2 Unix SMB/Netbios implementation.
4 change notify handling - linux kernel based implementation
5 Copyright (C) Andrew Tridgell 2000
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #if HAVE_KERNEL_CHANGE_NOTIFY
26 static VOLATILE
sig_atomic_t fd_pending
;
27 static VOLATILE
sig_atomic_t signals_received
;
28 static VOLATILE
sig_atomic_t signals_processed
;
31 #define DN_ACCESS 0x00000001 /* File accessed in directory */
32 #define DN_MODIFY 0x00000002 /* File modified in directory */
33 #define DN_CREATE 0x00000004 /* File created in directory */
34 #define DN_DELETE 0x00000008 /* File removed from directory */
35 #define DN_RENAME 0x00000010 /* File renamed in directory */
36 #define DN_ATTRIB 0x00000020 /* File changed attribute */
37 #define DN_MULTISHOT 0x80000000 /* Don't remove notifier */
41 #ifndef RT_SIGNAL_NOTIFY
42 #define RT_SIGNAL_NOTIFY 34
53 /****************************************************************************
54 This is the structure to keep the information needed to
55 determine if a directory has changed.
56 *****************************************************************************/
61 /****************************************************************************
62 the signal handler for change notify
63 *****************************************************************************/
64 static void signal_handler(int sig
, siginfo_t
*info
, void *unused
)
66 BlockSignals(True
, sig
);
67 fd_pending
= (sig_atomic_t)info
->si_fd
;
74 /****************************************************************************
75 Check if a change notify should be issued.
76 time non-zero means timeout check (used for hash). Ignore this (async method
77 where time is zero will be used instead).
78 *****************************************************************************/
79 static BOOL
kernel_check_notify(connection_struct
*conn
, uint16 vuid
, char *path
, uint32 flags
, void *datap
, time_t t
)
81 struct change_data
*data
= (struct change_data
*)datap
;
86 if (data
->directory_handle
!= (int)fd_pending
) return False
;
88 DEBUG(3,("kernel change notify on %s fd=%d\n", path
, (int)fd_pending
));
90 close((int)fd_pending
);
91 fd_pending
= (sig_atomic_t)-1;
92 data
->directory_handle
= -1;
94 BlockSignals(False
, RT_SIGNAL_NOTIFY
);
98 /****************************************************************************
99 remove a change notify data structure
100 *****************************************************************************/
101 static void kernel_remove_notify(void *datap
)
103 struct change_data
*data
= (struct change_data
*)datap
;
104 int fd
= data
->directory_handle
;
106 if (fd
== (int)fd_pending
) {
107 fd_pending
= (sig_atomic_t)-1;
109 BlockSignals(False
, RT_SIGNAL_NOTIFY
);
114 DEBUG(3,("removed kernel change notify fd=%d\n", fd
));
118 /****************************************************************************
119 register a change notify request
120 *****************************************************************************/
121 static void *kernel_register_notify(connection_struct
*conn
, char *path
, uint32 flags
)
123 struct change_data data
;
125 unsigned long kernel_flags
;
127 fd
= conn
->vfs_ops
.open(conn
, path
, O_RDONLY
, 0);
130 DEBUG(3,("Failed to open directory %s for change notify\n", path
));
134 if (fcntl(fd
, F_SETSIG
, RT_SIGNAL_NOTIFY
) == -1) {
135 DEBUG(3,("Failed to set signal handler for change notify\n"));
139 kernel_flags
= DN_CREATE
|DN_DELETE
|DN_RENAME
; /* creation/deletion changes everything! */
140 if (flags
& FILE_NOTIFY_CHANGE_FILE
) kernel_flags
|= DN_MODIFY
;
141 if (flags
& FILE_NOTIFY_CHANGE_DIR_NAME
) kernel_flags
|= DN_RENAME
|DN_DELETE
;
142 if (flags
& FILE_NOTIFY_CHANGE_ATTRIBUTES
) kernel_flags
|= DN_ATTRIB
;
143 if (flags
& FILE_NOTIFY_CHANGE_SIZE
) kernel_flags
|= DN_MODIFY
;
144 if (flags
& FILE_NOTIFY_CHANGE_LAST_WRITE
) kernel_flags
|= DN_MODIFY
;
145 if (flags
& FILE_NOTIFY_CHANGE_LAST_ACCESS
) kernel_flags
|= DN_ACCESS
;
146 if (flags
& FILE_NOTIFY_CHANGE_CREATION
) kernel_flags
|= DN_CREATE
;
147 if (flags
& FILE_NOTIFY_CHANGE_SECURITY
) kernel_flags
|= DN_ATTRIB
;
148 if (flags
& FILE_NOTIFY_CHANGE_EA
) kernel_flags
|= DN_ATTRIB
;
149 if (flags
& FILE_NOTIFY_CHANGE_FILE_NAME
) kernel_flags
|= DN_RENAME
|DN_DELETE
;
151 if (fcntl(fd
, F_NOTIFY
, kernel_flags
) == -1) {
152 DEBUG(3,("Failed to set async flag for change notify\n"));
156 data
.directory_handle
= fd
;
158 DEBUG(3,("kernel change notify on %s (ntflags=0x%x flags=0x%x) fd=%d\n",
159 path
, (int)flags
, (int)kernel_flags
, fd
));
161 return (void *)memdup(&data
, sizeof(data
));
164 /****************************************************************************
165 see if the kernel supports change notify
166 ****************************************************************************/
167 static BOOL
kernel_notify_available(void)
170 fd
= open("/tmp", O_RDONLY
);
171 if (fd
== -1) return False
; /* uggh! */
172 ret
= fcntl(fd
, F_NOTIFY
, 0);
178 /****************************************************************************
179 setup kernel based change notify
180 ****************************************************************************/
181 struct cnotify_fns
*kernel_notify_init(void)
183 static struct cnotify_fns cnotify
;
184 struct sigaction act
;
186 act
.sa_handler
= NULL
;
187 act
.sa_sigaction
= signal_handler
;
188 act
.sa_flags
= SA_SIGINFO
;
189 if (sigaction(RT_SIGNAL_NOTIFY
, &act
, NULL
) != 0) {
190 DEBUG(0,("Failed to setup RT_SIGNAL_NOTIFY handler\n"));
194 if (!kernel_notify_available()) return NULL
;
196 cnotify
.register_notify
= kernel_register_notify
;
197 cnotify
.check_notify
= kernel_check_notify
;
198 cnotify
.remove_notify
= kernel_remove_notify
;
199 cnotify
.select_time
= -1;
206 void notify_kernel_dummy(void) {}
207 #endif /* HAVE_KERNEL_CHANGE_NOTIFY */