96 lines
2.7 KiB
C
96 lines
2.7 KiB
C
/*
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* Copyright (c) 2003-2014 Erez Zadok
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* Copyright (c) 2003-2006 Charles P. Wright
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* Copyright (c) 2005-2007 Josef 'Jeff' Sipek
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* Copyright (c) 2005-2006 Junjiro Okajima
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* Copyright (c) 2005 Arun M. Krishnakumar
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* Copyright (c) 2004-2006 David P. Quigley
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* Copyright (c) 2003-2004 Mohammad Nayyer Zubair
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* Copyright (c) 2003 Puja Gupta
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* Copyright (c) 2003 Harikesavan Krishnan
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* Copyright (c) 2003-2014 Stony Brook University
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* Copyright (c) 2003-2014 The Research Foundation of SUNY
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include "union.h"
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/*
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* returns the right n_link value based on the inode type
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*/
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int unionfs_get_nlinks(const struct inode *inode)
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{
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/* don't bother to do all the work since we're unlinked */
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if (inode->i_nlink == 0)
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return 0;
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if (!S_ISDIR(inode->i_mode))
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return unionfs_lower_inode(inode)->i_nlink;
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/*
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* For directories, we return 1. The only place that could cares
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* about links is readdir, and there's d_type there so even that
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* doesn't matter.
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*/
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return 1;
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}
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/* copy a/m/ctime from the lower branch with the newest times */
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void unionfs_copy_attr_times(struct inode *upper)
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{
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int bindex;
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struct inode *lower;
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if (!upper)
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return;
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if (ibstart(upper) < 0) {
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#ifdef CONFIG_UNION_FS_DEBUG
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WARN_ON(ibstart(upper) < 0);
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#endif /* CONFIG_UNION_FS_DEBUG */
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return;
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}
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for (bindex = ibstart(upper); bindex <= ibend(upper); bindex++) {
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lower = unionfs_lower_inode_idx(upper, bindex);
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if (!lower)
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continue; /* not all lower dir objects may exist */
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if (unlikely(timespec_compare(&upper->i_mtime,
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&lower->i_mtime) < 0))
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upper->i_mtime = lower->i_mtime;
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if (unlikely(timespec_compare(&upper->i_ctime,
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&lower->i_ctime) < 0))
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upper->i_ctime = lower->i_ctime;
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if (unlikely(timespec_compare(&upper->i_atime,
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&lower->i_atime) < 0))
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upper->i_atime = lower->i_atime;
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}
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}
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/*
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* A unionfs/fanout version of fsstack_copy_attr_all. Uses a
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* unionfs_get_nlinks to properly calcluate the number of links to a file.
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* Also, copies the max() of all a/m/ctimes for all lower inodes (which is
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* important if the lower inode is a directory type)
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*/
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void unionfs_copy_attr_all(struct inode *dest,
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const struct inode *src)
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{
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dest->i_mode = src->i_mode;
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dest->i_uid = src->i_uid;
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dest->i_gid = src->i_gid;
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dest->i_rdev = src->i_rdev;
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unionfs_copy_attr_times(dest);
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dest->i_blkbits = src->i_blkbits;
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dest->i_flags = src->i_flags;
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/*
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* Update the nlinks AFTER updating the above fields, because the
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* get_links callback may depend on them.
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*/
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set_nlink(dest, unionfs_get_nlinks(dest));
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}
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