Commit dc56219f authored Apr 08, 2021 by Goldwyn Rodrigues Committed by David Sterba Jun 21, 2021

btrfs: correct try_lock_extent() usage in read_extent_buffer_subpage()



try_lock_extent() returns 1 on success or 0 for failure and not an error
code. If try_lock_extent() fails, read_extent_buffer_subpage() returns
zero indicating subpage extent read success.

Return EAGAIN/EWOULDBLOCK if try_lock_extent() fails in locking the
extent.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 13311e74

fs/btrfs/extent_io.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -6184,10 +6184,8 @@ static int read_extent_buffer_subpage(struct extent_buffer *eb, int wait,
		io_tree = &BTRFS_I(fs_info->btree_inode)->io_tree;

		if (wait == WAIT_NONE) {
		ret = try_lock_extent(io_tree, eb->start,
		eb->start + eb->len - 1);
		if (ret <= 0)
		return ret;
		if (!try_lock_extent(io_tree, eb->start, eb->start + eb->len - 1))
		return -EAGAIN;
		} else {
		ret = lock_extent(io_tree, eb->start, eb->start + eb->len - 1);
		if (ret < 0)