1 // SPDX-License-Identifier: GPL-2.0
14  * Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff.
15  * Returns true if found and updates @lastoff to the offset in file.
18 page_seek_hole_data(struct inode *inode, struct page *page, loff_t *lastoff,  in page_seek_hole_data()  argument
21 	const struct address_space_operations *ops = inode->i_mapping->a_ops;  in page_seek_hole_data()
24 	loff_t poff = page_offset(page);  in page_seek_hole_data()
31 		 * Last offset smaller than the start of the page means we found  in page_seek_hole_data()
40 	 * Just check the page unless we can and should check block ranges:  in page_seek_hole_data()
42 	if (bsize == PAGE_SIZE || !ops->is_partially_uptodate)  in page_seek_hole_data()
43 		return PageUptodate(page) == seek_data;  in page_seek_hole_data()
45 	lock_page(page);  in page_seek_hole_data()
46 	if (unlikely(page->mapping != inode->i_mapping))  in page_seek_hole_data()
52 		if (ops->is_partially_uptodate(page, off, bsize) == seek_data) {  in page_seek_hole_data()
53 			unlock_page(page);  in page_seek_hole_data()
60 	unlock_page(page);  in page_seek_hole_data()
65  * Seek for SEEK_DATA / SEEK_HOLE in the page cache.
67  * Within unwritten extents, the page cache determines which parts are holes
71  * Returns the resulting offset on successs, and -ENOENT otherwise.
74 page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length,  in page_cache_seek_hole_data()  argument
77 	pgoff_t index = offset >> PAGE_SHIFT;  in page_cache_seek_hole_data()
78 	pgoff_t end = DIV_ROUND_UP(offset + length, PAGE_SIZE);  in page_cache_seek_hole_data()
79 	loff_t lastoff = offset;  in page_cache_seek_hole_data()
83 		return -ENOENT;  in page_cache_seek_hole_data()
90 		nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, &index,  in page_cache_seek_hole_data()
91 						end - 1);  in page_cache_seek_hole_data()
96 			struct page *page = pvec.pages[i];  in page_cache_seek_hole_data()  local
98 			if (page_seek_hole_data(inode, page, &lastoff, whence))  in page_cache_seek_hole_data()
100 			lastoff = page_offset(page) + PAGE_SIZE;  in page_cache_seek_hole_data()
105 	/* When no page at lastoff and we are not done, we found a hole. */  in page_cache_seek_hole_data()
110 	if (lastoff < offset + length)  in page_cache_seek_hole_data()
113 	lastoff = -ENOENT;  in page_cache_seek_hole_data()
121 iomap_seek_hole_actor(struct inode *inode, loff_t offset, loff_t length,  in iomap_seek_hole_actor()  argument
124 	switch (iomap->type) {  in iomap_seek_hole_actor()
126 		offset = page_cache_seek_hole_data(inode, offset, length,  in iomap_seek_hole_actor()
128 		if (offset < 0)  in iomap_seek_hole_actor()
132 		*(loff_t *)data = offset;  in iomap_seek_hole_actor()
140 iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)  in iomap_seek_hole()  argument
146 	if (offset < 0 || offset >= size)  in iomap_seek_hole()
147 		return -ENXIO;  in iomap_seek_hole()
149 	while (offset < size) {  in iomap_seek_hole()
150 		ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,  in iomap_seek_hole()
151 				  ops, &offset, iomap_seek_hole_actor);  in iomap_seek_hole()
156 		offset += ret;  in iomap_seek_hole()
159 	return offset;  in iomap_seek_hole()
164 iomap_seek_data_actor(struct inode *inode, loff_t offset, loff_t length,  in iomap_seek_data_actor()  argument
167 	switch (iomap->type) {  in iomap_seek_data_actor()
171 		offset = page_cache_seek_hole_data(inode, offset, length,  in iomap_seek_data_actor()
173 		if (offset < 0)  in iomap_seek_data_actor()
177 		*(loff_t *)data = offset;  in iomap_seek_data_actor()
183 iomap_seek_data(struct inode *inode, loff_t offset, const struct iomap_ops *ops)  in iomap_seek_data()  argument
189 	if (offset < 0 || offset >= size)  in iomap_seek_data()
190 		return -ENXIO;  in iomap_seek_data()
192 	while (offset < size) {  in iomap_seek_data()
193 		ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,  in iomap_seek_data()
194 				  ops, &offset, iomap_seek_data_actor);  in iomap_seek_data()
198 			return offset;  in iomap_seek_data()
199 		offset += ret;  in iomap_seek_data()
203 	return -ENXIO;  in iomap_seek_data()