[PATCH v6 13/16] btrfs: add do_remap param to btrfs_discard_extent()

[Mark Harmstone <mark@harmstone.com>]

btrfs_discard_extent() can be called either when an extent is removed
or from walking the free-space tree. With a remapped block group these
two things are no longer equivalent: the extent's addresses are
remapped, while the free-space tree exclusively uses underlying
addresses.

Add a do_remap parameter to btrfs_discard_extent() and
btrfs_map_discard(), saying whether or not the address needs to be run
through the remap tree first.

Signed-off-by: Mark Harmstone <mark@harmstone.com>
Reviewed-by: Boris Burkov <boris@bur.io>
---
 fs/btrfs/extent-tree.c      | 11 +++++++----
 fs/btrfs/extent-tree.h      |  2 +-
 fs/btrfs/free-space-cache.c |  2 +-
 fs/btrfs/inode.c            |  2 +-
 fs/btrfs/volumes.c          | 23 +++++++++++++++++++++--
 fs/btrfs/volumes.h          |  2 +-
 6 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index ab20f7fed4cf..91b4e1b0842c 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1381,7 +1381,7 @@ static int do_discard_extent(struct btrfs_discard_stripe *stripe, u64 *bytes)
 }
 
 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
-			 u64 num_bytes, u64 *actual_bytes)
+			 u64 num_bytes, u64 *actual_bytes, bool do_remap)
 {
 	int ret = 0;
 	u64 discarded_bytes = 0;
@@ -1399,7 +1399,8 @@ int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
 		int i;
 
 		num_bytes = end - cur;
-		stripes = btrfs_map_discard(fs_info, cur, &num_bytes, &num_stripes);
+		stripes = btrfs_map_discard(fs_info, cur, &num_bytes,
+					    &num_stripes, do_remap);
 		if (IS_ERR(stripes)) {
 			ret = PTR_ERR(stripes);
 			if (ret == -EOPNOTSUPP)
@@ -2912,7 +2913,8 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
 
 		if (btrfs_test_opt(fs_info, DISCARD_SYNC))
 			ret = btrfs_discard_extent(fs_info, start,
-						   end + 1 - start, NULL);
+						   end + 1 - start, NULL,
+						   true);
 
 		next_state = btrfs_next_extent_state(unpin, cached_state);
 		btrfs_clear_extent_dirty(unpin, start, end, &cached_state);
@@ -2970,7 +2972,8 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
 		ret = -EROFS;
 		if (!TRANS_ABORTED(trans))
 			ret = btrfs_discard_extent(fs_info, block_group->start,
-						   block_group->length, NULL);
+						   block_group->length, NULL,
+						   true);
 
 		/*
 		 * Not strictly necessary to lock, as the block_group should be
diff --git a/fs/btrfs/extent-tree.h b/fs/btrfs/extent-tree.h
index a15a9497c9f3..0700cb8de3f3 100644
--- a/fs/btrfs/extent-tree.h
+++ b/fs/btrfs/extent-tree.h
@@ -161,7 +161,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 			struct extent_buffer *parent);
 void btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end);
 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
-			 u64 num_bytes, u64 *actual_bytes);
+			 u64 num_bytes, u64 *actual_bytes, bool do_remap);
 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
 void btrfs_handle_fully_remapped_bgs(struct btrfs_fs_info *fs_info);
 
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 05ce6b5a898f..30507fa8ad80 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -3677,7 +3677,7 @@ static int do_trimming(struct btrfs_block_group *block_group,
 	}
 	spin_unlock(&space_info->lock);
 
-	ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
+	ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed, false);
 	if (!ret) {
 		*total_trimmed += trimmed;
 		trim_state = BTRFS_TRIM_STATE_TRIMMED;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1a0c380ef464..0d0b36891bc7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3306,7 +3306,7 @@ int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent)
 				btrfs_discard_extent(fs_info,
 						ordered_extent->disk_bytenr,
 						ordered_extent->disk_num_bytes,
-						NULL);
+						NULL, true);
 			btrfs_free_reserved_extent(fs_info,
 					ordered_extent->disk_bytenr,
 					ordered_extent->disk_num_bytes, true);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 58ce94e99f7d..80749c8ef8b2 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3429,7 +3429,7 @@ static int btrfs_relocate_chunk_finish(struct btrfs_fs_info *fs_info,
 	 */
 	if (btrfs_is_zoned(fs_info)) {
 		ret = btrfs_discard_extent(fs_info, block_group->start, length,
-					   NULL);
+					   NULL, true);
 		if (ret)
 			btrfs_info(fs_info,
 				   "failed to reset zone %llu after relocation",
@@ -6114,7 +6114,7 @@ void btrfs_put_bioc(struct btrfs_io_context *bioc)
  */
 struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
 					       u64 logical, u64 *length_ret,
-					       u32 *num_stripes)
+					       u32 *num_stripes, bool do_remap)
 {
 	struct btrfs_chunk_map *map;
 	struct btrfs_discard_stripe *stripes;
@@ -6138,6 +6138,25 @@ struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
 	if (IS_ERR(map))
 		return ERR_CAST(map);
 
+	if (do_remap && map->type & BTRFS_BLOCK_GROUP_REMAPPED) {
+		u64 new_logical = logical;
+
+		ret = btrfs_translate_remap(fs_info, &new_logical, &length);
+		if (ret)
+			goto out_free_map;
+
+		if (new_logical != logical) {
+			btrfs_free_chunk_map(map);
+
+			map = btrfs_get_chunk_map(fs_info, new_logical,
+						  length);
+			if (IS_ERR(map))
+				return ERR_CAST(map);
+
+			logical = new_logical;
+		}
+	}
+
 	/* we don't discard raid56 yet */
 	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 		ret = -EOPNOTSUPP;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index ccf0a459180d..505a50689fb0 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -732,7 +732,7 @@ int btrfs_map_repair_block(struct btrfs_fs_info *fs_info,
 			   u32 length, int mirror_num);
 struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
 					       u64 logical, u64 *length_ret,
-					       u32 *num_stripes);
+					       u32 *num_stripes, bool do_remap);
 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
 struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
-- 
2.51.0