For the incoming subpage support, UNMAPPED extent buffer will have different behavior in btrfs_release_extent_buffer().
This means we need to set UNMAPPED bit early before calling btrfs_release_extent_buffer(). Currently there is only one caller which relies on btrfs_release_extent_buffer() in its error path while set UNMAPPED bit late: - btrfs_clone_extent_buffer() Make it subpage compatible by setting the UNMAPPED bit early, since we're here, also move the UPTODATE bit early. There is another caller, __alloc_dummy_extent_buffer(), setting UNAMPPED bit late, but that function clean up the allocated page manually, thus no need for any modification. Signed-off-by: Qu Wenruo <[email protected]> --- fs/btrfs/extent_io.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 6cd81c6e8996..a56391839aca 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5062,6 +5062,13 @@ struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src) if (new == NULL) return NULL; + /* + * Set UNMAPPED bfore calling btrfs_release_extent_buffer(), as + * btrfs_release_extent_buffer() have different behavior for + * UNMAPPED subpage extent buffer. + */ + set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags); + for (i = 0; i < num_pages; i++) { p = alloc_page(GFP_NOFS); if (!p) { @@ -5074,9 +5081,7 @@ struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src) new->pages[i] = p; copy_page(page_address(p), page_address(src->pages[i])); } - set_bit(EXTENT_BUFFER_UPTODATE, &new->bflags); - set_bit(EXTENT_BUFFER_UNMAPPED, &new->bflags); return new; } -- 2.30.0