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authorDan Williams <dan.j.williams@intel.com>2021-03-10 04:43:38 +0300
committerDan Williams <dan.j.williams@intel.com>2021-04-09 08:18:36 +0300
commit2361db89aaadfb671db6911b0063e01ec8922c28 (patch)
tree52602a2ca144d07620370d0f3fd4672a91702c13 /drivers/nvdimm/region_devs.c
parente49d033bddf5b565044e2abe4241353959bc9120 (diff)
downloadlinux-2361db89aaadfb671db6911b0063e01ec8922c28.tar.xz
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.c7
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);