new_vnode() now complains if the vnode already exists (and panics with when

it has a different data set).
Improved the kernel's PANIC() function (now accepts varargs).
sys_open_query() now has a flags field (that can be set to B_LIVE_QUERY).
The fs_shell now supports one live query; might be enhanced later to support
more than just one (concurrently).


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3318 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/tests/add-ons/kernel/file_systems/fs_shell/fsh.c

@@ -24,6 +24,7 @@
 #include "argv.h"
 
 #include <fs_attr.h>
+#include <fs_query.h>
 
 static void do_lat_fs(int argc, char **argv);
 static void do_fsh(void);
@@ -1060,6 +1061,50 @@ do_sync(int argc, char **argv)
 }
 
 
+void *gQueryCookie = NULL;
+
+
+static void
+do_stopquery(int argc, char **argv)
+{
+	int err;
+
+	if (gQueryCookie == NULL) {
+		printf("no query running (use the 'startquery' command to start a query).\n");
+		return;
+	}
+
+	err = sys_close_query(true, -1, "/myfs/.", gQueryCookie);
+	if (err < 0) {
+		printf("could not close query: %s\n", strerror(err));
+		return;
+	}
+
+	gQueryCookie = NULL;
+}
+
+
+static void
+do_startquery(int argc, char **argv)
+{
+	char *query;
+	int err;
+
+	if (argc != 2) {
+		printf("query string expected");
+		return;
+	}
+	query = argv[1];
+
+	err = sys_open_query(true, -1, "/myfs/.", query, B_LIVE_QUERY, &gQueryCookie);
+	if (err < 0) {
+		printf("could not open query: %s\n", strerror(err));
+		return;
+	} else
+		printf("query started - use the 'stopquery' command to stop it.");
+}
+
+
 static void
 do_query(int argc, char **argv)
 {
@@ -1076,14 +1121,14 @@ do_query(int argc, char **argv)
 	}
 	query = argv[1];
 
-	err = sys_open_query(true,-1,"/myfs/.",query,&cookie);
+	err = sys_open_query(true, -1, "/myfs/.", query, 0, &cookie);
 	if (err < 0) {
-		printf("could not open query: %s\n",strerror(err));
+		printf("could not open query: %s\n", strerror(err));
 		return;
 	}
 	
 	while (true) {
-		err = sys_read_query(true,-1,"/myfs/.",cookie, dent, sizeof(buffer), 1);
+		err = sys_read_query(true, -1, "/myfs/.", cookie, dent, sizeof(buffer), 1);
 		if (err < 0) {
 			printf("readdir failed for: %s\n", dent->d_name);
 			if (max_err-- <= 0)
@@ -1095,12 +1140,12 @@ do_query(int argc, char **argv)
 		if (err == 0)
 			break;
 
-		printf("%s\n",dent->d_name);
+		printf("%s\n", dent->d_name);
 	}
 
-	err = sys_close_query(true,-1,"/myfs/.",cookie);
+	err = sys_close_query(true, -1, "/myfs/.", cookie);
 	if (err < 0) {
-		printf("could not close query: %s\n",strerror(err));
+		printf("could not close query: %s\n", strerror(err));
 		return;
 	}
 }
@@ -1307,6 +1352,8 @@ cmd_entry fsh_cmds[] =
     { "create",  do_create, "create N files. default is 100" },
     { "delete",  do_delete, "delete N files. default is 100" },
     { "query",   do_query, "run a query on the file system" },
+    { "startquery", do_startquery, "run a live query on the file system" },
+    { "stopquery",  do_stopquery, "stops the live query" },
     { "ioctl",   do_ioctl, "execute ioctl() without an inode (okay, with the root node)" },
     { "fcntl",   do_fcntl, "execute ioctl() with the active inode" },
     { "cptest",  do_copytest, "copies all files from the given path" },

src/tests/add-ons/kernel/file_systems/fs_shell/kernel.c

@@ -215,9 +215,15 @@ static int          free_fds(fdarray *fds);
 #include <stdio.h>
 
 static void
-PANIC(char *s)
+PANIC(char *s, ...)
 {
-    printf(s);
+	va_list list;
+	
+	va_start(list, s);
+	vfprintf(stdout, s, list);
+	va_end(list);
+
+    exit(-1);
 }
 
 
@@ -1821,7 +1827,7 @@ error1:
 
 
 int
-sys_open_query(bool kernel, int fd, const char *path, const char *query, void **cookie)
+sys_open_query(bool kernel, int fd, const char *path, const char *query, ulong flags, void **cookie)
 {
 	int		err;
 	nspace	*ns;
@@ -1842,7 +1848,7 @@ sys_open_query(bool kernel, int fd, const char *path, const char *query, void **
 		dec_vnode(root, FALSE);
 		return EPERM;
 	}
-	err = (*fs->ops.open_query)(ns->data, query, 0, -1, 0, cookie);
+	err = (*fs->ops.open_query)(ns->data, query, flags, -1, 0, cookie);
 	printf("sys_open_query() -- end: %d\n",err);
 	dec_vnode(root, FALSE);
 
@@ -2232,11 +2238,38 @@ put_vnode(nspace_id nsid, vnode_id vnid)
 int
 new_vnode(nspace_id nsid, vnode_id vnid, void *data)
 {
-    int         err;
-    vnode       *vn;
+    int retries = 20;
+    vnode *vn;
+    int err;
 
-    LOCK(vnlock);
-    vn = steal_vnode(FREE_LIST);
+	LOCK(vnlock);
+
+restart:
+	if ((vn = lookup_vnode(nsid, vnid)) != NULL) {
+		// oh, we requested a new vnode although there already
+		// exist one - compare the private node data and bail
+		// out if needed.
+
+		if (vn->busy) {
+			printf("new_vnode(): vnode exists and is busy!\n");
+			snooze(500);
+			if (retries-- >= 0)
+				goto restart;
+
+			printf("new_vnode(): still busy, but continue to our doom!\n");
+		}
+
+		if (vn->data != data)
+			PANIC("new_vnode(): vnode already exists with different data (vnode id = %Ld)!\n", vnid);
+		else {
+			printf("new_vnode(): vnode already exists with the same data (vnode id = %Ld)\n", vnid);
+			vn->rcnt++;
+			return;
+        	UNLOCK(vnlock);
+		}
+	}
+
+	vn = steal_vnode(FREE_LIST);
     if (!vn) {
         vn = steal_vnode(USED_LIST);
         if (!vn) {

src/tests/add-ons/kernel/file_systems/fs_shell/kprotos.h

@@ -43,7 +43,7 @@ ssize_t sys_read_attr(bool kernel, int fd, const char *name, int type, void *buf
 ssize_t sys_write_attr(bool kernel, int fd, const char *name, int type, void *buffer, size_t len, off_t pos);
 ssize_t sys_remove_attr(bool kernel, int fd, const char *name);
 
-int sys_open_query(bool kernel, int fd, const char *path, const char *query, void **cookie);
+int sys_open_query(bool kernel, int fd, const char *path, const char *query, ulong flags, void **cookie);
 int sys_close_query(bool kernel, int fd, const char *path, void *cookie);
 int sys_read_query(bool kernel, int fd, const char *path, void *cookie,struct dirent *dent,size_t bufferSize,long num);