From: Filipe David Borba Manana Date: Sat, 11 Jan 2014 21:28:54 +0000 (+0000) Subject: Btrfs: fix btrfs_search_slot_for_read backwards iteration X-Git-Tag: Ubuntu-5.2.0-15.16~14079^2~3 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=23c6bf6a91e96c17a452e07b12b38ed66504e799;p=mirror_ubuntu-eoan-kernel.git 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 Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 30f5b11d7dd3..cbd3a7d6fa68 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -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)