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	Before this patch, function gfs2_drevalidate was a horrific tangle of unreadable labels, cases and goto statements. This patch tries to simplify the logic and make it more readable. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
		
			
				
	
	
		
			108 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
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 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
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 */
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#include <linux/spinlock.h>
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#include <linux/completion.h>
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#include <linux/buffer_head.h>
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#include <linux/gfs2_ondisk.h>
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#include <linux/namei.h>
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#include <linux/crc32.h>
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#include "gfs2.h"
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#include "incore.h"
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#include "dir.h"
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#include "glock.h"
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#include "super.h"
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#include "util.h"
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#include "inode.h"
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/**
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 * gfs2_drevalidate - Check directory lookup consistency
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 * @dentry: the mapping to check
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 * @flags: lookup flags
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 *
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 * Check to make sure the lookup necessary to arrive at this inode from its
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 * parent is still good.
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 *
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 * Returns: 1 if the dentry is ok, 0 if it isn't
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 */
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static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags)
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{
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	struct dentry *parent;
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	struct gfs2_sbd *sdp;
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	struct gfs2_inode *dip;
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	struct inode *inode;
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	struct gfs2_holder d_gh;
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	struct gfs2_inode *ip = NULL;
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	int error, valid = 0;
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	int had_lock = 0;
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	if (flags & LOOKUP_RCU)
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		return -ECHILD;
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	parent = dget_parent(dentry);
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	sdp = GFS2_SB(d_inode(parent));
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	dip = GFS2_I(d_inode(parent));
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	inode = d_inode(dentry);
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	if (inode) {
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		if (is_bad_inode(inode))
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			goto out;
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		ip = GFS2_I(inode);
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	}
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	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) {
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		valid = 1;
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		goto out;
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	}
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	had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
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	if (!had_lock) {
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		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
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		if (error)
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			goto out;
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	}
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	error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip);
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	valid = inode ? !error : (error == -ENOENT);
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	if (!had_lock)
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		gfs2_glock_dq_uninit(&d_gh);
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out:
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	dput(parent);
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	return valid;
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}
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static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
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{
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	str->hash = gfs2_disk_hash(str->name, str->len);
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	return 0;
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}
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static int gfs2_dentry_delete(const struct dentry *dentry)
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{
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	struct gfs2_inode *ginode;
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	if (d_really_is_negative(dentry))
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		return 0;
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	ginode = GFS2_I(d_inode(dentry));
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	if (!gfs2_holder_initialized(&ginode->i_iopen_gh))
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		return 0;
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	if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
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		return 1;
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	return 0;
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}
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const struct dentry_operations gfs2_dops = {
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	.d_revalidate = gfs2_drevalidate,
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	.d_hash = gfs2_dhash,
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	.d_delete = gfs2_dentry_delete,
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};
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