENV *dbenv;
- DB_LOCK elock;
- u_int8_t mbuf[DBMETASIZE];
- int ret;
- COMPQUIET(flags, 0);
- dbenv = dbp->dbenv;
- PANIC_CHECK(dbenv);
- LOCK_INIT(elock);
- /* Create locker if necessary. */
- if (LOCKING_ON(dbenv)) {
- if (txn != NULL)
- dbp->lid = txn->txnid;
- else if (dbp->lid == DB_LOCK_INVALIDID) {
- if ((ret = __lock_id(dbenv, &dbp->lid)) != 0)
- goto err;
- }
- }
- /*
- * 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(dbenv, dbp->lid, &elock);
- if ((ret = __fop_read_meta(dbenv,
- name, mbuf, sizeof(mbuf), NULL, 0, 0)) != 0)
- goto err;
- if ((ret =
- __db_meta_setup(dbenv, dbp, name, (DBMETA *)mbuf, flags, 1)) != 0)
- goto err;
- /* Now, release the environment and get the handle lock. */
- if ((ret = __fop_lock_handle(dbenv,
- dbp, dbp->lid, DB_LOCK_WRITE, &elock, 0)) != 0)
- goto err;
- return (0);
- err: (void)REL_ENVLOCK(dbenv, &elock);
- return (ret);
- }
- /*
- * __fop_read_meta --
- * Read the meta-data page from a file and return it in buf. The
- * open file handle is returned in fhp.
- *
- * PUBLIC: int __fop_read_meta __P((DB_ENV *,
- * PUBLIC: const char *, u_int8_t *, size_t, DB_FH *, int, u_int32_t));
- */
- int
- __fop_read_meta(dbenv, name, buf, size, fhp, errok, flags)
- DB_ENV *dbenv;
- const char *name;
- u_int8_t *buf;
- size_t size;
- DB_FH *fhp;
- int errok;
- u_int32_t flags;
- {
- DB_FH fh, *lfhp;
- size_t nr;
- int ret;
- lfhp = fhp == NULL ? &fh : fhp;
- memset(lfhp, 0, sizeof(*fhp));
- if ((ret = __os_open(dbenv, name, flags, 0, lfhp)) != 0)
- goto err;
- if ((ret = __os_read(dbenv, lfhp, buf, size, &nr)) != 0) {
- if (!errok)
- __db_err(dbenv, "%s: %s", name, db_strerror(ret));
- goto err;
- }
- if (nr != size) {
- if (!errok)
- __db_err(dbenv,
- "%s: unexpected file type or format", name);
- ret = EINVAL;
- goto err;
- }
- err: /*
- * On error, we always close the handle. If there is no error,
- * then we only return the handle if the user didn't pass us
- * a handle into which to return it. If fhp is valid, then
- * lfhp is the same as fhp.
- */
- if (F_ISSET(lfhp, DB_FH_VALID) && (ret != 0 || fhp == NULL))
- __os_closehandle(dbenv, lfhp);
- 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_ENV *dbenv;
- DB_LOCK elock;
- DB_LSN lsn;
- DBT fiddbt, namedbt, tmpdbt;
- DB_TXN *stxn;
- char *back;
- char *realback, *realnew, *realold;
- int ret, t_ret;
- u_int8_t mbuf[DBMETASIZE];
- u_int32_t locker, stxnid;
- dbenv = dbp->dbenv;
- LOCK_INIT(elock);
- realback = NULL;
- realnew = NULL;
- realold = NULL;
- back = NULL;
- stxn = NULL;
- tmpdbp = NULL;
- DB_ASSERT(txn != NULL);
- locker = txn->txnid;
- /* Begin sub transaction to encapsulate the rename. */
- if (TXN_ON(dbenv) &&
- (ret = dbenv->txn_begin(dbenv, txn, &stxn, 0)) != 0)
- goto err;
- /* We need to create a dummy file as a place holder. */
- if ((ret = __db_backup_name(dbenv, new, stxn, &back)) != 0)
- goto err;
- if ((ret = __db_appname(dbenv,
- DB_APP_DATA, back, flags, NULL, &realback)) != 0)
- goto err;
- if ((ret = __fop_create(dbenv, stxn, NULL, back, DB_APP_DATA, 0)) != 0)
- goto err;
- memset(mbuf, 0, sizeof(mbuf));
- if ((ret =
- __os_fileid(dbenv, realback, 1, ((DBMETA *)mbuf)->uid)) != 0)
- goto err;
- ((DBMETA *)mbuf)->magic = DB_RENAMEMAGIC;
- if ((ret = __fop_write(dbenv,
- stxn, back, DB_APP_DATA, NULL, 0, mbuf, DBMETASIZE, 1)) != 0)
- goto err;
- /* Create a dummy dbp handle. */
- if ((ret = db_create(&tmpdbp, dbenv, 0)) != 0)
- goto err;
- memcpy(&tmpdbp->fileid, ((DBMETA *)mbuf)->uid, DB_FILE_ID_LEN);
- /* Now, lock the name space while we initialize this file. */
- if ((ret = __db_appname(dbenv,
- DB_APP_DATA, new, 0, NULL, &realnew)) != 0)
- goto err;
- GET_ENVLOCK(dbenv, locker, &elock);
- if (__os_exists(realnew, NULL) == 0) {
- ret = EEXIST;
- goto err;
- }
- /*
- * While we have the namespace locked, do the renames and then
- * swap for the handle lock.
- */
- if ((ret = __fop_rename(dbenv,
- stxn, old, new, dbp->fileid, DB_APP_DATA)) != 0)
- goto err;
- if ((ret = __fop_rename(dbenv,
- stxn, back, old, tmpdbp->fileid, DB_APP_DATA)) != 0)
- goto err;
- if ((ret = __fop_lock_handle(dbenv,
- 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);
- if (stxn != NULL) {
- /* Commit the child. */
- stxnid = stxn->txnid;
- ret = stxn->commit(stxn, 0);
- stxn = NULL;
- /* Now log the child information in the parent. */
- memset(&fiddbt, 0, sizeof(fiddbt));
- memset(&tmpdbt, 0, sizeof(fiddbt));
- memset(&namedbt, 0, sizeof(namedbt));
- fiddbt.data = dbp->fileid;
- fiddbt.size = DB_FILE_ID_LEN;
- tmpdbt.data = tmpdbp->fileid;
- tmpdbt.size = DB_FILE_ID_LEN;
- namedbt.data = (void *)old;
- namedbt.size = (u_int32_t)strlen(old) + 1;
- if ((t_ret =
- __fop_file_remove_log(dbenv, txn, &lsn, 0, &fiddbt,
- &tmpdbt, &namedbt, DB_APP_DATA, stxnid)) != 0 && ret == 0)
- ret = t_ret;
- }
- /* This is a delayed delete of the dummy file. */
- if ((ret = __db_appname(dbenv,
- DB_APP_DATA, old, flags, NULL, &realold)) != 0)
- goto err;
- if ((ret = __txn_remevent(dbenv, txn, realold, NULL)) != 0)
- goto err;
- err: (void)REL_ENVLOCK(dbenv, &elock);
- if (stxn != NULL)
- (void)stxn->abort(stxn);
- if (tmpdbp != NULL &&
- (t_ret = __db_close_i(tmpdbp, NULL, 0)) != 0 && ret == 0)
- ret = t_ret;
- if (realold != NULL)
- __os_free(dbenv, realold);
- if (realnew != NULL)
- __os_free(dbenv, realnew);
- if (realback != NULL)
- __os_free(dbenv, realback);
- if (back != NULL)
- __os_free(dbenv, 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_ENV *dbenv;
- DB_LOCK elock;
- char *real_new, *real_old;
- int ret, tret;
- dbenv = dbp->dbenv;
- real_new = NULL;
- real_old = NULL;
- LOCK_INIT(elock);
- /* Find the real newname of the file. */
- if ((ret = __db_appname(dbenv,
- DB_APP_DATA, new, 0, NULL, &real_new)) != 0)
- goto err;
- /*
- * It is an error to rename a file over one that already exists,
- * as that wouldn't be transaction-safe.
- */
- GET_ENVLOCK(dbenv, dbp->lid, &elock);
- if (__os_exists(real_new, NULL) == 0) {
- ret = EEXIST;
- __db_err(dbenv, "rename: file %s exists", real_new);
- goto err;
- }
- if ((ret = __db_appname(dbenv,
- DB_APP_DATA, old, 0, NULL, &real_old)) != 0)
- goto err;
- ret = dbenv->memp_nameop(dbenv, dbp->fileid, new, real_old, real_new);
- err: if ((tret = REL_ENVLOCK(dbenv, &elock)) != 0 && ret == 0)
- ret = tret;
- if (real_old != NULL)
- __os_free(dbenv, real_old);
- if (real_new != NULL)
- __os_free(dbenv, real_new);
- return (ret);
- }