From 536870071dbc4278264f59c9a2f5f447e584d139 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Wed, 9 Oct 2019 17:43:59 +0100 Subject: [PATCH] Btrfs: fix metadata space leak on fixup worker failure to set range as delalloc In the fixup worker, if we fail to mark the range as delalloc in the io tree, we must release the previously reserved metadata, as well as update the outstanding extents counter for the inode, otherwise we leak metadata space. In pratice we can't return an error from btrfs_set_extent_delalloc(), which is just a wrapper around __set_extent_bit(), as for most errors __set_extent_bit() does a BUG_ON() (or panics which hits a BUG_ON() as well) and returning an -EEXIST error doesn't happen in this case since the exclusive bits parameter always has a value of 0 through this code path. Nevertheless, just fix the error handling in the fixup worker, in case one day __set_extent_bit() can return an error to this code path. Fixes: f3038ee3a3f101 ("btrfs: Handle btrfs_set_extent_delalloc failure in fixup worker") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Nikolay Borisov Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/inode.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 3315a6eb09a3..b943c9770533 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2254,12 +2254,16 @@ again: mapping_set_error(page->mapping, ret); end_extent_writepage(page, ret, page_start, page_end); ClearPageChecked(page); - goto out; + goto out_reserved; } ClearPageChecked(page); set_page_dirty(page); +out_reserved: btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); + if (ret) + btrfs_delalloc_release_space(inode, data_reserved, page_start, + PAGE_SIZE, true); out: unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state); -- 2.11.0