1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * This file contians vfs address (mmap) ops for 9P2000. |
4 | * |
5 | * Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com> |
6 | * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> |
7 | */ |
8 | |
9 | #include <linux/module.h> |
10 | #include <linux/errno.h> |
11 | #include <linux/fs.h> |
12 | #include <linux/file.h> |
13 | #include <linux/stat.h> |
14 | #include <linux/string.h> |
15 | #include <linux/pagemap.h> |
16 | #include <linux/sched.h> |
17 | #include <linux/swap.h> |
18 | #include <linux/uio.h> |
19 | #include <linux/netfs.h> |
20 | #include <net/9p/9p.h> |
21 | #include <net/9p/client.h> |
22 | #include <trace/events/netfs.h> |
23 | |
24 | #include "v9fs.h" |
25 | #include "v9fs_vfs.h" |
26 | #include "cache.h" |
27 | #include "fid.h" |
28 | |
29 | static void v9fs_upload_to_server(struct netfs_io_subrequest *subreq) |
30 | { |
31 | struct p9_fid *fid = subreq->rreq->netfs_priv; |
32 | int err, len; |
33 | |
34 | trace_netfs_sreq(sreq: subreq, what: netfs_sreq_trace_submit); |
35 | len = p9_client_write(fid, offset: subreq->start, from: &subreq->io_iter, err: &err); |
36 | netfs_write_subrequest_terminated(op: subreq, transferred_or_error: len ?: err, was_async: false); |
37 | } |
38 | |
39 | static void v9fs_upload_to_server_worker(struct work_struct *work) |
40 | { |
41 | struct netfs_io_subrequest *subreq = |
42 | container_of(work, struct netfs_io_subrequest, work); |
43 | |
44 | v9fs_upload_to_server(subreq); |
45 | } |
46 | |
47 | /* |
48 | * Set up write requests for a writeback slice. We need to add a write request |
49 | * for each write we want to make. |
50 | */ |
51 | static void v9fs_create_write_requests(struct netfs_io_request *wreq, loff_t start, size_t len) |
52 | { |
53 | struct netfs_io_subrequest *subreq; |
54 | |
55 | subreq = netfs_create_write_request(wreq, dest: NETFS_UPLOAD_TO_SERVER, |
56 | start, len, worker: v9fs_upload_to_server_worker); |
57 | if (subreq) |
58 | netfs_queue_write_request(subreq); |
59 | } |
60 | |
61 | /** |
62 | * v9fs_issue_read - Issue a read from 9P |
63 | * @subreq: The read to make |
64 | */ |
65 | static void v9fs_issue_read(struct netfs_io_subrequest *subreq) |
66 | { |
67 | struct netfs_io_request *rreq = subreq->rreq; |
68 | struct p9_fid *fid = rreq->netfs_priv; |
69 | int total, err; |
70 | |
71 | total = p9_client_read(fid, offset: subreq->start + subreq->transferred, |
72 | to: &subreq->io_iter, err: &err); |
73 | |
74 | /* if we just extended the file size, any portion not in |
75 | * cache won't be on server and is zeroes */ |
76 | __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); |
77 | |
78 | netfs_subreq_terminated(subreq, err ?: total, false); |
79 | } |
80 | |
81 | /** |
82 | * v9fs_init_request - Initialise a request |
83 | * @rreq: The read request |
84 | * @file: The file being read from |
85 | */ |
86 | static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file) |
87 | { |
88 | struct p9_fid *fid; |
89 | bool writing = (rreq->origin == NETFS_READ_FOR_WRITE || |
90 | rreq->origin == NETFS_WRITEBACK || |
91 | rreq->origin == NETFS_WRITETHROUGH || |
92 | rreq->origin == NETFS_LAUNDER_WRITE || |
93 | rreq->origin == NETFS_UNBUFFERED_WRITE || |
94 | rreq->origin == NETFS_DIO_WRITE); |
95 | |
96 | if (file) { |
97 | fid = file->private_data; |
98 | if (!fid) |
99 | goto no_fid; |
100 | p9_fid_get(fid); |
101 | } else { |
102 | fid = v9fs_fid_find_inode(inode: rreq->inode, want_writeable: writing, INVALID_UID, any: true); |
103 | if (!fid) |
104 | goto no_fid; |
105 | } |
106 | |
107 | /* we might need to read from a fid that was opened write-only |
108 | * for read-modify-write of page cache, use the writeback fid |
109 | * for that */ |
110 | WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR)); |
111 | rreq->netfs_priv = fid; |
112 | return 0; |
113 | |
114 | no_fid: |
115 | WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n" , |
116 | rreq->inode->i_ino); |
117 | return -EINVAL; |
118 | } |
119 | |
120 | /** |
121 | * v9fs_free_request - Cleanup request initialized by v9fs_init_rreq |
122 | * @rreq: The I/O request to clean up |
123 | */ |
124 | static void v9fs_free_request(struct netfs_io_request *rreq) |
125 | { |
126 | struct p9_fid *fid = rreq->netfs_priv; |
127 | |
128 | p9_fid_put(fid); |
129 | } |
130 | |
131 | const struct netfs_request_ops v9fs_req_ops = { |
132 | .init_request = v9fs_init_request, |
133 | .free_request = v9fs_free_request, |
134 | .issue_read = v9fs_issue_read, |
135 | .create_write_requests = v9fs_create_write_requests, |
136 | }; |
137 | |
138 | const struct address_space_operations v9fs_addr_operations = { |
139 | .read_folio = netfs_read_folio, |
140 | .readahead = netfs_readahead, |
141 | .dirty_folio = netfs_dirty_folio, |
142 | .release_folio = netfs_release_folio, |
143 | .invalidate_folio = netfs_invalidate_folio, |
144 | .launder_folio = netfs_launder_folio, |
145 | .direct_IO = noop_direct_IO, |
146 | .writepages = netfs_writepages, |
147 | }; |
148 | |