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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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/folio_batch.h>
struct address_space;struct fiemap_extent_info;struct inode;struct iomap_iter;struct iomap_dio;struct iomap_writepage_ctx;struct iomap_read_folio_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. * * IOMAP_F_BOUNDARY indicates that I/O and I/O completions for this iomap must * never be merged with the mapping before it. * * IOMAP_F_ANON_WRITE indicates that (write) I/O does not have a target block * assigned to it yet and the file system will do that in the bio submission * handler, splitting the I/O as needed. * * IOMAP_F_ATOMIC_BIO indicates that (write) I/O will be issued as an atomic * bio, i.e. set REQ_ATOMIC. * * IOMAP_F_INTEGRITY indicates that the filesystems handles integrity metadata. * * IOMAP_F_ZERO_TAIL indicates the remainder of the block after the data * written should be zeroed. */#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)#define IOMAP_F_BOUNDARY (1U << 6)#define IOMAP_F_ANON_WRITE (1U << 7)#define IOMAP_F_ATOMIC_BIO (1U << 8)#ifdef CONFIG_BLK_DEV_INTEGRITY#define IOMAP_F_INTEGRITY (1U << 9)#else#define IOMAP_F_INTEGRITY 0#endif /* CONFIG_BLK_DEV_INTEGRITY */#define IOMAP_F_ZERO_TAIL (1U << 10)
/* * Indicates reads and writes of fsverity metadata. * * Fsverity metadata is stored after the regular file data and thus beyond * i_size. */#define IOMAP_F_FSVERITY (1U << 11)
/* * Flag reserved for file system specific usage */#define IOMAP_F_PRIVATE (1U << 12)
/* * Flags set by the core iomap code during operations: * * IOMAP_F_FOLIO_BATCH indicates that the folio batch mechanism is active * for this operation, set by iomap_fill_dirty_folios(). * * 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_FOLIO_BATCH (1U << 13)#define IOMAP_F_SIZE_CHANGED (1U << 14)#define IOMAP_F_STALE (1U << 15)
/* * 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 */ u64 validity_cookie; /* used with .iomap_valid() */};
static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos){ if (iomap->flags & IOMAP_F_ANON_WRITE) return U64_MAX; /* invalid */ 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;}
/* * 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_write_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);
/* * Optional if the filesystem wishes to provide a custom handler for * reading in the contents of a folio, otherwise iomap will default to * submitting a bio read request. * * The read must be done synchronously. */ int (*read_folio_range)(const struct iomap_iter *iter, struct folio *folio, loff_t pos, size_t len);};
/* * 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 */#define IOMAP_ATOMIC (1 << 9) /* torn-write protection */#define IOMAP_DONTCACHE (1 << 10)
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. * @iter_start_pos: The original start pos for the current iomap. Used for * incremental iter advance. * @status: Status of the most recent iteration. Zero on success or a negative * errno on error. * @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; loff_t iter_start_pos; int status; unsigned flags; struct iomap iomap; struct iomap srcmap; struct folio_batch *fbatch; void *private;};
int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops);int iomap_iter_advance(struct iomap_iter *iter, u64 count);
/** * iomap_length_trim - trimmed length of the current iomap iteration * @iter: iteration structure * @pos: File position to trim from. * @len: Length of the mapping to trim to. * * Returns a trimmed length that the operation applies to for the current * iteration. */static inline u64 iomap_length_trim(const struct iomap_iter *iter, loff_t pos, u64 len){ 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(len, end - pos);}
/** * 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){ return iomap_length_trim(iter, iter->pos, iter->len);}
/** * iomap_iter_advance_full - advance by the full length of current map */static inline int iomap_iter_advance_full(struct iomap_iter *iter){ return iomap_iter_advance(iter, iomap_length(iter));}
/** * 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;}
/* * Return the file offset for the first unchanged block after a short write. * * If nothing was written, round @pos down to point at the first block in * the range, else round up to include the partially written block. */static inline loff_t iomap_last_written_block(struct inode *inode, loff_t pos, ssize_t written){ if (unlikely(!written)) return round_down(pos, i_blocksize(inode)); return round_up(pos + written, i_blocksize(inode));}
/* * Check if the range needs to be unshared for a FALLOC_FL_UNSHARE_RANGE * operation. * * Don't bother with blocks that are not shared to start with; or mappings that * cannot be shared, such as inline data, delalloc reservations, holes or * unwritten extents. * * Note that we use srcmap directly instead of iomap_iter_srcmap as unsharing * requires providing a separate source map, and the presence of one is a good * indicator that unsharing is needed, unlike IOMAP_F_SHARED which can be set * for any data that goes into the COW fork for XFS. */static inline bool iomap_want_unshare_iter(const struct iomap_iter *iter){ return (iter->iomap.flags & IOMAP_F_SHARED) && iter->srcmap.type == IOMAP_MAPPED;}
ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, const struct iomap_ops *ops, const struct iomap_write_ops *write_ops, void *private);int iomap_fsverity_write(struct file *file, loff_t pos, size_t length, const void *buf, const struct iomap_ops *ops, const struct iomap_write_ops *write_ops);void iomap_read_folio(const struct iomap_ops *ops, struct iomap_read_folio_ctx *ctx, void *private);void iomap_readahead(const struct iomap_ops *ops, struct iomap_read_folio_ctx *ctx, void *private);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, const struct iomap_write_ops *write_ops);unsigned int iomap_fill_dirty_folios(struct iomap_iter *iter, loff_t *start, loff_t end, unsigned int *iomap_flags);int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero, const struct iomap_ops *ops, const struct iomap_write_ops *write_ops, void *private);int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, const struct iomap_ops *ops, const struct iomap_write_ops *write_ops, void *private);vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops, void *private);typedef void (*iomap_punch_t)(struct inode *inode, loff_t offset, loff_t length, struct iomap *iomap);void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte, loff_t end_byte, unsigned flags, struct iomap *iomap, iomap_punch_t punch);
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);
/* * Flags for iomap_ioend->io_flags. *//* shared COW extent */#define IOMAP_IOEND_SHARED (1U << 0)/* unwritten extent */#define IOMAP_IOEND_UNWRITTEN (1U << 1)/* don't merge into previous ioend */#define IOMAP_IOEND_BOUNDARY (1U << 2)/* is direct I/O */#define IOMAP_IOEND_DIRECT (1U << 3)/* is DONTCACHE I/O */#define IOMAP_IOEND_DONTCACHE (1U << 4)
/* * Flags that if set on either ioend prevent the merge of two ioends. * (IOMAP_IOEND_BOUNDARY also prevents merges, but only one-way) */#define IOMAP_IOEND_NOMERGE_FLAGS \ (IOMAP_IOEND_SHARED | IOMAP_IOEND_UNWRITTEN | IOMAP_IOEND_DIRECT | \ IOMAP_IOEND_DONTCACHE)
/* * Structure for writeback I/O completions. * * File systems can split a bio generated by iomap. In that case the parent * ioend it was split from is recorded in ioend->io_parent. */struct iomap_ioend { struct list_head io_list; /* next ioend in chain */ u16 io_flags; /* IOMAP_IOEND_* */ struct inode *io_inode; /* file being written to */ size_t io_size; /* size of the extent */ atomic_t io_remaining; /* completetion defer count */ int io_error; /* stashed away status */ struct iomap_ioend *io_parent; /* parent for completions */ loff_t io_offset; /* offset in the file */ sector_t io_sector; /* start sector of ioend */ void *io_private; /* file system private data */ struct fsverity_info *io_vi; /* fsverity info */ struct bio io_bio; /* MUST BE LAST! */};
static inline struct iomap_ioend *iomap_ioend_from_bio(struct bio *bio){ return container_of(bio, struct iomap_ioend, io_bio);}
struct iomap_writeback_ops { /* * Performs writeback on the passed in range * * Can map arbitrarily large regions, but we need to call into it at * least once per folio to allow the file systems to synchronize with * the write path that could be invalidating mappings. * * An existing mapping from a previous call to this method can be reused * by the file system if it is still valid. * * If this succeeds, iomap_finish_folio_write() must be called once * writeback completes for the range, regardless of whether the * writeback succeeded or failed. * * Returns the number of bytes processed or a negative errno. */ ssize_t (*writeback_range)(struct iomap_writepage_ctx *wpc, struct folio *folio, u64 pos, unsigned int len, u64 end_pos);
/* * Submit a writeback context previously build up by ->writeback_range. * * Returns 0 if the context was successfully submitted, or a negative * error code if not. If @error is non-zero a failure occurred, and * the writeback context should be completed with an error. */ int (*writeback_submit)(struct iomap_writepage_ctx *wpc, int error);};
struct iomap_writepage_ctx { struct iomap iomap; struct inode *inode; struct writeback_control *wbc; const struct iomap_writeback_ops *ops; u32 nr_folios; /* folios added to the ioend */ void *wb_ctx; /* pending writeback context */};
struct iomap_ioend *iomap_init_ioend(struct inode *inode, struct bio *bio, loff_t file_offset, u16 ioend_flags);struct iomap_ioend *iomap_split_ioend(struct iomap_ioend *ioend, unsigned int max_len, bool is_append);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);ssize_t iomap_add_to_ioend(struct iomap_writepage_ctx *wpc, struct folio *folio, loff_t pos, loff_t end_pos, unsigned int dirty_len);int iomap_ioend_writeback_submit(struct iomap_writepage_ctx *wpc, int error);
void iomap_finish_folio_read(struct folio *folio, size_t off, size_t len, int error);void iomap_finish_folio_write(struct inode *inode, struct folio *folio, size_t len);
int iomap_writeback_folio(struct iomap_writepage_ctx *wpc, struct folio *folio);int iomap_writepages(struct iomap_writepage_ctx *wpc);
struct iomap_read_folio_ctx { const struct iomap_read_ops *ops; struct folio *cur_folio; struct readahead_control *rac; void *read_ctx; loff_t read_ctx_file_offset; struct fsverity_info *vi;};
struct iomap_read_ops { /* * Read in a folio range. * * If this succeeds, iomap_finish_folio_read() must be called after the * range is read in, regardless of whether the read succeeded or failed. * * Returns 0 on success or a negative error on failure. */ int (*read_folio_range)(const struct iomap_iter *iter, struct iomap_read_folio_ctx *ctx, size_t len);
/* * Submit any pending read requests. * * This is optional. */ void (*submit_read)(const struct iomap_iter *iter, struct iomap_read_folio_ctx *ctx);
/* * Optional, allows filesystem to specify own bio_set, so new bio's * can be allocated from the provided bio_set. */ struct bio_set *bio_set;};
/* * 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)
/* * Ensure each bio is aligned to fs block size. * * For filesystems which need to calculate/verify the checksum of each fs * block. Otherwise they may not be able to handle unaligned bios. */#define IOMAP_DIO_FSBLOCK_ALIGNED (1 << 3)
/* * Bounce buffer instead of using zero copy access. * * This is needed if the device needs stable data to checksum or generate * parity. The file system must hook into the I/O submission and offload * completions to user context for reads when this is set. */#define IOMAP_DIO_BOUNCE (1 << 4)
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_SWAPstruct 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 */
extern struct bio_set iomap_ioend_bioset;
#ifdef CONFIG_BLOCKint iomap_bio_read_folio_range(const struct iomap_iter *iter, struct iomap_read_folio_ctx *ctx, size_t plen);void iomap_bio_submit_read_endio(const struct iomap_iter *iter, struct iomap_read_folio_ctx *ctx, bio_end_io_t end_io);
extern const struct iomap_read_ops iomap_bio_read_ops;
static inline void iomap_bio_read_folio(struct folio *folio, const struct iomap_ops *ops){ struct iomap_read_folio_ctx ctx = { .ops = &iomap_bio_read_ops, .cur_folio = folio, };
iomap_read_folio(ops, &ctx, NULL);}
static inline void iomap_bio_readahead(struct readahead_control *rac, const struct iomap_ops *ops){ struct iomap_read_folio_ctx ctx = { .ops = &iomap_bio_read_ops, .rac = rac, };
iomap_readahead(ops, &ctx, NULL);}#endif /* CONFIG_BLOCK */
#endif /* LINUX_IOMAP_H */