Merge tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm and dax updates from Dan Williams:
 "Save for a few late fixes, all of these commits have shipped in -next
  releases since before the merge window opened, and 0day has given a
  build success notification.

  The ext4 touches came from Jan, and the xfs touches have Darrick's
  reviewed-by. An xfstest for the MAP_SYNC feature has been through
  a few round of reviews and is on track to be merged.

   - Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
     'userspace flush' of persistent memory updates via filesystem-dax
     mappings. It arranges for any filesystem metadata updates that may
     be required to satisfy a write fault to also be flushed ("on disk")
     before the kernel returns to userspace from the fault handler.
     Effectively every write-fault that dirties metadata completes an
     fsync() before returning from the fault handler. The new
     MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag
     is validated as supported by the filesystem's ->mmap() file
     operation.

   - Add support for the standard ACPI 6.2 label access methods that
     replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods.
     This enables interoperability with environments that only implement
     the standardized methods.

   - Add support for the ACPI 6.2 NVDIMM media error injection methods.

   - Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for
     latch last shutdown status, firmware update, SMART error injection,
     and SMART alarm threshold control.

   - Cleanup physical address information disclosures to be root-only.

   - Fix revalidation of the DIMM "locked label area" status to support
     dynamic unlock of the label area.

   - Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
     (system-physical-address) command and error injection commands.

  Acknowledgements that came after the commits were pushed to -next:

   - 957ac8c421ad ("dax: fix PMD faults on zero-length files"):
       Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>

   - a39e596baa07 ("xfs: support for synchronous DAX faults") and
     7b565c9f965b ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()")
        Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>"

* tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits)
  acpi, nfit: add 'Enable Latch System Shutdown Status' command support
  dax: fix general protection fault in dax_alloc_inode
  dax: fix PMD faults on zero-length files
  dax: stop requiring a live device for dax_flush()
  brd: remove dax support
  dax: quiet bdev_dax_supported()
  fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core
  tools/testing/nvdimm: unit test clear-error commands
  acpi, nfit: validate commands against the device type
  tools/testing/nvdimm: stricter bounds checking for error injection commands
  xfs: support for synchronous DAX faults
  xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
  ext4: Support for synchronous DAX faults
  ext4: Simplify error handling in ext4_dax_huge_fault()
  dax: Implement dax_finish_sync_fault()
  dax, iomap: Add support for synchronous faults
  mm: Define MAP_SYNC and VM_SYNC flags
  dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
  dax: Allow dax_iomap_fault() to return pfn
  dax: Fix comment describing dax_iomap_fault()
  ...

2 files changed, 0 insertions, 77 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 923b417eaf4c..40579d0cb3d1 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -302,7 +302,6 @@ config BLK_DEV_SX8
 
 config BLK_DEV_RAM
 	tristate "RAM block device support"
-	select DAX if BLK_DEV_RAM_DAX
 	---help---
 	  Saying Y here will allow you to use a portion of your RAM memory as
 	  a block device, so that you can make file systems on it, read and
@@ -338,17 +337,6 @@ config BLK_DEV_RAM_SIZE
 	  The default value is 4096 kilobytes. Only change this if you know
 	  what you are doing.
 
-config BLK_DEV_RAM_DAX
-	bool "Support Direct Access (DAX) to RAM block devices"
-	depends on BLK_DEV_RAM && FS_DAX
-	default n
-	help
-	  Support filesystems using DAX to access RAM block devices.  This
-	  avoids double-buffering data in the page cache before copying it
-	  to the block device.  Answering Y will slightly enlarge the kernel,
-	  and will prevent RAM block device backing store memory from being
-	  allocated from highmem (only a problem for highmem systems).
-
 config CDROM_PKTCDVD
 	tristate "Packet writing on CD/DVD media (DEPRECATED)"
 	depends on !UML
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 588360d79fca..8028a3a7e7fd 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -21,11 +21,6 @@
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/backing-dev.h>
-#ifdef CONFIG_BLK_DEV_RAM_DAX
-#include <linux/pfn_t.h>
-#include <linux/dax.h>
-#include <linux/uio.h>
-#endif
 
 #include <linux/uaccess.h>
 
@@ -45,9 +40,6 @@ struct brd_device {
 
 	struct request_queue	*brd_queue;
 	struct gendisk		*brd_disk;
-#ifdef CONFIG_BLK_DEV_RAM_DAX
-	struct dax_device	*dax_dev;
-#endif
 	struct list_head	brd_list;
 
 	/*
@@ -112,9 +104,6 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector)
 	 * restriction might be able to be lifted.
 	 */
 	gfp_flags = GFP_NOIO | __GFP_ZERO;
-#ifndef CONFIG_BLK_DEV_RAM_DAX
-	gfp_flags |= __GFP_HIGHMEM;
-#endif
 	page = alloc_page(gfp_flags);
 	if (!page)
 		return NULL;
@@ -334,43 +323,6 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector,
 	return err;
 }
 
-#ifdef CONFIG_BLK_DEV_RAM_DAX
-static long __brd_direct_access(struct brd_device *brd, pgoff_t pgoff,
-		long nr_pages, void **kaddr, pfn_t *pfn)
-{
-	struct page *page;
-
-	if (!brd)
-		return -ENODEV;
-	page = brd_insert_page(brd, (sector_t)pgoff << PAGE_SECTORS_SHIFT);
-	if (!page)
-		return -ENOSPC;
-	*kaddr = page_address(page);
-	*pfn = page_to_pfn_t(page);
-
-	return 1;
-}
-
-static long brd_dax_direct_access(struct dax_device *dax_dev,
-		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
-{
-	struct brd_device *brd = dax_get_private(dax_dev);
-
-	return __brd_direct_access(brd, pgoff, nr_pages, kaddr, pfn);
-}
-
-static size_t brd_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
-{
-	return copy_from_iter(addr, bytes, i);
-}
-
-static const struct dax_operations brd_dax_ops = {
-	.direct_access = brd_dax_direct_access,
-	.copy_from_iter = brd_dax_copy_from_iter,
-};
-#endif
-
 static const struct block_device_operations brd_fops = {
 	.owner =		THIS_MODULE,
 	.rw_page =		brd_rw_page,
@@ -451,21 +403,8 @@ static struct brd_device *brd_alloc(int i)
 	set_capacity(disk, rd_size * 2);
 	disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
 
-#ifdef CONFIG_BLK_DEV_RAM_DAX
-	queue_flag_set_unlocked(QUEUE_FLAG_DAX, brd->brd_queue);
-	brd->dax_dev = alloc_dax(brd, disk->disk_name, &brd_dax_ops);
-	if (!brd->dax_dev)
-		goto out_free_inode;
-#endif
-
-
 	return brd;
 
-#ifdef CONFIG_BLK_DEV_RAM_DAX
-out_free_inode:
-	kill_dax(brd->dax_dev);
-	put_dax(brd->dax_dev);
-#endif
 out_free_queue:
 	blk_cleanup_queue(brd->brd_queue);
 out_free_dev:
@@ -505,10 +444,6 @@ out:
 static void brd_del_one(struct brd_device *brd)
 {
 	list_del(&brd->brd_list);
-#ifdef CONFIG_BLK_DEV_RAM_DAX
-	kill_dax(brd->dax_dev);
-	put_dax(brd->dax_dev);
-#endif
 	del_gendisk(brd->brd_disk);
 	brd_free(brd);
 }