225 lines
6.7 KiB
C
225 lines
6.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#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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/* Flag for synchronous flush */
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#define DAXDEV_F_SYNC (1UL << 0)
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typedef unsigned long dax_entry_t;
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struct iomap_ops;
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struct iomap;
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struct dax_device;
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struct dax_operations {
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/*
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* direct_access: translate a device-relative
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* logical-page-offset into an absolute physical pfn. Return the
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* number of pages available for DAX at that pfn.
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*/
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long (*direct_access)(struct dax_device *, pgoff_t, long,
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void **, pfn_t *);
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/*
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* Validate whether this device is usable as an fsdax backing
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* device.
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*/
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bool (*dax_supported)(struct dax_device *, struct block_device *, int,
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sector_t, sector_t);
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/* copy_from_iter: required operation for fs-dax direct-i/o */
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size_t (*copy_from_iter)(struct dax_device *, pgoff_t, void *, size_t,
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struct iov_iter *);
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/* copy_to_iter: required operation for fs-dax direct-i/o */
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size_t (*copy_to_iter)(struct dax_device *, pgoff_t, void *, size_t,
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struct iov_iter *);
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/* zero_page_range: required operation. Zero page range */
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int (*zero_page_range)(struct dax_device *, pgoff_t, size_t);
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};
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extern struct attribute_group dax_attribute_group;
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#if IS_ENABLED(CONFIG_DAX)
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struct dax_device *dax_get_by_host(const char *host);
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struct dax_device *alloc_dax(void *private, const char *host,
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const struct dax_operations *ops, unsigned long flags);
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void put_dax(struct dax_device *dax_dev);
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void kill_dax(struct dax_device *dax_dev);
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void dax_write_cache(struct dax_device *dax_dev, bool wc);
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bool dax_write_cache_enabled(struct dax_device *dax_dev);
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bool __dax_synchronous(struct dax_device *dax_dev);
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static inline bool dax_synchronous(struct dax_device *dax_dev)
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{
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return __dax_synchronous(dax_dev);
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}
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void __set_dax_synchronous(struct dax_device *dax_dev);
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static inline void set_dax_synchronous(struct dax_device *dax_dev)
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{
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__set_dax_synchronous(dax_dev);
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}
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/*
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* Check if given mapping is supported by the file / underlying device.
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*/
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static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
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struct dax_device *dax_dev)
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{
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if (!(vma->vm_flags & VM_SYNC))
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return true;
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if (!IS_DAX(file_inode(vma->vm_file)))
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return false;
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return dax_synchronous(dax_dev);
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}
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#else
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static inline struct dax_device *dax_get_by_host(const char *host)
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{
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return NULL;
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}
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static inline struct dax_device *alloc_dax(void *private, const char *host,
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const struct dax_operations *ops, unsigned long flags)
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{
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/*
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* Callers should check IS_ENABLED(CONFIG_DAX) to know if this
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* NULL is an error or expected.
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*/
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return NULL;
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}
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static inline void put_dax(struct dax_device *dax_dev)
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{
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}
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static inline void kill_dax(struct dax_device *dax_dev)
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{
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}
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static inline void dax_write_cache(struct dax_device *dax_dev, bool wc)
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{
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}
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static inline bool dax_write_cache_enabled(struct dax_device *dax_dev)
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{
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return false;
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}
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static inline bool dax_synchronous(struct dax_device *dax_dev)
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{
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return true;
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}
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static inline void set_dax_synchronous(struct dax_device *dax_dev)
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{
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}
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static inline bool daxdev_mapping_supported(struct vm_area_struct *vma,
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struct dax_device *dax_dev)
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{
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return !(vma->vm_flags & VM_SYNC);
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}
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#endif
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struct writeback_control;
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int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
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#if IS_ENABLED(CONFIG_FS_DAX)
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bool __bdev_dax_supported(struct block_device *bdev, int blocksize);
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static inline bool bdev_dax_supported(struct block_device *bdev, int blocksize)
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{
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return __bdev_dax_supported(bdev, blocksize);
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}
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bool __generic_fsdax_supported(struct dax_device *dax_dev,
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struct block_device *bdev, int blocksize, sector_t start,
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sector_t sectors);
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static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
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struct block_device *bdev, int blocksize, sector_t start,
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sector_t sectors)
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{
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return __generic_fsdax_supported(dax_dev, bdev, blocksize, start,
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sectors);
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}
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static inline void fs_put_dax(struct dax_device *dax_dev)
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{
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put_dax(dax_dev);
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}
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struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
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int dax_writeback_mapping_range(struct address_space *mapping,
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struct dax_device *dax_dev, struct writeback_control *wbc);
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struct page *dax_layout_busy_page(struct address_space *mapping);
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dax_entry_t dax_lock_page(struct page *page);
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void dax_unlock_page(struct page *page, dax_entry_t cookie);
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#else
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static inline bool bdev_dax_supported(struct block_device *bdev,
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int blocksize)
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{
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return false;
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}
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static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
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struct block_device *bdev, int blocksize, sector_t start,
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sector_t sectors)
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{
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return false;
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}
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static inline void fs_put_dax(struct dax_device *dax_dev)
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{
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}
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static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
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{
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return NULL;
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}
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static inline struct page *dax_layout_busy_page(struct address_space *mapping)
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{
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return NULL;
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}
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static inline int dax_writeback_mapping_range(struct address_space *mapping,
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struct dax_device *dax_dev, struct writeback_control *wbc)
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{
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return -EOPNOTSUPP;
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}
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static inline dax_entry_t dax_lock_page(struct page *page)
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{
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if (IS_DAX(page->mapping->host))
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return ~0UL;
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return 0;
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}
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static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
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{
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}
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#endif
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int dax_read_lock(void);
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void dax_read_unlock(int id);
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bool dax_alive(struct dax_device *dax_dev);
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void *dax_get_private(struct dax_device *dax_dev);
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long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
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void **kaddr, pfn_t *pfn);
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bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
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int blocksize, sector_t start, sector_t len);
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size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
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size_t bytes, struct iov_iter *i);
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size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
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size_t bytes, struct iov_iter *i);
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int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
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size_t nr_pages);
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void dax_flush(struct dax_device *dax_dev, void *addr, size_t size);
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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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vm_fault_t dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
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pfn_t *pfnp, int *errp, const struct iomap_ops *ops);
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vm_fault_t dax_finish_sync_fault(struct vm_fault *vmf,
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enum page_entry_size pe_size, pfn_t pfn);
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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_sync(struct address_space *mapping,
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pgoff_t index);
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int dax_iomap_zero(loff_t pos, unsigned offset, unsigned size,
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struct iomap *iomap);
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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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#endif
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