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f057f6cdf6
This is the big patch that I've been working on for some time now. There are many reasons for wanting to make this change such as: o Reducing overhead by eliminating duplicated fields between structures o Simplifcation of the code (reduces the code size by a fair bit) o The locking interface is now the DLM interface itself as proposed some time ago. o Fewer lookups of glocks when processing replies from the DLM o Fewer memory allocations/deallocations for each glock o Scope to do further optimisations in the future (but this patch is more than big enough for now!) Please note that (a) this patch relates to the lock_dlm module and not the DLM itself, that is still a separate module; and (b) that we retain the ability to build GFS2 as a standalone single node filesystem with out requiring the DLM. This patch needs a lot of testing, hence my keeping it I restarted my -git tree after the last merge window. That way, this has the maximum exposure before its merged. This is (modulo a few minor bug fixes) the same patch that I've been posting on and off the the last three months and its passed a number of different tests so far. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
115 lines
2.4 KiB
C
115 lines
2.4 KiB
C
/*
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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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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License version 2.
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*/
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#include <linux/slab.h>
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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/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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* @nd:
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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, struct nameidata *nd)
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{
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struct dentry *parent = dget_parent(dentry);
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struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode);
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struct gfs2_inode *dip = GFS2_I(parent->d_inode);
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struct inode *inode = dentry->d_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;
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int had_lock = 0;
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if (inode) {
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if (is_bad_inode(inode))
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goto invalid;
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ip = GFS2_I(inode);
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}
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if (sdp->sd_args.ar_localcaching)
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goto valid;
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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 fail;
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}
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error = gfs2_dir_check(parent->d_inode, &dentry->d_name, ip);
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switch (error) {
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case 0:
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if (!inode)
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goto invalid_gunlock;
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break;
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case -ENOENT:
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if (!inode)
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goto valid_gunlock;
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goto invalid_gunlock;
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default:
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goto fail_gunlock;
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}
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valid_gunlock:
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if (!had_lock)
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gfs2_glock_dq_uninit(&d_gh);
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valid:
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dput(parent);
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return 1;
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invalid_gunlock:
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if (!had_lock)
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gfs2_glock_dq_uninit(&d_gh);
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invalid:
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if (inode && S_ISDIR(inode->i_mode)) {
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if (have_submounts(dentry))
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goto valid;
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shrink_dcache_parent(dentry);
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}
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d_drop(dentry);
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dput(parent);
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return 0;
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fail_gunlock:
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gfs2_glock_dq_uninit(&d_gh);
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fail:
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dput(parent);
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return 0;
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}
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static int gfs2_dhash(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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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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};
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