158 static inline unsigned dio_pages_present(struct dio_submit *sdio)  in dio_pages_present()  argument
160 	return sdio->tail - sdio->head;  in dio_pages_present()
166 static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)  in dio_refill_pages()  argument
172 	ret = iov_iter_extract_pages(sdio->iter, &pages, LONG_MAX,  in dio_refill_pages()
173 				     DIO_PAGES, 0, &sdio->from);  in dio_refill_pages()
175 	if (ret < 0 && sdio->blocks_available && dio_op == REQ_OP_WRITE) {  in dio_refill_pages()
184 		sdio->head = 0;  in dio_refill_pages()
185 		sdio->tail = 1;  in dio_refill_pages()
186 		sdio->from = 0;  in dio_refill_pages()
187 		sdio->to = PAGE_SIZE;  in dio_refill_pages()
192 		ret += sdio->from;  in dio_refill_pages()
193 		sdio->head = 0;  in dio_refill_pages()
194 		sdio->tail = (ret + PAGE_SIZE - 1) / PAGE_SIZE;  in dio_refill_pages()
195 		sdio->to = ((ret - 1) & (PAGE_SIZE - 1)) + 1;  in dio_refill_pages()
208 					struct dio_submit *sdio)  in dio_get_page()  argument
210 	if (dio_pages_present(sdio) == 0) {  in dio_get_page()
213 		ret = dio_refill_pages(dio, sdio);  in dio_get_page()
216 		BUG_ON(dio_pages_present(sdio) == 0);  in dio_get_page()
218 	return dio->pages[sdio->head];  in dio_get_page()
394 dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,  in dio_bio_alloc()  argument
414 	sdio->bio = bio;  in dio_bio_alloc()
415 	sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;  in dio_bio_alloc()
425 static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)  in dio_bio_submit()  argument
428 	struct bio *bio = sdio->bio;  in dio_bio_submit()
444 	sdio->bio = NULL;  in dio_bio_submit()
445 	sdio->boundary = 0;  in dio_bio_submit()
446 	sdio->logical_offset_in_bio = 0;  in dio_bio_submit()
452 static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio)  in dio_cleanup()  argument
455 		unpin_user_pages(dio->pages + sdio->head,  in dio_cleanup()
456 				 sdio->tail - sdio->head);  in dio_cleanup()
457 	sdio->head = sdio->tail;  in dio_cleanup()
545 static inline int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)  in dio_bio_reap()  argument
549 	if (sdio->reap_counter++ >= 64) {  in dio_bio_reap()
563 		sdio->reap_counter = 0;  in dio_bio_reap()
582  * of available blocks at sdio->blocks_available.  These are in units of the
603 static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,  in get_more_blocks()  argument
612 	unsigned int i_blkbits = sdio->blkbits + sdio->blkfactor;  in get_more_blocks()
621 		BUG_ON(sdio->block_in_file >= sdio->final_block_in_request);  in get_more_blocks()
622 		fs_startblk = sdio->block_in_file >> sdio->blkfactor;  in get_more_blocks()
623 		fs_endblk = (sdio->final_block_in_request - 1) >>  in get_more_blocks()
624 					sdio->blkfactor;  in get_more_blocks()
648 		ret = (*sdio->get_block)(dio->inode, fs_startblk,  in get_more_blocks()
663 static inline int dio_new_bio(struct dio *dio, struct dio_submit *sdio,  in dio_new_bio()  argument
669 	ret = dio_bio_reap(dio, sdio);  in dio_new_bio()
672 	sector = start_sector << (sdio->blkbits - 9);  in dio_new_bio()
673 	nr_pages = bio_max_segs(sdio->pages_in_io);  in dio_new_bio()
675 	dio_bio_alloc(dio, sdio, map_bh->b_bdev, sector, nr_pages);  in dio_new_bio()
676 	sdio->boundary = 0;  in dio_new_bio()
688 static inline int dio_bio_add_page(struct dio *dio, struct dio_submit *sdio)  in dio_bio_add_page()  argument
692 	ret = bio_add_page(sdio->bio, sdio->cur_page,  in dio_bio_add_page()
693 			sdio->cur_page_len, sdio->cur_page_offset);  in dio_bio_add_page()
694 	if (ret == sdio->cur_page_len) {  in dio_bio_add_page()
698 		if ((sdio->cur_page_len + sdio->cur_page_offset) == PAGE_SIZE)  in dio_bio_add_page()
699 			sdio->pages_in_io--;  in dio_bio_add_page()
700 		dio_pin_page(dio, sdio->cur_page);  in dio_bio_add_page()
701 		sdio->final_block_in_bio = sdio->cur_page_block +  in dio_bio_add_page()
702 			(sdio->cur_page_len >> sdio->blkbits);  in dio_bio_add_page()
720 static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,  in dio_send_cur_page()  argument
725 	if (sdio->bio) {  in dio_send_cur_page()
726 		loff_t cur_offset = sdio->cur_page_fs_offset;  in dio_send_cur_page()
727 		loff_t bio_next_offset = sdio->logical_offset_in_bio +  in dio_send_cur_page()
728 			sdio->bio->bi_iter.bi_size;  in dio_send_cur_page()
744 		if (sdio->final_block_in_bio != sdio->cur_page_block ||  in dio_send_cur_page()
746 			dio_bio_submit(dio, sdio);  in dio_send_cur_page()
749 	if (sdio->bio == NULL) {  in dio_send_cur_page()
750 		ret = dio_new_bio(dio, sdio, sdio->cur_page_block, map_bh);  in dio_send_cur_page()
755 	if (dio_bio_add_page(dio, sdio) != 0) {  in dio_send_cur_page()
756 		dio_bio_submit(dio, sdio);  in dio_send_cur_page()
757 		ret = dio_new_bio(dio, sdio, sdio->cur_page_block, map_bh);  in dio_send_cur_page()
759 			ret = dio_bio_add_page(dio, sdio);  in dio_send_cur_page()
785 submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,  in submit_page_section()  argument
791 	int boundary = sdio->boundary;	/* dio_send_cur_page may clear it */  in submit_page_section()
803 	if (sdio->cur_page == page &&  in submit_page_section()
804 	    sdio->cur_page_offset + sdio->cur_page_len == offset &&  in submit_page_section()
805 	    sdio->cur_page_block +  in submit_page_section()
806 	    (sdio->cur_page_len >> sdio->blkbits) == blocknr) {  in submit_page_section()
807 		sdio->cur_page_len += len;  in submit_page_section()
814 	if (sdio->cur_page) {  in submit_page_section()
815 		ret = dio_send_cur_page(dio, sdio, map_bh);  in submit_page_section()
816 		dio_unpin_page(dio, sdio->cur_page);  in submit_page_section()
817 		sdio->cur_page = NULL;  in submit_page_section()
823 	sdio->cur_page = page;  in submit_page_section()
824 	sdio->cur_page_offset = offset;  in submit_page_section()
825 	sdio->cur_page_len = len;  in submit_page_section()
826 	sdio->cur_page_block = blocknr;  in submit_page_section()
827 	sdio->cur_page_fs_offset = sdio->block_in_file << sdio->blkbits;  in submit_page_section()
834 		ret = dio_send_cur_page(dio, sdio, map_bh);  in submit_page_section()
835 		if (sdio->bio)  in submit_page_section()
836 			dio_bio_submit(dio, sdio);  in submit_page_section()
837 		dio_unpin_page(dio, sdio->cur_page);  in submit_page_section()
838 		sdio->cur_page = NULL;  in submit_page_section()
852 static inline void dio_zero_block(struct dio *dio, struct dio_submit *sdio,  in dio_zero_block()  argument
860 	sdio->start_zero_done = 1;  in dio_zero_block()
861 	if (!sdio->blkfactor || !buffer_new(map_bh))  in dio_zero_block()
864 	dio_blocks_per_fs_block = 1 << sdio->blkfactor;  in dio_zero_block()
865 	this_chunk_blocks = sdio->block_in_file & (dio_blocks_per_fs_block - 1);  in dio_zero_block()
877 	this_chunk_bytes = this_chunk_blocks << sdio->blkbits;  in dio_zero_block()
880 	if (submit_page_section(dio, sdio, page, 0, this_chunk_bytes,  in dio_zero_block()
881 				sdio->next_block_for_io, map_bh))  in dio_zero_block()
884 	sdio->next_block_for_io += this_chunk_blocks;  in dio_zero_block()
903 static int do_direct_IO(struct dio *dio, struct dio_submit *sdio,  in do_direct_IO()  argument
907 	const unsigned blkbits = sdio->blkbits;  in do_direct_IO()
908 	const unsigned i_blkbits = blkbits + sdio->blkfactor;  in do_direct_IO()
911 	while (sdio->block_in_file < sdio->final_block_in_request) {  in do_direct_IO()
915 		page = dio_get_page(dio, sdio);  in do_direct_IO()
920 		from = sdio->head ? 0 : sdio->from;  in do_direct_IO()
921 		to = (sdio->head == sdio->tail - 1) ? sdio->to : PAGE_SIZE;  in do_direct_IO()
922 		sdio->head++;  in do_direct_IO()
929 			if (sdio->blocks_available == 0) {  in do_direct_IO()
936 				ret = get_more_blocks(dio, sdio, map_bh);  in do_direct_IO()
944 				sdio->blocks_available =  in do_direct_IO()
946 				sdio->next_block_for_io =  in do_direct_IO()
947 					map_bh->b_blocknr << sdio->blkfactor;  in do_direct_IO()
955 				if (!sdio->blkfactor)  in do_direct_IO()
958 				blkmask = (1 << sdio->blkfactor) - 1;  in do_direct_IO()
959 				dio_remainder = (sdio->block_in_file & blkmask);  in do_direct_IO()
973 					sdio->next_block_for_io += dio_remainder;  in do_direct_IO()
974 				sdio->blocks_available -= dio_remainder;  in do_direct_IO()
993 				if (sdio->block_in_file >=  in do_direct_IO()
1000 				sdio->block_in_file++;  in do_direct_IO()
1011 			if (unlikely(sdio->blkfactor && !sdio->start_zero_done))  in do_direct_IO()
1012 				dio_zero_block(dio, sdio, 0, map_bh);  in do_direct_IO()
1018 			this_chunk_blocks = sdio->blocks_available;  in do_direct_IO()
1022 			u = sdio->final_block_in_request - sdio->block_in_file;  in do_direct_IO()
1028 			if (this_chunk_blocks == sdio->blocks_available)  in do_direct_IO()
1029 				sdio->boundary = buffer_boundary(map_bh);  in do_direct_IO()
1030 			ret = submit_page_section(dio, sdio, page,  in do_direct_IO()
1033 						  sdio->next_block_for_io,  in do_direct_IO()
1039 			sdio->next_block_for_io += this_chunk_blocks;  in do_direct_IO()
1041 			sdio->block_in_file += this_chunk_blocks;  in do_direct_IO()
1044 			sdio->blocks_available -= this_chunk_blocks;  in do_direct_IO()
1046 			BUG_ON(sdio->block_in_file > sdio->final_block_in_request);  in do_direct_IO()
1047 			if (sdio->block_in_file == sdio->final_block_in_request)  in do_direct_IO()
1100  * NOTE: if you pass "sdio" to anything by pointer make sure that function
1118 	struct dio_submit sdio = { NULL, };  in __blockdev_direct_IO()  local
1214 	sdio.blkbits = blkbits;  in __blockdev_direct_IO()
1215 	sdio.blkfactor = i_blkbits - blkbits;  in __blockdev_direct_IO()
1216 	sdio.block_in_file = offset >> blkbits;  in __blockdev_direct_IO()
1218 	sdio.get_block = get_block;  in __blockdev_direct_IO()
1220 	sdio.final_block_in_bio = -1;  in __blockdev_direct_IO()
1221 	sdio.next_block_for_io = -1;  in __blockdev_direct_IO()
1229 	sdio.iter = iter;  in __blockdev_direct_IO()
1230 	sdio.final_block_in_request = end >> blkbits;  in __blockdev_direct_IO()
1236 	if (unlikely(sdio.blkfactor))  in __blockdev_direct_IO()
1237 		sdio.pages_in_io = 2;  in __blockdev_direct_IO()
1239 	sdio.pages_in_io += iov_iter_npages(iter, INT_MAX);  in __blockdev_direct_IO()
1243 	retval = do_direct_IO(dio, &sdio, &map_bh);  in __blockdev_direct_IO()
1245 		dio_cleanup(dio, &sdio);  in __blockdev_direct_IO()
1258 	dio_zero_block(dio, &sdio, 1, &map_bh);  in __blockdev_direct_IO()
1260 	if (sdio.cur_page) {  in __blockdev_direct_IO()
1263 		ret2 = dio_send_cur_page(dio, &sdio, &map_bh);  in __blockdev_direct_IO()
1266 		dio_unpin_page(dio, sdio.cur_page);  in __blockdev_direct_IO()
1267 		sdio.cur_page = NULL;  in __blockdev_direct_IO()
1269 	if (sdio.bio)  in __blockdev_direct_IO()
1270 		dio_bio_submit(dio, &sdio);  in __blockdev_direct_IO()
1278 	dio_cleanup(dio, &sdio);  in __blockdev_direct_IO()