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e03abc0c96
While cacheing is generally frowned upon in the 9p world, it has its place -- particularly in situations where the remote file system is exclusive and/or read-only. The vacfs views of venti content addressable store are a real-world instance of such a situation. To facilitate higher performance for these workloads (and eventually use the fscache patches), we have enabled a "loose" cache mode which does not attempt to maintain any form of consistency on the page-cache or dcache. This results in over two orders of magnitude performance improvement for cacheable block reads in the Bonnie benchmark. The more aggressive use of the dcache also seems to improve metadata operational performance. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
119 lines
3 KiB
C
119 lines
3 KiB
C
/*
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* linux/fs/9p/vfs_dentry.c
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*
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* This file contians vfs dentry ops for the 9P2000 protocol.
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*
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* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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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
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* as published by the Free Software Foundation.
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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, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/pagemap.h>
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#include <linux/stat.h>
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#include <linux/string.h>
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#include <linux/smp_lock.h>
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#include <linux/inet.h>
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#include <linux/namei.h>
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#include <linux/idr.h>
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#include "debug.h"
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#include "v9fs.h"
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#include "9p.h"
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#include "v9fs_vfs.h"
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#include "fid.h"
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/**
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* v9fs_dentry_delete - called when dentry refcount equals 0
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* @dentry: dentry in question
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*
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* By returning 1 here we should remove cacheing of unused
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* dentry components.
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*
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*/
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static int v9fs_dentry_delete(struct dentry *dentry)
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{
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dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
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return 1;
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}
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/**
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* v9fs_cached_dentry_delete - called when dentry refcount equals 0
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* @dentry: dentry in question
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*
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* Only return 1 if our inode is invalid. Only non-synthetic files
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* (ones without mtime == 0) should be calling this function.
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*
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*/
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static int v9fs_cached_dentry_delete(struct dentry *dentry)
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{
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struct inode *inode = dentry->d_inode;
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dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
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if(!inode)
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return 1;
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return 0;
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}
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/**
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* v9fs_dentry_release - called when dentry is going to be freed
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* @dentry: dentry that is being release
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*
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*/
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void v9fs_dentry_release(struct dentry *dentry)
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{
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int err;
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dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
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if (dentry->d_fsdata != NULL) {
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struct list_head *fid_list = dentry->d_fsdata;
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struct v9fs_fid *temp = NULL;
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struct v9fs_fid *current_fid = NULL;
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list_for_each_entry_safe(current_fid, temp, fid_list, list) {
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err = v9fs_t_clunk(current_fid->v9ses, current_fid->fid);
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if (err < 0)
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dprintk(DEBUG_ERROR, "clunk failed: %d name %s\n",
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err, dentry->d_iname);
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v9fs_fid_destroy(current_fid);
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}
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kfree(dentry->d_fsdata); /* free the list_head */
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}
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}
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struct dentry_operations v9fs_cached_dentry_operations = {
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.d_delete = v9fs_cached_dentry_delete,
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.d_release = v9fs_dentry_release,
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};
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struct dentry_operations v9fs_dentry_operations = {
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.d_delete = v9fs_dentry_delete,
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.d_release = v9fs_dentry_release,
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};
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