a98f1946ea
commit 254a4cd50b9fe2291a12b8902e08e56dcc4e9b10 upstream.
The pmem driver does not honor a forced read-only setting for very long:
$ blockdev --setro /dev/pmem0
$ blockdev --getro /dev/pmem0
1
followed by various commands like these:
$ blockdev --rereadpt /dev/pmem0
or
$ mkfs.ext4 /dev/pmem0
results in this in the kernel serial log:
nd_pmem namespace0.0: region0 read-write, marking pmem0 read-write
with the read-only setting lost:
$ blockdev --getro /dev/pmem0
0
That's from bus.c nvdimm_revalidate_disk(), which always applies the
setting from nd_region (which is initially based on the ACPI NFIT
NVDIMM state flags not_armed bit).
In contrast, commit 20bd1d026aac ("scsi: sd: Keep disk read-only when
re-reading partition") fixed this issue for SCSI devices to preserve
the previous setting if it was set to read-only.
This patch modifies bus.c to preserve any previous read-only setting.
It also eliminates the kernel serial log print except for cases where
read-write is changed to read-only, so it doesn't print read-only to
read-only non-changes.
Cc: <stable@vger.kernel.org>
Fixes: 581388209405 ("libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only")
Signed-off-by: Robert Elliott <elliott@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.