Changes to centralise the default blocksize behaviour.

More likely to follow.

Submitted by: phk@freebsd.org

1 files changed, 20 insertions, 13 deletions

diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 0a08938..c42ebf6 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -429,22 +429,29 @@ vn_stat(vp, sb, p)
 	sb->st_atimespec = vap->va_atime;
 	sb->st_mtimespec = vap->va_mtime;
 	sb->st_ctimespec = vap->va_ctime;
-	/*
-	 * For block and char device nodes we don't really care
-	 * about what the filesystem told us, we want to know
-	 * what the device told us
+
+        /*
+	 * According to www.opengroup.org, the meaning of st_blksize is 
+	 *   "a filesystem-specific preferred I/O block size for this 
+	 *    object.  In some filesystem types, this may vary from file
+	 *    to file"
+	 * Default to zero to catch bogus uses of this field.
 	 */
-	switch (vap->va_type) {
-	case VBLK:
-		sb->st_blksize = vp->v_rdev->si_bsize_best;
-		break;
-	case VCHR:
-		sb->st_blksize = vp->v_rdev->si_bsize_max;
-		break;
-	default:
+
+	if (vap->va_type == VREG) {
 		sb->st_blksize = vap->va_blocksize;
-		break;
+	} else if ((vp->v_type == VBLK || vp->v_type == VCHR) &&
+	    devsw(vp->v_rdev) && (devsw(vp->v_rdev)->d_flags & D_DISK)) {
+		/* XXX use vn_isdisk() above once VCHR is also disk */
+		sb->st_blksize = vp->v_rdev->si_bsize_best;
+		if (sb->st_blksize < vp->v_rdev->si_bsize_phys)
+			sb->st_blksize = vp->v_rdev->si_bsize_phys;
+		if (sb->st_blksize < BLKDEV_IOSIZE)
+			sb->st_blksize = BLKDEV_IOSIZE;
+	} else {
+		sb->st_blksize = 0;
 	}
+	
 	sb->st_flags = vap->va_flags;
 	if (suser_xxx(p->p_ucred, 0, 0))
 		sb->st_gen = 0;