Remove code for zfs remap

The "zfs remap" command was disabled by
6e91a72fe3ff8bb282490773bd687632f3e8c79d, because it has little utility
and introduced some tricky bugs.  This commit removes the code for it,
the associated ZFS_IOC_REMAP ioctl, and tests.

Note that the ioctl and property will remain, but have no functionality.
This allows older software to fail gracefully if it attempts to use
these, and avoids a backwards incompatibility that would be introduced if
we renumbered the later ioctls/props.

Reviewed-by: Tom Caputi <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Matthew Ahrens <[email protected]>
Closes #8944 

1 files changed, 0 insertions, 54 deletions

diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
index 8afc3df37..abfae29ad 100644
--- a/module/zfs/dbuf.c
+++ b/module/zfs/dbuf.c
@@ -4445,60 +4445,6 @@ dbuf_remap_impl(dnode_t *dn, blkptr_t *bp, dmu_tx_t *tx)
 }
 
 /*
- * Returns true if a dbuf_remap would modify the dbuf. We do this by attempting
- * to remap a copy of every bp in the dbuf.
- */
-boolean_t
-dbuf_can_remap(const dmu_buf_impl_t *db)
-{
-	spa_t *spa = dmu_objset_spa(db->db_objset);
-	blkptr_t *bp = db->db.db_data;
-	boolean_t ret = B_FALSE;
-
-	ASSERT3U(db->db_level, >, 0);
-	ASSERT3S(db->db_state, ==, DB_CACHED);
-
-	ASSERT(spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL));
-
-	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
-	for (int i = 0; i < db->db.db_size >> SPA_BLKPTRSHIFT; i++) {
-		blkptr_t bp_copy = bp[i];
-		if (spa_remap_blkptr(spa, &bp_copy, NULL, NULL)) {
-			ret = B_TRUE;
-			break;
-		}
-	}
-	spa_config_exit(spa, SCL_VDEV, FTAG);
-
-	return (ret);
-}
-
-boolean_t
-dnode_needs_remap(const dnode_t *dn)
-{
-	spa_t *spa = dmu_objset_spa(dn->dn_objset);
-	boolean_t ret = B_FALSE;
-
-	if (dn->dn_phys->dn_nlevels == 0) {
-		return (B_FALSE);
-	}
-
-	ASSERT(spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL));
-
-	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
-	for (int j = 0; j < dn->dn_phys->dn_nblkptr; j++) {
-		blkptr_t bp_copy = dn->dn_phys->dn_blkptr[j];
-		if (spa_remap_blkptr(spa, &bp_copy, NULL, NULL)) {
-			ret = B_TRUE;
-			break;
-		}
-	}
-	spa_config_exit(spa, SCL_VDEV, FTAG);
-
-	return (ret);
-}
-
-/*
  * Remap any existing BP's to concrete vdevs, if possible.
  */
 static void