/*
- Unix SMB/CIFS implementation.
+ Unix SMB/Netbios implementation.
+ Version 3.0
change notify handling - linux kernel based implementation
Copyright (C) Andrew Tridgell 2000
#if HAVE_KERNEL_CHANGE_NOTIFY
-static VOLATILE sig_atomic_t fd_pending;
-static VOLATILE sig_atomic_t signals_received;
-static VOLATILE sig_atomic_t signals_processed;
+#define FD_PENDING_SIZE 20
+static SIG_ATOMIC_T fd_pending_array[FD_PENDING_SIZE];
+static SIG_ATOMIC_T signals_received;
#ifndef DN_ACCESS
#define DN_ACCESS 0x00000001 /* File accessed in directory */
This is the structure to keep the information needed to
determine if a directory has changed.
*****************************************************************************/
+
struct change_data {
int directory_handle;
};
/****************************************************************************
-the signal handler for change notify
+ The signal handler for change notify.
+ The Linux kernel has a bug in that we should be able to block any
+ further delivery of RT signals until the kernel_check_notify() function
+ unblocks them, but it seems that any signal mask we're setting here is
+ being overwritten on exit from this handler. I should create a standalone
+ test case for the kernel hackers. JRA.
*****************************************************************************/
+
static void signal_handler(int sig, siginfo_t *info, void *unused)
{
- BlockSignals(True, sig);
- fd_pending = (sig_atomic_t)info->si_fd;
- signals_received++;
+ if (signals_received < FD_PENDING_SIZE - 1) {
+ fd_pending_array[signals_received] = (SIG_ATOMIC_T)info->si_fd;
+ signals_received++;
+ } /* Else signal is lost. */
sys_select_signal();
}
-
-
/****************************************************************************
Check if a change notify should be issued.
time non-zero means timeout check (used for hash). Ignore this (async method
where time is zero will be used instead).
*****************************************************************************/
+
static BOOL kernel_check_notify(connection_struct *conn, uint16 vuid, char *path, uint32 flags, void *datap, time_t t)
{
struct change_data *data = (struct change_data *)datap;
+ int i;
+ BOOL ret = False;
if (t)
return False;
- if (data->directory_handle != (int)fd_pending) return False;
-
- DEBUG(3,("kernel change notify on %s fd=%d\n", path, (int)fd_pending));
-
- close((int)fd_pending);
- fd_pending = (sig_atomic_t)-1;
- data->directory_handle = -1;
- signals_processed++;
+ BlockSignals(True, RT_SIGNAL_NOTIFY);
+ for (i = 0; i < signals_received; i++) {
+ if (data->directory_handle == (int)fd_pending_array[i]) {
+ DEBUG(3,("kernel_check_notify: kernel change notify on %s fd[%d]=%d (signals_received=%d)\n",
+ path, i, (int)fd_pending_array[i], (int)signals_received ));
+
+ close((int)fd_pending_array[i]);
+ fd_pending_array[i] = (SIG_ATOMIC_T)-1;
+ if (signals_received - i - 1) {
+ memmove((void *)&fd_pending_array[i], (void *)&fd_pending_array[i+1],
+ sizeof(SIG_ATOMIC_T)*(signals_received-i-1));
+ }
+ data->directory_handle = -1;
+ signals_received--;
+ ret = True;
+ break;
+ }
+ }
BlockSignals(False, RT_SIGNAL_NOTIFY);
- return True;
+ return ret;
}
/****************************************************************************
-remove a change notify data structure
+ Remove a change notify data structure.
*****************************************************************************/
+
static void kernel_remove_notify(void *datap)
{
struct change_data *data = (struct change_data *)datap;
int fd = data->directory_handle;
if (fd != -1) {
- if (fd == (int)fd_pending) {
- fd_pending = (sig_atomic_t)-1;
- signals_processed++;
- BlockSignals(False, RT_SIGNAL_NOTIFY);
+ int i;
+ BlockSignals(True, RT_SIGNAL_NOTIFY);
+ for (i = 0; i < signals_received; i++) {
+ if (fd == (int)fd_pending_array[i]) {
+ close(fd);
+ fd_pending_array[i] = (SIG_ATOMIC_T)-1;
+ if (signals_received - i - 1) {
+ memmove((void *)&fd_pending_array[i], (void *)&fd_pending_array[i+1],
+ sizeof(SIG_ATOMIC_T)*(signals_received-i-1));
+ }
+ data->directory_handle = -1;
+ signals_received--;
+ break;
+ }
}
- close(fd);
+ BlockSignals(False, RT_SIGNAL_NOTIFY);
}
SAFE_FREE(data);
- DEBUG(3,("removed kernel change notify fd=%d\n", fd));
+ DEBUG(3,("kernel_remove_notify: fd=%d\n", fd));
}
-
/****************************************************************************
-register a change notify request
+ Register a change notify request.
*****************************************************************************/
+
static void *kernel_register_notify(connection_struct *conn, char *path, uint32 flags)
{
struct change_data data;
int fd;
unsigned long kernel_flags;
- fd = conn->vfs_ops.open(conn, path, O_RDONLY, 0);
+ fd = sys_open(path,O_RDONLY, 0);
if (fd == -1) {
DEBUG(3,("Failed to open directory %s for change notify\n", path));
return NULL;
}
- if (fcntl(fd, F_SETSIG, RT_SIGNAL_NOTIFY) == -1) {
+ if (sys_fcntl_long(fd, F_SETSIG, RT_SIGNAL_NOTIFY) == -1) {
DEBUG(3,("Failed to set signal handler for change notify\n"));
return NULL;
}
if (flags & FILE_NOTIFY_CHANGE_EA) kernel_flags |= DN_ATTRIB;
if (flags & FILE_NOTIFY_CHANGE_FILE_NAME) kernel_flags |= DN_RENAME|DN_DELETE;
- if (fcntl(fd, F_NOTIFY, kernel_flags) == -1) {
+ if (sys_fcntl_long(fd, F_NOTIFY, kernel_flags) == -1) {
DEBUG(3,("Failed to set async flag for change notify\n"));
return NULL;
}
}
/****************************************************************************
-see if the kernel supports change notify
+ See if the kernel supports change notify.
****************************************************************************/
+
static BOOL kernel_notify_available(void)
{
int fd, ret;
fd = open("/tmp", O_RDONLY);
- if (fd == -1) return False; /* uggh! */
- ret = fcntl(fd, F_NOTIFY, 0);
+ if (fd == -1)
+ return False; /* uggh! */
+ ret = sys_fcntl_long(fd, F_NOTIFY, 0);
close(fd);
return ret == 0;
}
-
/****************************************************************************
-setup kernel based change notify
+ Setup kernel based change notify.
****************************************************************************/
+
struct cnotify_fns *kernel_notify_init(void)
{
static struct cnotify_fns cnotify;
return NULL;
}
- if (!kernel_notify_available()) return NULL;
+ if (!kernel_notify_available())
+ return NULL;
cnotify.register_notify = kernel_register_notify;
cnotify.check_notify = kernel_check_notify;
return &cnotify;
}
-
#else
void notify_kernel_dummy(void) {}
#endif /* HAVE_KERNEL_CHANGE_NOTIFY */
git.samba.org / kai / samba.git / blobdiff