linux/drivers/cxl
Dan Williams 5877515912 cxl/mem: Fix synchronization mechanism for device removal vs ioctl operations
The percpu_ref to gate whether cxl_memdev_ioctl() is free to use the
driver context (@cxlm) to issue I/O is overkill, implemented incorrectly
(missing a device reference before accessing the percpu_ref), and the
complexities of shutting down a percpu_ref contributed to a bug in the
error unwind in cxl_mem_add_memdev() (missing put_device() to be fixed
separately).

Use an rwsem to explicitly synchronize the usage of cxlmd->cxlm, and add
the missing reference counting for cxlmd in cxl_memdev_open() and
cxl_memdev_release_file().

Fixes: b39cb1052a ("cxl/mem: Register CXL memX devices")
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/161728759948.2474381.17481500816783671817.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-04-06 11:41:30 -07:00
..
bus.c cxl/mem: Register CXL memX devices 2021-02-16 20:36:38 -08:00
cxl.h cxl/mem: Enable commands via CEL 2021-02-16 20:36:38 -08:00
Kconfig cxl/mem: Add a "RAW" send command 2021-02-16 20:36:38 -08:00
Makefile cxl/mem: Register CXL memX devices 2021-02-16 20:36:38 -08:00
mem.c cxl/mem: Fix synchronization mechanism for device removal vs ioctl operations 2021-04-06 11:41:30 -07:00
pci.h