@@ -7001,10 +7001,15 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
copy_size = min_t(u64, PAGE_SIZE,
btrfs_file_extent_ram_bytes(leaf, item));
- em->start = extent_start;
- em->len = ALIGN(copy_size, fs_info->sectorsize);
- em->orig_block_len = em->len;
- em->orig_start = em->start;
+
+ /*
+ * btrfs_extent_item_to_extent_map() should have properly
+ * initialized em members already.
+ *
+ * Other members are not utilized for inline extents.
+ */
+ ASSERT(em->block_start == EXTENT_MAP_INLINE);
+ ASSERT(em->len = fs_info->sectorsize);
if (!PageUptodate(page)) {
if (btrfs_file_extent_compression(leaf, item) !=
Currently for inline extents read inside btrfs_get_extent(), we will reset several extent map members: - em->start Reset to extent_start, which is completely unnecessary. The extent_start and em->start should have already be zero, ensured by tree-checker already. - em->len Reset the round_up(copy_size, fs_info->sectorsize), which is again unnecessary. - em->orig_block_len Reset to em->len (sectorsize), while it is originally unset from btrfs_extent_item_to_extent_map(). This makes no difference, as all extent map handling paths will ignore the orig_block_len if they found it's an inlined extent. Such inline extent orig_block_len ignoring examples can be found in btrfs_drop_extent_cache(). - em->orig_start Reset to em->start (0), while it is originally set to EXTENT_MAP_HOLE. This makes no difference either, as all extent map handling paths will ignore the em->orig_start if they found it's an inline extent. Thus all these em members resetting are unnecessary. Replace them with ASSERT()s checking the only two members (block_start and length) that make sense. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/inode.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)