diff options
Diffstat (limited to 'include/linux/iomap.h')
-rw-r--r-- | include/linux/iomap.h | 91 |
1 files changed, 77 insertions, 14 deletions
diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 479c1da3e221..24f8489583ca 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -91,13 +91,30 @@ struct iomap { const struct iomap_page_ops *page_ops; }; -static inline sector_t -iomap_sector(struct iomap *iomap, loff_t pos) +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 page_ops in an iomap mapping it returns, page_prepare * and page_done will be called for each page written to. This only applies to * buffered writes as unbuffered writes will not typically have pages @@ -108,10 +125,9 @@ iomap_sector(struct iomap *iomap, loff_t pos) * associated page could not be obtained. */ struct iomap_page_ops { - int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, - struct iomap *iomap); + int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len); void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, - struct page *page, struct iomap *iomap); + struct page *page); }; /* @@ -124,6 +140,7 @@ struct iomap_page_ops { #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 */ struct iomap_ops { /* @@ -145,15 +162,61 @@ struct iomap_ops { ssize_t written, unsigned flags, struct iomap *iomap); }; -/* - * Main iomap iterator function. +/** + * 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 */ -typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len, - void *data, struct iomap *iomap, struct iomap *srcmap); +struct iomap_iter { + struct inode *inode; + loff_t pos; + u64 len; + s64 processed; + unsigned flags; + struct iomap iomap; + struct iomap srcmap; +}; -loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length, - unsigned flags, const struct iomap_ops *ops, void *data, - iomap_actor_t actor); +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); @@ -250,8 +313,8 @@ int iomap_writepages(struct address_space *mapping, struct iomap_dio_ops { int (*end_io)(struct kiocb *iocb, ssize_t size, int error, unsigned flags); - blk_qc_t (*submit_io)(struct inode *inode, struct iomap *iomap, - struct bio *bio, loff_t file_offset); + blk_qc_t (*submit_io)(const struct iomap_iter *iter, struct bio *bio, + loff_t file_offset); }; /* |