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Message-ID: <56386E4B.5080506@oracle.com>
Date: Tue, 03 Nov 2015 16:20:27 +0800
From: Junxiao Bi <junxiao.bi@oracle.com>
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To: Gang He <ghe@suse.com>, Mark Fasheh <MFasheh@suse.com>, rgoldwyn@suse.de
CC: akpm@linux-foundation.org, ocfs2-devel@oss.oracle.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/4] ocfs2: sysfile interfaces for online file check
References: <1446013561-22121-1-git-send-email-ghe@suse.com> <1446013561-22121-3-git-send-email-ghe@suse.com> <5638604E.9030000@oracle.com> <5638D8CF020000F90001CC68@relay2.provo.novell.com>
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Hi Gang,

On 11/03/2015 03:54 PM, Gang He wrote:
> Hi Junxiao,
> 
> Thank for your reviewing.
> Current design, we use a sysfile as a interface to check/fix a file (via pass a ino number).
> But, this operation is manually triggered by user, instead of automatically  fix in the kernel.
> Why?
> 1) we should let users make this decision, since some users do not want to fix when encountering a file system corruption, maybe they want to keep the file system unchanged for a further investigation.
If user don't want this, they should not use error=continue option, let
fs go after a corruption is very dangerous.
> 2) frankly speaking, this feature will probably bring a second corruption if there is some error in the code, I do not suggest to use automatically fix by default in the first version.
I think if this feature could bring more corruption, then this should be
fixed first.

Thanks,
Junxiao
> 3) in the future, if this feature is well proved, we can add a mount option to make this automatically fix enabled.
> 
> 
> Thanks
> Gang
>    
> 
> 
>>>>
>> Hi Gang,
>>
>> I didn't see a need to add a sysfs file for the check and repair. This
>> leaves a hard problem for customer to decide. How they decide whether
>> they should repair the bad inode since this may cause corruption even
>> harder?
>> I think the error should be fixed by this feature automaticlly if repair
>> helps, of course this can be done only when error=continue is enabled or
>> add some mount option for it.
>>
>> Thanks,
>> Junxiao.
>>
>> On 10/28/2015 02:25 PM, Gang He wrote:
>>> Implement online file check sysfile interfaces, e.g.
>>> how to create the related sysfile according to device name,
>>> how to display/handle file check request from the sysfile.
>>>
>>> Signed-off-by: Gang He <ghe@suse.com>
>>> ---
>>>  fs/ocfs2/Makefile    |   3 +-
>>>  fs/ocfs2/filecheck.c | 566 
>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>>>  fs/ocfs2/filecheck.h |  48 +++++
>>>  fs/ocfs2/inode.h     |   3 +
>>>  4 files changed, 619 insertions(+), 1 deletion(-)
>>>  create mode 100644 fs/ocfs2/filecheck.c
>>>  create mode 100644 fs/ocfs2/filecheck.h
>>>
>>> diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
>>> index ce210d4..e27e652 100644
>>> --- a/fs/ocfs2/Makefile
>>> +++ b/fs/ocfs2/Makefile
>>> @@ -41,7 +41,8 @@ ocfs2-objs := \
>>>  	quota_local.o		\
>>>  	quota_global.o		\
>>>  	xattr.o			\
>>> -	acl.o
>>> +	acl.o	\
>>> +	filecheck.o
>>>  
>>>  ocfs2_stackglue-objs := stackglue.o
>>>  ocfs2_stack_o2cb-objs := stack_o2cb.o
>>> diff --git a/fs/ocfs2/filecheck.c b/fs/ocfs2/filecheck.c
>>> new file mode 100644
>>> index 0000000..f12ed1f
>>> --- /dev/null
>>> +++ b/fs/ocfs2/filecheck.c
>>> @@ -0,0 +1,566 @@
>>> +/* -*- mode: c; c-basic-offset: 8; -*-
>>> + * vim: noexpandtab sw=8 ts=8 sts=0:
>>> + *
>>> + * filecheck.c
>>> + *
>>> + * Code which implements online file check.
>>> + *
>>> + * Copyright (C) 2015 Novell.  All rights reserved.
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public
>>> + * License as published by the Free Software Foundation, version 2.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> + * General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/list.h>
>>> +#include <linux/spinlock.h>
>>> +#include <linux/module.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/kmod.h>
>>> +#include <linux/fs.h>
>>> +#include <linux/kobject.h>
>>> +#include <linux/sysfs.h>
>>> +#include <linux/sysctl.h>
>>> +#include <cluster/masklog.h>
>>> +
>>> +#include "ocfs2.h"
>>> +#include "ocfs2_fs.h"
>>> +#include "stackglue.h"
>>> +#include "inode.h"
>>> +
>>> +#include "filecheck.h"
>>> +
>>> +
>>> +/* File check error strings,
>>> + * must correspond with error number in header file.
>>> + */
>>> +static const char * const ocfs2_filecheck_errs[] = {
>>> +	"SUCCESS",
>>> +	"FAILED",
>>> +	"INPROGRESS",
>>> +	"READONLY",
>>> +	"INVALIDINO",
>>> +	"BLOCKECC",
>>> +	"BLOCKNO",
>>> +	"VALIDFLAG",
>>> +	"GENERATION",
>>> +	"UNSUPPORTED"
>>> +};
>>> +
>>> +static DEFINE_SPINLOCK(ocfs2_filecheck_sysfs_lock);
>>> +static LIST_HEAD(ocfs2_filecheck_sysfs_list);
>>> +
>>> +struct ocfs2_filecheck {
>>> +	struct list_head fc_head;	/* File check entry list head */
>>> +	spinlock_t fc_lock;
>>> +	unsigned int fc_max;	/* Maximum number of entry in list */
>>> +	unsigned int fc_size;	/* Current entry count in list */
>>> +	unsigned int fc_done;	/* File check entries are done in list */
>>> +};
>>> +
>>> +struct ocfs2_filecheck_sysfs_entry {
>>> +	struct list_head fs_list;
>>> +	atomic_t fs_count;
>>> +	struct super_block *fs_sb;
>>> +	struct kset *fs_kset;
>>> +	struct ocfs2_filecheck *fs_fcheck;
>>> +};
>>> +
>>> +#define OCFS2_FILECHECK_MAXSIZE		100
>>> +#define OCFS2_FILECHECK_MINSIZE		10
>>> +
>>> +/* File check operation type */
>>> +enum {
>>> +	OCFS2_FILECHECK_TYPE_CHK = 0,	/* Check a file */
>>> +	OCFS2_FILECHECK_TYPE_FIX,	/* Fix a file */
>>> +	OCFS2_FILECHECK_TYPE_SET = 100	/* Set file check options */
>>> +};
>>> +
>>> +struct ocfs2_filecheck_entry {
>>> +	struct list_head fe_list;
>>> +	unsigned long fe_ino;
>>> +	unsigned int fe_type;
>>> +	unsigned short fe_done:1;
>>> +	unsigned short fe_status:15;
>>> +};
>>> +
>>> +struct ocfs2_filecheck_args {
>>> +	unsigned int fa_type;
>>> +	union {
>>> +		unsigned long fa_ino;
>>> +		unsigned int fa_len;
>>> +	};
>>> +};
>>> +
>>> +static const char *
>>> +ocfs2_filecheck_error(int errno)
>>> +{
>>> +	if (!errno)
>>> +		return ocfs2_filecheck_errs[errno];
>>> +
>>> +	BUG_ON(errno < OCFS2_FILECHECK_ERR_START ||
>>> +			errno > OCFS2_FILECHECK_ERR_END);
>>> +	return ocfs2_filecheck_errs[errno - OCFS2_FILECHECK_ERR_START + 1];
>>> +}
>>> +
>>> +static ssize_t ocfs2_filecheck_show(struct kobject *kobj,
>>> +					struct kobj_attribute *attr,
>>> +					char *buf);
>>> +static ssize_t ocfs2_filecheck_store(struct kobject *kobj,
>>> +					struct kobj_attribute *attr,
>>> +					const char *buf, size_t count);
>>> +static struct kobj_attribute ocfs2_attr_filecheck =
>>> +					__ATTR(filecheck, S_IRUSR | S_IWUSR,
>>> +					ocfs2_filecheck_show,
>>> +					ocfs2_filecheck_store);
>>> +
>>> +static int ocfs2_filecheck_sysfs_wait(atomic_t *p)
>>> +{
>>> +	schedule();
>>> +	return 0;
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_sysfs_free(struct ocfs2_filecheck_sysfs_entry *entry)
>>> +{
>>> +	struct ocfs2_filecheck_entry *p;
>>> +
>>> +	if (!atomic_dec_and_test(&entry->fs_count))
>>> +		wait_on_atomic_t(&entry->fs_count, ocfs2_filecheck_sysfs_wait,
>>> +						TASK_UNINTERRUPTIBLE);
>>> +
>>> +	spin_lock(&entry->fs_fcheck->fc_lock);
>>> +	while (!list_empty(&entry->fs_fcheck->fc_head)) {
>>> +		p = list_first_entry(&entry->fs_fcheck->fc_head,
>>> +				struct ocfs2_filecheck_entry, fe_list);
>>> +		list_del(&p->fe_list);
>>> +		BUG_ON(!p->fe_done); /* To free a undone file check entry */
>>> +		kfree(p);
>>> +	}
>>> +	spin_unlock(&entry->fs_fcheck->fc_lock);
>>> +
>>> +	kset_unregister(entry->fs_kset);
>>> +	kfree(entry->fs_fcheck);
>>> +	kfree(entry);
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_sysfs_add(struct ocfs2_filecheck_sysfs_entry *entry)
>>> +{
>>> +	spin_lock(&ocfs2_filecheck_sysfs_lock);
>>> +	list_add_tail(&entry->fs_list, &ocfs2_filecheck_sysfs_list);
>>> +	spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +}
>>> +
>>> +static int ocfs2_filecheck_sysfs_del(const char *devname)
>>> +{
>>> +	struct ocfs2_filecheck_sysfs_entry *p;
>>> +
>>> +	spin_lock(&ocfs2_filecheck_sysfs_lock);
>>> +	list_for_each_entry(p, &ocfs2_filecheck_sysfs_list, fs_list) {
>>> +		if (!strcmp(p->fs_sb->s_id, devname)) {
>>> +			list_del(&p->fs_list);
>>> +			spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +			ocfs2_filecheck_sysfs_free(p);
>>> +			return 0;
>>> +		}
>>> +	}
>>> +	spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +	return 1;
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_sysfs_put(struct ocfs2_filecheck_sysfs_entry *entry)
>>> +{
>>> +	if (atomic_dec_and_test(&entry->fs_count))
>>> +		wake_up_atomic_t(&entry->fs_count);
>>> +}
>>> +
>>> +static struct ocfs2_filecheck_sysfs_entry *
>>> +ocfs2_filecheck_sysfs_get(const char *devname)
>>> +{
>>> +	struct ocfs2_filecheck_sysfs_entry *p = NULL;
>>> +
>>> +	spin_lock(&ocfs2_filecheck_sysfs_lock);
>>> +	list_for_each_entry(p, &ocfs2_filecheck_sysfs_list, fs_list) {
>>> +		if (!strcmp(p->fs_sb->s_id, devname)) {
>>> +			atomic_inc(&p->fs_count);
>>> +			spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +			return p;
>>> +		}
>>> +	}
>>> +	spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +	return NULL;
>>> +}
>>> +
>>> +int ocfs2_filecheck_create_sysfs(struct super_block *sb)
>>> +{
>>> +	int ret = 0;
>>> +	struct kset *ocfs2_filecheck_kset = NULL;
>>> +	struct ocfs2_filecheck *fcheck = NULL;
>>> +	struct ocfs2_filecheck_sysfs_entry *entry = NULL;
>>> +	struct attribute **attrs = NULL;
>>> +	struct attribute_group attrgp;
>>> +
>>> +	if (!ocfs2_kset)
>>> +		return -ENOMEM;
>>> +
>>> +	attrs = kmalloc(sizeof(struct attribute *) * 2, GFP_NOFS);
>>> +	if (!attrs) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	} else {
>>> +		attrs[0] = &ocfs2_attr_filecheck.attr;
>>> +		attrs[1] = NULL;
>>> +		memset(&attrgp, 0, sizeof(attrgp));
>>> +		attrgp.attrs = attrs;
>>> +	}
>>> +
>>> +	fcheck = kmalloc(sizeof(struct ocfs2_filecheck), GFP_NOFS);
>>> +	if (!fcheck) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	} else {
>>> +		INIT_LIST_HEAD(&fcheck->fc_head);
>>> +		spin_lock_init(&fcheck->fc_lock);
>>> +		fcheck->fc_max = OCFS2_FILECHECK_MINSIZE;
>>> +		fcheck->fc_size = 0;
>>> +		fcheck->fc_done = 0;
>>> +	}
>>> +
>>> +	if (strlen(sb->s_id) <= 0) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot get device basename when create filecheck sysfs\n");
>>> +		ret = -ENODEV;
>>> +		goto error;
>>> +	}
>>> +
>>> +	ocfs2_filecheck_kset = kset_create_and_add(sb->s_id, NULL,
>>> +						&ocfs2_kset->kobj);
>>> +	if (!ocfs2_filecheck_kset) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	}
>>> +
>>> +	ret = sysfs_create_group(&ocfs2_filecheck_kset->kobj, &attrgp);
>>> +	if (ret)
>>> +		goto error;
>>> +
>>> +	entry = kmalloc(sizeof(struct ocfs2_filecheck_sysfs_entry), GFP_NOFS);
>>> +	if (!entry) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	} else {
>>> +		atomic_set(&entry->fs_count, 1);
>>> +		entry->fs_sb = sb;
>>> +		entry->fs_kset = ocfs2_filecheck_kset;
>>> +		entry->fs_fcheck = fcheck;
>>> +		ocfs2_filecheck_sysfs_add(entry);
>>> +	}
>>> +
>>> +	kfree(attrs);
>>> +	return 0;
>>> +
>>> +error:
>>> +	kfree(attrs);
>>> +	kfree(entry);
>>> +	kfree(fcheck);
>>> +	kset_unregister(ocfs2_filecheck_kset);
>>> +	return ret;
>>> +}
>>> +
>>> +int ocfs2_filecheck_remove_sysfs(struct super_block *sb)
>>> +{
>>> +	return ocfs2_filecheck_sysfs_del(sb->s_id);
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_erase_entries(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				unsigned int count);
>>> +static int
>>> +ocfs2_filecheck_adjust_max(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				unsigned int len)
>>> +{
>>> +	int ret;
>>> +
>>> +	if ((len < OCFS2_FILECHECK_MINSIZE) || (len > OCFS2_FILECHECK_MAXSIZE))
>>> +		return -EINVAL;
>>> +
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	if (len < (ent->fs_fcheck->fc_size - ent->fs_fcheck->fc_done)) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot set online file check maximum entry number "
>>> +		"to %u due to too much pending entries(%u)\n",
>>> +		len, ent->fs_fcheck->fc_size - ent->fs_fcheck->fc_done);
>>> +		ret = -EBUSY;
>>> +	} else {
>>> +		if (len < ent->fs_fcheck->fc_size)
>>> +			BUG_ON(!ocfs2_filecheck_erase_entries(ent,
>>> +				ent->fs_fcheck->fc_size - len));
>>> +
>>> +		ent->fs_fcheck->fc_max = len;
>>> +		ret = 0;
>>> +	}
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +#define OCFS2_FILECHECK_ARGS_LEN	32
>>> +static int
>>> +ocfs2_filecheck_args_get_long(const char *buf, size_t count,
>>> +				unsigned long *val)
>>> +{
>>> +	char buffer[OCFS2_FILECHECK_ARGS_LEN];
>>> +
>>> +	if (count < 1)
>>> +		return 1;
>>> +
>>> +	memcpy(buffer, buf, count);
>>> +	buffer[count] = '\0';
>>> +
>>> +	if (kstrtoul(buffer, 0, val))
>>> +		return 1;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_args_parse(const char *buf, size_t count,
>>> +				struct ocfs2_filecheck_args *args)
>>> +{
>>> +	unsigned long val = 0;
>>> +
>>> +	/* too short/long args length */
>>> +	if ((count < 5) || (count > OCFS2_FILECHECK_ARGS_LEN))
>>> +		return 1;
>>> +
>>> +	if (!strncasecmp(buf, "FIX ", 4)) {
>>> +		if (ocfs2_filecheck_args_get_long(buf + 4, count - 4, &val))
>>> +			return 1;
>>> +
>>> +		args->fa_type = OCFS2_FILECHECK_TYPE_FIX;
>>> +		args->fa_ino = val;
>>> +		return 0;
>>> +	} else if ((count > 6) && !strncasecmp(buf, "CHECK ", 6)) {
>>> +		if (ocfs2_filecheck_args_get_long(buf + 6, count - 6, &val))
>>> +			return 1;
>>> +
>>> +		args->fa_type = OCFS2_FILECHECK_TYPE_CHK;
>>> +		args->fa_ino = val;
>>> +		return 0;
>>> +	} else if (!strncasecmp(buf, "SET ", 4)) {
>>> +		if (ocfs2_filecheck_args_get_long(buf + 4, count - 4, &val))
>>> +			return 1;
>>> +
>>> +		args->fa_type = OCFS2_FILECHECK_TYPE_SET;
>>> +		args->fa_len = (unsigned int)val;
>>> +		return 0;
>>> +	} else { /* invalid args */
>>> +		return 1;
>>> +	}
>>> +}
>>> +
>>> +static ssize_t ocfs2_filecheck_show(struct kobject *kobj,
>>> +					struct kobj_attribute *attr,
>>> +					char *buf)
>>> +{
>>> +
>>> +	ssize_t ret = 0, total = 0, remain = PAGE_SIZE;
>>> +	struct ocfs2_filecheck_entry *p;
>>> +	struct ocfs2_filecheck_sysfs_entry *ent;
>>> +
>>> +	ent = ocfs2_filecheck_sysfs_get(kobj->name);
>>> +	if (!ent) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot get the corresponding entry via device basename %s\n",
>>> +		kobj->name);
>>> +		return -ENODEV;
>>> +	}
>>> +
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	ret = snprintf(buf, remain, "INO\t\tTYPE\tDONE\tERROR\n");
>>> +	total += ret;
>>> +	remain -= ret;
>>> +
>>> +	list_for_each_entry(p, &ent->fs_fcheck->fc_head, fe_list) {
>>> +		ret = snprintf(buf + total, remain, "%lu\t\t%u\t%u\t%s\n",
>>> +			p->fe_ino, p->fe_type, p->fe_done,
>>> +			ocfs2_filecheck_error(p->fe_status));
>>> +		if (ret < 0) {
>>> +			total = ret;
>>> +			break;
>>> +		}
>>> +		if (ret == remain) {
>>> +			/* snprintf() didn't fit */
>>> +			total = -E2BIG;
>>> +			break;
>>> +		}
>>> +		total += ret;
>>> +		remain -= ret;
>>> +	}
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +
>>> +	ocfs2_filecheck_sysfs_put(ent);
>>> +	return total;
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_erase_entry(struct ocfs2_filecheck_sysfs_entry *ent)
>>> +{
>>> +	struct ocfs2_filecheck_entry *p;
>>> +
>>> +	list_for_each_entry(p, &ent->fs_fcheck->fc_head, fe_list) {
>>> +		if (p->fe_done) {
>>> +			list_del(&p->fe_list);
>>> +			kfree(p);
>>> +			ent->fs_fcheck->fc_size--;
>>> +			ent->fs_fcheck->fc_done--;
>>> +			return 1;
>>> +		}
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_erase_entries(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				unsigned int count)
>>> +{
>>> +	unsigned int i = 0;
>>> +	unsigned int ret = 0;
>>> +
>>> +	while (i++ < count) {
>>> +		if (ocfs2_filecheck_erase_entry(ent))
>>> +			ret++;
>>> +		else
>>> +			break;
>>> +	}
>>> +
>>> +	return (ret == count ? 1 : 0);
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_done_entry(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				struct ocfs2_filecheck_entry *entry)
>>> +{
>>> +	entry->fe_done = 1;
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	ent->fs_fcheck->fc_done++;
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +}
>>> +
>>> +static unsigned short
>>> +ocfs2_filecheck_handle(struct super_block *sb,
>>> +				unsigned long ino, unsigned int flags)
>>> +{
>>> +	unsigned short ret = OCFS2_FILECHECK_ERR_SUCCESS;
>>> +	struct inode *inode = NULL;
>>> +	int rc;
>>> +
>>> +	inode = ocfs2_iget(OCFS2_SB(sb), ino, flags, 0);
>>> +	if (IS_ERR(inode)) {
>>> +		rc = (int)(-(long)inode);
>>> +		if (rc >= OCFS2_FILECHECK_ERR_START &&
>>> +			rc < OCFS2_FILECHECK_ERR_END)
>>> +			ret = rc;
>>> +		else
>>> +			ret = OCFS2_FILECHECK_ERR_FAILED;
>>> +	} else
>>> +		iput(inode);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_handle_entry(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				struct ocfs2_filecheck_entry *entry)
>>> +{
>>> +	if (entry->fe_type == OCFS2_FILECHECK_TYPE_CHK)
>>> +		entry->fe_status = ocfs2_filecheck_handle(ent->fs_sb,
>>> +				entry->fe_ino, OCFS2_FI_FLAG_FILECHECK_CHK);
>>> +	else if (entry->fe_type == OCFS2_FILECHECK_TYPE_FIX)
>>> +		entry->fe_status = ocfs2_filecheck_handle(ent->fs_sb,
>>> +				entry->fe_ino, OCFS2_FI_FLAG_FILECHECK_FIX);
>>> +	else
>>> +		entry->fe_status = OCFS2_FILECHECK_ERR_UNSUPPORTED;
>>> +
>>> +	ocfs2_filecheck_done_entry(ent, entry);
>>> +}
>>> +
>>> +static ssize_t ocfs2_filecheck_store(struct kobject *kobj,
>>> +				struct kobj_attribute *attr,
>>> +				const char *buf, size_t count)
>>> +{
>>> +	struct ocfs2_filecheck_args args;
>>> +	struct ocfs2_filecheck_entry *entry = NULL;
>>> +	struct ocfs2_filecheck_sysfs_entry *ent;
>>> +	ssize_t ret = 0;
>>> +
>>> +	if (count == 0)
>>> +		return count;
>>> +
>>> +	if (ocfs2_filecheck_args_parse(buf, count, &args)) {
>>> +		mlog(ML_ERROR, "Invalid arguments for online file check\n");
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	ent = ocfs2_filecheck_sysfs_get(kobj->name);
>>> +	if (!ent) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot get the corresponding entry via device basename %s\n",
>>> +		kobj->name);
>>> +		return -ENODEV;
>>> +	}
>>> +
>>> +	if (args.fa_type == OCFS2_FILECHECK_TYPE_SET) {
>>> +		ret = ocfs2_filecheck_adjust_max(ent, args.fa_len);
>>> +		ocfs2_filecheck_sysfs_put(ent);
>>> +		return (!ret ? count : ret);
>>> +	}
>>> +
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	if ((ent->fs_fcheck->fc_size >= ent->fs_fcheck->fc_max) &&
>>> +		(ent->fs_fcheck->fc_done == 0)) {
>>> +		mlog(ML_ERROR,
>>> +		"Online file check queue(%u) is full\n",
>>> +		ent->fs_fcheck->fc_max);
>>> +		ret = -EBUSY;
>>> +	} else {
>>> +		if ((ent->fs_fcheck->fc_size >= ent->fs_fcheck->fc_max) &&
>>> +			(ent->fs_fcheck->fc_done > 0)) {
>>> +			/* Delete the oldest entry which was done,
>>> +			 * make sure the entry size in list does
>>> +			 * not exceed maximum value
>>> +			 */
>>> +			BUG_ON(!ocfs2_filecheck_erase_entry(ent));
>>> +		}
>>> +
>>> +		entry = kmalloc(sizeof(struct ocfs2_filecheck_entry), GFP_NOFS);
>>> +		if (entry) {
>>> +			entry->fe_ino = args.fa_ino;
>>> +			entry->fe_type = args.fa_type;
>>> +			entry->fe_done = 0;
>>> +			entry->fe_status = OCFS2_FILECHECK_ERR_INPROGRESS;
>>> +			list_add_tail(&entry->fe_list,
>>> +					&ent->fs_fcheck->fc_head);
>>> +
>>> +			ent->fs_fcheck->fc_size++;
>>> +			ret = count;
>>> +		} else {
>>> +			ret = -ENOMEM;
>>> +		}
>>> +	}
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +
>>> +	if (entry)
>>> +		ocfs2_filecheck_handle_entry(ent, entry);
>>> +
>>> +	ocfs2_filecheck_sysfs_put(ent);
>>> +	return ret;
>>> +}
>>> diff --git a/fs/ocfs2/filecheck.h b/fs/ocfs2/filecheck.h
>>> new file mode 100644
>>> index 0000000..5ec331b
>>> --- /dev/null
>>> +++ b/fs/ocfs2/filecheck.h
>>> @@ -0,0 +1,48 @@
>>> +/* -*- mode: c; c-basic-offset: 8; -*-
>>> + * vim: noexpandtab sw=8 ts=8 sts=0:
>>> + *
>>> + * filecheck.h
>>> + *
>>> + * Online file check.
>>> + *
>>> + * Copyright (C) 2015 Novell.  All rights reserved.
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public
>>> + * License as published by the Free Software Foundation, version 2.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> + * General Public License for more details.
>>> + */
>>> +
>>> +
>>> +#ifndef FILECHECK_H
>>> +#define FILECHECK_H
>>> +
>>> +#include <linux/types.h>
>>> +#include <linux/list.h>
>>> +
>>> +
>>> +/* File check errno */
>>> +enum {
>>> +	OCFS2_FILECHECK_ERR_SUCCESS = 0,	/* Success */
>>> +	OCFS2_FILECHECK_ERR_FAILED = 1000,	/* Other failure */
>>> +	OCFS2_FILECHECK_ERR_INPROGRESS,		/* In progress */
>>> +	OCFS2_FILECHECK_ERR_READONLY,		/* Read only */
>>> +	OCFS2_FILECHECK_ERR_INVALIDINO,		/* Invalid ino */
>>> +	OCFS2_FILECHECK_ERR_BLOCKECC,		/* Block ecc */
>>> +	OCFS2_FILECHECK_ERR_BLOCKNO,		/* Block number */
>>> +	OCFS2_FILECHECK_ERR_VALIDFLAG,		/* Inode valid flag */
>>> +	OCFS2_FILECHECK_ERR_GENERATION,		/* Inode generation */
>>> +	OCFS2_FILECHECK_ERR_UNSUPPORTED		/* Unsupported */
>>> +};
>>> +
>>> +#define OCFS2_FILECHECK_ERR_START	OCFS2_FILECHECK_ERR_FAILED
>>> +#define OCFS2_FILECHECK_ERR_END		OCFS2_FILECHECK_ERR_UNSUPPORTED
>>> +
>>> +int ocfs2_filecheck_create_sysfs(struct super_block *sb);
>>> +int ocfs2_filecheck_remove_sysfs(struct super_block *sb);
>>> +
>>> +#endif  /* FILECHECK_H */
>>> diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
>>> index 5e86b24..abd1018 100644
>>> --- a/fs/ocfs2/inode.h
>>> +++ b/fs/ocfs2/inode.h
>>> @@ -139,6 +139,9 @@ int ocfs2_drop_inode(struct inode *inode);
>>>  /* Flags for ocfs2_iget() */
>>>  #define OCFS2_FI_FLAG_SYSFILE		0x1
>>>  #define OCFS2_FI_FLAG_ORPHAN_RECOVERY	0x2
>>> +#define OCFS2_FI_FLAG_FILECHECK_CHK	0x4
>>> +#define OCFS2_FI_FLAG_FILECHECK_FIX	0x8
>>> +
>>>  struct inode *ocfs2_ilookup(struct super_block *sb, u64 feoff);
>>>  struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff, unsigned 
>> flags,
>>>  			 int sysfile_type);
>>>


From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junxiao Bi <junxiao.bi@oracle.com>
Date: Tue, 03 Nov 2015 16:20:27 +0800
Subject: [Ocfs2-devel] [PATCH v2 2/4] ocfs2: sysfile interfaces for
	online file check
In-Reply-To: <5638D8CF020000F90001CC68@relay2.provo.novell.com>
References: <1446013561-22121-1-git-send-email-ghe@suse.com>
	<1446013561-22121-3-git-send-email-ghe@suse.com>
	<5638604E.9030000@oracle.com>
	<5638D8CF020000F90001CC68@relay2.provo.novell.com>
Message-ID: <56386E4B.5080506@oracle.com>
List-Id: <ocfs2-devel.oss.oracle.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: Gang He <ghe@suse.com>, Mark Fasheh <MFasheh@suse.com>, rgoldwyn@suse.de
Cc: akpm@linux-foundation.org, ocfs2-devel@oss.oracle.com, linux-kernel@vger.kernel.org

Hi Gang,

On 11/03/2015 03:54 PM, Gang He wrote:
> Hi Junxiao,
> 
> Thank for your reviewing.
> Current design, we use a sysfile as a interface to check/fix a file (via pass a ino number).
> But, this operation is manually triggered by user, instead of automatically  fix in the kernel.
> Why?
> 1) we should let users make this decision, since some users do not want to fix when encountering a file system corruption, maybe they want to keep the file system unchanged for a further investigation.
If user don't want this, they should not use error=continue option, let
fs go after a corruption is very dangerous.
> 2) frankly speaking, this feature will probably bring a second corruption if there is some error in the code, I do not suggest to use automatically fix by default in the first version.
I think if this feature could bring more corruption, then this should be
fixed first.

Thanks,
Junxiao
> 3) in the future, if this feature is well proved, we can add a mount option to make this automatically fix enabled.
> 
> 
> Thanks
> Gang
>    
> 
> 
>>>>
>> Hi Gang,
>>
>> I didn't see a need to add a sysfs file for the check and repair. This
>> leaves a hard problem for customer to decide. How they decide whether
>> they should repair the bad inode since this may cause corruption even
>> harder?
>> I think the error should be fixed by this feature automaticlly if repair
>> helps, of course this can be done only when error=continue is enabled or
>> add some mount option for it.
>>
>> Thanks,
>> Junxiao.
>>
>> On 10/28/2015 02:25 PM, Gang He wrote:
>>> Implement online file check sysfile interfaces, e.g.
>>> how to create the related sysfile according to device name,
>>> how to display/handle file check request from the sysfile.
>>>
>>> Signed-off-by: Gang He <ghe@suse.com>
>>> ---
>>>  fs/ocfs2/Makefile    |   3 +-
>>>  fs/ocfs2/filecheck.c | 566 
>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>>>  fs/ocfs2/filecheck.h |  48 +++++
>>>  fs/ocfs2/inode.h     |   3 +
>>>  4 files changed, 619 insertions(+), 1 deletion(-)
>>>  create mode 100644 fs/ocfs2/filecheck.c
>>>  create mode 100644 fs/ocfs2/filecheck.h
>>>
>>> diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
>>> index ce210d4..e27e652 100644
>>> --- a/fs/ocfs2/Makefile
>>> +++ b/fs/ocfs2/Makefile
>>> @@ -41,7 +41,8 @@ ocfs2-objs := \
>>>  	quota_local.o		\
>>>  	quota_global.o		\
>>>  	xattr.o			\
>>> -	acl.o
>>> +	acl.o	\
>>> +	filecheck.o
>>>  
>>>  ocfs2_stackglue-objs := stackglue.o
>>>  ocfs2_stack_o2cb-objs := stack_o2cb.o
>>> diff --git a/fs/ocfs2/filecheck.c b/fs/ocfs2/filecheck.c
>>> new file mode 100644
>>> index 0000000..f12ed1f
>>> --- /dev/null
>>> +++ b/fs/ocfs2/filecheck.c
>>> @@ -0,0 +1,566 @@
>>> +/* -*- mode: c; c-basic-offset: 8; -*-
>>> + * vim: noexpandtab sw=8 ts=8 sts=0:
>>> + *
>>> + * filecheck.c
>>> + *
>>> + * Code which implements online file check.
>>> + *
>>> + * Copyright (C) 2015 Novell.  All rights reserved.
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public
>>> + * License as published by the Free Software Foundation, version 2.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> + * General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/list.h>
>>> +#include <linux/spinlock.h>
>>> +#include <linux/module.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/kmod.h>
>>> +#include <linux/fs.h>
>>> +#include <linux/kobject.h>
>>> +#include <linux/sysfs.h>
>>> +#include <linux/sysctl.h>
>>> +#include <cluster/masklog.h>
>>> +
>>> +#include "ocfs2.h"
>>> +#include "ocfs2_fs.h"
>>> +#include "stackglue.h"
>>> +#include "inode.h"
>>> +
>>> +#include "filecheck.h"
>>> +
>>> +
>>> +/* File check error strings,
>>> + * must correspond with error number in header file.
>>> + */
>>> +static const char * const ocfs2_filecheck_errs[] = {
>>> +	"SUCCESS",
>>> +	"FAILED",
>>> +	"INPROGRESS",
>>> +	"READONLY",
>>> +	"INVALIDINO",
>>> +	"BLOCKECC",
>>> +	"BLOCKNO",
>>> +	"VALIDFLAG",
>>> +	"GENERATION",
>>> +	"UNSUPPORTED"
>>> +};
>>> +
>>> +static DEFINE_SPINLOCK(ocfs2_filecheck_sysfs_lock);
>>> +static LIST_HEAD(ocfs2_filecheck_sysfs_list);
>>> +
>>> +struct ocfs2_filecheck {
>>> +	struct list_head fc_head;	/* File check entry list head */
>>> +	spinlock_t fc_lock;
>>> +	unsigned int fc_max;	/* Maximum number of entry in list */
>>> +	unsigned int fc_size;	/* Current entry count in list */
>>> +	unsigned int fc_done;	/* File check entries are done in list */
>>> +};
>>> +
>>> +struct ocfs2_filecheck_sysfs_entry {
>>> +	struct list_head fs_list;
>>> +	atomic_t fs_count;
>>> +	struct super_block *fs_sb;
>>> +	struct kset *fs_kset;
>>> +	struct ocfs2_filecheck *fs_fcheck;
>>> +};
>>> +
>>> +#define OCFS2_FILECHECK_MAXSIZE		100
>>> +#define OCFS2_FILECHECK_MINSIZE		10
>>> +
>>> +/* File check operation type */
>>> +enum {
>>> +	OCFS2_FILECHECK_TYPE_CHK = 0,	/* Check a file */
>>> +	OCFS2_FILECHECK_TYPE_FIX,	/* Fix a file */
>>> +	OCFS2_FILECHECK_TYPE_SET = 100	/* Set file check options */
>>> +};
>>> +
>>> +struct ocfs2_filecheck_entry {
>>> +	struct list_head fe_list;
>>> +	unsigned long fe_ino;
>>> +	unsigned int fe_type;
>>> +	unsigned short fe_done:1;
>>> +	unsigned short fe_status:15;
>>> +};
>>> +
>>> +struct ocfs2_filecheck_args {
>>> +	unsigned int fa_type;
>>> +	union {
>>> +		unsigned long fa_ino;
>>> +		unsigned int fa_len;
>>> +	};
>>> +};
>>> +
>>> +static const char *
>>> +ocfs2_filecheck_error(int errno)
>>> +{
>>> +	if (!errno)
>>> +		return ocfs2_filecheck_errs[errno];
>>> +
>>> +	BUG_ON(errno < OCFS2_FILECHECK_ERR_START ||
>>> +			errno > OCFS2_FILECHECK_ERR_END);
>>> +	return ocfs2_filecheck_errs[errno - OCFS2_FILECHECK_ERR_START + 1];
>>> +}
>>> +
>>> +static ssize_t ocfs2_filecheck_show(struct kobject *kobj,
>>> +					struct kobj_attribute *attr,
>>> +					char *buf);
>>> +static ssize_t ocfs2_filecheck_store(struct kobject *kobj,
>>> +					struct kobj_attribute *attr,
>>> +					const char *buf, size_t count);
>>> +static struct kobj_attribute ocfs2_attr_filecheck =
>>> +					__ATTR(filecheck, S_IRUSR | S_IWUSR,
>>> +					ocfs2_filecheck_show,
>>> +					ocfs2_filecheck_store);
>>> +
>>> +static int ocfs2_filecheck_sysfs_wait(atomic_t *p)
>>> +{
>>> +	schedule();
>>> +	return 0;
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_sysfs_free(struct ocfs2_filecheck_sysfs_entry *entry)
>>> +{
>>> +	struct ocfs2_filecheck_entry *p;
>>> +
>>> +	if (!atomic_dec_and_test(&entry->fs_count))
>>> +		wait_on_atomic_t(&entry->fs_count, ocfs2_filecheck_sysfs_wait,
>>> +						TASK_UNINTERRUPTIBLE);
>>> +
>>> +	spin_lock(&entry->fs_fcheck->fc_lock);
>>> +	while (!list_empty(&entry->fs_fcheck->fc_head)) {
>>> +		p = list_first_entry(&entry->fs_fcheck->fc_head,
>>> +				struct ocfs2_filecheck_entry, fe_list);
>>> +		list_del(&p->fe_list);
>>> +		BUG_ON(!p->fe_done); /* To free a undone file check entry */
>>> +		kfree(p);
>>> +	}
>>> +	spin_unlock(&entry->fs_fcheck->fc_lock);
>>> +
>>> +	kset_unregister(entry->fs_kset);
>>> +	kfree(entry->fs_fcheck);
>>> +	kfree(entry);
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_sysfs_add(struct ocfs2_filecheck_sysfs_entry *entry)
>>> +{
>>> +	spin_lock(&ocfs2_filecheck_sysfs_lock);
>>> +	list_add_tail(&entry->fs_list, &ocfs2_filecheck_sysfs_list);
>>> +	spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +}
>>> +
>>> +static int ocfs2_filecheck_sysfs_del(const char *devname)
>>> +{
>>> +	struct ocfs2_filecheck_sysfs_entry *p;
>>> +
>>> +	spin_lock(&ocfs2_filecheck_sysfs_lock);
>>> +	list_for_each_entry(p, &ocfs2_filecheck_sysfs_list, fs_list) {
>>> +		if (!strcmp(p->fs_sb->s_id, devname)) {
>>> +			list_del(&p->fs_list);
>>> +			spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +			ocfs2_filecheck_sysfs_free(p);
>>> +			return 0;
>>> +		}
>>> +	}
>>> +	spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +	return 1;
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_sysfs_put(struct ocfs2_filecheck_sysfs_entry *entry)
>>> +{
>>> +	if (atomic_dec_and_test(&entry->fs_count))
>>> +		wake_up_atomic_t(&entry->fs_count);
>>> +}
>>> +
>>> +static struct ocfs2_filecheck_sysfs_entry *
>>> +ocfs2_filecheck_sysfs_get(const char *devname)
>>> +{
>>> +	struct ocfs2_filecheck_sysfs_entry *p = NULL;
>>> +
>>> +	spin_lock(&ocfs2_filecheck_sysfs_lock);
>>> +	list_for_each_entry(p, &ocfs2_filecheck_sysfs_list, fs_list) {
>>> +		if (!strcmp(p->fs_sb->s_id, devname)) {
>>> +			atomic_inc(&p->fs_count);
>>> +			spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +			return p;
>>> +		}
>>> +	}
>>> +	spin_unlock(&ocfs2_filecheck_sysfs_lock);
>>> +	return NULL;
>>> +}
>>> +
>>> +int ocfs2_filecheck_create_sysfs(struct super_block *sb)
>>> +{
>>> +	int ret = 0;
>>> +	struct kset *ocfs2_filecheck_kset = NULL;
>>> +	struct ocfs2_filecheck *fcheck = NULL;
>>> +	struct ocfs2_filecheck_sysfs_entry *entry = NULL;
>>> +	struct attribute **attrs = NULL;
>>> +	struct attribute_group attrgp;
>>> +
>>> +	if (!ocfs2_kset)
>>> +		return -ENOMEM;
>>> +
>>> +	attrs = kmalloc(sizeof(struct attribute *) * 2, GFP_NOFS);
>>> +	if (!attrs) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	} else {
>>> +		attrs[0] = &ocfs2_attr_filecheck.attr;
>>> +		attrs[1] = NULL;
>>> +		memset(&attrgp, 0, sizeof(attrgp));
>>> +		attrgp.attrs = attrs;
>>> +	}
>>> +
>>> +	fcheck = kmalloc(sizeof(struct ocfs2_filecheck), GFP_NOFS);
>>> +	if (!fcheck) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	} else {
>>> +		INIT_LIST_HEAD(&fcheck->fc_head);
>>> +		spin_lock_init(&fcheck->fc_lock);
>>> +		fcheck->fc_max = OCFS2_FILECHECK_MINSIZE;
>>> +		fcheck->fc_size = 0;
>>> +		fcheck->fc_done = 0;
>>> +	}
>>> +
>>> +	if (strlen(sb->s_id) <= 0) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot get device basename when create filecheck sysfs\n");
>>> +		ret = -ENODEV;
>>> +		goto error;
>>> +	}
>>> +
>>> +	ocfs2_filecheck_kset = kset_create_and_add(sb->s_id, NULL,
>>> +						&ocfs2_kset->kobj);
>>> +	if (!ocfs2_filecheck_kset) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	}
>>> +
>>> +	ret = sysfs_create_group(&ocfs2_filecheck_kset->kobj, &attrgp);
>>> +	if (ret)
>>> +		goto error;
>>> +
>>> +	entry = kmalloc(sizeof(struct ocfs2_filecheck_sysfs_entry), GFP_NOFS);
>>> +	if (!entry) {
>>> +		ret = -ENOMEM;
>>> +		goto error;
>>> +	} else {
>>> +		atomic_set(&entry->fs_count, 1);
>>> +		entry->fs_sb = sb;
>>> +		entry->fs_kset = ocfs2_filecheck_kset;
>>> +		entry->fs_fcheck = fcheck;
>>> +		ocfs2_filecheck_sysfs_add(entry);
>>> +	}
>>> +
>>> +	kfree(attrs);
>>> +	return 0;
>>> +
>>> +error:
>>> +	kfree(attrs);
>>> +	kfree(entry);
>>> +	kfree(fcheck);
>>> +	kset_unregister(ocfs2_filecheck_kset);
>>> +	return ret;
>>> +}
>>> +
>>> +int ocfs2_filecheck_remove_sysfs(struct super_block *sb)
>>> +{
>>> +	return ocfs2_filecheck_sysfs_del(sb->s_id);
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_erase_entries(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				unsigned int count);
>>> +static int
>>> +ocfs2_filecheck_adjust_max(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				unsigned int len)
>>> +{
>>> +	int ret;
>>> +
>>> +	if ((len < OCFS2_FILECHECK_MINSIZE) || (len > OCFS2_FILECHECK_MAXSIZE))
>>> +		return -EINVAL;
>>> +
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	if (len < (ent->fs_fcheck->fc_size - ent->fs_fcheck->fc_done)) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot set online file check maximum entry number "
>>> +		"to %u due to too much pending entries(%u)\n",
>>> +		len, ent->fs_fcheck->fc_size - ent->fs_fcheck->fc_done);
>>> +		ret = -EBUSY;
>>> +	} else {
>>> +		if (len < ent->fs_fcheck->fc_size)
>>> +			BUG_ON(!ocfs2_filecheck_erase_entries(ent,
>>> +				ent->fs_fcheck->fc_size - len));
>>> +
>>> +		ent->fs_fcheck->fc_max = len;
>>> +		ret = 0;
>>> +	}
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +#define OCFS2_FILECHECK_ARGS_LEN	32
>>> +static int
>>> +ocfs2_filecheck_args_get_long(const char *buf, size_t count,
>>> +				unsigned long *val)
>>> +{
>>> +	char buffer[OCFS2_FILECHECK_ARGS_LEN];
>>> +
>>> +	if (count < 1)
>>> +		return 1;
>>> +
>>> +	memcpy(buffer, buf, count);
>>> +	buffer[count] = '\0';
>>> +
>>> +	if (kstrtoul(buffer, 0, val))
>>> +		return 1;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_args_parse(const char *buf, size_t count,
>>> +				struct ocfs2_filecheck_args *args)
>>> +{
>>> +	unsigned long val = 0;
>>> +
>>> +	/* too short/long args length */
>>> +	if ((count < 5) || (count > OCFS2_FILECHECK_ARGS_LEN))
>>> +		return 1;
>>> +
>>> +	if (!strncasecmp(buf, "FIX ", 4)) {
>>> +		if (ocfs2_filecheck_args_get_long(buf + 4, count - 4, &val))
>>> +			return 1;
>>> +
>>> +		args->fa_type = OCFS2_FILECHECK_TYPE_FIX;
>>> +		args->fa_ino = val;
>>> +		return 0;
>>> +	} else if ((count > 6) && !strncasecmp(buf, "CHECK ", 6)) {
>>> +		if (ocfs2_filecheck_args_get_long(buf + 6, count - 6, &val))
>>> +			return 1;
>>> +
>>> +		args->fa_type = OCFS2_FILECHECK_TYPE_CHK;
>>> +		args->fa_ino = val;
>>> +		return 0;
>>> +	} else if (!strncasecmp(buf, "SET ", 4)) {
>>> +		if (ocfs2_filecheck_args_get_long(buf + 4, count - 4, &val))
>>> +			return 1;
>>> +
>>> +		args->fa_type = OCFS2_FILECHECK_TYPE_SET;
>>> +		args->fa_len = (unsigned int)val;
>>> +		return 0;
>>> +	} else { /* invalid args */
>>> +		return 1;
>>> +	}
>>> +}
>>> +
>>> +static ssize_t ocfs2_filecheck_show(struct kobject *kobj,
>>> +					struct kobj_attribute *attr,
>>> +					char *buf)
>>> +{
>>> +
>>> +	ssize_t ret = 0, total = 0, remain = PAGE_SIZE;
>>> +	struct ocfs2_filecheck_entry *p;
>>> +	struct ocfs2_filecheck_sysfs_entry *ent;
>>> +
>>> +	ent = ocfs2_filecheck_sysfs_get(kobj->name);
>>> +	if (!ent) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot get the corresponding entry via device basename %s\n",
>>> +		kobj->name);
>>> +		return -ENODEV;
>>> +	}
>>> +
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	ret = snprintf(buf, remain, "INO\t\tTYPE\tDONE\tERROR\n");
>>> +	total += ret;
>>> +	remain -= ret;
>>> +
>>> +	list_for_each_entry(p, &ent->fs_fcheck->fc_head, fe_list) {
>>> +		ret = snprintf(buf + total, remain, "%lu\t\t%u\t%u\t%s\n",
>>> +			p->fe_ino, p->fe_type, p->fe_done,
>>> +			ocfs2_filecheck_error(p->fe_status));
>>> +		if (ret < 0) {
>>> +			total = ret;
>>> +			break;
>>> +		}
>>> +		if (ret == remain) {
>>> +			/* snprintf() didn't fit */
>>> +			total = -E2BIG;
>>> +			break;
>>> +		}
>>> +		total += ret;
>>> +		remain -= ret;
>>> +	}
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +
>>> +	ocfs2_filecheck_sysfs_put(ent);
>>> +	return total;
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_erase_entry(struct ocfs2_filecheck_sysfs_entry *ent)
>>> +{
>>> +	struct ocfs2_filecheck_entry *p;
>>> +
>>> +	list_for_each_entry(p, &ent->fs_fcheck->fc_head, fe_list) {
>>> +		if (p->fe_done) {
>>> +			list_del(&p->fe_list);
>>> +			kfree(p);
>>> +			ent->fs_fcheck->fc_size--;
>>> +			ent->fs_fcheck->fc_done--;
>>> +			return 1;
>>> +		}
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int
>>> +ocfs2_filecheck_erase_entries(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				unsigned int count)
>>> +{
>>> +	unsigned int i = 0;
>>> +	unsigned int ret = 0;
>>> +
>>> +	while (i++ < count) {
>>> +		if (ocfs2_filecheck_erase_entry(ent))
>>> +			ret++;
>>> +		else
>>> +			break;
>>> +	}
>>> +
>>> +	return (ret == count ? 1 : 0);
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_done_entry(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				struct ocfs2_filecheck_entry *entry)
>>> +{
>>> +	entry->fe_done = 1;
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	ent->fs_fcheck->fc_done++;
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +}
>>> +
>>> +static unsigned short
>>> +ocfs2_filecheck_handle(struct super_block *sb,
>>> +				unsigned long ino, unsigned int flags)
>>> +{
>>> +	unsigned short ret = OCFS2_FILECHECK_ERR_SUCCESS;
>>> +	struct inode *inode = NULL;
>>> +	int rc;
>>> +
>>> +	inode = ocfs2_iget(OCFS2_SB(sb), ino, flags, 0);
>>> +	if (IS_ERR(inode)) {
>>> +		rc = (int)(-(long)inode);
>>> +		if (rc >= OCFS2_FILECHECK_ERR_START &&
>>> +			rc < OCFS2_FILECHECK_ERR_END)
>>> +			ret = rc;
>>> +		else
>>> +			ret = OCFS2_FILECHECK_ERR_FAILED;
>>> +	} else
>>> +		iput(inode);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +static void
>>> +ocfs2_filecheck_handle_entry(struct ocfs2_filecheck_sysfs_entry *ent,
>>> +				struct ocfs2_filecheck_entry *entry)
>>> +{
>>> +	if (entry->fe_type == OCFS2_FILECHECK_TYPE_CHK)
>>> +		entry->fe_status = ocfs2_filecheck_handle(ent->fs_sb,
>>> +				entry->fe_ino, OCFS2_FI_FLAG_FILECHECK_CHK);
>>> +	else if (entry->fe_type == OCFS2_FILECHECK_TYPE_FIX)
>>> +		entry->fe_status = ocfs2_filecheck_handle(ent->fs_sb,
>>> +				entry->fe_ino, OCFS2_FI_FLAG_FILECHECK_FIX);
>>> +	else
>>> +		entry->fe_status = OCFS2_FILECHECK_ERR_UNSUPPORTED;
>>> +
>>> +	ocfs2_filecheck_done_entry(ent, entry);
>>> +}
>>> +
>>> +static ssize_t ocfs2_filecheck_store(struct kobject *kobj,
>>> +				struct kobj_attribute *attr,
>>> +				const char *buf, size_t count)
>>> +{
>>> +	struct ocfs2_filecheck_args args;
>>> +	struct ocfs2_filecheck_entry *entry = NULL;
>>> +	struct ocfs2_filecheck_sysfs_entry *ent;
>>> +	ssize_t ret = 0;
>>> +
>>> +	if (count == 0)
>>> +		return count;
>>> +
>>> +	if (ocfs2_filecheck_args_parse(buf, count, &args)) {
>>> +		mlog(ML_ERROR, "Invalid arguments for online file check\n");
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	ent = ocfs2_filecheck_sysfs_get(kobj->name);
>>> +	if (!ent) {
>>> +		mlog(ML_ERROR,
>>> +		"Cannot get the corresponding entry via device basename %s\n",
>>> +		kobj->name);
>>> +		return -ENODEV;
>>> +	}
>>> +
>>> +	if (args.fa_type == OCFS2_FILECHECK_TYPE_SET) {
>>> +		ret = ocfs2_filecheck_adjust_max(ent, args.fa_len);
>>> +		ocfs2_filecheck_sysfs_put(ent);
>>> +		return (!ret ? count : ret);
>>> +	}
>>> +
>>> +	spin_lock(&ent->fs_fcheck->fc_lock);
>>> +	if ((ent->fs_fcheck->fc_size >= ent->fs_fcheck->fc_max) &&
>>> +		(ent->fs_fcheck->fc_done == 0)) {
>>> +		mlog(ML_ERROR,
>>> +		"Online file check queue(%u) is full\n",
>>> +		ent->fs_fcheck->fc_max);
>>> +		ret = -EBUSY;
>>> +	} else {
>>> +		if ((ent->fs_fcheck->fc_size >= ent->fs_fcheck->fc_max) &&
>>> +			(ent->fs_fcheck->fc_done > 0)) {
>>> +			/* Delete the oldest entry which was done,
>>> +			 * make sure the entry size in list does
>>> +			 * not exceed maximum value
>>> +			 */
>>> +			BUG_ON(!ocfs2_filecheck_erase_entry(ent));
>>> +		}
>>> +
>>> +		entry = kmalloc(sizeof(struct ocfs2_filecheck_entry), GFP_NOFS);
>>> +		if (entry) {
>>> +			entry->fe_ino = args.fa_ino;
>>> +			entry->fe_type = args.fa_type;
>>> +			entry->fe_done = 0;
>>> +			entry->fe_status = OCFS2_FILECHECK_ERR_INPROGRESS;
>>> +			list_add_tail(&entry->fe_list,
>>> +					&ent->fs_fcheck->fc_head);
>>> +
>>> +			ent->fs_fcheck->fc_size++;
>>> +			ret = count;
>>> +		} else {
>>> +			ret = -ENOMEM;
>>> +		}
>>> +	}
>>> +	spin_unlock(&ent->fs_fcheck->fc_lock);
>>> +
>>> +	if (entry)
>>> +		ocfs2_filecheck_handle_entry(ent, entry);
>>> +
>>> +	ocfs2_filecheck_sysfs_put(ent);
>>> +	return ret;
>>> +}
>>> diff --git a/fs/ocfs2/filecheck.h b/fs/ocfs2/filecheck.h
>>> new file mode 100644
>>> index 0000000..5ec331b
>>> --- /dev/null
>>> +++ b/fs/ocfs2/filecheck.h
>>> @@ -0,0 +1,48 @@
>>> +/* -*- mode: c; c-basic-offset: 8; -*-
>>> + * vim: noexpandtab sw=8 ts=8 sts=0:
>>> + *
>>> + * filecheck.h
>>> + *
>>> + * Online file check.
>>> + *
>>> + * Copyright (C) 2015 Novell.  All rights reserved.
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public
>>> + * License as published by the Free Software Foundation, version 2.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>>> + * General Public License for more details.
>>> + */
>>> +
>>> +
>>> +#ifndef FILECHECK_H
>>> +#define FILECHECK_H
>>> +
>>> +#include <linux/types.h>
>>> +#include <linux/list.h>
>>> +
>>> +
>>> +/* File check errno */
>>> +enum {
>>> +	OCFS2_FILECHECK_ERR_SUCCESS = 0,	/* Success */
>>> +	OCFS2_FILECHECK_ERR_FAILED = 1000,	/* Other failure */
>>> +	OCFS2_FILECHECK_ERR_INPROGRESS,		/* In progress */
>>> +	OCFS2_FILECHECK_ERR_READONLY,		/* Read only */
>>> +	OCFS2_FILECHECK_ERR_INVALIDINO,		/* Invalid ino */
>>> +	OCFS2_FILECHECK_ERR_BLOCKECC,		/* Block ecc */
>>> +	OCFS2_FILECHECK_ERR_BLOCKNO,		/* Block number */
>>> +	OCFS2_FILECHECK_ERR_VALIDFLAG,		/* Inode valid flag */
>>> +	OCFS2_FILECHECK_ERR_GENERATION,		/* Inode generation */
>>> +	OCFS2_FILECHECK_ERR_UNSUPPORTED		/* Unsupported */
>>> +};
>>> +
>>> +#define OCFS2_FILECHECK_ERR_START	OCFS2_FILECHECK_ERR_FAILED
>>> +#define OCFS2_FILECHECK_ERR_END		OCFS2_FILECHECK_ERR_UNSUPPORTED
>>> +
>>> +int ocfs2_filecheck_create_sysfs(struct super_block *sb);
>>> +int ocfs2_filecheck_remove_sysfs(struct super_block *sb);
>>> +
>>> +#endif  /* FILECHECK_H */
>>> diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
>>> index 5e86b24..abd1018 100644
>>> --- a/fs/ocfs2/inode.h
>>> +++ b/fs/ocfs2/inode.h
>>> @@ -139,6 +139,9 @@ int ocfs2_drop_inode(struct inode *inode);
>>>  /* Flags for ocfs2_iget() */
>>>  #define OCFS2_FI_FLAG_SYSFILE		0x1
>>>  #define OCFS2_FI_FLAG_ORPHAN_RECOVERY	0x2
>>> +#define OCFS2_FI_FLAG_FILECHECK_CHK	0x4
>>> +#define OCFS2_FI_FLAG_FILECHECK_FIX	0x8
>>> +
>>>  struct inode *ocfs2_ilookup(struct super_block *sb, u64 feoff);
>>>  struct inode *ocfs2_iget(struct ocfs2_super *osb, u64 feoff, unsigned 
>> flags,
>>>  			 int sysfile_type);
>>>