Commit 23c6bf6a authored Jan 11, 2014 by Filipe David Borba Manana Committed by Chris Mason Jan 29, 2014

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>

parent 49fc647a

fs/btrfs/ctree.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -3142,7 +3142,9 @@ again:
		if (ret < 0)
		return ret;
		if (!ret) {
		p->slots[0] = btrfs_header_nritems(leaf) - 1;
		leaf = p->nodes[0];
		if (p->slots[0] == btrfs_header_nritems(leaf))
		p->slots[0]--;
		return 0;
		}
		if (!return_any)

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