On Thu, May 16, 2019 at 11:58 AM Mike Snitzer snitzer@redhat.com wrote:
On Tue, May 14 2019 at 11:48pm -0400, Dan Williams dan.j.williams@intel.com wrote:
Pankaj reports that starting with commit ad428cdb525a "dax: Check the end of the block-device capacity with dax_direct_access()" device-mapper no longer allows dax operation. This results from the stricter checks in __bdev_dax_supported() that validate that the start and end of a block-device map to the same 'pagemap' instance.
Teach the dax-core and device-mapper to validate the 'pagemap' on a per-target basis. This is accomplished by refactoring the bdev_dax_supported() internals into generic_fsdax_supported() which takes a sector range to validate. Consequently generic_fsdax_supported() is suitable to be used in a device-mapper ->iterate_devices() callback. A new ->dax_supported() operation is added to allow composite devices to split and route upper-level bdev_dax_supported() requests.
Fixes: ad428cdb525a ("dax: Check the end of the block-device...") Cc: stable@vger.kernel.org Cc: Jan Kara jack@suse.cz Cc: Ira Weiny ira.weiny@intel.com Cc: Dave Jiang dave.jiang@intel.com Cc: Mike Snitzer snitzer@redhat.com Cc: Keith Busch keith.busch@intel.com Cc: Matthew Wilcox willy@infradead.org Cc: Vishal Verma vishal.l.verma@intel.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: Martin Schwidefsky schwidefsky@de.ibm.com Reported-by: Pankaj Gupta pagupta@redhat.com Signed-off-by: Dan Williams dan.j.williams@intel.com
Hi Mike,
Another day another new dax operation to allow device-mapper to better scope dax operations.
Let me know if the device-mapper changes look sane. This passes a new unit test that indeed fails on current mainline.
https://github.com/pmem/ndctl/blob/device-mapper-pending/test/dm.sh
drivers/dax/super.c | 88 +++++++++++++++++++++++++++--------------- drivers/md/dm-table.c | 17 +++++--- drivers/md/dm.c | 20 ++++++++++ drivers/md/dm.h | 1 drivers/nvdimm/pmem.c | 1 drivers/s390/block/dcssblk.c | 1 include/linux/dax.h | 19 +++++++++ 7 files changed, 110 insertions(+), 37 deletions(-)
...
diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 2d539b82ec08..e5e240bfa2d0 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -78,6 +78,7 @@ void dm_unlock_md_type(struct mapped_device *md); void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type); enum dm_queue_mode dm_get_md_type(struct mapped_device *md); struct target_type *dm_get_immutable_target_type(struct mapped_device *md); +bool dm_table_supports_dax(struct dm_table *t, int blocksize);
int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
I'd prefer to have dm_table_supports_dax come just after dm_table_get_md_mempools in the preceding dm_table section of dm.h (just above this mapped_device section you extended).
But other than that nit, patch looks great on a DM level:
Reviewed-by: Mike Snitzer snitzer@redhat.com
Thanks Mike, I folded in this change:
@@ -72,13 +72,13 @@ bool dm_table_bio_based(struct dm_table *t); bool dm_table_request_based(struct dm_table *t); void dm_table_free_md_mempools(struct dm_table *t); struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); +bool dm_table_supports_dax(struct dm_table *t, int blocksize);
void dm_lock_md_type(struct mapped_device *md); void dm_unlock_md_type(struct mapped_device *md); void dm_set_md_type(struct mapped_device *md, enum dm_queue_mode type); enum dm_queue_mode dm_get_md_type(struct mapped_device *md); struct target_type *dm_get_immutable_target_type(struct mapped_device *md); -bool dm_table_supports_dax(struct dm_table *t, int blocksize);
int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);