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| author | Dan Williams <dan.j.williams@intel.com> | 2021-03-09 17:43:38 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2021-04-08 22:18:36 -0700 |
| commit | 2361db89aaadfb671db6911b0063e01ec8922c28 (patch) | |
| tree | 52602a2ca144d07620370d0f3fd4672a91702c13 /drivers/nvdimm/region_devs.c | |
| parent | e49d033bddf5b565044e2abe4241353959bc9120 (diff) | |
| download | linux-stable-2361db89aaadfb671db6911b0063e01ec8922c28.tar.gz linux-stable-2361db89aaadfb671db6911b0063e01ec8922c28.tar.bz2 linux-stable-2361db89aaadfb671db6911b0063e01ec8922c28.zip | |
libnvdimm: Notify disk drivers to revalidate region read-only
Previous kernels allowed the BLKROSET to override the disk's read-only
status. With that situation fixed the pmem driver needs to rely on
notification events to reevaluate the disk read-only status after the
host region has been marked read-write.
Recall that when libnvdimm determines that the persistent memory has
lost persistence (for example lack of energy to flush from DRAM to FLASH
on an NVDIMM-N device) it marks the region read-only, but that state can
be overridden by the user via:
echo 0 > /sys/bus/nd/devices/regionX/read_only
...to date there is no notification that the region has restored
persistence, so the user override is the only recovery.
Fixes: 52f019d43c22 ("block: add a hard-readonly flag to struct gendisk")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/161534060720.528671.2341213328968989192.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/region_devs.c')
| -rw-r--r-- | drivers/nvdimm/region_devs.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index ef23119db574..51870eb51da6 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -518,6 +518,12 @@ static ssize_t read_only_show(struct device *dev, return sprintf(buf, "%d\n", nd_region->ro); } +static int revalidate_read_only(struct device *dev, void *data) +{ + nd_device_notify(dev, NVDIMM_REVALIDATE_REGION); + return 0; +} + static ssize_t read_only_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { @@ -529,6 +535,7 @@ static ssize_t read_only_store(struct device *dev, return rc; nd_region->ro = ro; + device_for_each_child(dev, NULL, revalidate_read_only); return len; } static DEVICE_ATTR_RW(read_only); |