/* SPDX-License-Identifier: GPL-2.0 */ #ifndef LINUX_IOMAP_H #define LINUX_IOMAP_H … #include <linux/atomic.h> #include <linux/bitmap.h> #include <linux/blk_types.h> #include <linux/mm.h> #include <linux/types.h> #include <linux/mm_types.h> #include <linux/blkdev.h> struct address_space; struct fiemap_extent_info; struct inode; struct iomap_iter; struct iomap_dio; struct iomap_writepage_ctx; struct iov_iter; struct kiocb; struct page; struct vm_area_struct; struct vm_fault; /* * Types of block ranges for iomap mappings: */ #define IOMAP_HOLE … #define IOMAP_DELALLOC … #define IOMAP_MAPPED … #define IOMAP_UNWRITTEN … #define IOMAP_INLINE … /* * Flags reported by the file system from iomap_begin: * * IOMAP_F_NEW indicates that the blocks have been newly allocated and need * zeroing for areas that no data is copied to. * * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access * written data and requires fdatasync to commit them to persistent storage. * This needs to take into account metadata changes that *may* be made at IO * completion, such as file size updates from direct IO. * * IOMAP_F_SHARED indicates that the blocks are shared, and will need to be * unshared as part a write. * * IOMAP_F_MERGED indicates that the iomap contains the merge of multiple block * mappings. * * IOMAP_F_BUFFER_HEAD indicates that the file system requires the use of * buffer heads for this mapping. * * IOMAP_F_XATTR indicates that the iomap is for an extended attribute extent * rather than a file data extent. */ #define IOMAP_F_NEW … #define IOMAP_F_DIRTY … #define IOMAP_F_SHARED … #define IOMAP_F_MERGED … #ifdef CONFIG_BUFFER_HEAD #define IOMAP_F_BUFFER_HEAD … #else #define IOMAP_F_BUFFER_HEAD … #endif /* CONFIG_BUFFER_HEAD */ #define IOMAP_F_XATTR … /* * Flags set by the core iomap code during operations: * * IOMAP_F_SIZE_CHANGED indicates to the iomap_end method that the file size * has changed as the result of this write operation. * * IOMAP_F_STALE indicates that the iomap is not valid any longer and the file * range it covers needs to be remapped by the high level before the operation * can proceed. */ #define IOMAP_F_SIZE_CHANGED … #define IOMAP_F_STALE … /* * Flags from 0x1000 up are for file system specific usage: */ #define IOMAP_F_PRIVATE … /* * Magic value for addr: */ #define IOMAP_NULL_ADDR … struct iomap_folio_ops; struct iomap { … }; static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos) { … } /* * Returns the inline data pointer for logical offset @pos. */ static inline void *iomap_inline_data(const struct iomap *iomap, loff_t pos) { … } /* * Check if the mapping's length is within the valid range for inline data. * This is used to guard against accessing data beyond the page inline_data * points at. */ static inline bool iomap_inline_data_valid(const struct iomap *iomap) { … } /* * When a filesystem sets folio_ops in an iomap mapping it returns, get_folio * and put_folio will be called for each folio written to. This only applies * to buffered writes as unbuffered writes will not typically have folios * associated with them. * * When get_folio succeeds, put_folio will always be called to do any * cleanup work necessary. put_folio is responsible for unlocking and putting * @folio. */ struct iomap_folio_ops { … }; /* * Flags for iomap_begin / iomap_end. No flag implies a read. */ #define IOMAP_WRITE … #define IOMAP_ZERO … #define IOMAP_REPORT … #define IOMAP_FAULT … #define IOMAP_DIRECT … #define IOMAP_NOWAIT … #define IOMAP_OVERWRITE_ONLY … #define IOMAP_UNSHARE … #ifdef CONFIG_FS_DAX #define IOMAP_DAX … #else #define IOMAP_DAX … #endif /* CONFIG_FS_DAX */ struct iomap_ops { … }; /** * struct iomap_iter - Iterate through a range of a file * @inode: Set at the start of the iteration and should not change. * @pos: The current file position we are operating on. It is updated by * calls to iomap_iter(). Treat as read-only in the body. * @len: The remaining length of the file segment we're operating on. * It is updated at the same time as @pos. * @processed: The number of bytes processed by the body in the most recent * iteration, or a negative errno. 0 causes the iteration to stop. * @flags: Zero or more of the iomap_begin flags above. * @iomap: Map describing the I/O iteration * @srcmap: Source map for COW operations */ struct iomap_iter { … }; int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops); /** * iomap_length - length of the current iomap iteration * @iter: iteration structure * * Returns the length that the operation applies to for the current iteration. */ static inline u64 iomap_length(const struct iomap_iter *iter) { … } /** * iomap_iter_srcmap - return the source map for the current iomap iteration * @i: iteration structure * * Write operations on file systems with reflink support might require a * source and a destination map. This function retourns the source map * for a given operation, which may or may no be identical to the destination * map in &i->iomap. */ static inline const struct iomap *iomap_iter_srcmap(const struct iomap_iter *i) { … } /* * Return the file offset for the first unchanged block after a short write. * * If nothing was written, round @pos down to point at the first block in * the range, else round up to include the partially written block. */ static inline loff_t iomap_last_written_block(struct inode *inode, loff_t pos, ssize_t written) { … } /* * Check if the range needs to be unshared for a FALLOC_FL_UNSHARE_RANGE * operation. * * Don't bother with blocks that are not shared to start with; or mappings that * cannot be shared, such as inline data, delalloc reservations, holes or * unwritten extents. * * Note that we use srcmap directly instead of iomap_iter_srcmap as unsharing * requires providing a separate source map, and the presence of one is a good * indicator that unsharing is needed, unlike IOMAP_F_SHARED which can be set * for any data that goes into the COW fork for XFS. */ static inline bool iomap_want_unshare_iter(const struct iomap_iter *iter) { … } ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, const struct iomap_ops *ops, void *private); int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops); void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops); bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count); struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len); bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags); void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len); bool iomap_dirty_folio(struct address_space *mapping, struct folio *folio); int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, const struct iomap_ops *ops); int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero, const struct iomap_ops *ops); int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, const struct iomap_ops *ops); vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops); iomap_punch_t; void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte, loff_t end_byte, unsigned flags, struct iomap *iomap, iomap_punch_t punch); int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len, const struct iomap_ops *ops); loff_t iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops); loff_t iomap_seek_data(struct inode *inode, loff_t offset, const struct iomap_ops *ops); sector_t iomap_bmap(struct address_space *mapping, sector_t bno, const struct iomap_ops *ops); /* * Structure for writeback I/O completions. */ struct iomap_ioend { … }; static inline struct iomap_ioend *iomap_ioend_from_bio(struct bio *bio) { … } struct iomap_writeback_ops { … }; struct iomap_writepage_ctx { … }; void iomap_finish_ioends(struct iomap_ioend *ioend, int error); void iomap_ioend_try_merge(struct iomap_ioend *ioend, struct list_head *more_ioends); void iomap_sort_ioends(struct list_head *ioend_list); int iomap_writepages(struct address_space *mapping, struct writeback_control *wbc, struct iomap_writepage_ctx *wpc, const struct iomap_writeback_ops *ops); /* * Flags for direct I/O ->end_io: */ #define IOMAP_DIO_UNWRITTEN … #define IOMAP_DIO_COW … struct iomap_dio_ops { … }; /* * Wait for the I/O to complete in iomap_dio_rw even if the kiocb is not * synchronous. */ #define IOMAP_DIO_FORCE_WAIT … /* * Do not allocate blocks or zero partial blocks, but instead fall back to * the caller by returning -EAGAIN. Used to optimize direct I/O writes that * are not aligned to the file system block size. */ #define IOMAP_DIO_OVERWRITE_ONLY … /* * When a page fault occurs, return a partial synchronous result and allow * the caller to retry the rest of the operation after dealing with the page * fault. */ #define IOMAP_DIO_PARTIAL … ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, unsigned int dio_flags, void *private, size_t done_before); struct iomap_dio *__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, unsigned int dio_flags, void *private, size_t done_before); ssize_t iomap_dio_complete(struct iomap_dio *dio); void iomap_dio_bio_end_io(struct bio *bio); #ifdef CONFIG_SWAP struct file; struct swap_info_struct; int iomap_swapfile_activate(struct swap_info_struct *sis, struct file *swap_file, sector_t *pagespan, const struct iomap_ops *ops); #else #define iomap_swapfile_activate … #endif /* CONFIG_SWAP */ #endif /* LINUX_IOMAP_H */
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