linux_dsm_epyc7002/include/linux/dax.h
Linus Torvalds 478a1469a7 Filesystem DAX locking for 4.7
- We use a bit in an exceptional radix tree entry as a lock bit and use it
   similarly to how page lock is used for normal faults.  This fixes races
   between hole instantiation and read faults of the same index.
 
 - Filesystem DAX PMD faults are disabled, and will be re-enabled when PMD
   locking is implemented.
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Merge tag 'dax-locking-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull DAX locking updates from Ross Zwisler:
 "Filesystem DAX locking for 4.7

   - We use a bit in an exceptional radix tree entry as a lock bit and
     use it similarly to how page lock is used for normal faults.  This
     fixes races between hole instantiation and read faults of the same
     index.

   - Filesystem DAX PMD faults are disabled, and will be re-enabled when
     PMD locking is implemented"

* tag 'dax-locking-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Remove i_mmap_lock protection
  dax: Use radix tree entry lock to protect cow faults
  dax: New fault locking
  dax: Allow DAX code to replace exceptional entries
  dax: Define DAX lock bit for radix tree exceptional entry
  dax: Make huge page handling depend of CONFIG_BROKEN
  dax: Fix condition for filling of PMD holes
2016-05-26 20:00:28 -07:00

77 lines
2.6 KiB
C

#ifndef _LINUX_DAX_H
#define _LINUX_DAX_H
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/radix-tree.h>
#include <asm/pgtable.h>
/* We use lowest available exceptional entry bit for locking */
#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *,
get_block_t, dio_iodone_t, int flags);
int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
int dax_truncate_page(struct inode *, loff_t from, get_block_t);
int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
void dax_wake_mapping_entry_waiter(struct address_space *mapping,
pgoff_t index, bool wake_all);
#ifdef CONFIG_FS_DAX
struct page *read_dax_sector(struct block_device *bdev, sector_t n);
void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index);
int __dax_zero_page_range(struct block_device *bdev, sector_t sector,
unsigned int offset, unsigned int length);
#else
static inline struct page *read_dax_sector(struct block_device *bdev,
sector_t n)
{
return ERR_PTR(-ENXIO);
}
/* Shouldn't ever be called when dax is disabled. */
static inline void dax_unlock_mapping_entry(struct address_space *mapping,
pgoff_t index)
{
BUG();
}
static inline int __dax_zero_page_range(struct block_device *bdev,
sector_t sector, unsigned int offset, unsigned int length)
{
return -ENXIO;
}
#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
unsigned int flags, get_block_t);
int __dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
unsigned int flags, get_block_t);
#else
static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd, unsigned int flags, get_block_t gb)
{
return VM_FAULT_FALLBACK;
}
#define __dax_pmd_fault dax_pmd_fault
#endif
int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
#define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb)
#define __dax_mkwrite(vma, vmf, gb) __dax_fault(vma, vmf, gb)
static inline bool vma_is_dax(struct vm_area_struct *vma)
{
return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
}
static inline bool dax_mapping(struct address_space *mapping)
{
return mapping->host && IS_DAX(mapping->host);
}
struct writeback_control;
int dax_writeback_mapping_range(struct address_space *mapping,
struct block_device *bdev, struct writeback_control *wbc);
#endif