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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 | |
parent | e49d033bddf5b565044e2abe4241353959bc9120 (diff) | |
download | lwn-2361db89aaadfb671db6911b0063e01ec8922c28.tar.gz lwn-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')
-rw-r--r-- | drivers/nvdimm/bus.c | 14 | ||||
-rw-r--r-- | drivers/nvdimm/pmem.c | 37 | ||||
-rw-r--r-- | drivers/nvdimm/region_devs.c | 7 |
3 files changed, 46 insertions, 12 deletions
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..7daac795db39 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -26,6 +26,7 @@ #include <linux/mm.h> #include <asm/cacheflush.h> #include "pmem.h" +#include "btt.h" #include "pfn.h" #include "nd.h" @@ -585,7 +586,7 @@ static void nd_pmem_shutdown(struct device *dev) nvdimm_flush(to_nd_region(dev->parent), NULL); } -static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) +static void pmem_revalidate_poison(struct device *dev) { struct nd_region *nd_region; resource_size_t offset = 0, end_trunc = 0; @@ -595,9 +596,6 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) struct range range; struct kernfs_node *bb_state; - if (event != NVDIMM_REVALIDATE_POISON) - return; - if (is_nd_btt(dev)) { struct nd_btt *nd_btt = to_nd_btt(dev); @@ -635,6 +633,37 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) sysfs_notify_dirent(bb_state); } +static void pmem_revalidate_region(struct device *dev) +{ + struct pmem_device *pmem; + + if (is_nd_btt(dev)) { + struct nd_btt *nd_btt = to_nd_btt(dev); + struct btt *btt = nd_btt->btt; + + nvdimm_check_and_set_ro(btt->btt_disk); + return; + } + + pmem = dev_get_drvdata(dev); + nvdimm_check_and_set_ro(pmem->disk); +} + +static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) +{ + switch (event) { + case NVDIMM_REVALIDATE_POISON: + pmem_revalidate_poison(dev); + break; + case NVDIMM_REVALIDATE_REGION: + pmem_revalidate_region(dev); + break; + default: + dev_WARN_ONCE(dev, 1, "notify: unknown event: %d\n", event); + break; + } +} + MODULE_ALIAS("pmem"); MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO); MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM); 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); |