In size_show(), the dax_dev_rwsem only needs a read lock, but was acquiring a write lock. Change it to down_read_interruptible() so it doesn't unnecessarily hold a write lock. Link: https://lkml.kernel.org/r/20240430-vv-dax_abi_fixes-v3-4-e3dcd755774c@intel.com Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem") Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>