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294 lines
9.9 KiB
294 lines
9.9 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef LINUX_IOMAP_H |
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#define LINUX_IOMAP_H 1 |
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#include <linux/atomic.h> |
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#include <linux/bitmap.h> |
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#include <linux/blk_types.h> |
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#include <linux/mm.h> |
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#include <linux/types.h> |
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#include <linux/mm_types.h> |
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#include <linux/blkdev.h> |
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struct address_space; |
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struct fiemap_extent_info; |
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struct inode; |
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struct iomap_dio; |
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struct iomap_writepage_ctx; |
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struct iov_iter; |
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struct kiocb; |
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struct page; |
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struct vm_area_struct; |
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struct vm_fault; |
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/* |
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* Types of block ranges for iomap mappings: |
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*/ |
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#define IOMAP_HOLE 0 /* no blocks allocated, need allocation */ |
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#define IOMAP_DELALLOC 1 /* delayed allocation blocks */ |
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#define IOMAP_MAPPED 2 /* blocks allocated at @addr */ |
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#define IOMAP_UNWRITTEN 3 /* blocks allocated at @addr in unwritten state */ |
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#define IOMAP_INLINE 4 /* data inline in the inode */ |
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/* |
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* Flags reported by the file system from iomap_begin: |
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* |
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* IOMAP_F_NEW indicates that the blocks have been newly allocated and need |
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* zeroing for areas that no data is copied to. |
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* |
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* IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access |
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* written data and requires fdatasync to commit them to persistent storage. |
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* This needs to take into account metadata changes that *may* be made at IO |
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* completion, such as file size updates from direct IO. |
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* |
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* IOMAP_F_SHARED indicates that the blocks are shared, and will need to be |
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* unshared as part a write. |
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* |
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* IOMAP_F_MERGED indicates that the iomap contains the merge of multiple block |
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* mappings. |
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* |
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* IOMAP_F_BUFFER_HEAD indicates that the file system requires the use of |
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* buffer heads for this mapping. |
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*/ |
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#define IOMAP_F_NEW 0x01 |
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#define IOMAP_F_DIRTY 0x02 |
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#define IOMAP_F_SHARED 0x04 |
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#define IOMAP_F_MERGED 0x08 |
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#define IOMAP_F_BUFFER_HEAD 0x10 |
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#define IOMAP_F_ZONE_APPEND 0x20 |
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/* |
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* Flags set by the core iomap code during operations: |
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* |
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* IOMAP_F_SIZE_CHANGED indicates to the iomap_end method that the file size |
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* has changed as the result of this write operation. |
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*/ |
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#define IOMAP_F_SIZE_CHANGED 0x100 |
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/* |
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* Flags from 0x1000 up are for file system specific usage: |
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*/ |
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#define IOMAP_F_PRIVATE 0x1000 |
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/* |
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* Magic value for addr: |
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*/ |
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#define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ |
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struct iomap_page_ops; |
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struct iomap { |
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u64 addr; /* disk offset of mapping, bytes */ |
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loff_t offset; /* file offset of mapping, bytes */ |
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u64 length; /* length of mapping, bytes */ |
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u16 type; /* type of mapping */ |
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u16 flags; /* flags for mapping */ |
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struct block_device *bdev; /* block device for I/O */ |
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struct dax_device *dax_dev; /* dax_dev for dax operations */ |
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void *inline_data; |
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void *private; /* filesystem private */ |
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const struct iomap_page_ops *page_ops; |
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}; |
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static inline sector_t |
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iomap_sector(struct iomap *iomap, loff_t pos) |
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{ |
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return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT; |
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} |
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/* |
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* When a filesystem sets page_ops in an iomap mapping it returns, page_prepare |
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* and page_done will be called for each page written to. This only applies to |
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* buffered writes as unbuffered writes will not typically have pages |
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* associated with them. |
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* |
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* When page_prepare succeeds, page_done will always be called to do any |
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* cleanup work necessary. In that page_done call, @page will be NULL if the |
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* associated page could not be obtained. |
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*/ |
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struct iomap_page_ops { |
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int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, |
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struct iomap *iomap); |
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void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, |
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struct page *page, struct iomap *iomap); |
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}; |
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/* |
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* Flags for iomap_begin / iomap_end. No flag implies a read. |
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*/ |
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#define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ |
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#define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ |
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#define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ |
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#define IOMAP_FAULT (1 << 3) /* mapping for page fault */ |
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#define IOMAP_DIRECT (1 << 4) /* direct I/O */ |
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#define IOMAP_NOWAIT (1 << 5) /* do not block */ |
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#define IOMAP_OVERWRITE_ONLY (1 << 6) /* only pure overwrites allowed */ |
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struct iomap_ops { |
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/* |
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* Return the existing mapping at pos, or reserve space starting at |
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* pos for up to length, as long as we can do it as a single mapping. |
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* The actual length is returned in iomap->length. |
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*/ |
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int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, |
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unsigned flags, struct iomap *iomap, |
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struct iomap *srcmap); |
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/* |
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* Commit and/or unreserve space previous allocated using iomap_begin. |
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* Written indicates the length of the successful write operation which |
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* needs to be commited, while the rest needs to be unreserved. |
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* Written might be zero if no data was written. |
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*/ |
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int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, |
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ssize_t written, unsigned flags, struct iomap *iomap); |
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}; |
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/* |
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* Main iomap iterator function. |
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*/ |
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typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len, |
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void *data, struct iomap *iomap, struct iomap *srcmap); |
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loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length, |
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unsigned flags, const struct iomap_ops *ops, void *data, |
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iomap_actor_t actor); |
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ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, |
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const struct iomap_ops *ops); |
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int iomap_readpage(struct page *page, const struct iomap_ops *ops); |
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void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops); |
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int iomap_set_page_dirty(struct page *page); |
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int iomap_is_partially_uptodate(struct page *page, unsigned long from, |
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unsigned long count); |
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int iomap_releasepage(struct page *page, gfp_t gfp_mask); |
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void iomap_invalidatepage(struct page *page, unsigned int offset, |
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unsigned int len); |
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#ifdef CONFIG_MIGRATION |
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int iomap_migrate_page(struct address_space *mapping, struct page *newpage, |
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struct page *page, enum migrate_mode mode); |
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#else |
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#define iomap_migrate_page NULL |
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#endif |
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int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, |
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const struct iomap_ops *ops); |
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int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, |
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bool *did_zero, const struct iomap_ops *ops); |
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int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, |
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const struct iomap_ops *ops); |
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vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, |
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const struct iomap_ops *ops); |
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int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
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u64 start, u64 len, const struct iomap_ops *ops); |
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loff_t iomap_seek_hole(struct inode *inode, loff_t offset, |
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const struct iomap_ops *ops); |
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loff_t iomap_seek_data(struct inode *inode, loff_t offset, |
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const struct iomap_ops *ops); |
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sector_t iomap_bmap(struct address_space *mapping, sector_t bno, |
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const struct iomap_ops *ops); |
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/* |
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* Structure for writeback I/O completions. |
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*/ |
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struct iomap_ioend { |
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struct list_head io_list; /* next ioend in chain */ |
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u16 io_type; |
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u16 io_flags; /* IOMAP_F_* */ |
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struct inode *io_inode; /* file being written to */ |
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size_t io_size; /* size of the extent */ |
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loff_t io_offset; /* offset in the file */ |
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void *io_private; /* file system private data */ |
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struct bio *io_bio; /* bio being built */ |
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struct bio io_inline_bio; /* MUST BE LAST! */ |
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}; |
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struct iomap_writeback_ops { |
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/* |
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* Required, maps the blocks so that writeback can be performed on |
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* the range starting at offset. |
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*/ |
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int (*map_blocks)(struct iomap_writepage_ctx *wpc, struct inode *inode, |
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loff_t offset); |
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/* |
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* Optional, allows the file systems to perform actions just before |
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* submitting the bio and/or override the bio end_io handler for complex |
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* operations like copy on write extent manipulation or unwritten extent |
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* conversions. |
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*/ |
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int (*prepare_ioend)(struct iomap_ioend *ioend, int status); |
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/* |
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* Optional, allows the file system to discard state on a page where |
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* we failed to submit any I/O. |
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*/ |
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void (*discard_page)(struct page *page, loff_t fileoff); |
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}; |
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struct iomap_writepage_ctx { |
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struct iomap iomap; |
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struct iomap_ioend *ioend; |
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const struct iomap_writeback_ops *ops; |
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}; |
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void iomap_finish_ioends(struct iomap_ioend *ioend, int error); |
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void iomap_ioend_try_merge(struct iomap_ioend *ioend, |
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struct list_head *more_ioends, |
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void (*merge_private)(struct iomap_ioend *ioend, |
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struct iomap_ioend *next)); |
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void iomap_sort_ioends(struct list_head *ioend_list); |
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int iomap_writepage(struct page *page, struct writeback_control *wbc, |
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struct iomap_writepage_ctx *wpc, |
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const struct iomap_writeback_ops *ops); |
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int iomap_writepages(struct address_space *mapping, |
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struct writeback_control *wbc, struct iomap_writepage_ctx *wpc, |
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const struct iomap_writeback_ops *ops); |
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/* |
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* Flags for direct I/O ->end_io: |
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*/ |
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#define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ |
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#define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ |
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struct iomap_dio_ops { |
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int (*end_io)(struct kiocb *iocb, ssize_t size, int error, |
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unsigned flags); |
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blk_qc_t (*submit_io)(struct inode *inode, struct iomap *iomap, |
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struct bio *bio, loff_t file_offset); |
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}; |
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/* |
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* Wait for the I/O to complete in iomap_dio_rw even if the kiocb is not |
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* synchronous. |
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*/ |
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#define IOMAP_DIO_FORCE_WAIT (1 << 0) |
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/* |
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* Do not allocate blocks or zero partial blocks, but instead fall back to |
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* the caller by returning -EAGAIN. Used to optimize direct I/O writes that |
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* are not aligned to the file system block size. |
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*/ |
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#define IOMAP_DIO_OVERWRITE_ONLY (1 << 1) |
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ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, |
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const struct iomap_ops *ops, const struct iomap_dio_ops *dops, |
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unsigned int dio_flags); |
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struct iomap_dio *__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, |
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const struct iomap_ops *ops, const struct iomap_dio_ops *dops, |
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unsigned int dio_flags); |
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ssize_t iomap_dio_complete(struct iomap_dio *dio); |
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int iomap_dio_iopoll(struct kiocb *kiocb, bool spin); |
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#ifdef CONFIG_SWAP |
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struct file; |
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struct swap_info_struct; |
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int iomap_swapfile_activate(struct swap_info_struct *sis, |
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struct file *swap_file, sector_t *pagespan, |
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const struct iomap_ops *ops); |
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#else |
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# define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO) |
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#endif /* CONFIG_SWAP */ |
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#endif /* LINUX_IOMAP_H */
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