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1// SPDX-License-Identifier: GPL-2.0-only2/*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/*30 * Writeback calls this when it finds a folio that needs uploading. This isn't31 * called if writeback only has copy-to-cache to deal with.32 */33static void v9fs_begin_writeback(struct netfs_io_request *wreq)34{35 struct p9_fid *fid;36 37 fid = v9fs_fid_find_inode(wreq->inode, true, INVALID_UID, true);38 if (!fid) {39 WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",40 wreq->inode->i_ino);41 return;42 }43 44 wreq->wsize = fid->clnt->msize - P9_IOHDRSZ;45 if (fid->iounit)46 wreq->wsize = min(wreq->wsize, fid->iounit);47 wreq->netfs_priv = fid;48 wreq->io_streams[0].avail = true;49}50 51/*52 * Issue a subrequest to write to the server.53 */54static void v9fs_issue_write(struct netfs_io_subrequest *subreq)55{56 struct p9_fid *fid = subreq->rreq->netfs_priv;57 int err, len;58 59 len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);60 netfs_write_subrequest_terminated(subreq, len ?: err, false);61}62 63/**64 * v9fs_issue_read - Issue a read from 9P65 * @subreq: The read to make66 */67static void v9fs_issue_read(struct netfs_io_subrequest *subreq)68{69 struct netfs_io_request *rreq = subreq->rreq;70 struct p9_fid *fid = rreq->netfs_priv;71 unsigned long long pos = subreq->start + subreq->transferred;72 int total, err;73 74 total = p9_client_read(fid, pos, &subreq->io_iter, &err);75 76 /* if we just extended the file size, any portion not in77 * cache won't be on server and is zeroes */78 if (subreq->rreq->origin != NETFS_DIO_READ)79 __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);80 if (pos + total >= i_size_read(rreq->inode))81 __set_bit(NETFS_SREQ_HIT_EOF, &subreq->flags);82 83 if (!err)84 subreq->transferred += total;85 86 netfs_read_subreq_terminated(subreq, err, false);87}88 89/**90 * v9fs_init_request - Initialise a request91 * @rreq: The read request92 * @file: The file being read from93 */94static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)95{96 struct p9_fid *fid;97 bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||98 rreq->origin == NETFS_WRITETHROUGH ||99 rreq->origin == NETFS_UNBUFFERED_WRITE ||100 rreq->origin == NETFS_DIO_WRITE);101 102 if (rreq->origin == NETFS_WRITEBACK)103 return 0; /* We don't get the write handle until we find we104 * have actually dirty data and not just105 * copy-to-cache data.106 */107 108 if (file) {109 fid = file->private_data;110 if (!fid)111 goto no_fid;112 p9_fid_get(fid);113 } else {114 fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);115 if (!fid)116 goto no_fid;117 }118 119 rreq->wsize = fid->clnt->msize - P9_IOHDRSZ;120 if (fid->iounit)121 rreq->wsize = min(rreq->wsize, fid->iounit);122 123 /* we might need to read from a fid that was opened write-only124 * for read-modify-write of page cache, use the writeback fid125 * for that */126 WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR));127 rreq->netfs_priv = fid;128 return 0;129 130no_fid:131 WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",132 rreq->inode->i_ino);133 return -EINVAL;134}135 136/**137 * v9fs_free_request - Cleanup request initialized by v9fs_init_rreq138 * @rreq: The I/O request to clean up139 */140static void v9fs_free_request(struct netfs_io_request *rreq)141{142 struct p9_fid *fid = rreq->netfs_priv;143 144 p9_fid_put(fid);145}146 147const struct netfs_request_ops v9fs_req_ops = {148 .init_request = v9fs_init_request,149 .free_request = v9fs_free_request,150 .issue_read = v9fs_issue_read,151 .begin_writeback = v9fs_begin_writeback,152 .issue_write = v9fs_issue_write,153};154 155const struct address_space_operations v9fs_addr_operations = {156 .read_folio = netfs_read_folio,157 .readahead = netfs_readahead,158 .dirty_folio = netfs_dirty_folio,159 .release_folio = netfs_release_folio,160 .invalidate_folio = netfs_invalidate_folio,161 .direct_IO = noop_direct_IO,162 .writepages = netfs_writepages,163};164