Merge tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has appeared in -next and independently received a
  build success notification from the kbuild robot.  The 'for-4.5/block-
  dax' topic branch was rebased over the weekend to drop the "block
  device end-of-life" rework that Al would like to see re-implemented
  with a notifier, and to address bug reports against the badblocks
  integration.

  There is pending feedback against "libnvdimm: Add a poison list and
  export badblocks" received last week.  Linda identified some localized
  fixups that we will handle incrementally.

  Summary:

   - Media error handling: The 'badblocks' implementation that
     originated in md-raid is up-levelled to a generic capability of a
     block device.  This initial implementation is limited to being
     consulted in the pmem block-i/o path.  Later, 'badblocks' will be
     consulted when creating dax mappings.

   - Raw block device dax: For virtualization and other cases that want
     large contiguous mappings of persistent memory, add the capability
     to dax-mmap a block device directly.

   - Increased /dev/mem restrictions: Add an option to treat all
     io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access
     while a driver is actively using an address range.  This behavior
     is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be
     overridden by the existing "iomem=relaxed" kernel command line
     option.

   - Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
     block device shutdown crash fix, and other small libnvdimm fixes"

* tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits)
  block: kill disk_{check|set|clear|alloc}_badblocks
  libnvdimm, pmem: nvdimm_read_bytes() badblocks support
  pmem, dax: disable dax in the presence of bad blocks
  pmem: fail io-requests to known bad blocks
  libnvdimm: convert to statically allocated badblocks
  libnvdimm: don't fail init for full badblocks list
  block, badblocks: introduce devm_init_badblocks
  block: clarify badblocks lifetime
  badblocks: rename badblocks_free to badblocks_exit
  libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h
  libnvdimm: Add a poison list and export badblocks
  nfit_test: Enable DSMs for all test NFITs
  md: convert to use the generic badblocks code
  block: Add badblock management for gendisks
  badblocks: Add core badblock management code
  block: fix del_gendisk() vs blkdev_ioctl crash
  block: enable dax for raw block devices
  block: introduce bdev_file_inode()
  restrict /dev/mem to idle io memory ranges
  arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug
  ...

1 files changed, 107 insertions, 15 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 01b8e0d4b4ff..d878e4860fb7 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -156,11 +156,16 @@ blkdev_get_block(struct inode *inode, sector_t iblock,
         return 0;
 }
 
+static struct inode *bdev_file_inode(struct file *file)
+{
+        return file->f_mapping->host;
+}
+
 static ssize_t
 blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
-        struct inode *inode = file->f_mapping->host;
+        struct inode *inode = bdev_file_inode(file);
 
         if (IS_DAX(inode))
                 return dax_do_io(iocb, inode, iter, offset, blkdev_get_block,
@@ -338,7 +343,7 @@ static int blkdev_write_end(struct file *file, struct address_space *mapping,
  */
 static loff_t block_llseek(struct file *file, loff_t offset, int whence)
 {
-        struct inode *bd_inode = file->f_mapping->host;
+        struct inode *bd_inode = bdev_file_inode(file);
         loff_t retval;
 
         mutex_lock(&bd_inode->i_mutex);
@@ -349,7 +354,7 @@ static loff_t block_llseek(struct file *file, loff_t offset, int whence)
         
 int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 {
-        struct inode *bd_inode = filp->f_mapping->host;
+        struct inode *bd_inode = bdev_file_inode(filp);
         struct block_device *bdev = I_BDEV(bd_inode);
         int error;
         
@@ -1224,8 +1229,11 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
                                 }
                         }
 
-                        if (!ret)
+                        if (!ret) {
                                 bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
+                                if (!blkdev_dax_capable(bdev))
+                                        bdev->bd_inode->i_flags &= ~S_DAX;
+                        }
 
                         /*
                          * If the device is invalidated, rescan partition
@@ -1239,6 +1247,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
                                 else if (ret == -ENOMEDIUM)
                                         invalidate_partitions(disk, bdev);
                         }
+
                         if (ret)
                                 goto out_clear;
                 } else {
@@ -1259,12 +1268,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
                                 goto out_clear;
                         }
                         bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
-                        /*
-                         * If the partition is not aligned on a page
-                         * boundary, we can't do dax I/O to it.
-                         */
-                        if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512)) ||
-                            (bdev->bd_part->nr_sects % (PAGE_SIZE / 512)))
+                        if (!blkdev_dax_capable(bdev))
                                 bdev->bd_inode->i_flags &= ~S_DAX;
                 }
         } else {
@@ -1599,14 +1603,14 @@ EXPORT_SYMBOL(blkdev_put);
 
 static int blkdev_close(struct inode * inode, struct file * filp)
 {
-        struct block_device *bdev = I_BDEV(filp->f_mapping->host);
+        struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
         blkdev_put(bdev, filp->f_mode);
         return 0;
 }
 
 static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
-        struct block_device *bdev = I_BDEV(file->f_mapping->host);
+        struct block_device *bdev = I_BDEV(bdev_file_inode(file));
         fmode_t mode = file->f_mode;
 
         /*
@@ -1631,7 +1635,7 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
         struct file *file = iocb->ki_filp;
-        struct inode *bd_inode = file->f_mapping->host;
+        struct inode *bd_inode = bdev_file_inode(file);
         loff_t size = i_size_read(bd_inode);
         struct blk_plug plug;
         ssize_t ret;
@@ -1663,7 +1667,7 @@ EXPORT_SYMBOL_GPL(blkdev_write_iter);
 ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
         struct file *file = iocb->ki_filp;
-        struct inode *bd_inode = file->f_mapping->host;
+        struct inode *bd_inode = bdev_file_inode(file);
         loff_t size = i_size_read(bd_inode);
         loff_t pos = iocb->ki_pos;
 
@@ -1702,13 +1706,101 @@ static const struct address_space_operations def_blk_aops = {
         .is_dirty_writeback = buffer_check_dirty_writeback,
 };
 
+#ifdef CONFIG_FS_DAX
+/*
+ * In the raw block case we do not need to contend with truncation nor
+ * unwritten file extents.  Without those concerns there is no need for
+ * additional locking beyond the mmap_sem context that these routines
+ * are already executing under.
+ *
+ * Note, there is no protection if the block device is dynamically
+ * resized (partition grow/shrink) during a fault. A stable block device
+ * size is already not enforced in the blkdev_direct_IO path.
+ *
+ * For DAX, it is the responsibility of the block device driver to
+ * ensure the whole-disk device size is stable while requests are in
+ * flight.
+ *
+ * Finally, unlike the filemap_page_mkwrite() case there is no
+ * filesystem superblock to sync against freezing.  We still include a
+ * pfn_mkwrite callback for dax drivers to receive write fault
+ * notifications.
+ */
+static int blkdev_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        return __dax_fault(vma, vmf, blkdev_get_block, NULL);
+}
+
+static int blkdev_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
+                pmd_t *pmd, unsigned int flags)
+{
+        return __dax_pmd_fault(vma, addr, pmd, flags, blkdev_get_block, NULL);
+}
+
+static void blkdev_vm_open(struct vm_area_struct *vma)
+{
+        struct inode *bd_inode = bdev_file_inode(vma->vm_file);
+        struct block_device *bdev = I_BDEV(bd_inode);
+
+        mutex_lock(&bd_inode->i_mutex);
+        bdev->bd_map_count++;
+        mutex_unlock(&bd_inode->i_mutex);
+}
+
+static void blkdev_vm_close(struct vm_area_struct *vma)
+{
+        struct inode *bd_inode = bdev_file_inode(vma->vm_file);
+        struct block_device *bdev = I_BDEV(bd_inode);
+
+        mutex_lock(&bd_inode->i_mutex);
+        bdev->bd_map_count--;
+        mutex_unlock(&bd_inode->i_mutex);
+}
+
+static const struct vm_operations_struct blkdev_dax_vm_ops = {
+        .open           = blkdev_vm_open,
+        .close          = blkdev_vm_close,
+        .fault          = blkdev_dax_fault,
+        .pmd_fault      = blkdev_dax_pmd_fault,
+        .pfn_mkwrite    = blkdev_dax_fault,
+};
+
+static const struct vm_operations_struct blkdev_default_vm_ops = {
+        .open           = blkdev_vm_open,
+        .close          = blkdev_vm_close,
+        .fault          = filemap_fault,
+        .map_pages      = filemap_map_pages,
+};
+
+static int blkdev_mmap(struct file *file, struct vm_area_struct *vma)
+{
+        struct inode *bd_inode = bdev_file_inode(file);
+        struct block_device *bdev = I_BDEV(bd_inode);
+
+        file_accessed(file);
+        mutex_lock(&bd_inode->i_mutex);
+        bdev->bd_map_count++;
+        if (IS_DAX(bd_inode)) {
+                vma->vm_ops = &blkdev_dax_vm_ops;
+                vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
+        } else {
+                vma->vm_ops = &blkdev_default_vm_ops;
+        }
+        mutex_unlock(&bd_inode->i_mutex);
+
+        return 0;
+}
+#else
+#define blkdev_mmap generic_file_mmap
+#endif
+
 const struct file_operations def_blk_fops = {
         .open           = blkdev_open,
         .release        = blkdev_close,
         .llseek         = block_llseek,
         .read_iter      = blkdev_read_iter,
         .write_iter     = blkdev_write_iter,
-        .mmap           = generic_file_mmap,
+        .mmap           = blkdev_mmap,
         .fsync          = blkdev_fsync,
         .unlocked_ioctl = block_ioctl,
 #ifdef CONFIG_COMPAT