From 6c9caa4dd60b94e95ac3c8e3e1bcec228fc0b435 Mon Sep 17 00:00:00 2001 From: Filipe David Borba Manana Date: Wed, 7 May 2014 13:09:14 +0100 Subject: [PATCH] btrfs-progs: check, fix csum check in the presence of non-inlined refs When we have non-inlined extent references, we were failing to find the corresponding extent item for an existing csum item in the csum tree. Reproducer: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt xfs_io -f -c "falloc 780366 135302" /mnt/foo xfs_io -c "falloc 327680 151552" /mnt/foo xfs_io -c "pwrite -S 0xff -b 131072 0 131072" /mnt/foo sync for i in `seq 1 40`; do btrfs subvolume snapshot /mnt /mnt/snap$i ; done umount /mnt btrfs check /dev/sdd The check command exited with status 1 and the following output: Checking filesystem on /dev/sdd UUID: 2416ab5f-9d71-457e-bb13-a27d4f6b399a checking extents checking free space cache checking fs roots checking csums There are no extents for csum range 12980224-12984320 Csum exists for 12980224-12984320 but there is no extent record found 1388544 bytes used err is 1 total csum bytes: 132 total tree bytes: 704512 total fs tree bytes: 573440 total extent tree bytes: 16384 btree space waste bytes: 564479 file data blocks allocated: 19341312 referenced 14606336 Btrfs v3.14.1-94-g80597e7 After this change it no longer erroneously reports a missing extent for the csum item and exits with a status of 0. Also added missing btrfs_prev_leaf() return value checks, as we were ignoring errors and non-existence of left siblings completely. Signed-off-by: Filipe David Borba Manana Signed-off-by: David Sterba --- cmds-check.c | 38 +++++++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 11 deletions(-) diff --git a/cmds-check.c b/cmds-check.c index 64934a9..86ba1dd 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -3792,8 +3792,7 @@ static int check_extent_exists(struct btrfs_root *root, u64 bytenr, key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; - key.offset = 0; - + key.offset = (u64)-1; again: ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, @@ -3803,10 +3802,17 @@ again: btrfs_free_path(path); return ret; } else if (ret) { - if (path->slots[0]) + if (path->slots[0] > 0) { path->slots[0]--; - else - btrfs_prev_leaf(root, path); + } else { + ret = btrfs_prev_leaf(root, path); + if (ret < 0) { + goto out; + } else if (ret > 0) { + ret = 0; + goto out; + } + } } btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); @@ -3816,13 +3822,22 @@ again: * bytenr, so walk back one more just in case. Dear future traveler, * first congrats on mastering time travel. Now if it's not too much * trouble could you go back to 2006 and tell Chris to make the - * BLOCK_GROUP_ITEM_KEY lower than the EXTENT_ITEM_KEY please? + * BLOCK_GROUP_ITEM_KEY (and BTRFS_*_REF_KEY) lower than the + * EXTENT_ITEM_KEY please? */ - if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { - if (path->slots[0]) + while (key.type > BTRFS_EXTENT_ITEM_KEY) { + if (path->slots[0] > 0) { path->slots[0]--; - else - btrfs_prev_leaf(root, path); + } else { + ret = btrfs_prev_leaf(root, path); + if (ret < 0) { + goto out; + } else if (ret > 0) { + ret = 0; + goto out; + } + } + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); } while (num_bytes) { @@ -3894,7 +3909,8 @@ again: } ret = 0; - if (num_bytes) { +out: + if (num_bytes && !ret) { fprintf(stderr, "There are no extents for csum range " "%Lu-%Lu\n", bytenr, bytenr+num_bytes); ret = 1; -- 2.7.4