While pidfs dentries are never hashed and thus retain_dentry() will never
consider them for placing them on the LRU it isn't great to always have
to go and remember that. Raise DCACHE_DONTCACHE explicitly as a visual
marker that dentries aren't kept but freed immediately instead.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 fs/pidfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/pidfs.c b/fs/pidfs.c
index 0ef5b47d796a..db236427fc2c 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c

@@ -1022,6 +1022,7 @@ static int pidfs_init_fs_context(struct fs_context *fc)
 
 	fc->s_iflags |= SB_I_NOEXEC;
 	fc->s_iflags |= SB_I_NODEV;
+	ctx->s_d_flags |= DCACHE_DONTCACHE;
 	ctx->ops = &pidfs_sops;
 	ctx->eops = &pidfs_export_operations;
 	ctx->dops = &pidfs_dentry_operations;

-- 
2.47.3