[PATCH] libnvdimm: Let revalidate_disk() revalidate region read-only
From: Dan Williams <hidden>
Date: 2021-03-09 06:58:27
Also in:
lkml, nvdimm
Subsystem:
libnvdimm btt: block translation table, libnvdimm pmem: persistent memory driver, libnvdimm: non-volatile memory device subsystem, the rest · Maintainers:
Vishal Verma, Dan Williams, Dave Jiang, Alison Schofield, Linus Torvalds
Previous kernels allowed the BLKROSET to override the disk's read-only
status. With that situation fixed the pmem driver needs to rely on
revalidate_disk() to clear 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")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <redacted>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Reported-by: kernel test robot <redacted>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <redacted>
---
drivers/nvdimm/btt.c | 7 +++++++
drivers/nvdimm/bus.c | 14 ++++++--------
drivers/nvdimm/pmem.c | 7 +++++++
3 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 41aa1f01fc07..73d3bf5aa208 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c@@ -1508,11 +1508,18 @@ static int btt_getgeo(struct block_device *bd, struct hd_geometry *geo) return 0; } +static int btt_revalidate(struct gendisk *disk) +{ + nvdimm_check_and_set_ro(disk); + return 0; +} + static const struct block_device_operations btt_fops = { .owner = THIS_MODULE, .submit_bio = btt_submit_bio, .rw_page = btt_rw_page, .getgeo = btt_getgeo, + .revalidate_disk = btt_revalidate, }; static int btt_blk_init(struct btt *btt)
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 48f0985ca8a0..3a777d0073b7 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c@@ -631,16 +631,14 @@ void nvdimm_check_and_set_ro(struct gendisk *disk) struct nd_region *nd_region = to_nd_region(dev->parent); int disk_ro = get_disk_ro(disk); - /* - * Upgrade to read-only if the region is read-only preserve as - * read-only if the disk is already read-only. - */ - if (disk_ro || nd_region->ro == disk_ro) + /* catch the disk up with the region ro state */ + if (disk_ro == nd_region->ro) return; - dev_info(dev, "%s read-only, marking %s read-only\n", - dev_name(&nd_region->dev), disk->disk_name); - set_disk_ro(disk, 1); + dev_info(dev, "%s read-%s, marking %s read-%s\n", + dev_name(&nd_region->dev), nd_region->ro ? "only" : "write", + disk->disk_name, nd_region->ro ? "only" : "write"); + set_disk_ro(disk, nd_region->ro); } EXPORT_SYMBOL(nvdimm_check_and_set_ro);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index b8a85bfb2e95..af204fce1b1c 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c@@ -276,10 +276,17 @@ __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff, return PHYS_PFN(pmem->size - pmem->pfn_pad - offset); } +static int pmem_revalidate(struct gendisk *disk) +{ + nvdimm_check_and_set_ro(disk); + return 0; +} + static const struct block_device_operations pmem_fops = { .owner = THIS_MODULE, .submit_bio = pmem_submit_bio, .rw_page = pmem_rw_page, + .revalidate_disk = pmem_revalidate, }; static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,