diff options
Diffstat (limited to 'source4/lib/tdb/common/lock.c')
| -rw-r--r-- | source4/lib/tdb/common/lock.c | 81 |
1 files changed, 72 insertions, 9 deletions
diff --git a/source4/lib/tdb/common/lock.c b/source4/lib/tdb/common/lock.c index 14ccbe3976..72892febbd 100644 --- a/source4/lib/tdb/common/lock.c +++ b/source4/lib/tdb/common/lock.c @@ -28,6 +28,8 @@ #include "tdb_private.h" +#define TDB_MARK_LOCK 0x80000000 + /* a byte range locking function - return 0 on success this functions locks/unlocks 1 byte at the specified offset. @@ -109,6 +111,9 @@ 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 && @@ -158,7 +163,8 @@ static int _tdb_lock(struct tdb_context *tdb, int list, int ltype, int op) /* Since fcntl locks don't nest, we do a lock for the first one, and simply bump the count for future ones */ - if (tdb->methods->tdb_brlock(tdb,FREELIST_TOP+4*list,ltype, op, + if (!mark_lock && + tdb->methods->tdb_brlock(tdb,FREELIST_TOP+4*list, ltype, op, 0, 1)) { return -1; } @@ -200,6 +206,9 @@ 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 && @@ -244,8 +253,12 @@ int tdb_unlock(struct tdb_context *tdb, int list, int ltype) * anyway. */ - ret = tdb->methods->tdb_brlock(tdb, FREELIST_TOP+4*list, F_UNLCK, - F_SETLKW, 0, 1); + 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--; /* @@ -275,8 +288,12 @@ int tdb_unlock(struct tdb_context *tdb, int list, int ltype) /* lock/unlock entire database */ -static int _tdb_lockall(struct tdb_context *tdb, int ltype) +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); @@ -296,9 +313,12 @@ static int _tdb_lockall(struct tdb_context *tdb, int ltype) return TDB_ERRCODE(TDB_ERR_LOCK, -1); } - if (tdb->methods->tdb_brlock(tdb, FREELIST_TOP, ltype, F_SETLKW, + if (!mark_lock && + tdb->methods->tdb_brlock(tdb, FREELIST_TOP, ltype, op, 0, 4*tdb->header.hash_size)) { - TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lockall failed (%s)\n", strerror(errno))); + if (op == F_SETLKW) { + TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_lockall failed (%s)\n", strerror(errno))); + } return -1; } @@ -308,9 +328,15 @@ static int _tdb_lockall(struct tdb_context *tdb, int 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); @@ -325,7 +351,8 @@ static int _tdb_unlockall(struct tdb_context *tdb, int ltype) return 0; } - if (tdb->methods->tdb_brlock(tdb, FREELIST_TOP, F_UNLCK, F_SETLKW, + 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; @@ -340,7 +367,25 @@ static int _tdb_unlockall(struct tdb_context *tdb, int ltype) /* lock entire database with write lock */ int tdb_lockall(struct tdb_context *tdb) { - return _tdb_lockall(tdb, F_WRLCK); + 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 */ @@ -352,7 +397,13 @@ int tdb_unlockall(struct tdb_context *tdb) /* lock entire database with read lock */ int tdb_lockall_read(struct tdb_context *tdb) { - return _tdb_lockall(tdb, F_RDLCK); + 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 */ @@ -376,6 +427,18 @@ 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); |