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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef LINUX_IOMAP_H
- #define LINUX_IOMAP_H 1
- #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>
- #include <linux/android_kabi.h>
- struct address_space;
- struct fiemap_extent_info;
- struct inode;
- 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 0 /* no blocks allocated, need allocation */
- #define IOMAP_DELALLOC 1 /* delayed allocation blocks */
- #define IOMAP_MAPPED 2 /* blocks allocated at @addr */
- #define IOMAP_UNWRITTEN 3 /* blocks allocated at @addr in unwritten state */
- #define IOMAP_INLINE 4 /* data inline in the inode */
- /*
- * 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.
- */
- #define IOMAP_F_NEW 0x01
- #define IOMAP_F_DIRTY 0x02
- #define IOMAP_F_SHARED 0x04
- #define IOMAP_F_MERGED 0x08
- #define IOMAP_F_BUFFER_HEAD 0x10
- #define IOMAP_F_ZONE_APPEND 0x20
- /*
- * 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.
- */
- #define IOMAP_F_SIZE_CHANGED 0x100
- /*
- * Flags from 0x1000 up are for file system specific usage:
- */
- #define IOMAP_F_PRIVATE 0x1000
- /*
- * Magic value for addr:
- */
- #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
- struct iomap_page_ops;
- struct iomap {
- u64 addr; /* disk offset of mapping, bytes */
- loff_t offset; /* file offset of mapping, bytes */
- u64 length; /* length of mapping, bytes */
- u16 type; /* type of mapping */
- u16 flags; /* flags for mapping */
- struct block_device *bdev; /* block device for I/O */
- struct dax_device *dax_dev; /* dax_dev for dax operations */
- void *inline_data;
- void *private; /* filesystem private */
- const struct iomap_page_ops *page_ops;
- ANDROID_KABI_RESERVE(1);
- };
- static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos)
- {
- return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
- }
- /*
- * Returns the inline data pointer for logical offset @pos.
- */
- static inline void *iomap_inline_data(const struct iomap *iomap, loff_t pos)
- {
- return iomap->inline_data + pos - iomap->offset;
- }
- /*
- * 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)
- {
- return iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data);
- }
- /*
- * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare
- * and page_done will be called for each page written to. This only applies to
- * buffered writes as unbuffered writes will not typically have pages
- * associated with them.
- *
- * When page_prepare succeeds, page_done will always be called to do any
- * cleanup work necessary. In that page_done call, @page will be NULL if the
- * associated page could not be obtained.
- */
- struct iomap_page_ops {
- int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len);
- void (*page_done)(struct inode *inode, loff_t pos, unsigned copied,
- struct page *page);
- };
- /*
- * Flags for iomap_begin / iomap_end. No flag implies a read.
- */
- #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */
- #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
- #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
- #define IOMAP_FAULT (1 << 3) /* mapping for page fault */
- #define IOMAP_DIRECT (1 << 4) /* direct I/O */
- #define IOMAP_NOWAIT (1 << 5) /* do not block */
- #define IOMAP_OVERWRITE_ONLY (1 << 6) /* only pure overwrites allowed */
- #define IOMAP_UNSHARE (1 << 7) /* unshare_file_range */
- #ifdef CONFIG_FS_DAX
- #define IOMAP_DAX (1 << 8) /* DAX mapping */
- #else
- #define IOMAP_DAX 0
- #endif /* CONFIG_FS_DAX */
- struct iomap_ops {
- /*
- * Return the existing mapping at pos, or reserve space starting at
- * pos for up to length, as long as we can do it as a single mapping.
- * The actual length is returned in iomap->length.
- */
- int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
- unsigned flags, struct iomap *iomap,
- struct iomap *srcmap);
- /*
- * Commit and/or unreserve space previous allocated using iomap_begin.
- * Written indicates the length of the successful write operation which
- * needs to be commited, while the rest needs to be unreserved.
- * Written might be zero if no data was written.
- */
- int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
- ssize_t written, unsigned flags, struct iomap *iomap);
- ANDROID_KABI_RESERVE(1);
- ANDROID_KABI_RESERVE(2);
- };
- /**
- * 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 {
- struct inode *inode;
- loff_t pos;
- u64 len;
- s64 processed;
- unsigned flags;
- struct iomap iomap;
- struct iomap srcmap;
- void *private;
- };
- 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)
- {
- u64 end = iter->iomap.offset + iter->iomap.length;
- if (iter->srcmap.type != IOMAP_HOLE)
- end = min(end, iter->srcmap.offset + iter->srcmap.length);
- return min(iter->len, end - iter->pos);
- }
- /**
- * 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)
- {
- if (i->srcmap.type != IOMAP_HOLE)
- return &i->srcmap;
- return &i->iomap;
- }
- ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
- const struct iomap_ops *ops);
- 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);
- bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags);
- void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
- 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);
- 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 {
- struct list_head io_list; /* next ioend in chain */
- u16 io_type;
- u16 io_flags; /* IOMAP_F_* */
- u32 io_folios; /* folios added to ioend */
- struct inode *io_inode; /* file being written to */
- size_t io_size; /* size of the extent */
- loff_t io_offset; /* offset in the file */
- sector_t io_sector; /* start sector of ioend */
- struct bio *io_bio; /* bio being built */
- struct bio io_inline_bio; /* MUST BE LAST! */
- };
- struct iomap_writeback_ops {
- /*
- * Required, maps the blocks so that writeback can be performed on
- * the range starting at offset.
- */
- int (*map_blocks)(struct iomap_writepage_ctx *wpc, struct inode *inode,
- loff_t offset);
- /*
- * Optional, allows the file systems to perform actions just before
- * submitting the bio and/or override the bio end_io handler for complex
- * operations like copy on write extent manipulation or unwritten extent
- * conversions.
- */
- int (*prepare_ioend)(struct iomap_ioend *ioend, int status);
- /*
- * Optional, allows the file system to discard state on a page where
- * we failed to submit any I/O.
- */
- void (*discard_folio)(struct folio *folio, loff_t pos);
- };
- struct iomap_writepage_ctx {
- struct iomap iomap;
- struct iomap_ioend *ioend;
- const struct iomap_writeback_ops *ops;
- };
- 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 (1 << 0) /* covers unwritten extent(s) */
- #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
- struct iomap_dio_ops {
- int (*end_io)(struct kiocb *iocb, ssize_t size, int error,
- unsigned flags);
- void (*submit_io)(const struct iomap_iter *iter, struct bio *bio,
- loff_t file_offset);
- /*
- * Filesystems wishing to attach private information to a direct io bio
- * must provide a ->submit_io method that attaches the additional
- * information to the bio and changes the ->bi_end_io callback to a
- * custom function. This function should, at a minimum, perform any
- * relevant post-processing of the bio and end with a call to
- * iomap_dio_bio_end_io.
- */
- struct bio_set *bio_set;
- };
- /*
- * Wait for the I/O to complete in iomap_dio_rw even if the kiocb is not
- * synchronous.
- */
- #define IOMAP_DIO_FORCE_WAIT (1 << 0)
- /*
- * 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 (1 << 1)
- /*
- * 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 (1 << 2)
- /*
- * The caller will sync the write if needed; do not sync it within
- * iomap_dio_rw. Overrides IOMAP_DIO_FORCE_WAIT.
- */
- #define IOMAP_DIO_NOSYNC (1 << 3)
- 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(sis, swapfile, pagespan, ops) (-EIO)
- #endif /* CONFIG_SWAP */
- #endif /* LINUX_IOMAP_H */
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