From 73a894e51e5bcea9fddc4f3ded37d0ad81456e92 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 10 Sep 2015 16:36:04 +0200 Subject: [PATCH] btrfs-progs: fix cross stripe boundary check MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 854437ca3c228d8ab3eb24d2efc1c21b5d56a635 ("btrfs-progs: extent-tree: avoid allocating tree block that crosses stripe boundary") does not work for 64k nodesize. Due to an off-by-one error, all queries to check_crossing_stripes will return that all extents cross a stripe and this will lead to a false ENOSPC. This crashes later $ ./mkfs.btrfs -n 64k image ./mkfs.btrfs(btrfs_reserve_extent+0xb77)[0x417f38] ./mkfs.btrfs(btrfs_alloc_free_block+0x57)[0x417fe0] ./mkfs.btrfs(__btrfs_cow_block+0x163)[0x408eb7] ./mkfs.btrfs(btrfs_cow_block+0xd0)[0x4097c4] ./mkfs.btrfs(btrfs_search_slot+0x16f)[0x40be4d] ./mkfs.btrfs(btrfs_insert_empty_items+0xc0)[0x40d5f9] ./mkfs.btrfs(btrfs_insert_item+0x99)[0x40da5f] ./mkfs.btrfs(btrfs_make_block_group+0x4d)[0x41705c] ./mkfs.btrfs(main+0xeef)[0x434b56] Holger Hoffstätte reports that this also fixes false positives in case the nodesize is less than 64k. This happens when the node blocks end at the stripe boundary. Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- volumes.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/volumes.h b/volumes.h index f776131..4ecb993 100644 --- a/volumes.h +++ b/volumes.h @@ -156,7 +156,7 @@ struct map_lookup { static inline int check_crossing_stripes(u64 start, u64 len) { return (start / BTRFS_STRIPE_LEN) != - ((start + len) / BTRFS_STRIPE_LEN); + ((start + len - 1) / BTRFS_STRIPE_LEN); } int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw, -- 2.7.4