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-rw-r--r--source4/lib/tdb/common/lock.c81
-rw-r--r--source4/lib/tdb/common/tdb.c33
-rw-r--r--source4/lib/tdb/include/tdb.h8
3 files changed, 107 insertions, 15 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);
diff --git a/source4/lib/tdb/common/tdb.c b/source4/lib/tdb/common/tdb.c
index 25103d826e..70d050e7e6 100644
--- a/source4/lib/tdb/common/tdb.c
+++ b/source4/lib/tdb/common/tdb.c
@@ -31,10 +31,10 @@
TDB_DATA tdb_null;
/*
- increment the tdb sequence number if the tdb has been opened using
+ non-blocking increment of the tdb sequence number if the tdb has been opened using
the TDB_SEQNUM flag
*/
-static void tdb_increment_seqnum(struct tdb_context *tdb)
+void tdb_increment_seqnum_nonblock(struct tdb_context *tdb)
{
tdb_off_t seqnum=0;
@@ -42,16 +42,29 @@ static void tdb_increment_seqnum(struct tdb_context *tdb)
return;
}
- if (tdb_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1, 1) != 0) {
- return;
- }
-
/* we ignore errors from this, as we have no sane way of
dealing with them.
*/
tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
seqnum++;
tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum);
+}
+
+/*
+ increment the tdb sequence number if the tdb has been opened using
+ the TDB_SEQNUM flag
+*/
+static void tdb_increment_seqnum(struct tdb_context *tdb)
+{
+ if (!(tdb->flags & TDB_SEQNUM)) {
+ return;
+ }
+
+ if (tdb_brlock(tdb, TDB_SEQNUM_OFS, F_WRLCK, F_SETLKW, 1, 1) != 0) {
+ return;
+ }
+
+ tdb_increment_seqnum_nonblock(tdb);
tdb_brlock(tdb, TDB_SEQNUM_OFS, F_UNLCK, F_SETLKW, 1, 1);
}
@@ -649,3 +662,11 @@ int tdb_get_flags(struct tdb_context *tdb)
return tdb->flags;
}
+
+/*
+ enable sequence number handling on an open tdb
+*/
+void tdb_enable_seqnum(struct tdb_context *tdb)
+{
+ tdb->flags |= TDB_SEQNUM;
+}
diff --git a/source4/lib/tdb/include/tdb.h b/source4/lib/tdb/include/tdb.h
index e77b78f7ed..9a9a4b489a 100644
--- a/source4/lib/tdb/include/tdb.h
+++ b/source4/lib/tdb/include/tdb.h
@@ -116,9 +116,13 @@ int tdb_traverse(struct tdb_context *tdb, tdb_traverse_func fn, void *);
int tdb_traverse_read(struct tdb_context *tdb, tdb_traverse_func fn, void *);
int tdb_exists(struct tdb_context *tdb, TDB_DATA key);
int tdb_lockall(struct tdb_context *tdb);
+int tdb_lockall_nonblock(struct tdb_context *tdb);
int tdb_unlockall(struct tdb_context *tdb);
int tdb_lockall_read(struct tdb_context *tdb);
+int tdb_lockall_read_nonblock(struct tdb_context *tdb);
int tdb_unlockall_read(struct tdb_context *tdb);
+int tdb_lockall_mark(struct tdb_context *tdb);
+int tdb_lockall_unmark(struct tdb_context *tdb);
const char *tdb_name(struct tdb_context *tdb);
int tdb_fd(struct tdb_context *tdb);
tdb_log_func tdb_log_fn(struct tdb_context *tdb);
@@ -131,6 +135,8 @@ int tdb_get_seqnum(struct tdb_context *tdb);
int tdb_hash_size(struct tdb_context *tdb);
size_t tdb_map_size(struct tdb_context *tdb);
int tdb_get_flags(struct tdb_context *tdb);
+void tdb_enable_seqnum(struct tdb_context *tdb);
+void tdb_increment_seqnum_nonblock(struct tdb_context *tdb);
/* Low level locking functions: use with care */
int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key);
@@ -138,6 +144,8 @@ int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key);
int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key);
+int tdb_chainlock_mark(struct tdb_context *tdb, TDB_DATA key);
+int tdb_chainlock_unmark(struct tdb_context *tdb, TDB_DATA key);
/* Debug functions. Not used in production. */
void tdb_dump_all(struct tdb_context *tdb);
generated by cgit (git 2.34.1) at 2024-11-24 13:53:59 +0000