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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /include/linux/iomap.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/linux/iomap.h')
-rw-r--r-- | include/linux/iomap.h | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/include/linux/iomap.h b/include/linux/iomap.h new file mode 100644 index 0000000000..96dd0acbba --- /dev/null +++ b/include/linux/iomap.h @@ -0,0 +1,405 @@ +/* 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> + +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 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. + * + * IOMAP_F_XATTR indicates that the iomap is for an extended attribute extent + * rather than a file data extent. + */ +#define IOMAP_F_NEW (1U << 0) +#define IOMAP_F_DIRTY (1U << 1) +#define IOMAP_F_SHARED (1U << 2) +#define IOMAP_F_MERGED (1U << 3) +#ifdef CONFIG_BUFFER_HEAD +#define IOMAP_F_BUFFER_HEAD (1U << 4) +#else +#define IOMAP_F_BUFFER_HEAD 0 +#endif /* CONFIG_BUFFER_HEAD */ +#define IOMAP_F_XATTR (1U << 5) + +/* + * 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 (1U << 8) +#define IOMAP_F_STALE (1U << 9) + +/* + * Flags from 0x1000 up are for file system specific usage: + */ +#define IOMAP_F_PRIVATE (1U << 12) + + +/* + * Magic value for addr: + */ +#define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ + +struct iomap_folio_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_folio_ops *folio_ops; + u64 validity_cookie; /* used with .iomap_valid() */ +}; + +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 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 { + struct folio *(*get_folio)(struct iomap_iter *iter, loff_t pos, + unsigned len); + void (*put_folio)(struct inode *inode, loff_t pos, unsigned copied, + struct folio *folio); + + /* + * Check that the cached iomap still maps correctly to the filesystem's + * internal extent map. FS internal extent maps can change while iomap + * is iterating a cached iomap, so this hook allows iomap to detect that + * the iomap needs to be refreshed during a long running write + * operation. + * + * The filesystem can store internal state (e.g. a sequence number) in + * iomap->validity_cookie when the iomap is first mapped to be able to + * detect changes between mapping time and whenever .iomap_valid() is + * called. + * + * This is called with the folio over the specified file position held + * locked by the iomap code. + */ + bool (*iomap_valid)(struct inode *inode, const 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 */ +#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); +}; + +/** + * 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_file_buffered_write_punch_delalloc(struct inode *inode, + struct iomap *iomap, loff_t pos, loff_t length, ssize_t written, + int (*punch)(struct inode *inode, loff_t pos, loff_t length)); + +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); +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) + +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 */ |