sysfile.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * sysfile.c
  4 *
  5 * Initialize, read, write, etc. system files.
  6 *
  7 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  8 */
  9
 10#include <linux/fs.h>
 11#include <linux/types.h>
 12#include <linux/highmem.h>
 13
 14#include <cluster/masklog.h>
 15
 16#include "ocfs2.h"
 17
 18#include "alloc.h"
 19#include "dir.h"
 20#include "inode.h"
 21#include "journal.h"
 22#include "sysfile.h"
 23
 24#include "buffer_head_io.h"
 25
 26static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
 27						   int type,
 28						   u32 slot);
 29
 30#ifdef CONFIG_DEBUG_LOCK_ALLOC
 31static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
 32#endif
 33
 34static inline int is_global_system_inode(int type)
 35{
 36	return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
 37		type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
 38}
 39
 40static struct inode **get_local_system_inode(struct ocfs2_super *osb,
 41					     int type,
 42					     u32 slot)
 43{
 44	int index;
 45	struct inode **local_system_inodes, **free = NULL;
 46
 47	BUG_ON(slot == OCFS2_INVALID_SLOT);
 48	BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
 49	       type > OCFS2_LAST_LOCAL_SYSTEM_INODE);
 50
 51	spin_lock(&osb->osb_lock);
 52	local_system_inodes = osb->local_system_inodes;
 53	spin_unlock(&osb->osb_lock);
 54
 55	if (unlikely(!local_system_inodes)) {
 56		local_system_inodes =
 57			kzalloc(array3_size(sizeof(struct inode *),
 58					    NUM_LOCAL_SYSTEM_INODES,
 59					    osb->max_slots),
 60				GFP_NOFS);
 61		if (!local_system_inodes) {
 62			mlog_errno(-ENOMEM);
 63			/*
 64			 * return NULL here so that ocfs2_get_sytem_file_inodes
 65			 * will try to create an inode and use it. We will try
 66			 * to initialize local_system_inodes next time.
 67			 */
 68			return NULL;
 69		}
 70
 71		spin_lock(&osb->osb_lock);
 72		if (osb->local_system_inodes) {
 73			/* Someone has initialized it for us. */
 74			free = local_system_inodes;
 75			local_system_inodes = osb->local_system_inodes;
 76		} else
 77			osb->local_system_inodes = local_system_inodes;
 78		spin_unlock(&osb->osb_lock);
 79		kfree(free);
 80	}
 81
 82	index = (slot * NUM_LOCAL_SYSTEM_INODES) +
 83		(type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);
 84
 85	return &local_system_inodes[index];
 86}
 87
 88struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
 89					  int type,
 90					  u32 slot)
 91{
 92	struct inode *inode = NULL;
 93	struct inode **arr = NULL;
 94
 95	/* avoid the lookup if cached in local system file array */
 96	if (is_global_system_inode(type)) {
 97		arr = &(osb->global_system_inodes[type]);
 98	} else
 99		arr = get_local_system_inode(osb, type, slot);
100
101	mutex_lock(&osb->system_file_mutex);
102	if (arr && ((inode = *arr) != NULL)) {
103		/* get a ref in addition to the array ref */
104		inode = igrab(inode);
105		mutex_unlock(&osb->system_file_mutex);
106		BUG_ON(!inode);
107
108		return inode;
109	}
110
111	/* this gets one ref thru iget */
112	inode = _ocfs2_get_system_file_inode(osb, type, slot);
113
114	/* add one more if putting into array for first time */
115	if (arr && inode) {
116		*arr = igrab(inode);
117		BUG_ON(!*arr);
118	}
119	mutex_unlock(&osb->system_file_mutex);
120	return inode;
121}
122
123static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
124						   int type,
125						   u32 slot)
126{
127	char namebuf[40];
128	struct inode *inode = NULL;
129	u64 blkno;
130	int len, status = 0;
131
132	len = ocfs2_sprintf_system_inode_name(namebuf,
133					      sizeof(namebuf),
134					      type, slot);
135
136	status = ocfs2_lookup_ino_from_name(osb->sys_root_inode,
137					    namebuf, len, &blkno);
138	if (status < 0) {
139		goto bail;
140	}
141
142	inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
143	if (IS_ERR(inode)) {
144		mlog_errno(PTR_ERR(inode));
145		inode = NULL;
146		goto bail;
147	}
148#ifdef CONFIG_DEBUG_LOCK_ALLOC
149	if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
150	    type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
151	    type == JOURNAL_SYSTEM_INODE) {
152		/* Ignore inode lock on these inodes as the lock does not
153		 * really belong to any process and lockdep cannot handle
154		 * that */
155		OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
156	} else {
157		lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
158								l_lockdep_map,
159				 ocfs2_system_inodes[type].si_name,
160				 &ocfs2_sysfile_cluster_lock_key[type], 0);
161	}
162#endif
163bail:
164
165	return inode;
166}
167