totally rewrote the async signal, notification and oplock notification

handling in Samba. This was needed due to several limitations and
races in the previous code - as a side effect the new code is much
cleaner :)

in summary:

- changed sys_select() to avoid a signal/select race condition. It is a
  rare race but once we have signals doing notification and oplocks it
  is important.

- changed our main processing loop to take advantage of the new
  sys_select semantics

- split the notify code into implementaion dependent and general
  parts. Added the following structure that defines an implementation:

struct cnotify_fns {
	void * (*register_notify)(connection_struct *conn, char *path, uint32 flags);
	BOOL (*check_notify)(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *data, time_t t);
	void (*remove_notify)(void *data);
};


then I wrote two implementations, one using hash/poll (like our old
code) and the other using the new Linux kernel change notify. It
should be easy to add other change notify implementations by creating
a sructure of the above type.

- fixed a bug in change notify where we were returning the wrong error
  code.

- rewrote the core change notify code to be much simpler

- moved to real-time signals for leases and change notify

Amazingly, it all seems to work. I was very surprised!
(This used to be commit 44766c39e0027c762bee8b33b12c621c109a3267)

1 files changed, 26 insertions, 4 deletions

diff --git a/source3/include/proto.h b/source3/include/proto.h
index 4f5f3d42d3..eabacd4d21 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -183,6 +183,12 @@ void pidfile_create(char *name);
 
 char *rep_inet_ntoa(struct in_addr ip);
 
+/*The following definitions come from  lib/select.c  */
+
+void sys_select_signal(void);
+int sys_select(int maxfd, fd_set *fds,struct timeval *tval);
+int sys_select_intr(int maxfd, fd_set *fds,struct timeval *tval);
+
 /*The following definitions come from  lib/signal.c  */
 
 void BlockSignals(BOOL block,int signum);
@@ -212,9 +218,6 @@ void standard_sub_vsnum(char *str, user_struct *vuser, int snum);
 
 /*The following definitions come from  lib/system.c  */
 
-int sys_select(int maxfd, fd_set *fds,struct timeval *tval);
-int sys_select(int maxfd, fd_set *fds,struct timeval *tval);
-int sys_select_intr(int maxfd, fd_set *fds,struct timeval *tval);
 int sys_usleep(long usecs);
 int sys_stat(const char *fname,SMB_STRUCT_STAT *sbuf);
 int sys_fstat(int fd,SMB_STRUCT_STAT *sbuf);
@@ -3251,9 +3254,16 @@ BOOL disk_quotas(char *path,SMB_BIG_UINT *bsize,SMB_BIG_UINT *dfree,SMB_BIG_UINT
 void remove_pending_change_notify_requests_by_fid(files_struct *fsp);
 void remove_pending_change_notify_requests_by_mid(int mid);
 void remove_pending_change_notify_requests_by_filename(files_struct *fsp);
-BOOL process_pending_change_notify_queue(time_t t);
 BOOL change_notifies_pending(void);
+BOOL process_pending_change_notify_queue(time_t t);
 BOOL change_notify_set(char *inbuf, files_struct *fsp, connection_struct *conn, uint32 flags);
+BOOL init_change_notify(void);
+#endif
+
+/*The following definitions come from  smbd/notify_hash.c  */
+
+#if OLD_NTDOMAIN
+struct cnotify_fns *hash_notify_init(void) ;
 #endif
 
 /*The following definitions come from  smbd/nttrans.c  */
@@ -3301,6 +3311,18 @@ BOOL attempt_close_oplocked_file(files_struct *fsp);
 BOOL init_oplocks(void);
 #endif
 
+/*The following definitions come from  smbd/oplock_irix.c  */
+
+#if OLD_NTDOMAIN
+struct kernel_oplocks *irix_init_kernel_oplocks(void) ;
+#endif
+
+/*The following definitions come from  smbd/oplock_linux.c  */
+
+#if OLD_NTDOMAIN
+struct kernel_oplocks *linux_init_kernel_oplocks(void) ;
+#endif
+
 /*The following definitions come from  smbd/password.c  */
 
 #if OLD_NTDOMAIN