diff options
Diffstat (limited to 'fs/aufs/poll.c')
-rw-r--r-- | fs/aufs/poll.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/fs/aufs/poll.c b/fs/aufs/poll.c new file mode 100644 index 000000000..262a792fd --- /dev/null +++ b/fs/aufs/poll.c @@ -0,0 +1,52 @@ +/* + * Copyright (C) 2005-2015 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" + +unsigned int aufs_poll(struct file *file, poll_table *wait) +{ + unsigned int mask; + int err; + struct file *h_file; + struct super_block *sb; + + /* We should pretend an error happened. */ + mask = POLLERR /* | POLLIN | POLLOUT */; + sb = file->f_path.dentry->d_sb; + si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW); + + h_file = au_read_pre(file, /*keep_fi*/0); + err = PTR_ERR(h_file); + if (IS_ERR(h_file)) + goto out; + + /* it is not an error if h_file has no operation */ + mask = DEFAULT_POLLMASK; + if (h_file->f_op->poll) + mask = h_file->f_op->poll(h_file, wait); + fput(h_file); /* instead of au_read_post() */ + +out: + si_read_unlock(sb); + AuTraceErr((int)mask); + return mask; +} |