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 *,
  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_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
  18 void dax_wake_mapping_entry_waiter(struct address_space *mapping,
  19                                    pgoff_t index, bool wake_all);
  20
  21 #ifdef CONFIG_FS_DAX
  22 struct page *read_dax_sector(struct block_device *bdev, sector_t n);
  23 void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index);
  24 int __dax_zero_page_range(struct block_device *bdev, sector_t sector,
  25                 unsigned int offset, unsigned int length);
  26 #else
  27 static inline struct page *read_dax_sector(struct block_device *bdev,
  28                 sector_t n)
  29 {
  30         return ERR_PTR(-ENXIO);
  31 }
  32 /* Shouldn't ever be called when dax is disabled. */
  33 static inline void dax_unlock_mapping_entry(struct address_space *mapping,
  34                                             pgoff_t index)
  35 {
  36         BUG();
  37 }
  38 static inline int __dax_zero_page_range(struct block_device *bdev,
  39                 sector_t sector, unsigned int offset, unsigned int length)
  40 {
  41         return -ENXIO;
  42 }
  43 #endif
  44
  45 #if defined(CONFIG_TRANSPARENT_HUGEPAGE)
  46 int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
  47                                 unsigned int flags, get_block_t);
  48 #else
  49 static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
  50                                 pmd_t *pmd, unsigned int flags, get_block_t gb)
  51 {
  52         return VM_FAULT_FALLBACK;
  53 }
  54 #endif
  55 int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
  56 #define dax_mkwrite(vma, vmf, gb)       dax_fault(vma, vmf, gb)
  57
  58 static inline bool vma_is_dax(struct vm_area_struct *vma)
  59 {
  60         return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
  61 }
  62
  63 static inline bool dax_mapping(struct address_space *mapping)
  64 {
  65         return mapping->host && IS_DAX(mapping->host);
  66 }
  67
  68 struct writeback_control;
  69 int dax_writeback_mapping_range(struct address_space *mapping,
  70                 struct block_device *bdev, struct writeback_control *wbc);
  71 #endif