102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
#ifndef _LINUX_DAX_H
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#define _LINUX_DAX_H
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/radix-tree.h>
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#include <asm/pgtable.h>
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struct iomap_ops;
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/*
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* We use lowest available bit in exceptional entry for locking, one bit for
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* the entry size (PMD) and two more to tell us if the entry is a huge zero
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* page (HZP) or an empty entry that is just used for locking. In total four
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* special bits.
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*
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* If the PMD bit isn't set the entry has size PAGE_SIZE, and if the HZP and
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* EMPTY bits aren't set the entry is a normal DAX entry with a filesystem
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* block allocation.
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*/
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#define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 4)
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#define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT)
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#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1))
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#define RADIX_DAX_HZP (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2))
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#define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3))
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static inline unsigned long dax_radix_sector(void *entry)
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{
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return (unsigned long)entry >> RADIX_DAX_SHIFT;
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}
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static inline void *dax_radix_locked_entry(sector_t sector, unsigned long flags)
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{
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return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags |
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((unsigned long)sector << RADIX_DAX_SHIFT) |
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RADIX_DAX_ENTRY_LOCK);
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}
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ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
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const struct iomap_ops *ops);
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int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
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const struct iomap_ops *ops);
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int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
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int dax_invalidate_mapping_entry(struct address_space *mapping, pgoff_t index);
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int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
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pgoff_t index);
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void dax_wake_mapping_entry_waiter(struct address_space *mapping,
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pgoff_t index, void *entry, bool wake_all);
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#ifdef CONFIG_FS_DAX
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struct page *read_dax_sector(struct block_device *bdev, sector_t n);
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int __dax_zero_page_range(struct block_device *bdev, sector_t sector,
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unsigned int offset, unsigned int length);
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#else
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static inline struct page *read_dax_sector(struct block_device *bdev,
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sector_t n)
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{
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return ERR_PTR(-ENXIO);
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}
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static inline int __dax_zero_page_range(struct block_device *bdev,
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sector_t sector, unsigned int offset, unsigned int length)
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{
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return -ENXIO;
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}
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#endif
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#ifdef CONFIG_FS_DAX_PMD
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static inline unsigned int dax_radix_order(void *entry)
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{
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if ((unsigned long)entry & RADIX_DAX_PMD)
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return PMD_SHIFT - PAGE_SHIFT;
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return 0;
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}
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int dax_iomap_pmd_fault(struct vm_fault *vmf, const struct iomap_ops *ops);
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#else
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static inline unsigned int dax_radix_order(void *entry)
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{
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return 0;
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}
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static inline int dax_iomap_pmd_fault(struct vm_fault *vmf,
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const struct iomap_ops *ops)
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{
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return VM_FAULT_FALLBACK;
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}
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#endif
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int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *);
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static inline bool vma_is_dax(struct vm_area_struct *vma)
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{
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return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
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}
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static inline bool dax_mapping(struct address_space *mapping)
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{
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return mapping->host && IS_DAX(mapping->host);
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}
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struct writeback_control;
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int dax_writeback_mapping_range(struct address_space *mapping,
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struct block_device *bdev, struct writeback_control *wbc);
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#endif
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