linux_dsm_epyc7002/fs/aufs/poll.c

52 lines
1.4 KiB
C
Raw Permalink Normal View History

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2005-2019 Junjiro R. Okajima
*
* This program, aufs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* poll operation
* There is only one filesystem which implements ->poll operation, currently.
*/
#include "aufs.h"
__poll_t aufs_poll(struct file *file, struct poll_table_struct *pt)
{
__poll_t mask;
struct file *h_file;
struct super_block *sb;
/* We should pretend an error happened. */
mask = EPOLLERR /* | EPOLLIN | EPOLLOUT */;
sb = file->f_path.dentry->d_sb;
si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
h_file = au_read_pre(file, /*keep_fi*/0, /*lsc*/0);
if (IS_ERR(h_file)) {
AuDbg("h_file %ld\n", PTR_ERR(h_file));
goto out;
}
mask = vfs_poll(h_file, pt);
fput(h_file); /* instead of au_read_post() */
out:
si_read_unlock(sb);
if (mask & EPOLLERR)
AuDbg("mask 0x%x\n", mask);
return mask;
}