From: Minchan Kim <minc...@kernel.org> commit 8b7b2eb131d3476062ffd34358785b44be25172f upstream.
The swap address_space doesn't have host. Thus, it makes kernel crash once swap write meets error. Fix it. Fixes: 735e4ae5ba28 ("vfs: track per-sb writeback errors and report them to syncfs") Signed-off-by: Minchan Kim <minc...@kernel.org> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Acked-by: Jeff Layton <jlay...@kernel.org> Cc: Jan Kara <j...@suse.cz> Cc: Andres Freund <and...@anarazel.de> Cc: Matthew Wilcox <wi...@infradead.org> Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: Christoph Hellwig <h...@infradead.org> Cc: Dave Chinner <da...@fromorbit.com> Cc: David Howells <dhowe...@redhat.com> Cc: <sta...@vger.kernel.org> Link: https://lkml.kernel.org/r/20201010000650.750063-1-minc...@kernel.org Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- include/linux/pagemap.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -54,7 +54,8 @@ static inline void mapping_set_error(str __filemap_set_wb_err(mapping, error); /* Record it in superblock */ - errseq_set(&mapping->host->i_sb->s_wb_err, error); + if (mapping->host) + errseq_set(&mapping->host->i_sb->s_wb_err, error); /* Record it in flags for now, for legacy callers */ if (error == -ENOSPC)