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-rw-r--r--tdb/common/lock.c553
1 files changed, 0 insertions, 553 deletions
diff --git a/tdb/common/lock.c b/tdb/common/lock.c
deleted file mode 100644
index f156c0fa..00000000
--- a/tdb/common/lock.c
+++ /dev/null
@@ -1,553 +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 "tdb_private.h"
-
-#define TDB_MARK_LOCK 0x80000000
-
-void tdb_setalarm_sigptr(struct tdb_context *tdb, volatile sig_atomic_t *ptr)
-{
- tdb->interrupt_sig_ptr = ptr;
-}
-
-/* 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 tdb_open().
-
- note that a len of zero means lock to end of file
-*/
-int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset,
- int rw_type, int lck_type, int probe, size_t len)
-{
- struct flock fl;
- int ret;
-
- if (tdb->flags & TDB_NOLOCK) {
- return 0;
- }
-
- if ((rw_type == F_WRLCK) && (tdb->read_only || tdb->traverse_read)) {
- tdb->ecode = TDB_ERR_RDONLY;
- return -1;
- }
-
- fl.l_type = rw_type;
- fl.l_whence = SEEK_SET;
- fl.l_start = offset;
- fl.l_len = len;
- fl.l_pid = 0;
-
- do {
- ret = fcntl(tdb->fd,lck_type,&fl);
-
- /* Check for a sigalarm break. */
- if (ret == -1 && errno == EINTR &&
- tdb->interrupt_sig_ptr &&
- *tdb->interrupt_sig_ptr) {
- break;
- }
- } while (ret == -1 && errno == EINTR);
-
- if (ret == -1) {
- /* Generic lock error. errno set by fcntl.
- * EAGAIN is an expected return from non-blocking
- * locks. */
- if (!probe && lck_type != F_SETLK) {
- /* Ensure error code is set for log fun to examine. */
- tdb->ecode = TDB_ERR_LOCK;
- TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d len=%d\n",
- tdb->fd, offset, rw_type, lck_type, (int)len));
- }
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
- return 0;
-}
-
-
-/*
- upgrade a read lock to a write lock. This needs to be handled in a
- special way as some OSes (such as solaris) have too conservative
- deadlock detection and claim a deadlock when progress can be
- made. For those OSes we may loop for a while.
-*/
-int tdb_brlock_upgrade(struct tdb_context *tdb, tdb_off_t offset, size_t len)
-{
- int count = 1000;
- while (count--) {
- struct timeval tv;
- if (tdb_brlock(tdb, offset, F_WRLCK, F_SETLKW, 1, len) == 0) {
- return 0;
- }
- if (errno != EDEADLK) {
- break;
- }
- /* sleep for as short a time as we can - more portable than usleep() */
- tv.tv_sec = 0;
- tv.tv_usec = 1;
- select(0, NULL, NULL, NULL, &tv);
- }
- TDB_LOG((tdb, TDB_DEBUG_TRACE,"tdb_brlock_upgrade failed at offset %d\n", offset));
- return -1;
-}
-
-
-/* lock a list in the database. list -1 is the alloc list */
-static int _tdb_lock(struct tdb_context *tdb, int list, int ltype, int op)
-{
- struct tdb_lock_type *new_lck;
- int i;
- bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK);
-
- ltype &= ~TDB_MARK_LOCK;
-
- /* a global lock allows us to avoid per chain locks */
- if (tdb->global_lock.count &&
- (ltype == tdb->global_lock.ltype || ltype == F_RDLCK)) {
- return 0;
- }
-
- if (tdb->global_lock.count) {
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
-
- if (list < -1 || list >= (int)tdb->header.hash_size) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR,"tdb_lock: invalid list %d for ltype=%d\n",
- list, ltype));
- return -1;
- }
- if (tdb->flags & TDB_NOLOCK)
- return 0;
-
- for (i=0; i<tdb->num_lockrecs; i++) {
- if (tdb->lockrecs[i].list == list) {
- if (tdb->lockrecs[i].count == 0) {
- /*
- * Can't happen, see tdb_unlock(). It should
- * be an assert.
- */
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock: "
- "lck->count == 0 for list %d", list));
- }
- /*
- * Just increment the in-memory struct, posix locks
- * don't stack.
- */
- tdb->lockrecs[i].count++;
- return 0;
- }
- }
-
- new_lck = (struct tdb_lock_type *)realloc(
- tdb->lockrecs,
- sizeof(*tdb->lockrecs) * (tdb->num_lockrecs+1));
- if (new_lck == NULL) {
- errno = ENOMEM;
- return -1;
- }
- tdb->lockrecs = new_lck;
-
- /* Since fcntl locks don't nest, we do a lock for the first one,
- and simply bump the count for future ones */
- if (!mark_lock &&
- tdb->methods->tdb_brlock(tdb,FREELIST_TOP+4*list, ltype, op,
- 0, 1)) {
- return -1;
- }
-
- tdb->num_locks++;
-
- tdb->lockrecs[tdb->num_lockrecs].list = list;
- tdb->lockrecs[tdb->num_lockrecs].count = 1;
- tdb->lockrecs[tdb->num_lockrecs].ltype = ltype;
- tdb->num_lockrecs += 1;
-
- return 0;
-}
-
-/* lock a list in the database. list -1 is the alloc list */
-int tdb_lock(struct tdb_context *tdb, int list, int ltype)
-{
- int ret;
- ret = _tdb_lock(tdb, list, ltype, F_SETLKW);
- if (ret) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lock failed on list %d "
- "ltype=%d (%s)\n", list, ltype, strerror(errno)));
- }
- return ret;
-}
-
-/* lock a list in the database. list -1 is the alloc list. non-blocking lock */
-int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype)
-{
- return _tdb_lock(tdb, list, ltype, F_SETLK);
-}
-
-
-/* unlock the database: returns void because it's too late for errors. */
- /* changed to return int it may be interesting to know there
- has been an error --simo */
-int tdb_unlock(struct tdb_context *tdb, int list, int ltype)
-{
- int ret = -1;
- int i;
- struct tdb_lock_type *lck = NULL;
- bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK);
-
- ltype &= ~TDB_MARK_LOCK;
-
- /* a global lock allows us to avoid per chain locks */
- if (tdb->global_lock.count &&
- (ltype == tdb->global_lock.ltype || ltype == F_RDLCK)) {
- return 0;
- }
-
- if (tdb->global_lock.count) {
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
-
- if (tdb->flags & TDB_NOLOCK)
- return 0;
-
- /* Sanity checks */
- if (list < -1 || list >= (int)tdb->header.hash_size) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: list %d invalid (%d)\n", list, tdb->header.hash_size));
- return ret;
- }
-
- for (i=0; i<tdb->num_lockrecs; i++) {
- if (tdb->lockrecs[i].list == list) {
- lck = &tdb->lockrecs[i];
- break;
- }
- }
-
- if ((lck == NULL) || (lck->count == 0)) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: count is 0\n"));
- return -1;
- }
-
- if (lck->count > 1) {
- lck->count--;
- return 0;
- }
-
- /*
- * This lock has count==1 left, so we need to unlock it in the
- * kernel. We don't bother with decrementing the in-memory array
- * element, we're about to overwrite it with the last array element
- * anyway.
- */
-
- if (mark_lock) {
- ret = 0;
- } else {
- ret = tdb->methods->tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK,
- F_SETLKW, 0, 1);
- }
- tdb->num_locks--;
-
- /*
- * Shrink the array by overwriting the element just unlocked with the
- * last array element.
- */
-
- if (tdb->num_lockrecs > 1) {
- *lck = tdb->lockrecs[tdb->num_lockrecs-1];
- }
- tdb->num_lockrecs -= 1;
-
- /*
- * We don't bother with realloc when the array shrinks, but if we have
- * a completely idle tdb we should get rid of the locked array.
- */
-
- if (tdb->num_lockrecs == 0) {
- SAFE_FREE(tdb->lockrecs);
- }
-
- if (ret)
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlock: An error occurred unlocking!\n"));
- return ret;
-}
-
-/*
- get the transaction lock
- */
-int tdb_transaction_lock(struct tdb_context *tdb, int ltype)
-{
- if (tdb->have_transaction_lock || tdb->global_lock.count) {
- return 0;
- }
- if (tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, ltype,
- F_SETLKW, 0, 1) == -1) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_transaction_lock: failed to get transaction lock\n"));
- tdb->ecode = TDB_ERR_LOCK;
- return -1;
- }
- tdb->have_transaction_lock = 1;
- return 0;
-}
-
-/*
- release the transaction lock
- */
-int tdb_transaction_unlock(struct tdb_context *tdb)
-{
- int ret;
- if (!tdb->have_transaction_lock) {
- return 0;
- }
- ret = tdb->methods->tdb_brlock(tdb, TRANSACTION_LOCK, F_UNLCK, F_SETLKW, 0, 1);
- if (ret == 0) {
- tdb->have_transaction_lock = 0;
- }
- return ret;
-}
-
-
-
-
-/* lock/unlock entire database */
-static int _tdb_lockall(struct tdb_context *tdb, int ltype, int op)
-{
- bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK);
-
- ltype &= ~TDB_MARK_LOCK;
-
- /* There are no locks on read-only dbs */
- if (tdb->read_only || tdb->traverse_read)
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
-
- if (tdb->global_lock.count && tdb->global_lock.ltype == ltype) {
- tdb->global_lock.count++;
- return 0;
- }
-
- if (tdb->global_lock.count) {
- /* a global lock of a different type exists */
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
-
- if (tdb->num_locks != 0) {
- /* can't combine global and chain locks */
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
-
- if (!mark_lock &&
- tdb->methods->tdb_brlock(tdb, FREELIST_TOP, ltype, op,
- 0, 4*tdb->header.hash_size)) {
- if (op == F_SETLKW) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lockall failed (%s)\n", strerror(errno)));
- }
- return -1;
- }
-
- tdb->global_lock.count = 1;
- tdb->global_lock.ltype = ltype;
-
- return 0;
-}
-
-
-
-/* unlock entire db */
-static int _tdb_unlockall(struct tdb_context *tdb, int ltype)
-{
- bool mark_lock = ((ltype & TDB_MARK_LOCK) == TDB_MARK_LOCK);
-
- ltype &= ~TDB_MARK_LOCK;
-
- /* There are no locks on read-only dbs */
- if (tdb->read_only || tdb->traverse_read) {
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
-
- if (tdb->global_lock.ltype != ltype || tdb->global_lock.count == 0) {
- return TDB_ERRCODE(TDB_ERR_LOCK, -1);
- }
-
- if (tdb->global_lock.count > 1) {
- tdb->global_lock.count--;
- return 0;
- }
-
- if (!mark_lock &&
- tdb->methods->tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW,
- 0, 4*tdb->header.hash_size)) {
- TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_unlockall failed (%s)\n", strerror(errno)));
- return -1;
- }
-
- tdb->global_lock.count = 0;
- tdb->global_lock.ltype = 0;
-
- return 0;
-}
-
-/* lock entire database with write lock */
-int tdb_lockall(struct tdb_context *tdb)
-{
- return _tdb_lockall(tdb, F_WRLCK, F_SETLKW);
-}
-
-/* lock entire database with write lock - mark only */
-int tdb_lockall_mark(struct tdb_context *tdb)
-{
- return _tdb_lockall(tdb, F_WRLCK | TDB_MARK_LOCK, F_SETLKW);
-}
-
-/* unlock entire database with write lock - unmark only */
-int tdb_lockall_unmark(struct tdb_context *tdb)
-{
- return _tdb_unlockall(tdb, F_WRLCK | TDB_MARK_LOCK);
-}
-
-/* lock entire database with write lock - nonblocking varient */
-int tdb_lockall_nonblock(struct tdb_context *tdb)
-{
- return _tdb_lockall(tdb, F_WRLCK, F_SETLK);
-}
-
-/* unlock entire database with write lock */
-int tdb_unlockall(struct tdb_context *tdb)
-{
- return _tdb_unlockall(tdb, F_WRLCK);
-}
-
-/* lock entire database with read lock */
-int tdb_lockall_read(struct tdb_context *tdb)
-{
- return _tdb_lockall(tdb, F_RDLCK, F_SETLKW);
-}
-
-/* lock entire database with read lock - nonblock varient */
-int tdb_lockall_read_nonblock(struct tdb_context *tdb)
-{
- return _tdb_lockall(tdb, F_RDLCK, F_SETLK);
-}
-
-/* unlock entire database with read lock */
-int tdb_unlockall_read(struct tdb_context *tdb)
-{
- return _tdb_unlockall(tdb, F_RDLCK);
-}
-
-/* lock/unlock one hash chain. This is meant to be used to reduce
- contention - it cannot guarantee how many records will be locked */
-int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
-}
-
-/* lock/unlock one hash chain, non-blocking. This is meant to be used
- to reduce contention - it cannot guarantee how many records will be
- locked */
-int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_lock_nonblock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
-}
-
-/* mark a chain as locked without actually locking it. Warning! use with great caution! */
-int tdb_chainlock_mark(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK);
-}
-
-/* unmark a chain as locked without actually locking it. Warning! use with great caution! */
-int tdb_chainlock_unmark(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK);
-}
-
-int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
-}
-
-int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
-}
-
-int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key)
-{
- return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
-}
-
-
-
-/* record lock stops delete underneath */
-int tdb_lock_record(struct tdb_context *tdb, tdb_off_t off)
-{
- if (tdb->global_lock.count) {
- return 0;
- }
- return off ? tdb->methods->tdb_brlock(tdb, off, F_RDLCK, F_SETLKW, 0, 1) : 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 tdb_write_lock_record(struct tdb_context *tdb, tdb_off_t off)
-{
- struct tdb_traverse_lock *i;
- for (i = &tdb->travlocks; i; i = i->next)
- if (i->off == off)
- return -1;
- return tdb->methods->tdb_brlock(tdb, off, F_WRLCK, F_SETLK, 1, 1);
-}
-
-/*
- 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 tdb_write_unlock_record(struct tdb_context *tdb, tdb_off_t off)
-{
- return tdb->methods->tdb_brlock(tdb, off, F_UNLCK, F_SETLK, 0, 1);
-}
-
-/* fcntl locks don't stack: avoid unlocking someone else's */
-int tdb_unlock_record(struct tdb_context *tdb, tdb_off_t off)
-{
- struct tdb_traverse_lock *i;
- uint32_t count = 0;
-
- if (tdb->global_lock.count) {
- return 0;
- }
-
- if (off == 0)
- return 0;
- for (i = &tdb->travlocks; i; i = i->next)
- if (i->off == off)
- count++;
- return (count == 1 ? tdb->methods->tdb_brlock(tdb, off, F_UNLCK, F_SETLKW, 0, 1) : 0);
-}
generated by cgit (git 2.34.1) at 2024-12-30 11:53:23 +0000