r20932: This is the basic infrastructure for inotify support. This is far from being

complete, in particular the various mask bits are not correctly supported
yet. Checkin in now, I want to see how the build farm likes it.

Volker
(This used to be commit c9a5d011a91359b242f6c26f46e96ecea6a44a3b)

1 files changed, 263 insertions, 0 deletions

diff --git a/source3/smbd/notify_inotify.c b/source3/smbd/notify_inotify.c
new file mode 100644
index 0000000000..92af6b473d
--- /dev/null
+++ b/source3/smbd/notify_inotify.c
@@ -0,0 +1,263 @@
+/*
+ * inotify change notify support
+ *
+ * Copyright (c) Andrew Tridgell 2006
+ * Copyright (c) Volker Lendecke 2007
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include "includes.h"
+
+#include <linux/inotify.h>
+#include <asm/unistd.h>
+
+#ifdef HAVE_INOTIFY
+
+#ifndef HAVE_INOTIFY_INIT
+/*
+  glibc doesn't define these functions yet (as of March 2006)
+*/
+static int inotify_init(void)
+{
+	return syscall(__NR_inotify_init);
+}
+
+static int inotify_add_watch(int fd, const char *path, __u32 mask)
+{
+	return syscall(__NR_inotify_add_watch, fd, path, mask);
+}
+
+static int inotify_rm_watch(int fd, int wd)
+{
+	return syscall(__NR_inotify_rm_watch, fd, wd);
+}
+#endif
+
+struct inotify_ctx {
+	struct inotify_ctx *prev, *next;
+	int wd;
+	files_struct *fsp;
+};
+
+static struct inotify_ctx *inotify_list;
+
+static int inotify_watch_fd;
+
+/*
+  map from a change notify mask to a inotify mask. Remove any bits
+  which we can handle
+*/
+static const struct {
+	uint32_t notify_mask;
+	uint32_t inotify_mask;
+} inotify_mapping[] = {
+	{FILE_NOTIFY_CHANGE_FILE_NAME,
+	 IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
+	{FILE_NOTIFY_CHANGE_DIR_NAME,
+	 IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
+	{FILE_NOTIFY_CHANGE_ATTRIBUTES,
+	 IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
+	{FILE_NOTIFY_CHANGE_LAST_WRITE,  IN_ATTRIB},
+	{FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
+	{FILE_NOTIFY_CHANGE_EA,          IN_ATTRIB},
+	{FILE_NOTIFY_CHANGE_SECURITY,    IN_ATTRIB}
+};
+
+static uint32_t inotify_map(uint32 *filter)
+{
+	int i;
+	uint32_t out=0;
+	for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
+		if (inotify_mapping[i].notify_mask & *filter) {
+			out |= inotify_mapping[i].inotify_mask;
+			*filter &= ~inotify_mapping[i].notify_mask;
+		}
+	}
+	return out;
+}
+
+static int inotify_ctx_destructor(struct inotify_ctx *ctx)
+{
+	if (inotify_rm_watch(inotify_watch_fd, ctx->wd) == -1) {
+		DEBUG(0, ("inotify_rm_watch failed: %s\n", strerror(errno)));
+	}
+	DLIST_REMOVE(inotify_list, ctx);
+	return 0;
+}
+
+static void *inotify_add(TALLOC_CTX *mem_ctx, 
+			 struct event_context *event_ctx,
+			 files_struct *fsp, uint32 *pfilter)
+{
+	struct inotify_ctx *ctx;
+	uint32_t inotify_mask;
+	pstring fullpath;
+	uint32 filter;
+	
+	filter = *pfilter;
+	if ((filter & (FILE_NOTIFY_CHANGE_FILE
+		       |FILE_NOTIFY_CHANGE_DIR_NAME)) == 0) {
+		/*
+		 * This first implementation only looks at create/delete
+		 */
+		return NULL;
+	}
+
+	inotify_mask = inotify_map(&filter);
+
+	if (inotify_mask == 0) {
+		DEBUG(10, ("inotify_mask == 0, nothing to do\n"));
+		return NULL;
+	}
+
+	pstrcpy(fullpath, fsp->fsp_name);
+	if (!canonicalize_path(fsp->conn, fullpath)) {
+		DEBUG(0, ("failed to canonicalize path '%s'\n", fullpath));
+		return NULL;
+	}
+
+	if (*fullpath != '/') {
+		DEBUG(0, ("canonicalized path '%s' into `%s`\n", fsp->fsp_name,
+			  fullpath));
+		DEBUGADD(0, ("but expected an absolute path\n"));
+		return NULL;
+	}
+	
+	if (!(ctx = TALLOC_P(mem_ctx, struct inotify_ctx))) {
+		DEBUG(0, ("talloc failed\n"));
+		return NULL;
+	}
+
+	ctx->fsp = fsp;
+	ctx->wd = inotify_add_watch(inotify_watch_fd, fullpath, inotify_mask);
+
+	if (ctx->wd == -1) {
+		DEBUG(5, ("inotify_add_watch failed: %s\n", strerror(errno)));
+		TALLOC_FREE(ctx);
+		return NULL;
+	}
+
+	DLIST_ADD(inotify_list, ctx);
+	talloc_set_destructor(ctx, inotify_ctx_destructor);
+
+	*pfilter = filter;
+	return ctx;
+}
+
+static void inotify_dispatch(struct inotify_event *e)
+{
+	struct inotify_ctx *ctx;
+
+	for (ctx = inotify_list; ctx; ctx = ctx->next) {
+		if (ctx->wd == e->wd) {
+			break;
+		}
+	}
+
+	if (ctx == NULL) {
+		/* not found */
+		return;
+	}
+
+	if (e->mask & IN_CREATE) {
+		notify_fsp(ctx->fsp, NOTIFY_ACTION_ADDED, e->name);
+	}
+
+	if (e->mask & IN_DELETE) {
+		notify_fsp(ctx->fsp, NOTIFY_ACTION_REMOVED, e->name);
+	}
+}
+
+static void inotify_callback(struct event_context *event_ctx,
+			     struct fd_event *event,
+			     uint16 flags,
+			     void *private_data)
+{
+	char *buf, *p;
+	int bufsize;
+
+	/*
+	  we must use FIONREAD as we cannot predict the length of the
+	  filenames, and thus can't know how much to allocate
+	  otherwise
+	*/
+	if ((ioctl(inotify_watch_fd, FIONREAD, &bufsize) != 0)
+	    || (bufsize == 0)) {
+		DEBUG(0,("No data on inotify fd?!\n"));
+		return;
+	}
+
+	if (!(buf = SMB_MALLOC_ARRAY(char, bufsize))) {
+		DEBUG(0, ("malloc failed\n"));
+		return;
+	}
+
+	if (read(inotify_watch_fd, buf, bufsize) != bufsize) {
+		DEBUG(0,("Failed to read all inotify data\n"));
+		SAFE_FREE(buf);
+		return;
+	}
+
+	p = buf;
+
+	while (bufsize > sizeof(struct inotify_event)) {
+		struct inotify_event *iev = (struct inotify_event *)p;
+		size_t len = sizeof(struct inotify_event) + iev->len;
+
+		if ((len > bufsize)
+		    || ((iev->len != 0) && (iev->name[iev->len-1] != '\0'))) {
+			smb_panic("invalid inotify reply\n");
+		}
+
+		inotify_dispatch(iev);
+
+		p += len;
+		bufsize -= len;
+	}
+
+	SAFE_FREE(buf);
+	return;
+}
+
+static struct cnotify_fns inotify_fns =
+{
+    inotify_add,
+};
+
+struct cnotify_fns *inotify_notify_init(struct event_context *event_ctx)
+{
+	inotify_watch_fd = inotify_init();
+
+	DEBUG(10, ("inotify_notify_init called\n"));
+
+	if (inotify_watch_fd == -1) {
+		DEBUG(0, ("inotify_init failed: %s\n", strerror(errno)));
+		return NULL;
+	}
+
+	if (event_add_fd(event_ctx, NULL, inotify_watch_fd,
+			 EVENT_FD_READ, inotify_callback,
+			 NULL) == NULL) {
+		DEBUG(0, ("event_add_fd failed\n"));
+		close(inotify_watch_fd);
+		inotify_watch_fd = -1;
+		return NULL;
+	}
+
+	return &inotify_fns;
+}
+
+#endif