X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Ftdb2%2Ftdb1_lock.c;fp=ccan%2Ftdb2%2Ftdb1_lock.c;h=0000000000000000000000000000000000000000;hb=b91dafc6ab5075355d508f051977a15dd7794b0e;hp=5cc0ad656729c51877aebf5f1fe7489bb11b972a;hpb=0b93bd102aad6b61f1e569fb12aabc6352a1d7cd;p=ccan

diff --git a/ccan/tdb2/tdb1_lock.c b/ccan/tdb2/tdb1_lock.c
deleted file mode 100644
index 5cc0ad65..00000000
--- a/ccan/tdb2/tdb1_lock.c
+++ /dev/null
@@ -1,560 +0,0 @@
- /*
-   Unix SMB/CIFS implementation.
-
-   trivial database library
-
-   Copyright (C) Andrew Tridgell              1999-2005
-   Copyright (C) Paul `Rusty' Russell		   2000
-   Copyright (C) Jeremy Allison			   2000-2003
-
-     ** NOTE! The following LGPL license applies to the tdb
-     ** library. This does NOT imply that all of Samba is released
-     ** under the LGPL
-
-   This library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 3 of the License, or (at your option) any later version.
-
-   This library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with this library; if not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "tdb1_private.h"
-
-/* list -1 is the alloc list, otherwise a hash chain. */
-static tdb1_off_t lock_offset(int list)
-{
-	return TDB1_FREELIST_TOP + 4*list;
-}
-
-/* a byte range locking function - return 0 on success
-   this functions locks/unlocks 1 byte at the specified offset.
-
-   On error, errno is also set so that errors are passed back properly
-   through tdb1_open().
-
-   note that a len of zero means lock to end of file
-*/
-int tdb1_brlock(struct tdb_context *tdb,
-	       int rw_type, tdb1_off_t offset, size_t len,
-	       enum tdb_lock_flags flags)
-{
-	enum TDB_ERROR ecode = tdb_brlock(tdb, rw_type, offset, len, flags
-					  | TDB_LOCK_NOCHECK);
-	if (ecode == TDB_SUCCESS)
-		return 0;
-	tdb->last_error = ecode;
-	return -1;
-}
-
-int tdb1_brunlock(struct tdb_context *tdb,
-		 int rw_type, tdb1_off_t offset, size_t len)
-{
-	enum TDB_ERROR ecode = tdb_brunlock(tdb, rw_type, offset, len);
-	if (ecode == TDB_SUCCESS)
-		return 0;
-	tdb->last_error = ecode;
-	return -1;
-}
-
-int tdb1_allrecord_upgrade(struct tdb_context *tdb)
-{
-	enum TDB_ERROR ecode = tdb_allrecord_upgrade(tdb, TDB1_FREELIST_TOP);
-	if (ecode == TDB_SUCCESS)
-		return 0;
-	tdb->last_error = ecode;
-	return -1;
-}
-
-static struct tdb_lock *tdb1_find_nestlock(struct tdb_context *tdb,
-					   tdb1_off_t offset)
-{
-	unsigned int i;
-
-	for (i=0; i<tdb->file->num_lockrecs; i++) {
-		if (tdb->file->lockrecs[i].off == offset) {
-			return &tdb->file->lockrecs[i];
-		}
-	}
-	return NULL;
-}
-
-/* lock an offset in the database. */
-int tdb1_nest_lock(struct tdb_context *tdb, uint32_t offset, int ltype,
-		  enum tdb_lock_flags flags)
-{
-	enum TDB_ERROR ecode;
-
-	if (offset >= lock_offset(tdb->tdb1.header.hash_size)) {
-		tdb->last_error = tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
-					"tdb1_lock: invalid offset %u for"
-					" ltype=%d",
-					offset, ltype);
-		return -1;
-	}
-
-	ecode = tdb_nest_lock(tdb, offset, ltype, flags | TDB_LOCK_NOCHECK);
-	if (unlikely(ecode != TDB_SUCCESS)) {
-		tdb->last_error = ecode;
-		return -1;
-	}
-	return 0;
-}
-
-static int tdb1_lock_and_recover(struct tdb_context *tdb)
-{
-	int ret;
-
-	/* We need to match locking order in transaction commit. */
-	if (tdb1_brlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0,
-			TDB_LOCK_WAIT|TDB_LOCK_NOCHECK)) {
-		return -1;
-	}
-
-	if (tdb1_brlock(tdb, F_WRLCK, TDB1_OPEN_LOCK, 1,
-			TDB_LOCK_WAIT|TDB_LOCK_NOCHECK)) {
-		tdb1_brunlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0);
-		return -1;
-	}
-
-	ret = tdb1_transaction_recover(tdb);
-
-	tdb1_brunlock(tdb, F_WRLCK, TDB1_OPEN_LOCK, 1);
-	tdb1_brunlock(tdb, F_WRLCK, TDB1_FREELIST_TOP, 0);
-
-	return ret;
-}
-
-static bool have_data_locks(const struct tdb_context *tdb)
-{
-	unsigned int i;
-
-	for (i = 0; i < tdb->file->num_lockrecs; i++) {
-		if (tdb->file->lockrecs[i].off >= lock_offset(-1))
-			return true;
-	}
-	return false;
-}
-
-static int tdb1_lock_list(struct tdb_context *tdb, int list, int ltype,
-			 enum tdb_lock_flags waitflag)
-{
-	int ret;
-	bool check = false;
-
-	/* a allrecord lock allows us to avoid per chain locks */
-	if (tdb->file->allrecord_lock.count) {
-		if (!check_lock_pid(tdb, "tdb1_lock_list", true)) {
-			tdb->last_error = TDB_ERR_LOCK;
-			return -1;
-		}
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error = owner_conflict(tdb, "tdb1_lock_list");
-			return -1;
-		}
-		if (ltype == tdb->file->allrecord_lock.ltype
-		    || ltype == F_RDLCK) {
-			return 0;
-		}
-		tdb->last_error = tdb_logerr(tdb, TDB_ERR_LOCK,
-					     TDB_LOG_USE_ERROR,
-					     "tdb1_lock_list:"
-					     " already have read lock");
-		return -1;
-	}
-
-	/* Only check when we grab first data lock. */
-	check = !have_data_locks(tdb);
-	ret = tdb1_nest_lock(tdb, lock_offset(list), ltype, waitflag);
-
-	if (ret == 0 && check) {
-		tdb_bool_err berr = tdb1_needs_recovery(tdb);
-
-		if (berr < 0) {
-			return -1;
-		}
-		if (berr == true) {
-			tdb1_nest_unlock(tdb, lock_offset(list), ltype);
-
-			if (tdb1_lock_and_recover(tdb) == -1) {
-				return -1;
-			}
-			return tdb1_lock_list(tdb, list, ltype, waitflag);
-		}
-	}
-	return ret;
-}
-
-/* lock a list in the database. list -1 is the alloc list */
-int tdb1_lock(struct tdb_context *tdb, int list, int ltype)
-{
-	int ret;
-
-	ret = tdb1_lock_list(tdb, list, ltype, TDB_LOCK_WAIT);
-	/* Don't log for EAGAIN and EINTR: they could have overridden lock fns */
-	if (ret && errno != EAGAIN && errno != EINTR) {
-		tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
-			   "tdb1_lock failed on list %d "
-			   "ltype=%d (%s)",  list, ltype, strerror(errno));
-	}
-	return ret;
-}
-
-int tdb1_nest_unlock(struct tdb_context *tdb, uint32_t offset, int ltype)
-{
-	enum TDB_ERROR ecode;
-
-	/* Sanity checks */
-	if (offset >= lock_offset(tdb->tdb1.header.hash_size)) {
-		tdb->last_error = tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
-					"tdb1_unlock: offset %u invalid (%d)",
-					offset, tdb->tdb1.header.hash_size);
-		return -1;
-	}
-
-	ecode = tdb_nest_unlock(tdb, offset, ltype);
-	if (unlikely(ecode != TDB_SUCCESS)) {
-		tdb->last_error = ecode;
-		return -1;
-	}
-	return 0;
-}
-
-int tdb1_unlock(struct tdb_context *tdb, int list, int ltype)
-{
-	/* a global lock allows us to avoid per chain locks */
-	if (tdb->file->allrecord_lock.count &&
-	    (ltype == tdb->file->allrecord_lock.ltype || ltype == F_RDLCK)) {
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error = owner_conflict(tdb, "tdb1_unlock");
-			return -1;
-		}
-		return 0;
-	}
-
-	if (tdb->file->allrecord_lock.count) {
-		tdb->last_error = TDB_ERR_LOCK;
-		return -1;
-	}
-
-	return tdb1_nest_unlock(tdb, lock_offset(list), ltype);
-}
-
-/*
-  get the transaction lock
- */
-int tdb1_transaction_lock(struct tdb_context *tdb, int ltype,
-			 enum tdb_lock_flags lockflags)
-{
-	return tdb1_nest_lock(tdb, TDB1_TRANSACTION_LOCK, ltype, lockflags);
-}
-
-/*
-  release the transaction lock
- */
-int tdb1_transaction_unlock(struct tdb_context *tdb, int ltype)
-{
-	return tdb1_nest_unlock(tdb, TDB1_TRANSACTION_LOCK, ltype);
-}
-
-/* lock/unlock entire database.  It can only be upgradable if you have some
- * other way of guaranteeing exclusivity (ie. transaction write lock).
- * We do the locking gradually to avoid being starved by smaller locks. */
-int tdb1_allrecord_lock(struct tdb_context *tdb, int ltype,
-		       enum tdb_lock_flags flags, bool upgradable)
-{
-	enum TDB_ERROR ecode;
-	tdb_bool_err berr;
-
-	/* tdb_lock_gradual() doesn't know about tdb->tdb1.traverse_read. */
-	if (tdb->tdb1.traverse_read && !(tdb->flags & TDB_NOLOCK)) {
-		tdb->last_error = tdb_logerr(tdb, TDB_ERR_LOCK,
-					     TDB_LOG_USE_ERROR,
-					     "tdb1_allrecord_lock during"
-					     " tdb1_read_traverse");
-		return -1;
-	}
-
-	if (tdb->file->allrecord_lock.count
-	    && tdb->file->allrecord_lock.ltype == ltype) {
-		tdb->file->allrecord_lock.count++;
-		return 0;
-	}
-
-	if (tdb1_have_extra_locks(tdb)) {
-		/* can't combine global and chain locks */
-		tdb->last_error = tdb_logerr(tdb, TDB_ERR_LOCK,
-					     TDB_LOG_USE_ERROR,
-					     "tdb1_allrecord_lock holding"
-					     " other locks");
-		return -1;
-	}
-
-	if (upgradable && ltype != F_RDLCK) {
-		/* tdb error: you can't upgrade a write lock! */
-		tdb->last_error = tdb_logerr(tdb, TDB_ERR_LOCK,
-					     TDB_LOG_ERROR,
-					     "tdb1_allrecord_lock cannot"
-					     " have upgradable write lock");
-		return -1;
-	}
-
-	/* We cover two kinds of locks:
-	 * 1) Normal chain locks.  Taken for almost all operations.
-	 * 3) Individual records locks.  Taken after normal or free
-	 *    chain locks.
-	 *
-	 * It is (1) which cause the starvation problem, so we're only
-	 * gradual for that. */
-	ecode = tdb_lock_gradual(tdb, ltype, flags | TDB_LOCK_NOCHECK,
-				 TDB1_FREELIST_TOP, tdb->tdb1.header.hash_size * 4);
-	if (ecode != TDB_SUCCESS) {
-		tdb->last_error = ecode;
-		return -1;
-	}
-
-	/* Grab individual record locks. */
-	if (tdb1_brlock(tdb, ltype, lock_offset(tdb->tdb1.header.hash_size), 0,
-		       flags) == -1) {
-		tdb1_brunlock(tdb, ltype, TDB1_FREELIST_TOP,
-			     tdb->tdb1.header.hash_size * 4);
-		return -1;
-	}
-
-	tdb->file->allrecord_lock.owner = tdb;
-	tdb->file->allrecord_lock.count = 1;
-	tdb->file->locker = getpid();
-	/* If it's upgradable, it's actually exclusive so we can treat
-	 * it as a write lock. */
-	tdb->file->allrecord_lock.ltype = upgradable ? F_WRLCK : ltype;
-	tdb->file->allrecord_lock.off = upgradable;
-
-	berr = tdb1_needs_recovery(tdb);
-	if (berr < 0) {
-		return -1;
-	}
-
-	if (berr == true) {
-		tdb1_allrecord_unlock(tdb, ltype);
-		if (tdb1_lock_and_recover(tdb) == -1) {
-			return -1;
-		}
-		return tdb1_allrecord_lock(tdb, ltype, flags, upgradable);
-	}
-
-	return 0;
-}
-
-
-
-/* unlock entire db */
-int tdb1_allrecord_unlock(struct tdb_context *tdb, int ltype)
-{
-	/* Don't try this during r/o traversal! */
-	if (tdb->tdb1.traverse_read) {
-		tdb->last_error = TDB_ERR_LOCK;
-		return -1;
-	}
-
-	if (tdb->file->allrecord_lock.count == 0) {
-		tdb->last_error = TDB_ERR_LOCK;
-		return -1;
-	}
-
-	/* Upgradable locks are marked as write locks. */
-	if (tdb->file->allrecord_lock.ltype != ltype
-	    && (!tdb->file->allrecord_lock.off || ltype != F_RDLCK)) {
-		tdb->last_error = TDB_ERR_LOCK;
-		return -1;
-	}
-
-	if (tdb->file->allrecord_lock.count > 1) {
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error
-				= owner_conflict(tdb, "tdb1_allrecord_unlock");
-			return -1;
-		}
-		tdb->file->allrecord_lock.count--;
-		return 0;
-	}
-
-	tdb->file->allrecord_lock.count = 0;
-	tdb->file->allrecord_lock.ltype = 0;
-
-	if (tdb1_brunlock(tdb, ltype, TDB1_FREELIST_TOP, 0)) {
-		tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
-			   "tdb1_unlockall failed (%s)", strerror(errno));
-		return -1;
-	}
-
-	return 0;
-}
-
-/* lock/unlock one hash chain. This is meant to be used to reduce
-   contention - it cannot guarantee how many records will be locked */
-int tdb1_chainlock(struct tdb_context *tdb, TDB_DATA key)
-{
-	int ret = tdb1_lock(tdb,
-			    TDB1_BUCKET(tdb_hash(tdb, key.dptr, key.dsize)),
-			    F_WRLCK);
-	return ret;
-}
-
-int tdb1_chainunlock(struct tdb_context *tdb, TDB_DATA key)
-{
-	return tdb1_unlock(tdb, TDB1_BUCKET(tdb_hash(tdb, key.dptr, key.dsize)),
-			   F_WRLCK);
-}
-
-int tdb1_chainlock_read(struct tdb_context *tdb, TDB_DATA key)
-{
-	int ret;
-	ret = tdb1_lock(tdb, TDB1_BUCKET(tdb_hash(tdb, key.dptr, key.dsize)),
-			F_RDLCK);
-	return ret;
-}
-
-int tdb1_chainunlock_read(struct tdb_context *tdb, TDB_DATA key)
-{
-	return tdb1_unlock(tdb, TDB1_BUCKET(tdb_hash(tdb, key.dptr, key.dsize)),
-			   F_RDLCK);
-}
-
-/* record lock stops delete underneath */
-int tdb1_lock_record(struct tdb_context *tdb, tdb1_off_t off)
-{
-	if (tdb->file->allrecord_lock.count) {
-		if (!check_lock_pid(tdb, "tdb1_lock_record", true)) {
-			tdb->last_error = TDB_ERR_LOCK;
-			return -1;
-		}
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error = owner_conflict(tdb,
-							 "tdb1_lock_record");
-			return -1;
-		}
-		return 0;
-	}
-	return off ? tdb1_brlock(tdb, F_RDLCK, off, 1, TDB_LOCK_WAIT) : 0;
-}
-
-/*
-  Write locks override our own fcntl readlocks, so check it here.
-  Note this is meant to be F_SETLK, *not* F_SETLKW, as it's not
-  an error to fail to get the lock here.
-*/
-int tdb1_write_lock_record(struct tdb_context *tdb, tdb1_off_t off)
-{
-	struct tdb1_traverse_lock *i;
-	for (i = &tdb->tdb1.travlocks; i; i = i->next)
-		if (i->off == off)
-			return -1;
-	if (tdb->file->allrecord_lock.count) {
-		if (!check_lock_pid(tdb, "tdb1_write_lock_record", true)) {
-			tdb->last_error = TDB_ERR_LOCK;
-			return -1;
-		}
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error
-				= owner_conflict(tdb, "tdb1_write_lock_record");
-			return -1;
-		}
-		if (tdb->file->allrecord_lock.ltype == F_WRLCK) {
-			return 0;
-		}
-		return -1;
-	}
-	return tdb1_brlock(tdb, F_WRLCK, off, 1, TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
-}
-
-int tdb1_write_unlock_record(struct tdb_context *tdb, tdb1_off_t off)
-{
-	if (tdb->file->allrecord_lock.count) {
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error
-				= owner_conflict(tdb,
-						 "tdb1_write_unlock_record");
-			return -1;
-		}
-		return 0;
-	}
-	return tdb1_brunlock(tdb, F_WRLCK, off, 1);
-}
-
-/* fcntl locks don't stack: avoid unlocking someone else's */
-int tdb1_unlock_record(struct tdb_context *tdb, tdb1_off_t off)
-{
-	struct tdb1_traverse_lock *i;
-	uint32_t count = 0;
-
-	if (tdb->file->allrecord_lock.count) {
-		if (tdb->file->allrecord_lock.owner != tdb) {
-			tdb->last_error = owner_conflict(tdb,
-							 "tdb1_unlock_record");
-			return -1;
-		}
-		return 0;
-	}
-
-	if (off == 0)
-		return 0;
-	for (i = &tdb->tdb1.travlocks; i; i = i->next)
-		if (i->off == off)
-			count++;
-	return (count == 1 ? tdb1_brunlock(tdb, F_RDLCK, off, 1) : 0);
-}
-
-bool tdb1_have_extra_locks(struct tdb_context *tdb)
-{
-	unsigned int extra = tdb->file->num_lockrecs;
-
-	/* A transaction holds the lock for all records. */
-	if (!tdb->tdb1.transaction && tdb->file->allrecord_lock.count) {
-		return true;
-	}
-
-	/* We always hold the active lock if CLEAR_IF_FIRST. */
-	if (tdb1_find_nestlock(tdb, TDB1_ACTIVE_LOCK)) {
-		extra--;
-	}
-
-	/* In a transaction, we expect to hold the transaction lock */
-	if (tdb->tdb1.transaction
-	    && tdb1_find_nestlock(tdb, TDB1_TRANSACTION_LOCK)) {
-		extra--;
-	}
-
-	return extra;
-}
-
-/* The transaction code uses this to remove all locks. */
-void tdb1_release_transaction_locks(struct tdb_context *tdb)
-{
-	unsigned int i, active = 0;
-
-	if (tdb->file->allrecord_lock.count != 0) {
-		tdb1_brunlock(tdb, tdb->file->allrecord_lock.ltype, TDB1_FREELIST_TOP, 0);
-		tdb->file->allrecord_lock.count = 0;
-	}
-
-	for (i=0;i<tdb->file->num_lockrecs;i++) {
-		struct tdb_lock *lck = &tdb->file->lockrecs[i];
-
-		/* Don't release the active lock!  Copy it to first entry. */
-		if (lck->off == TDB1_ACTIVE_LOCK) {
-			tdb->file->lockrecs[active++] = *lck;
-		} else {
-			tdb1_brunlock(tdb, lck->ltype, lck->off, 1);
-		}
-	}
-	tdb->file->num_lockrecs = active;
-	if (tdb->file->num_lockrecs == 0) {
-		SAFE_FREE(tdb->file->lockrecs);
-	}
-}