r14616: added notify change support to the posix backend

It doesn't fully work yet, and doesn't yet have all the efficiency
that is planned, but it doesn't break anything and I wanted to get the
code in the tree to minimise the chance of collisions with the work
metze is doing.
(This used to be commit 1624ea88e6eef89caacc36e7513aa79df0d579b9)

6 files changed, 162 insertions, 0 deletions

diff --git a/source4/ntvfs/posix/config.mk b/source4/ntvfs/posix/config.mk
index ccf2c2d1a9..c49fbc88b7 100644
--- a/source4/ntvfs/posix/config.mk
+++ b/source4/ntvfs/posix/config.mk
@@ -29,6 +29,7 @@ OBJ_FILES = \
 		pvfs_xattr.o \
 		pvfs_streams.o \
 		pvfs_acl.o \
+		pvfs_notify.o \
 		xattr_system.o \
 		xattr_tdb.o
 REQUIRED_SUBSYSTEMS = NDR_XATTR EXT_LIB_XATTR EXT_LIB_BLKID
diff --git a/source4/ntvfs/posix/pvfs_notify.c b/source4/ntvfs/posix/pvfs_notify.c
new file mode 100644
index 0000000000..566b6bc0e2
--- /dev/null
+++ b/source4/ntvfs/posix/pvfs_notify.c
@@ -0,0 +1,141 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   POSIX NTVFS backend - notify
+
+   Copyright (C) Andrew Tridgell 2006
+
+   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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "vfs_posix.h"
+#include "lib/messaging/irpc.h"
+#include "messaging/messaging.h"
+
+/* pending notifies buffer, hung off struct pvfs_file for open directories
+   that have used change notify */
+struct pvfs_notify_buffer {
+	struct pvfs_file *f;
+	uint32_t num_changes;
+	struct notify_changes *changes;
+	uint32_t max_buffer_size;
+	uint32_t current_buffer_size;
+	void *wait_handle;
+};
+
+
+/*
+  destroy a notify buffer. Called when the handle is closed
+ */
+static int pvfs_notify_destructor(void *ptr)
+{
+	struct pvfs_notify_buffer *n = talloc_get_type(ptr, struct pvfs_notify_buffer);
+	notify_remove(n->f->pvfs->notify_context, n);
+	n->f->notify_buffer = NULL;
+	return 0;
+}
+
+
+/*
+  called when a async notify event comes in
+*/
+static void pvfs_notify_callback(void *private, const struct notify_event *ev)
+{
+	struct pvfs_notify_buffer *n = talloc_get_type(private, struct pvfs_notify_buffer);
+	DEBUG(0,("got notify for '%s'\n", ev->path));
+}
+
+/*
+  setup a notify buffer on a directory handle
+*/
+static NTSTATUS pvfs_notify_setup(struct pvfs_state *pvfs, struct pvfs_file *f, 
+				  uint32_t buffer_size, uint32_t filter, BOOL recursive)
+{
+	NTSTATUS status;
+	struct notify_entry e;
+
+	f->notify_buffer = talloc_zero(f, struct pvfs_notify_buffer);
+	NT_STATUS_HAVE_NO_MEMORY(f->notify_buffer);
+
+	f->notify_buffer->max_buffer_size = buffer_size;
+	f->notify_buffer->f = f;
+
+	e.filter    = filter;
+	e.path      = f->handle->name->full_name;
+	e.recursive = recursive;
+
+	status = notify_add(pvfs->notify_context, &e, 
+			    pvfs_notify_callback, f->notify_buffer);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	talloc_set_destructor(f->notify_buffer, pvfs_notify_destructor);
+
+	return NT_STATUS_OK;
+}
+
+
+/* change notify request - always async. This request blocks until the
+   event buffer is non-empty */
+NTSTATUS pvfs_notify(struct ntvfs_module_context *ntvfs, 
+		     struct ntvfs_request *req,
+		     struct smb_notify *info)
+{
+	struct pvfs_state *pvfs = talloc_get_type(ntvfs->private_data, 
+						  struct pvfs_state);
+	struct pvfs_file *f;
+	NTSTATUS status;
+
+	f = pvfs_find_fd(pvfs, req, info->in.file.fnum);
+	if (!f) {
+		return NT_STATUS_INVALID_HANDLE;
+	}
+
+	/* this request doesn't make sense unless its async */
+	if (!(req->async_states->state & NTVFS_ASYNC_STATE_MAY_ASYNC)) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	/* its only valid for directories */
+	if (f->handle->fd != -1) {
+		return NT_STATUS_NOT_A_DIRECTORY;
+	}
+
+	/* if the handle doesn't currently have a notify buffer then
+	   create one */
+	if (f->notify_buffer == NULL) {
+		status = pvfs_notify_setup(pvfs, f, 
+					   info->in.buffer_size, 
+					   info->in.completion_filter,
+					   info->in.recursive);
+		NT_STATUS_NOT_OK_RETURN(status);
+	}
+
+	/* if the buffer is empty then start waiting */
+	if (f->notify_buffer->num_changes == 0) {
+		req->async_states->state |= NTVFS_ASYNC_STATE_ASYNC;
+		return NT_STATUS_OK;
+	}
+
+	/* otherwise if the buffer is not empty then return its
+	   contents immediately */
+	info->out.num_changes = f->notify_buffer->num_changes;
+	info->out.changes = talloc_steal(req, f->notify_buffer->changes);
+	f->notify_buffer->num_changes = 0;
+	f->notify_buffer->changes = NULL;
+	f->notify_buffer->current_buffer_size = 0;
+
+	return NT_STATUS_OK;
+}
diff --git a/source4/ntvfs/posix/pvfs_open.c b/source4/ntvfs/posix/pvfs_open.c
index 2724339323..3c3e13bc91 100644
--- a/source4/ntvfs/posix/pvfs_open.c
+++ b/source4/ntvfs/posix/pvfs_open.c
@@ -271,6 +271,7 @@ static NTSTATUS pvfs_open_directory(struct pvfs_state *pvfs,
 	f->share_access  = io->generic.in.share_access;
 	f->impersonation = io->generic.in.impersonation;
 	f->access_mask   = access_mask;
+	f->notify_buffer = NULL;
 
 	f->handle->pvfs              = pvfs;
 	f->handle->name              = talloc_steal(f->handle, name);
@@ -688,6 +689,7 @@ static NTSTATUS pvfs_create_file(struct pvfs_state *pvfs,
 	f->share_access      = io->generic.in.share_access;
 	f->access_mask       = access_mask;
 	f->impersonation     = io->generic.in.impersonation;
+	f->notify_buffer     = NULL;
 
 	f->handle->pvfs              = pvfs;
 	f->handle->name              = talloc_steal(f->handle, name);
@@ -1113,6 +1115,7 @@ NTSTATUS pvfs_open(struct ntvfs_module_context *ntvfs,
 	f->share_access  = io->generic.in.share_access;
 	f->access_mask   = access_mask;
 	f->impersonation = io->generic.in.impersonation;
+	f->notify_buffer = NULL;
 
 	f->handle->pvfs              = pvfs;
 	f->handle->fd                = -1;
diff --git a/source4/ntvfs/posix/pvfs_unlink.c b/source4/ntvfs/posix/pvfs_unlink.c
index 76c9bc10a4..3a6e4bba2f 100644
--- a/source4/ntvfs/posix/pvfs_unlink.c
+++ b/source4/ntvfs/posix/pvfs_unlink.c
@@ -103,6 +103,11 @@ static NTSTATUS pvfs_unlink_one(struct pvfs_state *pvfs,
 		status = pvfs_map_errno(pvfs, errno);
 	}
 
+	if (NT_STATUS_IS_OK(status)) {
+		notify_trigger(pvfs->notify_context, NOTIFY_ACTION_REMOVED, 
+			       name->full_name);
+	}
+
 	talloc_free(name);
 
 	return status;
diff --git a/source4/ntvfs/posix/vfs_posix.c b/source4/ntvfs/posix/vfs_posix.c
index cb441cb4c9..0469e54d35 100644
--- a/source4/ntvfs/posix/vfs_posix.c
+++ b/source4/ntvfs/posix/vfs_posix.c
@@ -185,6 +185,13 @@ static NTSTATUS pvfs_connect(struct ntvfs_module_context *ntvfs,
 		return NT_STATUS_INTERNAL_DB_CORRUPTION;
 	}
 
+	pvfs->notify_context = notify_init(pvfs, 
+					   pvfs->ntvfs->ctx->server_id,  
+					   pvfs->ntvfs->ctx->msg_ctx);
+	if (pvfs->notify_context == NULL) {
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
+
 	pvfs->sidmap = sidmap_open(pvfs);
 	if (pvfs->sidmap == NULL) {
 		return NT_STATUS_INTERNAL_DB_CORRUPTION;
@@ -317,6 +324,7 @@ NTSTATUS ntvfs_posix_init(void)
 	ops.logoff = pvfs_logoff;
 	ops.async_setup = pvfs_async_setup;
 	ops.cancel = pvfs_cancel;
+	ops.notify = pvfs_notify;
 
 	/* register ourselves with the NTVFS subsystem. We register
 	   under the name 'default' as we wish to be the default
diff --git a/source4/ntvfs/posix/vfs_posix.h b/source4/ntvfs/posix/vfs_posix.h
index 59e4ec1abf..aa452c6a13 100644
--- a/source4/ntvfs/posix/vfs_posix.h
+++ b/source4/ntvfs/posix/vfs_posix.h
@@ -42,6 +42,7 @@ struct pvfs_state {
 
 	struct brl_context *brl_context;
 	struct odb_context *odb_context;
+	struct notify_context *notify_context;
 	struct sidmap_context *sidmap;
 
 	/* a list of pending async requests. Needed to support
@@ -179,6 +180,9 @@ struct pvfs_file {
 	/* a count of active locks - used to avoid calling brl_close on
 	   file close */
 	uint64_t lock_count;
+
+	/* for directories, a buffer of pending notify events */
+	struct pvfs_notify_buffer *notify_buffer;
 };
 
 /* the state of a search started with pvfs_search_first() */