libzfs: Fail making a dataset handle gracefully

When a dataset is in the process of being received it gets marked as
inconsistent and should not be used.  We should check for this when
opening a dataset handle in libzfs and return with an appropriate error
set, rather than hitting an abort because of the incomplete data.

zfs_open() passes errno to zfs_standard_error() after observing
make_dataset_handle() fail, which ends up aborting if errno is 0.
Set errno before returning where we know it has not been set already.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <freqlabs@FreeBSD.org>
Closes #13077

diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 6b9f43285c8904b7d2f27063a6af5d3bec582ffd..ba120c244926c3c07a33edb2946721f1b164293e 100644 (file)
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -449,14 +449,19 @@ make_dataset_handle_common(zfs_handle_t *zhp, zfs_cmd_t *zc)
         * We've managed to open the dataset and gather statistics.  Determine
         * the high-level type.
         */
-       if (zhp->zfs_dmustats.dds_type == DMU_OST_ZVOL)
+       if (zhp->zfs_dmustats.dds_type == DMU_OST_ZVOL) {
                zhp->zfs_head_type = ZFS_TYPE_VOLUME;
-       else if (zhp->zfs_dmustats.dds_type == DMU_OST_ZFS)
+       } else if (zhp->zfs_dmustats.dds_type == DMU_OST_ZFS) {
                zhp->zfs_head_type = ZFS_TYPE_FILESYSTEM;
-       else if (zhp->zfs_dmustats.dds_type == DMU_OST_OTHER)
+       } else if (zhp->zfs_dmustats.dds_type == DMU_OST_OTHER) {
+               errno = EINVAL;
                return (-1);
-       else
+       } else if (zhp->zfs_dmustats.dds_inconsistent) {
+               errno = EBUSY;
+               return (-1);
+       } else {
                abort();
+       }
 
        if (zhp->zfs_dmustats.dds_is_snapshot)
                zhp->zfs_type = ZFS_TYPE_SNAPSHOT;