From: David Sterba Date: Fri, 7 Oct 2011 16:06:13 +0000 (+0200) Subject: btrfs: silence warning in raid array setup X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=8a3344269465b26761b74493cfbeeaa75d821614;p=openwrt%2Fstaging%2Fblogic.git btrfs: silence warning in raid array setup Raid array setup code creates an extent buffer in an usual way. When the PAGE_CACHE_SIZE is > super block size, the extent pages are not marked up-to-date, which triggers a WARN_ON in the following write_extent_buffer call. Add an explicit up-to-date call to silence the warning. Signed-off-by: David Sterba --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7ffdb154daec..d8f282b5baa9 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4357,6 +4357,20 @@ int btrfs_read_sys_array(struct btrfs_root *root) return -ENOMEM; btrfs_set_buffer_uptodate(sb); btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0); + /* + * The sb extent buffer is artifical and just used to read the system array. + * btrfs_set_buffer_uptodate() call does not properly mark all it's + * pages up-to-date when the page is larger: extent does not cover the + * whole page and consequently check_page_uptodate does not find all + * the page's extents up-to-date (the hole beyond sb), + * write_extent_buffer then triggers a WARN_ON. + * + * Regular short extents go through mark_extent_buffer_dirty/writeback cycle, + * but sb spans only this function. Add an explicit SetPageUptodate call + * to silence the warning eg. on PowerPC 64. + */ + if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE) + SetPageUptodate(sb->first_page); write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); array_size = btrfs_super_sys_array_size(super_copy);