include/linux/iomap.h

1 /* SPDX-License-Identifier: GPL-2.0 */
32 #define IOMAP_INLINE	4	/* data inline in the inode */
38  * zeroing for areas that no data is copied to.
41  * written data and requires fdatasync to commit them to persistent storage.
52  * buffer heads for this mapping.
55  * rather than a file data extent.
90 #define IOMAP_NULL_ADDR -1ULL	/* addr is not valid */
95 	u64			addr; /* disk offset of mapping, bytes */
96 	loff_t			offset;	/* file offset of mapping, bytes */
97 	u64			length;	/* length of mapping, bytes */
98 	u16			type;	/* type of mapping */
99 	u16			flags;	/* flags for mapping */
110 	return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;  in iomap_sector()
114  * Returns the inline data pointer for logical offset @pos.
118 	return iomap->inline_data + pos - iomap->offset;  in iomap_inline_data()
122  * Check if the mapping's length is within the valid range for inline data.
123  * This is used to guard against accessing data beyond the page inline_data
128 	return iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data);  in iomap_inline_data_valid()
132  * When a filesystem sets folio_ops in an iomap mapping it returns, get_folio
155 	 * iomap->validity_cookie when the iomap is first mapped to be able to
156 	 * detect changes between mapping time and whenever .iomap_valid() is
171 #define IOMAP_FAULT		(1 << 3) /* mapping for page fault */
177 #define IOMAP_DAX		(1 << 8) /* DAX mapping */
184 	 * Return the existing mapping at pos, or reserve space starting at
185 	 * pos for up to length, as long as we can do it as a single mapping.
186 	 * The actual length is returned in iomap->length.
196 	 * Written might be zero if no data was written.
203  * struct iomap_iter - Iterate through a range of a file
206  *	calls to iomap_iter().  Treat as read-only in the body.
229  * iomap_length - length of the current iomap iteration
236 	u64 end = iter->iomap.offset + iter->iomap.length;  in iomap_length()
238 	if (iter->srcmap.type != IOMAP_HOLE)  in iomap_length()
239 		end = min(end, iter->srcmap.offset + iter->srcmap.length);  in iomap_length()
240 	return min(iter->len, end - iter->pos);  in iomap_length()
244  * iomap_iter_srcmap - return the source map for the current iomap iteration
250  * map in &i->iomap.
254 	if (i->srcmap.type != IOMAP_HOLE)  in iomap_iter_srcmap()
255 		return &i->srcmap;  in iomap_iter_srcmap()
256 	return &i->iomap;  in iomap_iter_srcmap()
271 bool iomap_dirty_folio(struct address_space *mapping, struct folio *folio);
286 sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
338 int iomap_writepages(struct address_space *mapping,
343  * Flags for direct I/O ->end_io:
356 	 * must provide a ->submit_io method that attaches the additional
357 	 * information to the bio and changes the ->bi_end_io callback to a
359 	 * relevant post-processing of the bio and end with a call to
373  * the caller by returning -EAGAIN.  Used to optimize direct I/O writes that
402 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops)	(-EIO)