Add pn_alloc()/pn_free() functions

In order to remove the HAVE_PN_UTILS wrappers the pn_alloc() and
pn_free() functions must be implemented.  The existing illumos
implementation were used for this purpose.

The `flags` argument which was used in places wrapped by the
HAVE_PN_UTILS condition has beed added back to zfs_remove() and
zfs_link() functions.  This removes a small point of divergence
between the ZoL code and upstream.

Signed-off-by: Brian Behlendorf <[email protected]>
Closes #4522

10 files changed, 178 insertions, 32 deletions

diff --git a/include/sys/Makefile.am b/include/sys/Makefile.am
index 73e86d03b..98d7ad6fb 100644
--- a/include/sys/Makefile.am
+++ b/include/sys/Makefile.am
@@ -38,6 +38,7 @@ COMMON_H = \
 	$(top_srcdir)/include/sys/multilist.h \
 	$(top_srcdir)/include/sys/nvpair.h \
 	$(top_srcdir)/include/sys/nvpair_impl.h \
+	$(top_srcdir)/include/sys/pathname.h \
 	$(top_srcdir)/include/sys/range_tree.h \
 	$(top_srcdir)/include/sys/refcount.h \
 	$(top_srcdir)/include/sys/rrwlock.h \
diff --git a/include/sys/pathname.h b/include/sys/pathname.h
new file mode 100644
index 000000000..5db69b178
--- /dev/null
+++ b/include/sys/pathname.h
@@ -0,0 +1,70 @@
+/*
+ * 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 http://www.opensolaris.org/os/licensing.
+ * 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 (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+/*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
+/*	  All Rights Reserved  	*/
+
+/*
+ * Portions of this source code were derived from Berkeley 4.3 BSD
+ * under license from the Regents of the University of California.
+ */
+
+#ifndef _SYS_PATHNAME_H
+#define	_SYS_PATHNAME_H
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/*
+ * Pathname structure.
+ * System calls that operate on path names gather the path name
+ * from the system call into this structure and reduce it by
+ * peeling off translated components.  If a symbolic link is
+ * encountered the new path name to be translated is also
+ * assembled in this structure.
+ *
+ * By convention pn_buf is not changed once it's been set to point
+ * to the underlying storage; routines which manipulate the pathname
+ * do so by changing pn_path and pn_pathlen.  pn_pathlen is redundant
+ * since the path name is null-terminated, but is provided to make
+ * some computations faster.
+ */
+typedef struct pathname {
+	char	*pn_buf;		/* underlying storage */
+	char	*pn_path;		/* remaining pathname */
+	size_t	pn_pathlen;		/* remaining length */
+	size_t	pn_bufsize;		/* total size of pn_buf */
+} pathname_t;
+
+extern void	pn_alloc(struct pathname *);
+extern void	pn_alloc_sz(struct pathname *, size_t);
+extern void	pn_free(struct pathname *);
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _SYS_PATHNAME_H */
diff --git a/include/sys/zfs_vnops.h b/include/sys/zfs_vnops.h
index c331035c5..157e7f9d5 100644
--- a/include/sys/zfs_vnops.h
+++ b/include/sys/zfs_vnops.h
@@ -47,7 +47,7 @@ extern int zfs_lookup(struct inode *dip, char *nm, struct inode **ipp,
     int flags, cred_t *cr, int *direntflags, pathname_t *realpnp);
 extern int zfs_create(struct inode *dip, char *name, vattr_t *vap, int excl,
     int mode, struct inode **ipp, cred_t *cr, int flag, vsecattr_t *vsecp);
-extern int zfs_remove(struct inode *dip, char *name, cred_t *cr);
+extern int zfs_remove(struct inode *dip, char *name, cred_t *cr, int flags);
 extern int zfs_mkdir(struct inode *dip, char *dirname, vattr_t *vap,
     struct inode **ipp, cred_t *cr, int flags, vsecattr_t *vsecp);
 extern int zfs_rmdir(struct inode *dip, char *name, struct inode *cwd,
@@ -64,7 +64,7 @@ extern int zfs_symlink(struct inode *dip, char *name, vattr_t *vap,
 extern int zfs_follow_link(struct dentry *dentry, struct nameidata *nd);
 extern int zfs_readlink(struct inode *ip, uio_t *uio, cred_t *cr);
 extern int zfs_link(struct inode *tdip, struct inode *sip,
-    char *name, cred_t *cr);
+    char *name, cred_t *cr, int flags);
 extern void zfs_inactive(struct inode *ip);
 extern int zfs_space(struct inode *ip, int cmd, flock64_t *bfp, int flag,
     offset_t offset, cred_t *cr);
diff --git a/lib/libzpool/Makefile.am b/lib/libzpool/Makefile.am
index f45a57d71..3e59efa5c 100644
--- a/lib/libzpool/Makefile.am
+++ b/lib/libzpool/Makefile.am
@@ -64,6 +64,7 @@ KERNEL_C = \
 	lz4.c \
 	metaslab.c \
 	multilist.c \
+	pathname.c \
 	range_tree.c \
 	refcount.c \
 	rrwlock.c \
diff --git a/module/zfs/Makefile.in b/module/zfs/Makefile.in
index d3a0206c9..f33faf157 100644
--- a/module/zfs/Makefile.in
+++ b/module/zfs/Makefile.in
@@ -42,6 +42,7 @@ $(MODULE)-objs += lzjb.o
 $(MODULE)-objs += lz4.o
 $(MODULE)-objs += metaslab.o
 $(MODULE)-objs += multilist.o
+$(MODULE)-objs += pathname.o
 $(MODULE)-objs += range_tree.o
 $(MODULE)-objs += refcount.o
 $(MODULE)-objs += rrwlock.o
diff --git a/module/zfs/pathname.c b/module/zfs/pathname.c
new file mode 100644
index 000000000..4ec132066
--- /dev/null
+++ b/module/zfs/pathname.c
@@ -0,0 +1,89 @@
+/*
+ * 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 http://www.opensolaris.org/os/licensing.
+ * 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.
+ */
+
+/*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
+/*	  All Rights Reserved  	*/
+
+/*
+ * University Copyright- Copyright (c) 1982, 1986, 1988
+ * The Regents of the University of California
+ * All Rights Reserved
+ *
+ * University Acknowledgment- Portions of this document are derived from
+ * software developed by the University of California, Berkeley, and its
+ * contributors.
+ */
+
+
+#include <sys/types.h>
+#include <sys/systm.h>
+#include <sys/pathname.h>
+#include <sys/kmem.h>
+
+/*
+ * Pathname utilities.
+ *
+ * In translating file names we copy each argument file
+ * name into a pathname structure where we operate on it.
+ * Each pathname structure can hold "pn_bufsize" characters
+ * including a terminating null, and operations here support
+ * allocating and freeing pathname structures, fetching
+ * strings from user space, getting the next character from
+ * a pathname, combining two pathnames (used in symbolic
+ * link processing), and peeling off the first component
+ * of a pathname.
+ */
+
+/*
+ * Allocate contents of pathname structure.  Structure is typically
+ * an automatic variable in calling routine for convenience.
+ *
+ * May sleep in the call to kmem_alloc() and so must not be called
+ * from interrupt level.
+ */
+void
+pn_alloc(struct pathname *pnp)
+{
+	pn_alloc_sz(pnp, MAXPATHLEN);
+}
+void
+pn_alloc_sz(struct pathname *pnp, size_t sz)
+{
+	pnp->pn_path = pnp->pn_buf = kmem_alloc(sz, KM_SLEEP);
+	pnp->pn_pathlen = 0;
+	pnp->pn_bufsize = sz;
+}
+
+/*
+ * Free pathname resources.
+ */
+void
+pn_free(struct pathname *pnp)
+{
+	/* pn_bufsize is usually MAXPATHLEN, but may not be */
+	kmem_free(pnp->pn_buf, pnp->pn_bufsize);
+	pnp->pn_path = pnp->pn_buf = NULL;
+	pnp->pn_pathlen = pnp->pn_bufsize = 0;
+}
diff --git a/module/zfs/zfs_replay.c b/module/zfs/zfs_replay.c
index 0ca1e03b5..b97a60ed8 100644
--- a/module/zfs/zfs_replay.c
+++ b/module/zfs/zfs_replay.c
@@ -548,7 +548,7 @@ zfs_replay_remove(zfs_sb_t *zsb, lr_remove_t *lr, boolean_t byteswap)
 
 	switch ((int)lr->lr_common.lrc_txtype) {
 	case TX_REMOVE:
-		error = zfs_remove(ZTOI(dzp), name, kcred);
+		error = zfs_remove(ZTOI(dzp), name, kcred, vflg);
 		break;
 	case TX_RMDIR:
 		error = zfs_rmdir(ZTOI(dzp), name, NULL, kcred, vflg);
@@ -584,7 +584,7 @@ zfs_replay_link(zfs_sb_t *zsb, lr_link_t *lr, boolean_t byteswap)
 	if (lr->lr_common.lrc_txtype & TX_CI)
 		vflg |= FIGNORECASE;
 
-	error = zfs_link(ZTOI(dzp), ZTOI(zp), name, kcred);
+	error = zfs_link(ZTOI(dzp), ZTOI(zp), name, kcred, vflg);
 
 	iput(ZTOI(zp));
 	iput(ZTOI(dzp));
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 3c3d587e8..7a8cef017 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -1512,7 +1512,7 @@ uint64_t null_xattr = 0;
 
 /*ARGSUSED*/
 int
-zfs_remove(struct inode *dip, char *name, cred_t *cr)
+zfs_remove(struct inode *dip, char *name, cred_t *cr, int flags)
 {
 	znode_t		*zp, *dzp = ITOZ(dip);
 	znode_t		*xzp;
@@ -1528,9 +1528,7 @@ zfs_remove(struct inode *dip, char *name, cred_t *cr)
 	boolean_t	unlinked, toobig = FALSE;
 	uint64_t	txtype;
 	pathname_t	*realnmp = NULL;
-#ifdef HAVE_PN_UTILS
 	pathname_t	realnm;
-#endif /* HAVE_PN_UTILS */
 	int		error;
 	int		zflg = ZEXISTS;
 	boolean_t	waited = B_FALSE;
@@ -1539,13 +1537,11 @@ zfs_remove(struct inode *dip, char *name, cred_t *cr)
 	ZFS_VERIFY_ZP(dzp);
 	zilog = zsb->z_log;
 
-#ifdef HAVE_PN_UTILS
 	if (flags & FIGNORECASE) {
 		zflg |= ZCILOOK;
 		pn_alloc(&realnm);
 		realnmp = &realnm;
 	}
-#endif /* HAVE_PN_UTILS */
 
 top:
 	xattr_obj = 0;
@@ -1555,10 +1551,8 @@ top:
 	 */
 	if ((error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
 	    NULL, realnmp))) {
-#ifdef HAVE_PN_UTILS
 		if (realnmp)
 			pn_free(realnmp);
-#endif /* HAVE_PN_UTILS */
 		ZFS_EXIT(zsb);
 		return (error);
 	}
@@ -1642,10 +1636,8 @@ top:
 			dmu_tx_abort(tx);
 			goto top;
 		}
-#ifdef HAVE_PN_UTILS
 		if (realnmp)
 			pn_free(realnmp);
-#endif /* HAVE_PN_UTILS */
 		dmu_tx_abort(tx);
 		ZFS_EXIT(zsb);
 		return (error);
@@ -1711,18 +1703,14 @@ top:
 	}
 
 	txtype = TX_REMOVE;
-#ifdef HAVE_PN_UTILS
 	if (flags & FIGNORECASE)
 		txtype |= TX_CI;
-#endif /* HAVE_PN_UTILS */
 	zfs_log_remove(zilog, tx, txtype, dzp, name, obj);
 
 	dmu_tx_commit(tx);
 out:
-#ifdef HAVE_PN_UTILS
 	if (realnmp)
 		pn_free(realnmp);
-#endif /* HAVE_PN_UTILS */
 
 	zfs_dirent_unlock(dl);
 	zfs_inode_update(dzp);
@@ -3782,7 +3770,8 @@ EXPORT_SYMBOL(zfs_readlink);
  */
 /* ARGSUSED */
 int
-zfs_link(struct inode *tdip, struct inode *sip, char *name, cred_t *cr)
+zfs_link(struct inode *tdip, struct inode *sip, char *name, cred_t *cr,
+    int flags)
 {
 	znode_t		*dzp = ITOZ(tdip);
 	znode_t		*tzp, *szp;
@@ -3840,10 +3829,8 @@ zfs_link(struct inode *tdip, struct inode *sip, char *name, cred_t *cr)
 		ZFS_EXIT(zsb);
 		return (SET_ERROR(EILSEQ));
 	}
-#ifdef HAVE_PN_UTILS
 	if (flags & FIGNORECASE)
 		zf |= ZCILOOK;
-#endif /* HAVE_PN_UTILS */
 
 	/*
 	 * We do not support links between attributes and non-attributes
@@ -3900,10 +3887,8 @@ top:
 
 	if (error == 0) {
 		uint64_t txtype = TX_LINK;
-#ifdef HAVE_PN_UTILS
 		if (flags & FIGNORECASE)
 			txtype |= TX_CI;
-#endif /* HAVE_PN_UTILS */
 		zfs_log_link(zilog, tx, txtype, dzp, szp, name);
 	}
 
diff --git a/module/zfs/zpl_inode.c b/module/zfs/zpl_inode.c
index 7cf62783f..089e3a1bc 100644
--- a/module/zfs/zpl_inode.c
+++ b/module/zfs/zpl_inode.c
@@ -59,8 +59,7 @@ zpl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 	/* If we are a case insensitive fs, we need the real name */
 	if (zsb->z_case == ZFS_CASE_INSENSITIVE) {
 		zfs_flags = FIGNORECASE;
-		pn.pn_bufsize = ZFS_MAXNAMELEN;
-		pn.pn_buf = kmem_zalloc(ZFS_MAXNAMELEN, KM_SLEEP);
+		pn_alloc(&pn);
 		ppn = &pn;
 	}
 
@@ -83,7 +82,7 @@ zpl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 		 * Fall through if the error is not ENOENT. Also free memory.
 		 */
 		if (ppn) {
-			kmem_free(pn.pn_buf, ZFS_MAXNAMELEN);
+			pn_free(ppn);
 			if (error == -ENOENT)
 				return (NULL);
 		}
@@ -105,7 +104,7 @@ zpl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
 		ci_name.name = pn.pn_buf;
 		ci_name.len = strlen(pn.pn_buf);
 		new_dentry = d_add_ci(dentry, ip, &ci_name);
-		kmem_free(pn.pn_buf, ZFS_MAXNAMELEN);
+		pn_free(ppn);
 		return (new_dentry);
 	} else {
 		return (d_splice_alias(ip, dentry));
@@ -157,7 +156,7 @@ zpl_create(struct inode *dir, struct dentry *dentry, zpl_umode_t mode,
 			error = zpl_init_acl(ip, dir);
 
 		if (error)
-			(void) zfs_remove(dir, dname(dentry), cr);
+			(void) zfs_remove(dir, dname(dentry), cr, 0);
 	}
 
 	spl_fstrans_unmark(cookie);
@@ -200,7 +199,7 @@ zpl_mknod(struct inode *dir, struct dentry *dentry, zpl_umode_t mode,
 			error = zpl_init_acl(ip, dir);
 
 		if (error)
-			(void) zfs_remove(dir, dname(dentry), cr);
+			(void) zfs_remove(dir, dname(dentry), cr, 0);
 	}
 
 	spl_fstrans_unmark(cookie);
@@ -221,7 +220,7 @@ zpl_unlink(struct inode *dir, struct dentry *dentry)
 
 	crhold(cr);
 	cookie = spl_fstrans_mark();
-	error = -zfs_remove(dir, dname(dentry), cr);
+	error = -zfs_remove(dir, dname(dentry), cr, 0);
 
 	/*
 	 * For a CI FS we must invalidate the dentry to prevent the
@@ -389,7 +388,7 @@ zpl_symlink(struct inode *dir, struct dentry *dentry, const char *name)
 
 		error = zpl_xattr_security_init(ip, dir, &dentry->d_name);
 		if (error)
-			(void) zfs_remove(dir, dname(dentry), cr);
+			(void) zfs_remove(dir, dname(dentry), cr, 0);
 	}
 
 	spl_fstrans_unmark(cookie);
@@ -537,7 +536,7 @@ zpl_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 	igrab(ip); /* Use ihold() if available */
 
 	cookie = spl_fstrans_mark();
-	error = -zfs_link(dir, ip, dname(dentry), cr);
+	error = -zfs_link(dir, ip, dname(dentry), cr, 0);
 	if (error) {
 		iput(ip);
 		goto out;
diff --git a/module/zfs/zpl_xattr.c b/module/zfs/zpl_xattr.c
index 420091953..e8623384c 100644
--- a/module/zfs/zpl_xattr.c
+++ b/module/zfs/zpl_xattr.c
@@ -465,7 +465,7 @@ zpl_xattr_set_dir(struct inode *ip, const char *name, const void *value,
 	/* Remove a specific name xattr when value is set to NULL. */
 	if (value == NULL) {
 		if (xip)
-			error = -zfs_remove(dxip, (char *)name, cr);
+			error = -zfs_remove(dxip, (char *)name, cr, 0);
 
 		goto out;
 	}