Check the dataset type more rigorously when fetching properties.

When fetching property values of snapshots, a check against the head
dataset type must be performed.  Previously, this additional check was
performed only when fetching "version", "normalize", "utf8only" or "case".

This caused the ZPL properties "acltype", "exec", "devices", "nbmand",
"setuid" and "xattr" to be erroneously displayed with meaningless values
for snapshots of volumes.  It also did not allow for the display of
"volsize" of a snapshot of a volume.

This patch adds the headcheck flag paramater to zfs_prop_valid_for_type()
and zprop_valid_for_type() to indicate the check is being done
against a head dataset's type in order that properties valid only for
snapshots are handled correctly.  This allows the the head check in
get_numeric_property() to be performed when fetching a property for
a snapshot.

Signed-off-by: Tim Chase <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2265

3 files changed, 16 insertions, 8 deletions

diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 316927c0a..5e43aab2b 100644
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -948,7 +948,7 @@ zfs_valid_proplist(libzfs_handle_t *hdl, zfs_type_t type, nvlist_t *nvl,
 			goto error;
 		}
 
-		if (!zfs_prop_valid_for_type(prop, type)) {
+		if (!zfs_prop_valid_for_type(prop, type, B_FALSE)) {
 			zfs_error_aux(hdl,
 			    dgettext(TEXT_DOMAIN, "'%s' does not "
 			    "apply to datasets of this type"), propname);
@@ -1610,7 +1610,7 @@ zfs_prop_inherit(zfs_handle_t *zhp, const char *propname, boolean_t received)
 	/*
 	 * Check to see if the value applies to this type
 	 */
-	if (!zfs_prop_valid_for_type(prop, zhp->zfs_type))
+	if (!zfs_prop_valid_for_type(prop, zhp->zfs_type, B_FALSE))
 		return (zfs_error(hdl, EZFS_PROPTYPE, errbuf));
 
 	/*
@@ -1760,6 +1760,14 @@ get_numeric_property(zfs_handle_t *zhp, zfs_prop_t prop, zprop_source_t *src,
 
 	*source = NULL;
 
+	/*
+	 * If the property is being fetched for a snapshot, check whether
+	 * the property is valid for the snapshot's head dataset type.
+	 */
+	if (zhp->zfs_type == ZFS_TYPE_SNAPSHOT &&
+		!zfs_prop_valid_for_type(prop, zhp->zfs_head_type, B_TRUE))
+			return (-1);
+
 	switch (prop) {
 	case ZFS_PROP_ATIME:
 		mntopt_on = MNTOPT_ATIME;
@@ -1880,8 +1888,7 @@ get_numeric_property(zfs_handle_t *zhp, zfs_prop_t prop, zprop_source_t *src,
 	case ZFS_PROP_NORMALIZE:
 	case ZFS_PROP_UTF8ONLY:
 	case ZFS_PROP_CASE:
-		if (!zfs_prop_valid_for_type(prop, zhp->zfs_head_type) ||
-		    zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
+		if (zcmd_alloc_dst_nvlist(zhp->zfs_hdl, &zc, 0) != 0)
 			return (-1);
 		(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
 		if (zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_OBJSET_ZPLPROPS, &zc)) {
@@ -2124,7 +2131,7 @@ zfs_prop_get(zfs_handle_t *zhp, zfs_prop_t prop, char *propbuf, size_t proplen,
 	/*
 	 * Check to see if this property applies to our object
 	 */
-	if (!zfs_prop_valid_for_type(prop, zhp->zfs_type))
+	if (!zfs_prop_valid_for_type(prop, zhp->zfs_type, B_FALSE))
 		return (-1);
 
 	if (received && zfs_prop_readonly(prop))
@@ -2445,7 +2452,7 @@ zfs_prop_get_numeric(zfs_handle_t *zhp, zfs_prop_t prop, uint64_t *value,
 	/*
 	 * Check to see if this property applies to our object
 	 */
-	if (!zfs_prop_valid_for_type(prop, zhp->zfs_type)) {
+	if (!zfs_prop_valid_for_type(prop, zhp->zfs_type, B_FALSE)) {
 		return (zfs_error_fmt(zhp->zfs_hdl, EZFS_PROPTYPE,
 		    dgettext(TEXT_DOMAIN, "cannot get property '%s'"),
 		    zfs_prop_to_name(prop)));
diff --git a/lib/libzfs/libzfs_mount.c b/lib/libzfs/libzfs_mount.c
index 83396c402..ac3b68226 100644
--- a/lib/libzfs/libzfs_mount.c
+++ b/lib/libzfs/libzfs_mount.c
@@ -231,7 +231,8 @@ zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
 	char sourceloc[ZFS_MAXNAMELEN];
 	zprop_source_t sourcetype;
 
-	if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type))
+	if (!zfs_prop_valid_for_type(ZFS_PROP_MOUNTPOINT, zhp->zfs_type,
+	    B_FALSE))
 		return (B_FALSE);
 
 	verify(zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, buf, buflen,
diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index e99603b49..d029b61e7 100644
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -1531,7 +1531,7 @@ addlist(libzfs_handle_t *hdl, char *propname, zprop_list_t **listp,
 
 	prop = zprop_name_to_prop(propname, type);
 
-	if (prop != ZPROP_INVAL && !zprop_valid_for_type(prop, type))
+	if (prop != ZPROP_INVAL && !zprop_valid_for_type(prop, type, B_FALSE))
 		prop = ZPROP_INVAL;
 
 	/*