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