linux/fs/ocfs2/filecheck.c
Dan Carpenter 54e948c60c ocfs2: fix snprintf() checking
The snprintf() function returns the number of bytes which would have been
printed if the buffer was large enough.  In other words it can return ">=
remain" but this code assumes it returns "== remain".

The run time impact of this bug is not very severe.  The next iteration
through the loop would trigger a WARN() when we pass a negative limit to
snprintf().  We would then return success instead of -E2BIG.

The kernel implementation of snprintf() will never return negatives so
there is no need to check and I have deleted that dead code.

Link: https://lkml.kernel.org/r/20210511135350.GV1955@kadam
Fixes: a860f6eb4c ("ocfs2: sysfile interfaces for online file check")
Fixes: 74ae4e104d ("ocfs2: Create stack glue sysfs files.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:46 -07:00

509 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* filecheck.c
*
* Code which implements online file check.
*
* Copyright (C) 2016 SuSE. All rights reserved.
*/
#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",
"INJBD",
"INVALIDINO",
"BLOCKECC",
"BLOCKNO",
"VALIDFLAG",
"GENERATION",
"UNSUPPORTED"
};
struct ocfs2_filecheck_entry {
struct list_head fe_list;
unsigned long fe_ino;
unsigned int fe_type;
unsigned int fe_done:1;
unsigned int fe_status:31;
};
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_attr_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf);
static ssize_t ocfs2_filecheck_attr_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count);
static struct kobj_attribute ocfs2_filecheck_attr_chk =
__ATTR(check, S_IRUSR | S_IWUSR,
ocfs2_filecheck_attr_show,
ocfs2_filecheck_attr_store);
static struct kobj_attribute ocfs2_filecheck_attr_fix =
__ATTR(fix, S_IRUSR | S_IWUSR,
ocfs2_filecheck_attr_show,
ocfs2_filecheck_attr_store);
static struct kobj_attribute ocfs2_filecheck_attr_set =
__ATTR(set, S_IRUSR | S_IWUSR,
ocfs2_filecheck_attr_show,
ocfs2_filecheck_attr_store);
static struct attribute *ocfs2_filecheck_attrs[] = {
&ocfs2_filecheck_attr_chk.attr,
&ocfs2_filecheck_attr_fix.attr,
&ocfs2_filecheck_attr_set.attr,
NULL
};
static void ocfs2_filecheck_release(struct kobject *kobj)
{
struct ocfs2_filecheck_sysfs_entry *entry = container_of(kobj,
struct ocfs2_filecheck_sysfs_entry, fs_kobj);
complete(&entry->fs_kobj_unregister);
}
static ssize_t
ocfs2_filecheck_show(struct kobject *kobj, struct attribute *attr, char *buf)
{
ssize_t ret = -EIO;
struct kobj_attribute *kattr = container_of(attr,
struct kobj_attribute, attr);
kobject_get(kobj);
if (kattr->show)
ret = kattr->show(kobj, kattr, buf);
kobject_put(kobj);
return ret;
}
static ssize_t
ocfs2_filecheck_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t count)
{
ssize_t ret = -EIO;
struct kobj_attribute *kattr = container_of(attr,
struct kobj_attribute, attr);
kobject_get(kobj);
if (kattr->store)
ret = kattr->store(kobj, kattr, buf, count);
kobject_put(kobj);
return ret;
}
static const struct sysfs_ops ocfs2_filecheck_ops = {
.show = ocfs2_filecheck_show,
.store = ocfs2_filecheck_store,
};
static struct kobj_type ocfs2_ktype_filecheck = {
.default_attrs = ocfs2_filecheck_attrs,
.sysfs_ops = &ocfs2_filecheck_ops,
.release = ocfs2_filecheck_release,
};
static void
ocfs2_filecheck_sysfs_free(struct ocfs2_filecheck_sysfs_entry *entry)
{
struct ocfs2_filecheck_entry *p;
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);
kfree(entry->fs_fcheck);
entry->fs_fcheck = NULL;
}
int ocfs2_filecheck_create_sysfs(struct ocfs2_super *osb)
{
int ret;
struct ocfs2_filecheck *fcheck;
struct ocfs2_filecheck_sysfs_entry *entry = &osb->osb_fc_ent;
fcheck = kmalloc(sizeof(struct ocfs2_filecheck), GFP_NOFS);
if (!fcheck)
return -ENOMEM;
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;
entry->fs_kobj.kset = osb->osb_dev_kset;
init_completion(&entry->fs_kobj_unregister);
ret = kobject_init_and_add(&entry->fs_kobj, &ocfs2_ktype_filecheck,
NULL, "filecheck");
if (ret) {
kobject_put(&entry->fs_kobj);
kfree(fcheck);
return ret;
}
entry->fs_fcheck = fcheck;
return 0;
}
void ocfs2_filecheck_remove_sysfs(struct ocfs2_super *osb)
{
if (!osb->osb_fc_ent.fs_fcheck)
return;
kobject_del(&osb->osb_fc_ent.fs_kobj);
kobject_put(&osb->osb_fc_ent.fs_kobj);
wait_for_completion(&osb->osb_fc_ent.fs_kobj_unregister);
ocfs2_filecheck_sysfs_free(&osb->osb_fc_ent);
}
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_NOTICE,
"Cannot set online file check maximum entry number "
"to %u due to too many 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 24
static int
ocfs2_filecheck_args_get_long(const char *buf, size_t count,
unsigned long *val)
{
char buffer[OCFS2_FILECHECK_ARGS_LEN];
memcpy(buffer, buf, count);
buffer[count] = '\0';
if (kstrtoul(buffer, 0, val))
return 1;
return 0;
}
static int
ocfs2_filecheck_type_parse(const char *name, unsigned int *type)
{
if (!strncmp(name, "fix", 4))
*type = OCFS2_FILECHECK_TYPE_FIX;
else if (!strncmp(name, "check", 6))
*type = OCFS2_FILECHECK_TYPE_CHK;
else if (!strncmp(name, "set", 4))
*type = OCFS2_FILECHECK_TYPE_SET;
else
return 1;
return 0;
}
static int
ocfs2_filecheck_args_parse(const char *name, const char *buf, size_t count,
struct ocfs2_filecheck_args *args)
{
unsigned long val = 0;
unsigned int type;
/* too short/long args length */
if ((count < 1) || (count >= OCFS2_FILECHECK_ARGS_LEN))
return 1;
if (ocfs2_filecheck_type_parse(name, &type))
return 1;
if (ocfs2_filecheck_args_get_long(buf, count, &val))
return 1;
if (val <= 0)
return 1;
args->fa_type = type;
if (type == OCFS2_FILECHECK_TYPE_SET)
args->fa_len = (unsigned int)val;
else
args->fa_ino = val;
return 0;
}
static ssize_t ocfs2_filecheck_attr_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
{
ssize_t ret = 0, total = 0, remain = PAGE_SIZE;
unsigned int type;
struct ocfs2_filecheck_entry *p;
struct ocfs2_filecheck_sysfs_entry *ent = container_of(kobj,
struct ocfs2_filecheck_sysfs_entry, fs_kobj);
if (ocfs2_filecheck_type_parse(attr->attr.name, &type))
return -EINVAL;
if (type == OCFS2_FILECHECK_TYPE_SET) {
spin_lock(&ent->fs_fcheck->fc_lock);
total = snprintf(buf, remain, "%u\n", ent->fs_fcheck->fc_max);
spin_unlock(&ent->fs_fcheck->fc_lock);
goto exit;
}
ret = snprintf(buf, remain, "INO\t\tDONE\tERROR\n");
total += ret;
remain -= ret;
spin_lock(&ent->fs_fcheck->fc_lock);
list_for_each_entry(p, &ent->fs_fcheck->fc_head, fe_list) {
if (p->fe_type != type)
continue;
ret = snprintf(buf + total, remain, "%lu\t\t%u\t%s\n",
p->fe_ino, p->fe_done,
ocfs2_filecheck_error(p->fe_status));
if (ret >= remain) {
/* snprintf() didn't fit */
total = -E2BIG;
break;
}
total += ret;
remain -= ret;
}
spin_unlock(&ent->fs_fcheck->fc_lock);
exit:
return total;
}
static inline int
ocfs2_filecheck_is_dup_entry(struct ocfs2_filecheck_sysfs_entry *ent,
unsigned long ino)
{
struct ocfs2_filecheck_entry *p;
list_for_each_entry(p, &ent->fs_fcheck->fc_head, fe_list) {
if (!p->fe_done) {
if (p->fe_ino == ino)
return 1;
}
}
return 0;
}
static inline 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)
{
spin_lock(&ent->fs_fcheck->fc_lock);
entry->fe_done = 1;
ent->fs_fcheck->fc_done++;
spin_unlock(&ent->fs_fcheck->fc_lock);
}
static unsigned int
ocfs2_filecheck_handle(struct ocfs2_super *osb,
unsigned long ino, unsigned int flags)
{
unsigned int ret = OCFS2_FILECHECK_ERR_SUCCESS;
struct inode *inode = NULL;
int rc;
inode = ocfs2_iget(osb, 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)
{
struct ocfs2_super *osb = container_of(ent, struct ocfs2_super,
osb_fc_ent);
if (entry->fe_type == OCFS2_FILECHECK_TYPE_CHK)
entry->fe_status = ocfs2_filecheck_handle(osb,
entry->fe_ino, OCFS2_FI_FLAG_FILECHECK_CHK);
else if (entry->fe_type == OCFS2_FILECHECK_TYPE_FIX)
entry->fe_status = ocfs2_filecheck_handle(osb,
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_attr_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
ssize_t ret = 0;
struct ocfs2_filecheck_args args;
struct ocfs2_filecheck_entry *entry;
struct ocfs2_filecheck_sysfs_entry *ent = container_of(kobj,
struct ocfs2_filecheck_sysfs_entry, fs_kobj);
if (count == 0)
return count;
if (ocfs2_filecheck_args_parse(attr->attr.name, buf, count, &args))
return -EINVAL;
if (args.fa_type == OCFS2_FILECHECK_TYPE_SET) {
ret = ocfs2_filecheck_adjust_max(ent, args.fa_len);
goto exit;
}
entry = kmalloc(sizeof(struct ocfs2_filecheck_entry), GFP_NOFS);
if (!entry) {
ret = -ENOMEM;
goto exit;
}
spin_lock(&ent->fs_fcheck->fc_lock);
if (ocfs2_filecheck_is_dup_entry(ent, args.fa_ino)) {
ret = -EEXIST;
kfree(entry);
} else if ((ent->fs_fcheck->fc_size >= ent->fs_fcheck->fc_max) &&
(ent->fs_fcheck->fc_done == 0)) {
mlog(ML_NOTICE,
"Cannot do more file check "
"since file check queue(%u) is full now\n",
ent->fs_fcheck->fc_max);
ret = -EAGAIN;
kfree(entry);
} 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->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++;
}
spin_unlock(&ent->fs_fcheck->fc_lock);
if (!ret)
ocfs2_filecheck_handle_entry(ent, entry);
exit:
return (!ret ? count : ret);
}