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(subreq, netfs_sreq_trace_submit); 35 len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err); 36 netfs_write_subrequest_terminated(subreq, len ?: err, 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, NETFS_UPLOAD_TO_SERVER, 56 start, len, 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, subreq->start + subreq->transferred, 72 &subreq->io_iter, &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(rreq->inode, writing, INVALID_UID, 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