f2fs: fix cgroup writeback accounting with fs-layer encryption

commit 844545c51a5b2a524b22a2fe9d0b353b827d24b4 upstream.

When writing a page from an encrypted file that is using
filesystem-layer encryption (not inline encryption), f2fs encrypts the
pagecache page into a bounce page, then writes the bounce page.

It also passes the bounce page to wbc_account_cgroup_owner().  That's
incorrect, because the bounce page is a newly allocated temporary page
that doesn't have the memory cgroup of the original pagecache page.
This makes wbc_account_cgroup_owner() not account the I/O to the owner
of the pagecache page as it should.

Fix this by always passing the pagecache page to
wbc_account_cgroup_owner().

Fixes: f0358c725228 ("f2fs: implement cgroup writeback support")
Cc: stable@vger.kernel.org
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 773028921c481ecad24c49057de4e54da58e1501..03dffb126d5cc74df7e537030cd448b24db420b3 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -496,7 +496,7 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
        }
 
        if (fio->io_wbc && !is_read_io(fio->op))
-               wbc_account_cgroup_owner(fio->io_wbc, page, PAGE_SIZE);
+               wbc_account_cgroup_owner(fio->io_wbc, fio->page, PAGE_SIZE);
 
        bio_set_op_attrs(bio, fio->op, fio->op_flags);
 
@@ -575,7 +575,7 @@ alloc_new:
        }
 
        if (fio->io_wbc)
-               wbc_account_cgroup_owner(fio->io_wbc, page, PAGE_SIZE);
+               wbc_account_cgroup_owner(fio->io_wbc, fio->page, PAGE_SIZE);
 
        inc_page_count(fio->sbi, WB_DATA_TYPE(page));
 
@@ -652,7 +652,7 @@ alloc_new:
        }
 
        if (fio->io_wbc)
-               wbc_account_cgroup_owner(fio->io_wbc, bio_page, PAGE_SIZE);
+               wbc_account_cgroup_owner(fio->io_wbc, fio->page, PAGE_SIZE);
 
        io->last_block_in_bio = fio->new_blkaddr;
        f2fs_trace_ios(fio, 0);