Commit 829ddec9 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: only clear EXTENT_LOCK bit in extent_invalidatepage 



extent_invalidatepage() will try to clear all possible bits since it's
calling clear_extent_bit() with delete == 1.

This is currently fine, since for btree io tree, it only utilizes
EXTENT_LOCK bit.  But this could be a problem for later subpage support,
which will utilize extra io tree bit to represent additional info.

This patch will just convert that clear_extent_bit() to
unlock_extent_cached().

For current code since only EXTENT_LOCKED bit is utilized, this doesn't
change the behavior, but provides a much cleaner basis for incoming
subpage support.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 8e1dc982

fs/btrfs/extent_io.c

+10 −2
Original line number Diff line number Diff line
@@ -4431,14 +4431,22 @@ int extent_invalidatepage(struct extent_io_tree *tree, 
	u64 end = start + PAGE_SIZE - 1;

	size_t blocksize = page->mapping->host->i_sb->s_blocksize;



	/* This function is only called for the btree inode */

	ASSERT(tree->owner == IO_TREE_BTREE_INODE_IO);



	start += ALIGN(offset, blocksize);

	if (start > end)

		return 0;



	lock_extent_bits(tree, start, end, &cached_state);

	wait_on_page_writeback(page);

	clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DELALLOC |

			 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state);



	/*

	 * Currently for btree io tree, only EXTENT_LOCKED is utilized,

	 * so here we only need to unlock the extent range to free any

	 * existing extent state.

	 */

	unlock_extent_cached(tree, start, end, &cached_state);

	return 0;

}