include/linux/dax.h

   1 #ifndef _LINUX_DAX_H
   2 #define _LINUX_DAX_H
   3
   4 #include <linux/fs.h>
   5 #include <linux/mm.h>
   6 #include <linux/radix-tree.h>
   7 #include <asm/pgtable.h>
   8
   9 /* We use lowest available exceptional entry bit for locking */
  10 #define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
  11
  12 ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t,
  13                   get_block_t, dio_iodone_t, int flags);
  14 int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
  15 int dax_truncate_page(struct inode *, loff_t from, get_block_t);
  16 int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
  17 int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
  18
  19 #ifdef CONFIG_FS_DAX
  20 struct page *read_dax_sector(struct block_device *bdev, sector_t n);
  21 int __dax_zero_page_range(struct block_device *bdev, sector_t sector,
  22                 unsigned int offset, unsigned int length);
  23 #else
  24 static inline struct page *read_dax_sector(struct block_device *bdev,
  25                 sector_t n)
  26 {
  27         return ERR_PTR(-ENXIO);
  28 }
  29 static inline int __dax_zero_page_range(struct block_device *bdev,
  30                 sector_t sector, unsigned int offset, unsigned int length)
  31 {
  32         return -ENXIO;
  33 }
  34 #endif
  35
  36 #if defined(CONFIG_TRANSPARENT_HUGEPAGE)
  37 int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
  38                                 unsigned int flags, get_block_t);
  39 int __dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
  40                                 unsigned int flags, get_block_t);
  41 #else
  42 static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
  43                                 pmd_t *pmd, unsigned int flags, get_block_t gb)
  44 {
  45         return VM_FAULT_FALLBACK;
  46 }
  47 #define __dax_pmd_fault dax_pmd_fault
  48 #endif
  49 int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
  50 #define dax_mkwrite(vma, vmf, gb)       dax_fault(vma, vmf, gb)
  51 #define __dax_mkwrite(vma, vmf, gb)     __dax_fault(vma, vmf, gb)
  52
  53 static inline bool vma_is_dax(struct vm_area_struct *vma)
  54 {
  55         return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
  56 }
  57
  58 static inline bool dax_mapping(struct address_space *mapping)
  59 {
  60         return mapping->host && IS_DAX(mapping->host);
  61 }
  62
  63 struct writeback_control;
  64 int dax_writeback_mapping_range(struct address_space *mapping,
  65                 struct block_device *bdev, struct writeback_control *wbc);
  66 #endif