dax: Use radix tree entry lock to protect cow faults

[sfrench/cifs-2.6.git] / include / linux / dax.h

diff --git a/include/linux/dax.h b/include/linux/dax.h
index 636dd59ab505c6633ae3184b9c283cad06ab893f..7bf12277c006534f16a6ba49e6446f88eb438f68 100644 (file)
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -3,45 +3,62 @@
 
 #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 *, loff_t,
                  get_block_t, dio_iodone_t, int flags);
-int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size);
 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,
-               dax_iodone_t);
-int __dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t,
-               dax_iodone_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
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
 int dax_pmd_fault(struct vm_area_struct *, unsigned long addr, pmd_t *,
-                               unsigned int flags, get_block_t, dax_iodone_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, dax_iodone_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,
-                               dax_iodone_t di)
+                               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, iod)         dax_fault(vma, vmf, gb, iod)
-#define __dax_mkwrite(vma, vmf, gb, iod)       __dax_fault(vma, vmf, gb, iod)
+#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)
 {