From: Filipe Manana fdmanana@suse.com
commit 536870071dbc4278264f59c9a2f5f447e584d139 upstream.
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 nborisov@suse.com Signed-off-by: Filipe Manana fdmanana@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/inode.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2214,12 +2214,16 @@ 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);