jbd2: don't clear and reset errors after waiting on writeback

Resetting this flag is almost certainly racy, and will be problematic
with some coming changes.

Make filemap_fdatawait_keep_errors return int, but not clear the flag(s).
Have jbd2 call it instead of filemap_fdatawait and don't attempt to
re-set the error flag if it fails.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>

1 files changed, 4 insertions, 12 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index b6b194ec1b4f..3c1c31321d9b 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -263,18 +263,10 @@ static int journal_finish_inode_data_buffers(journal_t *journal,
 			continue;
 		jinode->i_flags |= JI_COMMIT_RUNNING;
 		spin_unlock(&journal->j_list_lock);
-		err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
-		if (err) {
-			/*
-			 * Because AS_EIO is cleared by
-			 * filemap_fdatawait_range(), set it again so
-			 * that user process can get -EIO from fsync().
-			 */
-			mapping_set_error(jinode->i_vfs_inode->i_mapping, -EIO);
-
-			if (!ret)
-				ret = err;
-		}
+		err = filemap_fdatawait_keep_errors(
+				jinode->i_vfs_inode->i_mapping);
+		if (!ret)
+			ret = err;
 		spin_lock(&journal->j_list_lock);
 		jinode->i_flags &= ~JI_COMMIT_RUNNING;
 		smp_mb();