[Libsysio-commit] HEAD: libsysio/src access.c init.c

[Lee W. <lw...@us...>]

Update of /cvsroot/libsysio/libsysio/src
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv24736/src

Modified Files:
	access.c init.c 
Log Message:


Speed up group ID checks a little by keeping memory allocated instead
of reallocating every time.


Index: access.c
===================================================================
RCS file: /cvsroot/libsysio/libsysio/src/access.c,v
retrieving revision 1.10
retrieving revision 1.11
diff -u -w -b -B -p -r1.10 -r1.11
--- access.c	21 Sep 2004 16:18:30 -0000	1.10
+++ access.c	3 May 2006 15:57:28 -0000	1.11
@@ -9,7 +9,7 @@
  *    terms of the GNU Lesser General Public License
  *    (see cit/LGPL or http://www.gnu.org/licenses/lgpl.html)
  *
- *    Cplant(TM) Copyright 1998-2003 Sandia Corporation. 
+ *    Cplant(TM) Copyright 1998-2006 Sandia Corporation. 
  *    Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
  *    license for use of this work by or on behalf of the US Government.
  *    Export of this program may require a license from the United States
@@ -50,9 +50,14 @@
 #include <sys/queue.h>
 
 #include "sysio.h"
+#include "mount.h"
+#include "fs.h"
 #include "inode.h"
 #include "sysio-symbols.h"
 
+static gid_t *gids = NULL;				/* space for gids */
+static unsigned ngids = 0;				/* max # gids */
+
 /*
  * Check given access type on given inode.
  */
@@ -82,6 +87,13 @@ _sysio_check_permission(struct inode *in
 	if (amode & X_OK)
 		mask |= S_IXUSR;
 
+	/*
+	 * Check for RO access to the file due to mount
+	 * options.
+	 */
+	if (amode & W_OK && IS_RDONLY(NULL, ino))
+		return -EROFS;
+
 	stat = &ino->i_stbuf;
 	if (stat->st_uid == uid && (stat->st_mode & mask) == mask) 
 		return 0;
@@ -110,22 +122,33 @@ int
 _sysio_permitted(struct inode *ino, int amode)
 {
 	int	err;
-	gid_t	*gids;
 	int	n;
 	void	*p;
 
 	err = 0;
-	gids = NULL;
 	for (;;) {
+		/*
+		 * This is far more expensive than I would like. Each time
+		 * called it has to go to some length to acquire the
+		 * current uid and groups membership. We can't just cache
+		 * the result, either. The caller could have altered something
+		 * asynchronously. Wish we had easy access to this info.
+		 */
 		n = getgroups(0, NULL);
-		if (!n)
+		if (n < 0) {
+			err = -errno;
 			break;
+		}
+		if ((unsigned )n > ngids) {
 		p = realloc(gids, n * sizeof(gid_t));
 		if (!p && gids) {
 			err = -ENOMEM;
 			break;
 		}
+			ngids = n;
 		gids = p;
+		}
+		if (n) {
 		err = getgroups(n, gids);
 		if (err < 0) {
 			if (errno == EINVAL)
@@ -133,6 +156,7 @@ _sysio_permitted(struct inode *ino, int 
 			err = -errno;
 			break;
 		}
+		}
 		err =
 		    _sysio_check_permission(ino,
 					    geteuid(), getegid(),
@@ -142,10 +166,24 @@ _sysio_permitted(struct inode *ino, int 
 	}
 	if (!gids)
 		return err;
-	free(gids);
 	return err;
 }
 
+#ifdef ZERO_SUM_MEMORY
+/*
+ * Clean up persistent resource on shutdown.
+ */
+void
+_sysio_access_shutdown()
+{
+
+	if (gids)
+		free(gids);
+	gids = NULL;
+	ngids = 0;
+}
+#endif
+
 int
 SYSIO_INTERFACE_NAME(access)(const char *path, int amode)
 {

Index: init.c
===================================================================
RCS file: /cvsroot/libsysio/libsysio/src/init.c,v
retrieving revision 1.26
retrieving revision 1.27
diff -u -w -b -B -p -r1.26 -r1.27
--- init.c	27 Feb 2006 17:26:55 -0000	1.26
+++ init.c	3 May 2006 15:57:28 -0000	1.27
@@ -210,6 +210,7 @@ _sysio_shutdown()
 	_sysio_fd_shutdown();
 	_sysio_i_shutdown();
 	_sysio_fssw_shutdown();
+	_sysio_access_shutdown();
 #if SYSIO_TRACING
 	{
 		struct trace_callback *tcb;