Sending this now to get opinions, but I do not plan any change for 6.0.
Since I started to use OpenBSD I've always found confusing that
cat /directory/
doesn't error out. I initially assumed that it was historical behavior,
but, as hinted by Theo, in rev. 1.1 the behavior was actually to return
the raw directory entry.
Both behaviors match POSIX, which allows a third possibility as an XSI
extension: fail with EISDIR. I think this is the most useful behavior;
dumping binary junk is useless, and returning en empty read can hide
errors.
I haven't performed extensive testing but if base/xenocara/ports bulk
builds show errors I can fix them. The question is, is it worth it?
Comments / objections?
Index: lib/libc/sys/read.2
===================================================================
RCS file: /cvs/src/lib/libc/sys/read.2,v
retrieving revision 1.35
diff -u -p -r1.35 read.2
--- lib/libc/sys/read.2 5 Feb 2015 02:33:09 -0000 1.35
+++ lib/libc/sys/read.2 9 Jul 2016 17:20:39 -0000
@@ -152,13 +152,15 @@ is not a valid file or socket descriptor
Part of
.Fa buf
points outside the process's allocated address space.
-.It Bq Er EIO
-An I/O error occurred while reading from the file system.
.It Bq Er EINTR
A read from a slow device
(i.e. one that might block for an arbitrary amount of time)
was interrupted by the delivery of a signal
before any data arrived.
+.It Bq Er EIO
+An I/O error occurred while reading from the file system.
+.It Bq Er EISDIR
+The underlying file is a directory.
.El
.Pp
In addition,
Index: sys/kern/vfs_vnops.c
===================================================================
RCS file: /cvs/src/sys/kern/vfs_vnops.c,v
retrieving revision 1.85
diff -u -p -r1.85 vfs_vnops.c
--- sys/kern/vfs_vnops.c 19 Jun 2016 11:54:33 -0000 1.85
+++ sys/kern/vfs_vnops.c 9 Jul 2016 17:20:39 -0000
@@ -336,11 +336,13 @@ vn_read(struct file *fp, off_t *poff, st
if (vp->v_type != VCHR && count > LLONG_MAX - *poff)
return (EINVAL);
+ if (vp->v_type == VDIR)
+ return (EISDIR);
+
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
uio->uio_offset = *poff;
- if (vp->v_type != VDIR)
- error = VOP_READ(vp, uio,
- (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, cred);
+ error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0,
+ cred);
*poff += count - uio->uio_resid;
VOP_UNLOCK(vp, p);
return (error);
--
jca | PGP : 0x1524E7EE / 5135 92C1 AD36 5293 2BDF DDCC 0DFA 74AE 1524 E7EE
