151 static inline unsigned dio_pages_present(struct dio_submit *sdio)  in dio_pages_present()  argument
153 	return sdio->tail - sdio->head;  in dio_pages_present()
159 static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)  in dio_refill_pages()  argument
163 	ret = iov_iter_get_pages(sdio->iter, dio->pages, LONG_MAX, DIO_PAGES,  in dio_refill_pages()
164 				&sdio->from);  in dio_refill_pages()
166 	if (ret < 0 && sdio->blocks_available && (dio->rw & WRITE)) {  in dio_refill_pages()
177 		sdio->head = 0;  in dio_refill_pages()
178 		sdio->tail = 1;  in dio_refill_pages()
179 		sdio->from = 0;  in dio_refill_pages()
180 		sdio->to = PAGE_SIZE;  in dio_refill_pages()
185 		iov_iter_advance(sdio->iter, ret);  in dio_refill_pages()
186 		ret += sdio->from;  in dio_refill_pages()
187 		sdio->head = 0;  in dio_refill_pages()
188 		sdio->tail = (ret + PAGE_SIZE - 1) / PAGE_SIZE;  in dio_refill_pages()
189 		sdio->to = ((ret - 1) & (PAGE_SIZE - 1)) + 1;  in dio_refill_pages()
202 					struct dio_submit *sdio)  in dio_get_page()  argument
204 	if (dio_pages_present(sdio) == 0) {  in dio_get_page()
207 		ret = dio_refill_pages(dio, sdio);  in dio_get_page()
210 		BUG_ON(dio_pages_present(sdio) == 0);  in dio_get_page()
212 	return dio->pages[sdio->head];  in dio_get_page()
358 dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,  in dio_bio_alloc()  argument
377 	sdio->bio = bio;  in dio_bio_alloc()
378 	sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;  in dio_bio_alloc()
388 static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)  in dio_bio_submit()  argument
390 	struct bio *bio = sdio->bio;  in dio_bio_submit()
404 	if (sdio->submit_io) {  in dio_bio_submit()
405 		sdio->submit_io(dio->rw, bio, dio->inode,  in dio_bio_submit()
406 			       sdio->logical_offset_in_bio);  in dio_bio_submit()
411 	sdio->bio = NULL;  in dio_bio_submit()
412 	sdio->boundary = 0;  in dio_bio_submit()
413 	sdio->logical_offset_in_bio = 0;  in dio_bio_submit()
419 static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio)  in dio_cleanup()  argument
421 	while (sdio->head < sdio->tail)  in dio_cleanup()
422 		page_cache_release(dio->pages[sdio->head++]);  in dio_cleanup()
516 static inline int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)  in dio_bio_reap()  argument
520 	if (sdio->reap_counter++ >= 64) {  in dio_bio_reap()
534 		sdio->reap_counter = 0;  in dio_bio_reap()
598 static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,  in get_more_blocks()  argument
606 	unsigned int i_blkbits = sdio->blkbits + sdio->blkfactor;  in get_more_blocks()
614 		BUG_ON(sdio->block_in_file >= sdio->final_block_in_request);  in get_more_blocks()
615 		fs_startblk = sdio->block_in_file >> sdio->blkfactor;  in get_more_blocks()
616 		fs_endblk = (sdio->final_block_in_request - 1) >>  in get_more_blocks()
617 					sdio->blkfactor;  in get_more_blocks()
636 			if (sdio->block_in_file < (i_size_read(dio->inode) >>  in get_more_blocks()
637 							sdio->blkbits))  in get_more_blocks()
641 		ret = (*sdio->get_block)(dio->inode, fs_startblk,  in get_more_blocks()
656 static inline int dio_new_bio(struct dio *dio, struct dio_submit *sdio,  in dio_new_bio()  argument
662 	ret = dio_bio_reap(dio, sdio);  in dio_new_bio()
665 	sector = start_sector << (sdio->blkbits - 9);  in dio_new_bio()
666 	nr_pages = min(sdio->pages_in_io, BIO_MAX_PAGES);  in dio_new_bio()
668 	dio_bio_alloc(dio, sdio, map_bh->b_bdev, sector, nr_pages);  in dio_new_bio()
669 	sdio->boundary = 0;  in dio_new_bio()
681 static inline int dio_bio_add_page(struct dio_submit *sdio)  in dio_bio_add_page()  argument
685 	ret = bio_add_page(sdio->bio, sdio->cur_page,  in dio_bio_add_page()
686 			sdio->cur_page_len, sdio->cur_page_offset);  in dio_bio_add_page()
687 	if (ret == sdio->cur_page_len) {  in dio_bio_add_page()
691 		if ((sdio->cur_page_len + sdio->cur_page_offset) == PAGE_SIZE)  in dio_bio_add_page()
692 			sdio->pages_in_io--;  in dio_bio_add_page()
693 		page_cache_get(sdio->cur_page);  in dio_bio_add_page()
694 		sdio->final_block_in_bio = sdio->cur_page_block +  in dio_bio_add_page()
695 			(sdio->cur_page_len >> sdio->blkbits);  in dio_bio_add_page()
713 static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,  in dio_send_cur_page()  argument
718 	if (sdio->bio) {  in dio_send_cur_page()
719 		loff_t cur_offset = sdio->cur_page_fs_offset;  in dio_send_cur_page()
720 		loff_t bio_next_offset = sdio->logical_offset_in_bio +  in dio_send_cur_page()
721 			sdio->bio->bi_iter.bi_size;  in dio_send_cur_page()
737 		if (sdio->final_block_in_bio != sdio->cur_page_block ||  in dio_send_cur_page()
739 			dio_bio_submit(dio, sdio);  in dio_send_cur_page()
742 	if (sdio->bio == NULL) {  in dio_send_cur_page()
743 		ret = dio_new_bio(dio, sdio, sdio->cur_page_block, map_bh);  in dio_send_cur_page()
748 	if (dio_bio_add_page(sdio) != 0) {  in dio_send_cur_page()
749 		dio_bio_submit(dio, sdio);  in dio_send_cur_page()
750 		ret = dio_new_bio(dio, sdio, sdio->cur_page_block, map_bh);  in dio_send_cur_page()
752 			ret = dio_bio_add_page(sdio);  in dio_send_cur_page()
778 submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,  in submit_page_section()  argument
794 	if (sdio->cur_page == page &&  in submit_page_section()
795 	    sdio->cur_page_offset + sdio->cur_page_len == offset &&  in submit_page_section()
796 	    sdio->cur_page_block +  in submit_page_section()
797 	    (sdio->cur_page_len >> sdio->blkbits) == blocknr) {  in submit_page_section()
798 		sdio->cur_page_len += len;  in submit_page_section()
805 	if (sdio->cur_page) {  in submit_page_section()
806 		ret = dio_send_cur_page(dio, sdio, map_bh);  in submit_page_section()
807 		page_cache_release(sdio->cur_page);  in submit_page_section()
808 		sdio->cur_page = NULL;  in submit_page_section()
814 	sdio->cur_page = page;  in submit_page_section()
815 	sdio->cur_page_offset = offset;  in submit_page_section()
816 	sdio->cur_page_len = len;  in submit_page_section()
817 	sdio->cur_page_block = blocknr;  in submit_page_section()
818 	sdio->cur_page_fs_offset = sdio->block_in_file << sdio->blkbits;  in submit_page_section()
824 	if (sdio->boundary) {  in submit_page_section()
825 		ret = dio_send_cur_page(dio, sdio, map_bh);  in submit_page_section()
826 		dio_bio_submit(dio, sdio);  in submit_page_section()
827 		page_cache_release(sdio->cur_page);  in submit_page_section()
828 		sdio->cur_page = NULL;  in submit_page_section()
860 static inline void dio_zero_block(struct dio *dio, struct dio_submit *sdio,  in dio_zero_block()  argument
868 	sdio->start_zero_done = 1;  in dio_zero_block()
869 	if (!sdio->blkfactor || !buffer_new(map_bh))  in dio_zero_block()
872 	dio_blocks_per_fs_block = 1 << sdio->blkfactor;  in dio_zero_block()
873 	this_chunk_blocks = sdio->block_in_file & (dio_blocks_per_fs_block - 1);  in dio_zero_block()
885 	this_chunk_bytes = this_chunk_blocks << sdio->blkbits;  in dio_zero_block()
888 	if (submit_page_section(dio, sdio, page, 0, this_chunk_bytes,  in dio_zero_block()
889 				sdio->next_block_for_io, map_bh))  in dio_zero_block()
892 	sdio->next_block_for_io += this_chunk_blocks;  in dio_zero_block()
911 static int do_direct_IO(struct dio *dio, struct dio_submit *sdio,  in do_direct_IO()  argument
914 	const unsigned blkbits = sdio->blkbits;  in do_direct_IO()
917 	while (sdio->block_in_file < sdio->final_block_in_request) {  in do_direct_IO()
921 		page = dio_get_page(dio, sdio);  in do_direct_IO()
926 		from = sdio->head ? 0 : sdio->from;  in do_direct_IO()
927 		to = (sdio->head == sdio->tail - 1) ? sdio->to : PAGE_SIZE;  in do_direct_IO()
928 		sdio->head++;  in do_direct_IO()
935 			if (sdio->blocks_available == 0) {  in do_direct_IO()
942 				ret = get_more_blocks(dio, sdio, map_bh);  in do_direct_IO()
950 				sdio->blocks_available =  in do_direct_IO()
951 						map_bh->b_size >> sdio->blkbits;  in do_direct_IO()
952 				sdio->next_block_for_io =  in do_direct_IO()
953 					map_bh->b_blocknr << sdio->blkfactor;  in do_direct_IO()
957 				if (!sdio->blkfactor)  in do_direct_IO()
960 				blkmask = (1 << sdio->blkfactor) - 1;  in do_direct_IO()
961 				dio_remainder = (sdio->block_in_file & blkmask);  in do_direct_IO()
975 					sdio->next_block_for_io += dio_remainder;  in do_direct_IO()
976 				sdio->blocks_available -= dio_remainder;  in do_direct_IO()
995 				if (sdio->block_in_file >=  in do_direct_IO()
1002 				sdio->block_in_file++;  in do_direct_IO()
1013 			if (unlikely(sdio->blkfactor && !sdio->start_zero_done))  in do_direct_IO()
1014 				dio_zero_block(dio, sdio, 0, map_bh);  in do_direct_IO()
1020 			this_chunk_blocks = sdio->blocks_available;  in do_direct_IO()
1024 			u = sdio->final_block_in_request - sdio->block_in_file;  in do_direct_IO()
1030 			if (this_chunk_blocks == sdio->blocks_available)  in do_direct_IO()
1031 				sdio->boundary = buffer_boundary(map_bh);  in do_direct_IO()
1032 			ret = submit_page_section(dio, sdio, page,  in do_direct_IO()
1035 						  sdio->next_block_for_io,  in do_direct_IO()
1041 			sdio->next_block_for_io += this_chunk_blocks;  in do_direct_IO()
1043 			sdio->block_in_file += this_chunk_blocks;  in do_direct_IO()
1046 			sdio->blocks_available -= this_chunk_blocks;  in do_direct_IO()
1048 			BUG_ON(sdio->block_in_file > sdio->final_block_in_request);  in do_direct_IO()
1049 			if (sdio->block_in_file == sdio->final_block_in_request)  in do_direct_IO()
1120 	struct dio_submit sdio = { 0, };  in do_blockdev_direct_IO()  local
1224 	sdio.blkbits = blkbits;  in do_blockdev_direct_IO()
1225 	sdio.blkfactor = i_blkbits - blkbits;  in do_blockdev_direct_IO()
1226 	sdio.block_in_file = offset >> blkbits;  in do_blockdev_direct_IO()
1228 	sdio.get_block = get_block;  in do_blockdev_direct_IO()
1230 	sdio.submit_io = submit_io;  in do_blockdev_direct_IO()
1231 	sdio.final_block_in_bio = -1;  in do_blockdev_direct_IO()
1232 	sdio.next_block_for_io = -1;  in do_blockdev_direct_IO()
1240 	sdio.iter = iter;  in do_blockdev_direct_IO()
1241 	sdio.final_block_in_request =  in do_blockdev_direct_IO()
1248 	if (unlikely(sdio.blkfactor))  in do_blockdev_direct_IO()
1249 		sdio.pages_in_io = 2;  in do_blockdev_direct_IO()
1251 	sdio.pages_in_io += iov_iter_npages(iter, INT_MAX);  in do_blockdev_direct_IO()
1255 	retval = do_direct_IO(dio, &sdio, &map_bh);  in do_blockdev_direct_IO()
1257 		dio_cleanup(dio, &sdio);  in do_blockdev_direct_IO()
1270 	dio_zero_block(dio, &sdio, 1, &map_bh);  in do_blockdev_direct_IO()
1272 	if (sdio.cur_page) {  in do_blockdev_direct_IO()
1275 		ret2 = dio_send_cur_page(dio, &sdio, &map_bh);  in do_blockdev_direct_IO()
1278 		page_cache_release(sdio.cur_page);  in do_blockdev_direct_IO()
1279 		sdio.cur_page = NULL;  in do_blockdev_direct_IO()
1281 	if (sdio.bio)  in do_blockdev_direct_IO()
1282 		dio_bio_submit(dio, &sdio);  in do_blockdev_direct_IO()
1290 	dio_cleanup(dio, &sdio);  in do_blockdev_direct_IO()