MFC r329783: 8942 zfs promote .../%recv should be an error

illumos/illumos-gate@add927f8c8d101e16c23eb9cd270be4fd7edf7d5

Reported on the ZFSonLinux https://github.com/zfsonlinux/zfs/issues/4843,
fixed by https://github.com/zfsonlinux/zfs/pull/6339:

If we are in the middle of an incremental zfs receive, the child .../%recv
will exist. If you concurrently run zfs promote .../%recv, it will "work",
but then zfs gets confused. For example, there's no obvious way to destroy
the containing filesystem (because it is now a clone of its invisible child).

Attempting to do this promote should be an error. We could fix this by
having zfs_ioc_promote() check if zc_name contains a %, similar to
zfs_ioc_rename().

Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: loli10K <ezomori.nozomu@gmail.com>

2 files changed, 17 insertions, 2 deletions

diff --git a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
index 0b51e1cc..fad1c05 100644
--- a/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
+++ b/cddl/contrib/opensolaris/lib/libzfs/common/libzfs_dataset.c
@@ -3786,6 +3786,9 @@ zfs_promote(zfs_handle_t *zhp)
 		return (zfs_error(hdl, EZFS_BADTYPE, errbuf));
 	}
 
+	if (!zfs_validate_name(hdl, zhp->zfs_name, zhp->zfs_type, B_TRUE))
+		return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
+
 	ret = lzc_promote(zhp->zfs_name, snapname, sizeof (snapname));
 
 	if (ret != 0) {
@@ -4156,6 +4159,10 @@ zfs_rename(zfs_handle_t *zhp, const char *source, const char *target,
 		zhp->zfs_type = ZFS_TYPE_SNAPSHOT;
 	}
 
+	/* make sure source name is valid */
+	if (!zfs_validate_name(hdl, zhp->zfs_name, zhp->zfs_type, B_TRUE))
+		return (zfs_error(hdl, EZFS_INVALIDNAME, errbuf));
+
 	/*
 	 * Make sure the target name is valid
 	 */
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
index c7a9b91..543faa8 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c
@@ -3920,9 +3920,12 @@ zfs_ioc_rename(zfs_cmd_t *zc)
 	allow_mounted = (zc->zc_cookie & 2) != 0;
 #endif
 
+	/* "zfs rename" from and to ...%recv datasets should both fail */
+	zc->zc_name[sizeof (zc->zc_name) - 1] = '\0';
 	zc->zc_value[sizeof (zc->zc_value) - 1] = '\0';
-	if (dataset_namecheck(zc->zc_value, NULL, NULL) != 0 ||
-	    strchr(zc->zc_value, '%'))
+	if (dataset_namecheck(zc->zc_name, NULL, NULL) != 0 ||
+	    dataset_namecheck(zc->zc_value, NULL, NULL) != 0 ||
+	    strchr(zc->zc_name, '%') || strchr(zc->zc_value, '%'))
 		return (SET_ERROR(EINVAL));
 
 	at = strchr(zc->zc_name, '@');
@@ -4974,6 +4977,11 @@ zfs_ioc_promote(zfs_cmd_t *zc)
 	char *cp;
 	int error;
 
+	zc->zc_name[sizeof (zc->zc_name) - 1] = '\0';
+	if (dataset_namecheck(zc->zc_name, NULL, NULL) != 0 ||
+	    strchr(zc->zc_name, '%'))
+		return (SET_ERROR(EINVAL));
+
 	error = dsl_pool_hold(zc->zc_name, FTAG, &dp);
 	if (error != 0)
 		return (error);