zfs: implement vnop_create

This operation is very different from FreeBSD and Solaris because our
VFS uses create just for the actual entry creation and not for opening
the file, similar to how Linux splits the operation.  A lot of code
that is already handled in vnop_open or the VFS thus can go away.

bsd/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c

@@ -1272,36 +1272,8 @@ zfs_lookup(struct vnode *dvp, char *nm, struct vnode *vp)
 	return error;
 }
 
-#ifdef NOTYET
-/*
- * Attempt to create a new entry in a directory.  If the entry
- * already exists, truncate the file if permissible, else return
- * an error.  Return the vp of the created or trunc'd file.
- *
- *	IN:	dvp	- vnode of directory to put new file entry in.
- *		name	- name of new file entry.
- *		vap	- attributes of new file.
- *		excl	- flag indicating exclusive or non-exclusive mode.
- *		mode	- mode to open file with.
- *		cr	- credentials of caller.
- *		flag	- large file flag [UNUSED].
- *		ct	- caller context
- *		vsecp 	- ACL to be set
- *
- *	OUT:	vpp	- vnode of created or trunc'd entry.
- *
- *	RETURN:	0 if success
- *		error code if failure
- *
- * Timestamps:
- *	dvp - ctime|mtime updated if new entry created
- *	 vp - ctime|mtime always, atime if new
- */
-
-/* ARGSUSED */
 static int
-zfs_create(vnode_t *dvp, char *name, vattr_t *vap, int excl, int mode,
-    vnode_t **vpp, cred_t *cr, kthread_t *td)
+zfs_create(struct vnode *dvp, char *name, mode_t mode)
 {
 	znode_t		*zp, *dzp = VTOZ(dvp);
 	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
@@ -1318,22 +1290,15 @@ zfs_create(vnode_t *dvp, char *name, vattr_t *vap, int excl, int mode,
 	boolean_t	have_acl = B_FALSE;
 	void		*vsecp = NULL;
 	int		flag = 0;
+	cred_t		*cr = CRED();
+	uint64_t	txtype;
+	vattr_t		va = {
+		.va_mask	= AT_TYPE|AT_MODE,
+		.va_type	= VREG,
+		.va_mode	= mode,
+	}, *vap = &va;
 
-	/*
-	 * If we have an ephemeral id, ACL, or XVATTR then
-	 * make sure file system is at proper version
-	 */
-
-	ksid = crgetsid(cr, KSID_OWNER);
-	if (ksid)
-		uid = ksid_getid(ksid);
-	else
-		uid = crgetuid(cr);
-
-	if (zfsvfs->z_use_fuids == B_FALSE &&
-	    (vsecp || (vap->va_mask & AT_XVATTR) ||
-	    IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
-		return (EINVAL);
+	uid = crgetuid(cr);
 
 	ZFS_ENTER(zfsvfs);
 	ZFS_VERIFY_ZP(dzp);
@@ -1346,184 +1311,89 @@ zfs_create(vnode_t *dvp, char *name, vattr_t *vap, int excl, int mode,
 		return (EILSEQ);
 	}
 
-	if (vap->va_mask & AT_XVATTR) {
-		if ((error = secpolicy_xvattr(dvp, (xvattr_t *)vap,
-		    crgetuid(cr), cr, vap->va_type)) != 0) {
-			ZFS_EXIT(zfsvfs);
-			return (error);
-		}
-	}
 top:
-	*vpp = NULL;
-
-	if ((vap->va_mode & S_ISVTX) && secpolicy_vnode_stky_modify(cr))
-		vap->va_mode &= ~S_ISVTX;
-
-	if (*name == '\0') {
-		/*
-		 * Null component name refers to the directory itself.
-		 */
-		VN_HOLD(dvp);
-		zp = dzp;
-		dl = NULL;
-		error = 0;
-	} else {
-		/* possible VN_HOLD(zp) */
-		int zflg = 0;
-
-		if (flag & FIGNORECASE)
-			zflg |= ZCILOOK;
-
-		error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
-		    NULL, NULL);
-		if (error) {
-			if (have_acl)
-				zfs_acl_ids_free(&acl_ids);
-			if (strcmp(name, "..") == 0)
-				error = EISDIR;
-			ZFS_EXIT(zfsvfs);
-			return (error);
-		}
+	error = zfs_dirent_lock(&dl, dzp, name, &zp, 0, NULL, NULL);
+	if (error) {
+		if (have_acl)
+			zfs_acl_ids_free(&acl_ids);
+		if (strcmp(name, "..") == 0)
+			error = EISDIR;
+		ZFS_EXIT(zfsvfs);
+		return (error);
 	}
 
-	if (zp == NULL) {
-		uint64_t txtype;
-
-		/*
-		 * Create a new file object and update the directory
-		 * to reference it.
-		 */
-		if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
-			if (have_acl)
-				zfs_acl_ids_free(&acl_ids);
-			goto out;
-		}
-
-		/*
-		 * We only support the creation of regular files in
-		 * extended attribute directories.
-		 */
+	if (zp != NULL) {
+		error = EEXIST;
+		goto out;
+	}
 
-		if ((dzp->z_pflags & ZFS_XATTR) &&
-		    (vap->va_type != VREG)) {
-			if (have_acl)
-				zfs_acl_ids_free(&acl_ids);
-			error = EINVAL;
-			goto out;
-		}
+#ifdef ACL_TODO
+	/*
+	 * Create a new file object and update the directory
+	 * to reference it.
+	 */
+	if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
+		if (have_acl)
+			zfs_acl_ids_free(&acl_ids);
+		goto out;
+	}
+#endif
 
-		if (!have_acl && (error = zfs_acl_ids_create(dzp, 0, vap,
-		    cr, vsecp, &acl_ids)) != 0)
-			goto out;
-		have_acl = B_TRUE;
+	if (!have_acl && (error = zfs_acl_ids_create(dzp, 0, vap,
+	    cr, vsecp, &acl_ids)) != 0)
+		goto out;
+	have_acl = B_TRUE;
 
-		if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
-			zfs_acl_ids_free(&acl_ids);
-			error = EDQUOT;
-			goto out;
-		}
+	if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
+		zfs_acl_ids_free(&acl_ids);
+		error = EDQUOT;
+		goto out;
+	}
 
-		tx = dmu_tx_create(os);
+	tx = dmu_tx_create(os);
 
-		dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
-		    ZFS_SA_BASE_ATTR_SIZE);
+	dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
+	    ZFS_SA_BASE_ATTR_SIZE);
 
-		fuid_dirtied = zfsvfs->z_fuid_dirty;
-		if (fuid_dirtied)
-			zfs_fuid_txhold(zfsvfs, tx);
-		dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
-		dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
-		if (!zfsvfs->z_use_sa &&
-		    acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
+	fuid_dirtied = zfsvfs->z_fuid_dirty;
+	if (fuid_dirtied)
+		zfs_fuid_txhold(zfsvfs, tx);
+	dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
+	dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
+	if (!zfsvfs->z_use_sa &&
+	    acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
 			dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
-			    0, acl_ids.z_aclp->z_acl_bytes);
-		}
-		error = dmu_tx_assign(tx, TXG_NOWAIT);
-		if (error) {
-			zfs_dirent_unlock(dl);
-			if (error == ERESTART) {
-				dmu_tx_wait(tx);
-				dmu_tx_abort(tx);
-				goto top;
-			}
-			zfs_acl_ids_free(&acl_ids);
+		    0, acl_ids.z_aclp->z_acl_bytes);
+	}
+	error = dmu_tx_assign(tx, TXG_NOWAIT);
+	if (error) {
+		zfs_dirent_unlock(dl);
+		if (error == ERESTART) {
+			dmu_tx_wait(tx);
 			dmu_tx_abort(tx);
-			ZFS_EXIT(zfsvfs);
-			return (error);
+			goto top;
 		}
-		zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
-
-		if (fuid_dirtied)
-			zfs_fuid_sync(zfsvfs, tx);
-
-		(void) zfs_link_create(dl, zp, tx, ZNEW);
-		txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
-		if (flag & FIGNORECASE)
-			txtype |= TX_CI;
-		zfs_log_create(zilog, tx, txtype, dzp, zp, name,
-		    vsecp, acl_ids.z_fuidp, vap);
 		zfs_acl_ids_free(&acl_ids);
-		dmu_tx_commit(tx);
-	} else {
-		int aflags = (flag & FAPPEND) ? V_APPEND : 0;
-
-		if (have_acl)
-			zfs_acl_ids_free(&acl_ids);
-		have_acl = B_FALSE;
-
-		/*
-		 * A directory entry already exists for this name.
-		 */
-		/*
-		 * Can't truncate an existing file if in exclusive mode.
-		 */
-		if (excl == EXCL) {
-			error = EEXIST;
-			goto out;
-		}
-		/*
-		 * Can't open a directory for writing.
-		 */
-		if ((ZTOV(zp)->v_type == VDIR) && (mode & S_IWRITE)) {
-			error = EISDIR;
-			goto out;
-		}
-		/*
-		 * Verify requested access to file.
-		 */
-		if (mode && (error = zfs_zaccess_rwx(zp, mode, aflags, cr))) {
-			goto out;
-		}
+		dmu_tx_abort(tx);
+		ZFS_EXIT(zfsvfs);
+		return (error);
+	}
+	zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
 
-		mutex_enter(&dzp->z_lock);
-		dzp->z_seq++;
-		mutex_exit(&dzp->z_lock);
+	if (fuid_dirtied)
+		zfs_fuid_sync(zfsvfs, tx);
 
-		/*
-		 * Truncate regular files if requested.
-		 */
-		if ((ZTOV(zp)->v_type == VREG) &&
-		    (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) {
-			/* we can't hold any locks when calling zfs_freesp() */
-			zfs_dirent_unlock(dl);
-			dl = NULL;
-			error = zfs_freesp(zp, 0, 0, mode, TRUE);
-			if (error == 0) {
-				vnevent_create(ZTOV(zp), ct);
-			}
-		}
-	}
+	(void) zfs_link_create(dl, zp, tx, ZNEW);
+	txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
+	zfs_log_create(zilog, tx, txtype, dzp, zp, name,
+	    vsecp, acl_ids.z_fuidp, vap);
+	zfs_acl_ids_free(&acl_ids);
+	dmu_tx_commit(tx);
 out:
 	if (dl)
 		zfs_dirent_unlock(dl);
 
-	if (error) {
-		if (zp)
-			VN_RELE(ZTOV(zp));
-	} else {
-		*vpp = ZTOV(zp);
-		error = specvp_check(vpp, cr);
-	}
+	zfs_zinactive(zp);
 
 	if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
 		zil_commit(zilog, 0);
@@ -1532,6 +1402,7 @@ out:
 	return (error);
 }
 
+#ifdef NOTYET
 /*
  * Remove an entry from a directory.
  *
@@ -5848,7 +5719,7 @@ struct vnops zfs_vnops = {
 	zfs_fsync,			/* fsync */
 	zfs_readdir,			/* readdir */
 	zfs_lookup,			/* lookup */
-	NULL,				/* create */
+	zfs_create,			/* create */
 	NULL,				/* remove */
 	NULL,				/* rename */
 	NULL,				/* mkdir */