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, 9 insertions, 8 deletions

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index e9f3b3e4bbf4..6833ada237ab 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -222,7 +222,8 @@ __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
 {
 	struct resource *res;
-	phys_addr_t phys;
+	/* gcc-4.6.3-nolibc for i386 complains that this is uninitialized */
+	phys_addr_t uninitialized_var(phys);
 	int i;
 
 	for (i = 0; i < dev_dax->num_resources; i++) {
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 557b93703532..3ec804672601 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -92,21 +92,21 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
 	long len;
 
 	if (blocksize != PAGE_SIZE) {
-		pr_err("VFS (%s): error: unsupported blocksize for dax\n",
+		pr_debug("VFS (%s): error: unsupported blocksize for dax\n",
 				sb->s_id);
 		return -EINVAL;
 	}
 
 	err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff);
 	if (err) {
-		pr_err("VFS (%s): error: unaligned partition for dax\n",
+		pr_debug("VFS (%s): error: unaligned partition for dax\n",
 				sb->s_id);
 		return err;
 	}
 
 	dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
 	if (!dax_dev) {
-		pr_err("VFS (%s): error: device does not support dax\n",
+		pr_debug("VFS (%s): error: device does not support dax\n",
 				sb->s_id);
 		return -EOPNOTSUPP;
 	}
@@ -118,7 +118,7 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
 	put_dax(dax_dev);
 
 	if (len < 1) {
-		pr_err("VFS (%s): error: dax access failed (%ld)",
+		pr_debug("VFS (%s): error: dax access failed (%ld)\n",
 				sb->s_id, len);
 		return len < 0 ? len : -EIO;
 	}
@@ -273,9 +273,6 @@ EXPORT_SYMBOL_GPL(dax_copy_from_iter);
 void arch_wb_cache_pmem(void *addr, size_t size);
 void dax_flush(struct dax_device *dax_dev, void *addr, size_t size)
 {
-	if (unlikely(!dax_alive(dax_dev)))
-		return;
-
 	if (unlikely(!test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags)))
 		return;
 
@@ -344,6 +341,9 @@ static struct inode *dax_alloc_inode(struct super_block *sb)
 	struct inode *inode;
 
 	dax_dev = kmem_cache_alloc(dax_cache, GFP_KERNEL);
+	if (!dax_dev)
+		return NULL;
+
 	inode = &dax_dev->inode;
 	inode->i_rdev = 0;
 	return inode;