1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Network filesystem high-level buffered read support.
20 	pgoff_t start_page = rreq->start / PAGE_SIZE;  in netfs_rreq_unlock_folios()
21 	pgoff_t last_page = ((rreq->start + rreq->len) / PAGE_SIZE) - 1;  in netfs_rreq_unlock_folios()
25 	XA_STATE(xas, &rreq->mapping->i_pages, start_page);  in netfs_rreq_unlock_folios()
27 	if (test_bit(NETFS_RREQ_FAILED, &rreq->flags)) {  in netfs_rreq_unlock_folios()
28 		__clear_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags);  in netfs_rreq_unlock_folios()
29 		list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {  in netfs_rreq_unlock_folios()
30 			__clear_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags);  in netfs_rreq_unlock_folios()
40 	subreq = list_first_entry(&rreq->subrequests,  in netfs_rreq_unlock_folios()
42 	subreq_failed = (subreq->error < 0);  in netfs_rreq_unlock_folios()
55 		pg_end = folio_pos(folio) + folio_size(folio) - 1;  in netfs_rreq_unlock_folios()
65 			if (!folio_started && test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {  in netfs_rreq_unlock_folios()
70 			sreq_end = subreq->start + subreq->len - 1;  in netfs_rreq_unlock_folios()
74 			account += subreq->transferred;  in netfs_rreq_unlock_folios()
75 			if (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {  in netfs_rreq_unlock_folios()
77 				subreq_failed = (subreq->error < 0);  in netfs_rreq_unlock_folios()
92 		if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) {  in netfs_rreq_unlock_folios()
93 			if (folio_index(folio) == rreq->no_unlock_folio &&  in netfs_rreq_unlock_folios()
94 			    test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags))  in netfs_rreq_unlock_folios()
103 	if (rreq->netfs_ops->done)  in netfs_rreq_unlock_folios()
104 		rreq->netfs_ops->done(rreq);  in netfs_rreq_unlock_folios()
110 	struct netfs_cache_resources *cres = &rreq->cache_resources;  in netfs_cache_expand_readahead()
112 	if (cres->ops && cres->ops->expand_readahead)  in netfs_cache_expand_readahead()
113 		cres->ops->expand_readahead(cres, _start, _len, i_size);  in netfs_cache_expand_readahead()
122 	netfs_cache_expand_readahead(rreq, &rreq->start, &rreq->len, rreq->i_size);  in netfs_rreq_expand()
127 	if (rreq->netfs_ops->expand_readahead)  in netfs_rreq_expand()
128 		rreq->netfs_ops->expand_readahead(rreq);  in netfs_rreq_expand()
139 	if (rreq->start  != readahead_pos(ractl) ||  in netfs_rreq_expand()
140 	    rreq->len != readahead_length(ractl)) {  in netfs_rreq_expand()
141 		readahead_expand(ractl, rreq->start, rreq->len);  in netfs_rreq_expand()
142 		rreq->start  = readahead_pos(ractl);  in netfs_rreq_expand()
143 		rreq->len = readahead_length(ractl);  in netfs_rreq_expand()
151  * netfs_readahead - Helper to manage a read request
155  * the netfs if not.  Space beyond the EOF is zero-filled.  Multiple I/O
168 	struct netfs_inode *ctx = netfs_inode(ractl->mapping->host);  in netfs_readahead()
176 	rreq = netfs_alloc_request(ractl->mapping, ractl->file,  in netfs_readahead()
183 	if (ctx->ops->begin_cache_operation) {  in netfs_readahead()
184 		ret = ctx->ops->begin_cache_operation(rreq);  in netfs_readahead()
185 		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)  in netfs_readahead()
211  * netfs_read_folio - Helper to manage a read_folio request
216  * possible, or the netfs if not.  Space beyond the EOF is zero-filled.
228 	struct netfs_inode *ctx = netfs_inode(mapping->host);  in netfs_read_folio()
241 	if (ctx->ops->begin_cache_operation) {  in netfs_read_folio()
242 		ret = ctx->ops->begin_cache_operation(rreq);  in netfs_read_folio()
243 		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)  in netfs_read_folio()
248 	trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage);  in netfs_read_folio()
264  * @always_fill: T if the folio should always be completely filled/cleared
267  * - full folio write
268  * - write that lies in a folio that is completely beyond EOF
269  * - write that covers the folio from start to EOF or beyond it
283 		if (pos - offset + len <= i_size)  in netfs_skip_folio_read()
285 		zero_user_segment(&folio->page, 0, plen);  in netfs_skip_folio_read()
295 	if (pos - offset >= i_size)  in netfs_skip_folio_read()
304 	zero_user_segments(&folio->page, 0, offset, offset + len, plen);  in netfs_skip_folio_read()
309  * netfs_write_begin - Helper to prepare for writing
318  * Pre-read data for a write-begin request by drawing data from the cache if
319  * possible, or the netfs if not.  Space beyond the EOF is zero-filled.
334  * will cause the folio to be re-got and the process to be retried.
359 	if (ctx->ops->check_write_begin) {  in netfs_write_begin()
361 		ret = ctx->ops->check_write_begin(file, pos, len, &folio, _fsdata);  in netfs_write_begin()
373 	/* If the page is beyond the EOF, we want to clear it - unless it's  in netfs_write_begin()
390 	rreq->no_unlock_folio	= folio_index(folio);  in netfs_write_begin()
391 	__set_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags);  in netfs_write_begin()
393 	if (ctx->ops->begin_cache_operation) {  in netfs_write_begin()
394 		ret = ctx->ops->begin_cache_operation(rreq);  in netfs_write_begin()
395 		if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS)  in netfs_write_begin()