svn commit: r192013 - head/sys/fs/fdescfs

[Konstantin Belousov]

Author: kib
Date: Tue May 12 09:28:45 2009
New Revision: 192013
URL: http://svn.freebsd.org/changeset/base/192013

Log:
  Report all fdescfs vnodes as VCHR for stat(2). Fake the unique
  major/minor numbers of the devices.
  
  Pretending that the vnodes are character devices prevents file tree
  walkers from descending into the directories opened by current process.
  Also, not doing stat on the filedescriptors prevents the recursive entry
  into the VFS.
  
  Requested by:	kientzle
  Discussed with:	Jilles Tjoelker <jilles stack nl>

Modified:
  head/sys/fs/fdescfs/fdesc_vnops.c

Modified: head/sys/fs/fdescfs/fdesc_vnops.c
==============================================================================
--- head/sys/fs/fdescfs/fdesc_vnops.c	Tue May 12 09:22:33 2009	(r192012)
+++ head/sys/fs/fdescfs/fdesc_vnops.c	Tue May 12 09:28:45 2009	(r192013)
@@ -389,78 +389,34 @@ fdesc_getattr(ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct vattr *vap = ap->a_vap;
-	struct thread *td = curthread;
-	struct file *fp;
-	struct stat stb;
-	u_int fd;
-	int error = 0;
+
+	vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
+	vap->va_fileid = VTOFDESC(vp)->fd_ix;
+	vap->va_uid = 0;
+	vap->va_gid = 0;
+	vap->va_blocksize = DEV_BSIZE;
+	vap->va_atime.tv_sec = boottime.tv_sec;
+	vap->va_atime.tv_nsec = 0;
+	vap->va_mtime = vap->va_atime;
+	vap->va_ctime = vap->va_mtime;
+	vap->va_gen = 0;
+	vap->va_flags = 0;
+	vap->va_bytes = 0;
+	vap->va_filerev = 0;
 
 	switch (VTOFDESC(vp)->fd_type) {
 	case Froot:
-		vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
 		vap->va_type = VDIR;
 		vap->va_nlink = 2;
 		vap->va_size = DEV_BSIZE;
-		vap->va_fileid = VTOFDESC(vp)->fd_ix;
-		vap->va_uid = 0;
-		vap->va_gid = 0;
-		vap->va_blocksize = DEV_BSIZE;
-		vap->va_atime.tv_sec = boottime.tv_sec;
-		vap->va_atime.tv_nsec = 0;
-		vap->va_mtime = vap->va_atime;
-		vap->va_ctime = vap->va_mtime;
-		vap->va_gen = 0;
-		vap->va_flags = 0;
 		vap->va_rdev = NODEV;
-		vap->va_bytes = 0;
-		vap->va_filerev = 0;
 		break;
 
 	case Fdesc:
-		fd = VTOFDESC(vp)->fd_fd;
-
-		if ((error = fget(td, fd, &fp)) != 0)
-			return (error);
-
-		bzero(&stb, sizeof(stb));
-		error = fo_stat(fp, &stb, td->td_ucred, td);
-		fdrop(fp, td);
-		if (error == 0) {
-			vap->va_type = IFTOVT(stb.st_mode);
-			vap->va_mode = stb.st_mode;
-			if (vap->va_type == VDIR)
-				vap->va_mode &= ~(S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
-			vap->va_nlink = 1;
-			vap->va_flags = 0;
-			vap->va_bytes = stb.st_blocks * stb.st_blksize;
-			vap->va_fileid = VTOFDESC(vp)->fd_ix;
-			vap->va_size = stb.st_size;
-			vap->va_blocksize = stb.st_blksize;
-			vap->va_rdev = stb.st_rdev;
-
-			/*
-			 * If no time data is provided, use the current time.
-			 */
-			if (stb.st_atimespec.tv_sec == 0 &&
-			    stb.st_atimespec.tv_nsec == 0)
-				nanotime(&stb.st_atimespec);
-
-			if (stb.st_ctimespec.tv_sec == 0 &&
-			    stb.st_ctimespec.tv_nsec == 0)
-				nanotime(&stb.st_ctimespec);
-
-			if (stb.st_mtimespec.tv_sec == 0 &&
-			    stb.st_mtimespec.tv_nsec == 0)
-				nanotime(&stb.st_mtimespec);
-
-			vap->va_atime = stb.st_atimespec;
-			vap->va_mtime = stb.st_mtimespec;
-			vap->va_ctime = stb.st_ctimespec;
-			vap->va_uid = stb.st_uid;
-			vap->va_gid = stb.st_gid;
-			vap->va_gen = 0;
-			vap->va_filerev = 0;
-		}
+		vap->va_type = VCHR;
+		vap->va_nlink = 1;
+		vap->va_size = 0;
+		vap->va_rdev = makedev(0, vap->va_fileid);
 		break;
 
 	default:
@@ -468,9 +424,8 @@ fdesc_getattr(ap)
 		break;
 	}
 
-	if (error == 0)
-		vp->v_type = vap->va_type;
-	return (error);
+	vp->v_type = vap->va_type;
+	return (0);
 }
 
 static int