103 lines
3.6 KiB
C
103 lines
3.6 KiB
C
#ifndef LINUX_IOMAP_H
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#define LINUX_IOMAP_H 1
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#include <linux/types.h>
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struct fiemap_extent_info;
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struct inode;
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struct iov_iter;
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struct kiocb;
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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 0x01 /* no blocks allocated, need allocation */
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#define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */
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#define IOMAP_MAPPED 0x03 /* blocks allocated @blkno */
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#define IOMAP_UNWRITTEN 0x04 /* blocks allocated @blkno in unwritten state */
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/*
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* Flags for all iomap mappings:
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*/
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#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
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/*
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* Flags that only need to be reported for IOMAP_REPORT requests:
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*/
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#define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */
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#define IOMAP_F_SHARED 0x20 /* block shared with another file */
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/*
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* Magic value for blkno:
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*/
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#define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */
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struct iomap {
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sector_t blkno; /* 1st sector of mapping, 512b units */
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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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};
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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) /* Don't wait for writeback */
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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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/*
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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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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_file_dirty(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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int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops);
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int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
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loff_t start, loff_t 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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/*
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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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typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
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unsigned flags);
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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, iomap_dio_end_io_t end_io);
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#endif /* LINUX_IOMAP_H */
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