4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Josef Bacik josef@toxicpanda.com
commit 58bfe2ccec5f9f137b41dd38f335290dcc13cd5c upstream.
A user reported some issues with smaller file systems that get very full. While investigating this issue I noticed that df wasn't showing 100% full, despite having 0 chunk space and having < 1MiB of available metadata space.
This turns out to be an overflow issue, we're doing:
total_available_metadata_space - SZ_4M < global_block_rsv_size
to determine if there's not enough space to make metadata allocations, which overflows if total_available_metadata_space is < 4M. Fix this by checking to see if our available space is greater than the 4M threshold. This makes df properly report 100% usage on the file system.
CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Josef Bacik josef@toxicpanda.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/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2196,7 +2196,7 @@ static int btrfs_statfs(struct dentry *d * calculated f_bavail. */ if (!mixed && block_rsv->space_info->full && - total_free_meta - thresh < block_rsv->size) + (total_free_meta < thresh || total_free_meta - thresh < block_rsv->size)) buf->f_bavail = 0;
buf->f_type = BTRFS_SUPER_MAGIC;