From cb44921a09221f0a90217b44044448f63190f3e5 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Sun, 24 Oct 2010 11:01:27 -0400 Subject: [PATCH] Btrfs: don't loop forever on bad btree blocks When btrfs discovers the generation number in a btree block is incorrect, it can loop forever without forcing the RAID code to try a valid mirror, and without returning EIO. This changes things to properly kick out the EIO. Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index c3df14ce2cc2..6921231e0efb 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1577,13 +1577,33 @@ read_block_for_search(struct btrfs_trans_handle *trans, blocksize = btrfs_level_size(root, level - 1); tmp = btrfs_find_tree_block(root, blocknr, blocksize); - if (tmp && btrfs_buffer_uptodate(tmp, gen)) { - /* - * we found an up to date block without sleeping, return - * right away - */ - *eb_ret = tmp; - return 0; + if (tmp) { + if (btrfs_buffer_uptodate(tmp, 0)) { + if (btrfs_buffer_uptodate(tmp, gen)) { + /* + * we found an up to date block without + * sleeping, return + * right away + */ + *eb_ret = tmp; + return 0; + } + /* the pages were up to date, but we failed + * the generation number check. Do a full + * read for the generation number that is correct. + * We must do this without dropping locks so + * we can trust our generation number + */ + free_extent_buffer(tmp); + tmp = read_tree_block(root, blocknr, blocksize, gen); + if (tmp && btrfs_buffer_uptodate(tmp, gen)) { + *eb_ret = tmp; + return 0; + } + free_extent_buffer(tmp); + btrfs_release_path(NULL, p); + return -EIO; + } } /* @@ -1596,8 +1616,7 @@ read_block_for_search(struct btrfs_trans_handle *trans, btrfs_unlock_up_safe(p, level + 1); btrfs_set_path_blocking(p); - if (tmp) - free_extent_buffer(tmp); + free_extent_buffer(tmp); if (p->reada) reada_for_search(root, p, level, slot, key->objectid);