FreeBSD: Cleanup zfs_readdir()

The FreeBSD project's coverity scans found dead code in `zfs_readdir()`.
Also, the comment above `zfs_readdir()` is out of date.

I fixed the comment and deleted all of the dead code, plus additional
dead code that was found upon review.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13924

include/os/freebsd/Makefile.am

@@ -21,7 +21,6 @@ noinst_HEADERS = \
 	%D%/spl/sys/dirent.h \
 	%D%/spl/sys/disp.h \
 	%D%/spl/sys/dkio.h \
-	%D%/spl/sys/extdirent.h \
 	%D%/spl/sys/fcntl.h \
 	%D%/spl/sys/file.h \
 	%D%/spl/sys/freebsd_rwlock.h \

include/os/freebsd/spl/sys/extdirent.h

@@ -1,71 +0,0 @@
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or https://opensource.org/licenses/CDDL-1.0.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- */
-
-#ifndef _SYS_EXTDIRENT_H
-#define	_SYS_EXTDIRENT_H
-
-#ifdef	__cplusplus
-extern "C" {
-#endif
-
-#include <sys/types.h>
-#include <sys/dirent.h>
-
-/*
- * Extended file-system independent directory entry.  This style of
- * dirent provides additional informational flag bits for each
- * directory entry.  This dirent will be returned instead of the
- * standard dirent if a VOP_READDIR() requests dirent flags via
- * V_RDDIR_ENTFLAGS, and if the file system supports the flags.
- */
-typedef struct edirent {
-	ino64_t		ed_ino;		/* "inode number" of entry */
-	off64_t		ed_off;		/* offset of disk directory entry */
-	uint32_t	ed_eflags;	/* per-entry flags */
-	unsigned short	ed_reclen;	/* length of this record */
-	char		ed_name[1];	/* name of file */
-} edirent_t;
-
-#define	EDIRENT_RECLEN(namelen)	\
-	((offsetof(edirent_t, ed_name[0]) + 1 + (namelen) + 7) & ~ 7)
-#define	EDIRENT_NAMELEN(reclen)	\
-	((reclen) - (offsetof(edirent_t, ed_name[0])))
-
-/*
- * Extended entry flags
- *	Extended entries include a bitfield of extra information
- *	regarding that entry.
- */
-#define	ED_CASE_CONFLICT  0x10  /* Disconsidering case, entry is not unique */
-
-/*
- * Extended flags accessor function
- */
-#define	ED_CASE_CONFLICTS(x)	((x)->ed_eflags & ED_CASE_CONFLICT)
-#ifdef	__cplusplus
-}
-#endif
-
-#endif	/* _SYS_EXTDIRENT_H */

include/os/freebsd/spl/sys/vnode_impl.h

@@ -44,8 +44,6 @@
 #define	IS_DEVVP(vp)	\
 	((vp)->v_type == VCHR || (vp)->v_type == VBLK || (vp)->v_type == VFIFO)
 
-#define	V_XATTRDIR	0x0000	/* attribute unnamed directory */
-
 #define	AV_SCANSTAMP_SZ	32		/* length of anti-virus scanstamp */
 
 /*
@@ -193,11 +191,6 @@
 #define	MODEMASK	07777		/* mode bits plus permission bits */
 #define	PERMMASK	00777		/* permission bits */
 
-/*
- * VOP_ACCESS flags
- */
-#define	V_ACE_MASK	0x1	/* mask represents  NFSv4 ACE permissions */
-
 /*
  * Flags for vnode operations.
  */
@@ -234,12 +227,6 @@ struct taskq;
 #define	CREATE_XATTR_DIR	0x04	/* Create extended attr dir */
 #define	LOOKUP_HAVE_SYSATTR_DIR	0x08	/* Already created virtual GFS dir */
 
-/*
- * Flags for VOP_READDIR
- */
-#define	V_RDDIR_ENTFLAGS	0x01	/* request dirent flags */
-#define	V_RDDIR_ACCFILTER	0x02	/* filter out inaccessible dirents */
-
 /*
  * Public vnode manipulation functions.
  */

module/os/freebsd/zfs/zfs_dir.c

@@ -33,7 +33,6 @@
 #include <sys/resource.h>
 #include <sys/vfs.h>
 #include <sys/vnode.h>
-#include <sys/extdirent.h>
 #include <sys/file.h>
 #include <sys/kmem.h>
 #include <sys/uio.h>

module/os/freebsd/zfs/zfs_vnops_os.c

@@ -76,7 +76,6 @@
 #include <sys/zfs_quota.h>
 #include <sys/zfs_sa.h>
 #include <sys/zfs_rlock.h>
-#include <sys/extdirent.h>
 #include <sys/bio.h>
 #include <sys/buf.h>
 #include <sys/sched.h>
@@ -1648,10 +1647,11 @@ zfs_rmdir(znode_t *dzp, const char *name, znode_t *cwd, cred_t *cr, int flags)
  *			  and return buffer.
  *		cr	- credentials of caller.
  *		ct	- caller context
- *		flags	- case flags
  *
  *	OUT:	uio	- updated offset and range, buffer filled.
  *		eofp	- set to true if end-of-file detected.
+ *		ncookies- number of entries in cookies
+ *		cookies	- offsets to directory entries
  *
  *	RETURN:	0 on success, error code on failure.
  *
@@ -1669,7 +1669,6 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 {
 	znode_t		*zp = VTOZ(vp);
 	iovec_t		*iovp;
-	edirent_t	*eodp;
 	dirent64_t	*odp;
 	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
 	objset_t	*os;
@@ -1687,7 +1686,6 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 	uint8_t		type;
 	int		ncooks;
 	cookie_t	*cooks = NULL;
-	int		flags = 0;
 
 	if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
 		return (error);
@@ -1755,7 +1753,6 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 		outbuf = NULL;
 		odp = (struct dirent64 *)iovp->iov_base;
 	}
-	eodp = (struct edirent *)odp;
 
 	if (ncookies != NULL) {
 		/*
@@ -1824,25 +1821,7 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 			type = ZFS_DIRENT_TYPE(zap.za_first_integer);
 		}
 
-		if (flags & V_RDDIR_ACCFILTER) {
+		reclen = DIRENT64_RECLEN(strlen(zap.za_name));
-			/*
-			 * If we have no access at all, don't include
-			 * this entry in the returned information
-			 */
-			znode_t	*ezp;
-			if (zfs_zget(zp->z_zfsvfs, objnum, &ezp) != 0)
-				goto skip_entry;
-			if (!zfs_has_access(ezp, cr)) {
-				vrele(ZTOV(ezp));
-				goto skip_entry;
-			}
-			vrele(ZTOV(ezp));
-		}
-
-		if (flags & V_RDDIR_ENTFLAGS)
-			reclen = EDIRENT_RECLEN(strlen(zap.za_name));
-		else
-			reclen = DIRENT64_RECLEN(strlen(zap.za_name));
 
 		/*
 		 * Will this entry fit in the buffer?
@@ -1857,33 +1836,19 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 			}
 			break;
 		}
-		if (flags & V_RDDIR_ENTFLAGS) {
+		/*
-			/*
+		 * Add normal entry:
-			 * Add extended flag entry:
+		 */
-			 */
+		odp->d_ino = objnum;
-			eodp->ed_ino = objnum;
+		odp->d_reclen = reclen;
-			eodp->ed_reclen = reclen;
+		odp->d_namlen = strlen(zap.za_name);
-			/* NOTE: ed_off is the offset for the *next* entry */
+		/* NOTE: d_off is the offset for the *next* entry. */
-			next = &(eodp->ed_off);
+		next = &odp->d_off;
-			eodp->ed_eflags = zap.za_normalization_conflict ?
+		strlcpy(odp->d_name, zap.za_name, odp->d_namlen + 1);
-			    ED_CASE_CONFLICT : 0;
+		odp->d_type = type;
-			(void) strncpy(eodp->ed_name, zap.za_name,
+		dirent_terminate(odp);
-			    EDIRENT_NAMELEN(reclen));
+		odp = (dirent64_t *)((intptr_t)odp + reclen);
-			eodp = (edirent_t *)((intptr_t)eodp + reclen);
+
-		} else {
-			/*
-			 * Add normal entry:
-			 */
-			odp->d_ino = objnum;
-			odp->d_reclen = reclen;
-			odp->d_namlen = strlen(zap.za_name);
-			/* NOTE: d_off is the offset for the *next* entry. */
-			next = &odp->d_off;
-			strlcpy(odp->d_name, zap.za_name, odp->d_namlen + 1);
-			odp->d_type = type;
-			dirent_terminate(odp);
-			odp = (dirent64_t *)((intptr_t)odp + reclen);
-		}
 		outcount += reclen;
 
 		ASSERT3S(outcount, <=, bufsize);
@@ -1893,7 +1858,6 @@ zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
 			dmu_prefetch(os, objnum, 0, 0, 0,
 			    ZIO_PRIORITY_SYNC_READ);
 
-	skip_entry:
 		/*
 		 * Move to the next entry, fill in the previous offset.
 		 */