1 // SPDX-License-Identifier: GPL-2.0-or-later
21 	struct netfs_io_request *rreq = subreq->rreq;  in netfs_prepare_dio_read_iterator()
24 	rsize = umin(subreq->len, rreq->io_streams[0].sreq_max_len);  in netfs_prepare_dio_read_iterator()
25 	subreq->len = rsize;  in netfs_prepare_dio_read_iterator()
27 	if (unlikely(rreq->io_streams[0].sreq_max_segs)) {  in netfs_prepare_dio_read_iterator()
28 		size_t limit = netfs_limit_iter(&rreq->buffer.iter, 0, rsize,  in netfs_prepare_dio_read_iterator()
29 						rreq->io_streams[0].sreq_max_segs);  in netfs_prepare_dio_read_iterator()
32 			subreq->len = limit;  in netfs_prepare_dio_read_iterator()
39 	subreq->io_iter	= rreq->buffer.iter;  in netfs_prepare_dio_read_iterator()
40 	iov_iter_truncate(&subreq->io_iter, subreq->len);  in netfs_prepare_dio_read_iterator()
41 	iov_iter_advance(&rreq->buffer.iter, subreq->len);  in netfs_prepare_dio_read_iterator()
45  * Perform a read to a buffer from the server, slicing up the region to be read
50 	struct netfs_io_stream *stream = &rreq->io_streams[0];  in netfs_dispatch_unbuffered_reads()
51 	unsigned long long start = rreq->start;  in netfs_dispatch_unbuffered_reads()
52 	ssize_t size = rreq->len;  in netfs_dispatch_unbuffered_reads()
61 			ret = -ENOMEM;  in netfs_dispatch_unbuffered_reads()
65 		subreq->source	= NETFS_DOWNLOAD_FROM_SERVER;  in netfs_dispatch_unbuffered_reads()
66 		subreq->start	= start;  in netfs_dispatch_unbuffered_reads()
67 		subreq->len	= size;  in netfs_dispatch_unbuffered_reads()
69 		__set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags);  in netfs_dispatch_unbuffered_reads()
71 		spin_lock(&rreq->lock);  in netfs_dispatch_unbuffered_reads()
72 		list_add_tail(&subreq->rreq_link, &stream->subrequests);  in netfs_dispatch_unbuffered_reads()
73 		if (list_is_first(&subreq->rreq_link, &stream->subrequests)) {  in netfs_dispatch_unbuffered_reads()
74 			stream->front = subreq;  in netfs_dispatch_unbuffered_reads()
75 			if (!stream->active) {  in netfs_dispatch_unbuffered_reads()
76 				stream->collected_to = stream->front->start;  in netfs_dispatch_unbuffered_reads()
78 				smp_store_release(&stream->active, true);  in netfs_dispatch_unbuffered_reads()
82 		spin_unlock(&rreq->lock);  in netfs_dispatch_unbuffered_reads()
85 		if (rreq->netfs_ops->prepare_read) {  in netfs_dispatch_unbuffered_reads()
86 			ret = rreq->netfs_ops->prepare_read(subreq);  in netfs_dispatch_unbuffered_reads()
94 		slice = subreq->len;  in netfs_dispatch_unbuffered_reads()
95 		size -= slice;  in netfs_dispatch_unbuffered_reads()
97 		rreq->submitted += slice;  in netfs_dispatch_unbuffered_reads()
100 			set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags);  in netfs_dispatch_unbuffered_reads()
103 		rreq->netfs_ops->issue_read(subreq);  in netfs_dispatch_unbuffered_reads()
105 		if (test_bit(NETFS_RREQ_PAUSE, &rreq->flags))  in netfs_dispatch_unbuffered_reads()
107 		if (test_bit(NETFS_RREQ_FAILED, &rreq->flags))  in netfs_dispatch_unbuffered_reads()
114 		set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags);  in netfs_dispatch_unbuffered_reads()
122  * Perform a read to an application buffer, bypassing the pagecache and the
125 static ssize_t netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync)  in netfs_unbuffered_read()  argument
129 	_enter("R=%x %llx-%llx",  in netfs_unbuffered_read()
130 	       rreq->debug_id, rreq->start, rreq->start + rreq->len - 1);  in netfs_unbuffered_read()
132 	if (rreq->len == 0) {  in netfs_unbuffered_read()
133 		pr_err("Zero-sized read [R=%x]\n", rreq->debug_id);  in netfs_unbuffered_read()
135 		return -EIO;  in netfs_unbuffered_read()
140 	inode_dio_begin(rreq->inode);  in netfs_unbuffered_read()
144 	if (!rreq->submitted) {  in netfs_unbuffered_read()
146 		inode_dio_end(rreq->inode);  in netfs_unbuffered_read()
151 	if (sync)  in netfs_unbuffered_read()
154 		ret = -EIOCBQUEUED;  in netfs_unbuffered_read()
161  * netfs_unbuffered_read_iter_locked - Perform an unbuffered or direct I/O read
162  * @iocb: The I/O control descriptor describing the read
163  * @iter: The output buffer (also specifies read length)
175 	bool sync = is_sync_kiocb(iocb);  in netfs_unbuffered_read_iter_locked()  local
185 	file_accessed(iocb->ki_filp);  in netfs_unbuffered_read_iter_locked()
187 	rreq = netfs_alloc_request(iocb->ki_filp->f_mapping, iocb->ki_filp,  in netfs_unbuffered_read_iter_locked()
188 				   iocb->ki_pos, orig_count,  in netfs_unbuffered_read_iter_locked()
189 				   iocb->ki_flags & IOCB_DIRECT ?  in netfs_unbuffered_read_iter_locked()
195 	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_dio_read);  in netfs_unbuffered_read_iter_locked()
207 		ret = netfs_extract_user_iter(iter, rreq->len, &rreq->buffer.iter, 0);  in netfs_unbuffered_read_iter_locked()
210 		rreq->direct_bv = (struct bio_vec *)rreq->buffer.iter.bvec;  in netfs_unbuffered_read_iter_locked()
211 		rreq->direct_bv_count = ret;  in netfs_unbuffered_read_iter_locked()
212 		rreq->direct_bv_unpin = iov_iter_extract_will_pin(iter);  in netfs_unbuffered_read_iter_locked()
213 		rreq->len = iov_iter_count(&rreq->buffer.iter);  in netfs_unbuffered_read_iter_locked()
215 		rreq->buffer.iter = *iter;  in netfs_unbuffered_read_iter_locked()
216 		rreq->len = orig_count;  in netfs_unbuffered_read_iter_locked()
217 		rreq->direct_bv_unpin = false;  in netfs_unbuffered_read_iter_locked()
223 	if (!sync) {  in netfs_unbuffered_read_iter_locked()
224 		rreq->iocb = iocb;  in netfs_unbuffered_read_iter_locked()
225 		__set_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags);  in netfs_unbuffered_read_iter_locked()
228 	ret = netfs_unbuffered_read(rreq, sync);  in netfs_unbuffered_read_iter_locked()
230 		goto out; /* May be -EIOCBQUEUED */  in netfs_unbuffered_read_iter_locked()
231 	if (sync) {  in netfs_unbuffered_read_iter_locked()
233 		iocb->ki_pos += rreq->transferred;  in netfs_unbuffered_read_iter_locked()
234 		ret = rreq->transferred;  in netfs_unbuffered_read_iter_locked()
240 		orig_count -= ret;  in netfs_unbuffered_read_iter_locked()
250  * netfs_unbuffered_read_iter - Perform an unbuffered or direct I/O read
251  * @iocb: The I/O control descriptor describing the read
252  * @iter: The output buffer (also specifies read length)
259 	struct inode *inode = file_inode(iocb->ki_filp);  in netfs_unbuffered_read_iter()
262 	if (!iter->count)  in netfs_unbuffered_read_iter()