158 lines
4.1 KiB
C
158 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* This file contians vfs address (mmap) ops for 9P2000.
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*
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* Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/pagemap.h>
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#include <linux/sched.h>
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#include <linux/swap.h>
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#include <linux/uio.h>
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#include <linux/netfs.h>
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#include <net/9p/9p.h>
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#include <net/9p/client.h>
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#include <trace/events/netfs.h>
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#include "v9fs.h"
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#include "v9fs_vfs.h"
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#include "cache.h"
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#include "fid.h"
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/*
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* Writeback calls this when it finds a folio that needs uploading. This isn't
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* called if writeback only has copy-to-cache to deal with.
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*/
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static void v9fs_begin_writeback(struct netfs_io_request *wreq)
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{
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struct p9_fid *fid;
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fid = v9fs_fid_find_inode(wreq->inode, true, INVALID_UID, true);
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if (!fid) {
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WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
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wreq->inode->i_ino);
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return;
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}
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wreq->wsize = fid->clnt->msize - P9_IOHDRSZ;
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if (fid->iounit)
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wreq->wsize = min(wreq->wsize, fid->iounit);
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wreq->netfs_priv = fid;
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wreq->io_streams[0].avail = true;
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}
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/*
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* Issue a subrequest to write to the server.
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*/
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static void v9fs_issue_write(struct netfs_io_subrequest *subreq)
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{
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struct p9_fid *fid = subreq->rreq->netfs_priv;
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int err, len;
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len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);
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netfs_write_subrequest_terminated(subreq, len ?: err, false);
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}
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/**
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* v9fs_issue_read - Issue a read from 9P
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* @subreq: The read to make
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*/
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static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
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{
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struct netfs_io_request *rreq = subreq->rreq;
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struct p9_fid *fid = rreq->netfs_priv;
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int total, err;
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total = p9_client_read(fid, subreq->start + subreq->transferred,
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&subreq->io_iter, &err);
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/* if we just extended the file size, any portion not in
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* cache won't be on server and is zeroes */
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__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
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netfs_subreq_terminated(subreq, err ?: total, false);
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}
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/**
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* v9fs_init_request - Initialise a request
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* @rreq: The read request
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* @file: The file being read from
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*/
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static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
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{
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struct p9_fid *fid;
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bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||
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rreq->origin == NETFS_WRITETHROUGH ||
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rreq->origin == NETFS_UNBUFFERED_WRITE ||
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rreq->origin == NETFS_DIO_WRITE);
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if (rreq->origin == NETFS_WRITEBACK)
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return 0; /* We don't get the write handle until we find we
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* have actually dirty data and not just
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* copy-to-cache data.
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*/
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if (file) {
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fid = file->private_data;
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if (!fid)
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goto no_fid;
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p9_fid_get(fid);
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} else {
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fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);
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if (!fid)
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goto no_fid;
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}
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rreq->wsize = fid->clnt->msize - P9_IOHDRSZ;
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if (fid->iounit)
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rreq->wsize = min(rreq->wsize, fid->iounit);
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/* we might need to read from a fid that was opened write-only
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* for read-modify-write of page cache, use the writeback fid
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* for that */
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WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR));
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rreq->netfs_priv = fid;
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return 0;
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no_fid:
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WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
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rreq->inode->i_ino);
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return -EINVAL;
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}
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/**
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* v9fs_free_request - Cleanup request initialized by v9fs_init_rreq
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* @rreq: The I/O request to clean up
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*/
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static void v9fs_free_request(struct netfs_io_request *rreq)
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{
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struct p9_fid *fid = rreq->netfs_priv;
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p9_fid_put(fid);
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}
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const struct netfs_request_ops v9fs_req_ops = {
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.init_request = v9fs_init_request,
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.free_request = v9fs_free_request,
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.issue_read = v9fs_issue_read,
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.begin_writeback = v9fs_begin_writeback,
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.issue_write = v9fs_issue_write,
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};
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const struct address_space_operations v9fs_addr_operations = {
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.read_folio = netfs_read_folio,
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.readahead = netfs_readahead,
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.dirty_folio = netfs_dirty_folio,
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.release_folio = netfs_release_folio,
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.invalidate_folio = netfs_invalidate_folio,
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.direct_IO = noop_direct_IO,
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.writepages = netfs_writepages,
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};
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