zfs_create: round up volume size to multiple of bs

Round up the volume size requested in `zfs create -V size` to the next
higher multiple of the volblocksize. Updates the man page and adds a
test to verify the new behavior.

Reviewed-by: Brian Behlendorf <[email protected]>
Reported-by: puffi <[email protected]>
Signed-off-by: Alex John <[email protected]>
Closes #8541 
Closes #10196 

1 files changed, 25 insertions, 0 deletions

diff --git a/cmd/zfs/zfs_main.c b/cmd/zfs/zfs_main.c
index 15e350313..27f34b9fd 100644
--- a/cmd/zfs/zfs_main.c
+++ b/cmd/zfs/zfs_main.c
@@ -1038,6 +1038,31 @@ zfs_do_create(int argc, char **argv)
 		}
 	}
 
+	/*
+	 * if volsize is not a multiple of volblocksize, round it up to the
+	 * nearest multiple of the volblocksize
+	 */
+	if (type == ZFS_TYPE_VOLUME) {
+		uint64_t volblocksize;
+
+		if (nvlist_lookup_uint64(props,
+		    zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE),
+		    &volblocksize) != 0)
+			volblocksize = ZVOL_DEFAULT_BLOCKSIZE;
+
+		if (volsize % volblocksize) {
+			volsize = P2ROUNDUP_TYPED(volsize, volblocksize,
+			    uint64_t);
+
+			if (nvlist_add_uint64(props,
+			    zfs_prop_to_name(ZFS_PROP_VOLSIZE), volsize) != 0) {
+				nvlist_free(props);
+				nomem();
+			}
+		}
+	}
+
+
 	if (type == ZFS_TYPE_VOLUME && !noreserve) {
 		uint64_t spa_version;
 		zfs_prop_t resv_prop;