56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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* Copyright (C) 2005-2014 Junjiro R. Okajima
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*
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* This program, aufs is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* poll operation
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* There is only one filesystem which implements ->poll operation, currently.
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*/
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#include "aufs.h"
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unsigned int aufs_poll(struct file *file, poll_table *wait)
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{
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unsigned int mask;
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int err;
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struct file *h_file;
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struct dentry *dentry;
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struct super_block *sb;
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/* We should pretend an error happened. */
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mask = POLLERR /* | POLLIN | POLLOUT */;
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dentry = file->f_dentry;
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sb = dentry->d_sb;
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si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
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err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
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if (unlikely(err))
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goto out;
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/* it is not an error if h_file has no operation */
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mask = DEFAULT_POLLMASK;
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h_file = au_hf_top(file);
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if (h_file->f_op && h_file->f_op->poll)
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mask = h_file->f_op->poll(h_file, wait);
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di_read_unlock(dentry, AuLock_IR);
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fi_read_unlock(file);
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out:
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si_read_unlock(sb);
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AuTraceErr((int)mask);
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return mask;
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}
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