tree c5955ef322a2034945408f873c0e6fa55af4e281
parent 49fc647a2c558862145357f3a25892248042f6fe
author Filipe David Borba Manana <fdmanana@gmail.com> 1389475734 +0000
committer Chris Mason <clm@fb.com> 1391007988 -0800

Btrfs: fix btrfs_search_slot_for_read backwards iteration

If the current path's leaf slot is 0, we do search for the previous
leaf (via btrfs_prev_leaf) and set the new path's leaf slot to a
value corresponding to the number of items - 1 of the former leaf.
Fix this by using the slot set by btrfs_prev_leaf, decrementing it
by 1 if it's equal to the leaf's number of items.

Use of btrfs_search_slot_for_read() for backward iteration is used in
particular by the send feature, which could miss items when the input
leaf has less items than its previous leaf.

This could be reproduced by running btrfs/007 from xfstests in a loop.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>