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https://github.com/torvalds/linux
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d680efe9d8
Replace the dentry vote mechanism with a cluster lock which covers a set of dentries. This allows us to force d_delete() only on nodes which actually care about an unlink. Every node that does a ->lookup() gets a read only lock on the dentry, until an unlink during which the unlinking node, will request an exclusive lock, forcing the other nodes who care about that dentry to d_delete() it. The effect is that we retain a very lightweight ->d_revalidate(), and at the same time get to make large improvements to the average case performance of the ocfs2 unlink and rename operations. This patch adds the cluster lock type which OCFS2 can attach to dentries. A small number of fs/ocfs2/dcache.c functions are stubbed out so that this change can compile. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
98 lines
2.5 KiB
C
98 lines
2.5 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* ocfs2_lockid.h
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*
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* Defines OCFS2 lockid bits.
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*
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* Copyright (C) 2002, 2005 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (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 GNU
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* 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
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef OCFS2_LOCKID_H
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#define OCFS2_LOCKID_H
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/* lock ids are made up in the following manner:
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* name[0] --> type
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* name[1-6] --> 6 pad characters, reserved for now
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* name[7-22] --> block number, expressed in hex as 16 chars
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* name[23-30] --> i_generation, expressed in hex 8 chars
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* name[31] --> '\0' */
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#define OCFS2_LOCK_ID_MAX_LEN 32
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#define OCFS2_LOCK_ID_PAD "000000"
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#define OCFS2_DENTRY_LOCK_INO_START 18
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enum ocfs2_lock_type {
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OCFS2_LOCK_TYPE_META = 0,
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OCFS2_LOCK_TYPE_DATA,
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OCFS2_LOCK_TYPE_SUPER,
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OCFS2_LOCK_TYPE_RENAME,
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OCFS2_LOCK_TYPE_RW,
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OCFS2_LOCK_TYPE_DENTRY,
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OCFS2_NUM_LOCK_TYPES
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};
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static inline char ocfs2_lock_type_char(enum ocfs2_lock_type type)
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{
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char c;
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switch (type) {
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case OCFS2_LOCK_TYPE_META:
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c = 'M';
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break;
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case OCFS2_LOCK_TYPE_DATA:
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c = 'D';
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break;
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case OCFS2_LOCK_TYPE_SUPER:
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c = 'S';
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break;
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case OCFS2_LOCK_TYPE_RENAME:
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c = 'R';
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break;
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case OCFS2_LOCK_TYPE_RW:
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c = 'W';
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break;
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case OCFS2_LOCK_TYPE_DENTRY:
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c = 'N';
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break;
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default:
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c = '\0';
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}
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return c;
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}
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static char *ocfs2_lock_type_strings[] = {
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[OCFS2_LOCK_TYPE_META] = "Meta",
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[OCFS2_LOCK_TYPE_DATA] = "Data",
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[OCFS2_LOCK_TYPE_SUPER] = "Super",
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[OCFS2_LOCK_TYPE_RENAME] = "Rename",
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/* Need to differntiate from [R]ename.. serializing writes is the
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* important job it does, anyway. */
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[OCFS2_LOCK_TYPE_RW] = "Write/Read",
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[OCFS2_LOCK_TYPE_DENTRY] = "Dentry",
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};
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static inline const char *ocfs2_lock_type_string(enum ocfs2_lock_type type)
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{
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#ifdef __KERNEL__
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mlog_bug_on_msg(type >= OCFS2_NUM_LOCK_TYPES, "%d\n", type);
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#endif
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return ocfs2_lock_type_strings[type];
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}
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#endif /* OCFS2_LOCKID_H */
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