parallel lookups: actual switch to rwsem

ta-da!

The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.

lockdep side also might need more work

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 6ec1e43a9a54..da186ee4f846 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -218,7 +218,9 @@ static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
         cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
         old_cred = override_creds(override_cred);
 
-        err = mutex_lock_killable(&dir->d_inode->i_mutex);
+        inode_lock(dir->d_inode);
+        err = 0;
+        // XXX: err = mutex_lock_killable(&dir->d_inode->i_mutex);
         if (!err) {
                 while (rdd->first_maybe_whiteout) {
                         p = rdd->first_maybe_whiteout;