diff options
Diffstat (limited to 'include/linux/iomap.h')
| -rw-r--r-- | include/linux/iomap.h | 176 |
1 files changed, 145 insertions, 31 deletions
diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 6fc1c858013d..68416b135151 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -53,6 +53,16 @@ struct vm_fault; * * 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. */ #define IOMAP_F_NEW (1U << 0) #define IOMAP_F_DIRTY (1U << 1) @@ -64,6 +74,14 @@ struct vm_fault; #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) + +/* + * Flag reserved for file system specific usage + */ +#define IOMAP_F_PRIVATE (1U << 12) /* * Flags set by the core iomap code during operations: @@ -75,14 +93,8 @@ struct vm_fault; * 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) - +#define IOMAP_F_SIZE_CHANGED (1U << 14) +#define IOMAP_F_STALE (1U << 15) /* * Magic value for addr: @@ -107,6 +119,8 @@ struct iomap { 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; } @@ -178,6 +192,8 @@ struct iomap_folio_ops { #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 { /* @@ -206,8 +222,10 @@ struct iomap_ops { * 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. + * @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 @@ -216,7 +234,8 @@ struct iomap_iter { struct inode *inode; loff_t pos; u64 len; - s64 processed; + loff_t iter_start_pos; + int status; unsigned flags; struct iomap iomap; struct iomap srcmap; @@ -224,20 +243,46 @@ struct iomap_iter { }; int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops); +int iomap_iter_advance(struct iomap_iter *iter, u64 *count); /** - * iomap_length - length of the current iomap iteration + * 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 the length that the operation applies to for the current iteration. + * Returns a trimmed length that the operation applies to for the current + * iteration. */ -static inline u64 iomap_length(const struct iomap_iter *iter) +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(iter->len, end - iter->pos); + 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) +{ + u64 length = iomap_length(iter); + + return iomap_iter_advance(iter, &length); } /** @@ -256,12 +301,41 @@ static inline const struct iomap *iomap_iter_srcmap(const struct iomap_iter *i) 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)); +/* + * 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, void *private); 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); @@ -272,11 +346,17 @@ 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); + bool *did_zero, const struct iomap_ops *ops, void *private); 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); + const struct iomap_ops *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, @@ -287,16 +367,42 @@ 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) + +/* + * 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) + +/* * Structure for writeback I/O completions. + * + * File systems implementing ->submit_ioend (for buffered I/O) or ->submit_io + * for direct I/O) 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_type; - u16 io_flags; /* IOMAP_F_* */ + 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 bio io_bio; /* MUST BE LAST! */ }; @@ -321,12 +427,14 @@ struct iomap_writeback_ops { loff_t offset, unsigned len); /* - * 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. + * Optional, allows the file systems to hook into bio submission, + * including overriding the bi_end_io handler. + * + * Returns 0 if the bio was successfully submitted, or a negative + * error code if status was non-zero or another error happened and + * the bio could not be submitted. */ - int (*prepare_ioend)(struct iomap_ioend *ioend, int status); + int (*submit_ioend)(struct iomap_writepage_ctx *wpc, int status); /* * Optional, allows the file system to discard state on a page where @@ -342,6 +450,10 @@ struct iomap_writepage_ctx { u32 nr_folios; /* folios added to the ioend */ }; +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); @@ -413,4 +525,6 @@ int iomap_swapfile_activate(struct swap_info_struct *sis, # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO) #endif /* CONFIG_SWAP */ +extern struct bio_set iomap_ioend_bioset; + #endif /* LINUX_IOMAP_H */ |