/* 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/mm.h> #include <linux/types.h> struct address_space; struct fiemap_extent_info; struct inode; struct iov_iter; struct kiocb; struct page; struct vm_area_struct; struct vm_fault; /* * Types of block ranges for iomap mappings: */ #define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */ #define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */ #define IOMAP_MAPPED 0x03 /* blocks allocated at @addr */ #define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */ #define IOMAP_INLINE 0x05 /* data inline in the inode */ /* * Flags for all iomap mappings: * * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access * written data and requires fdatasync to commit them to persistent storage. */ #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ #define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */ #define IOMAP_F_BUFFER_HEAD 0x04 /* file system requires buffer heads */ /* * Flags that only need to be reported for IOMAP_REPORT requests: */ #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ #define IOMAP_F_SHARED 0x20 /* block shared with another file */ /* * 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 { 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 */ /* * Called when finished processing a page in the mapping returned in * this iomap. At least for now this is only supported in the buffered * write path. */ void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, struct page *page, struct iomap *iomap); }; /* * 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 */ 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); /* * 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); }; /* * Structure allocate for each page when block size < PAGE_SIZE to track * sub-page uptodate status and I/O completions. */ struct iomap_page { atomic_t read_count; atomic_t write_count; DECLARE_BITMAP(uptodate, PAGE_SIZE / 512); }; static inline struct iomap_page *to_iomap_page(struct page *page) { if (page_has_private(page)) return (struct iomap_page *)page_private(page); return NULL; } ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, const struct iomap_ops *ops); int iomap_readpage(struct page *page, const struct iomap_ops *ops); int iomap_readpages(struct address_space *mapping, struct list_head *pages, unsigned nr_pages, const struct iomap_ops *ops); int iomap_set_page_dirty(struct page *page); int iomap_is_partially_uptodate(struct page *page, unsigned long from, unsigned long count); int iomap_releasepage(struct page *page, gfp_t gfp_mask); void iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len); #ifdef CONFIG_MIGRATION int iomap_migrate_page(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode); #else #define iomap_migrate_page NULL #endif int iomap_file_dirty(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); int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops); int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, loff_t start, loff_t 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); /* * 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) */ typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, unsigned flags); ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, iomap_dio_end_io_t end_io); #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 */