fs/ocfs2/ioctl.c - kernel/msm - Gitiles

 /*
  * linux/fs/ocfs2/ioctl.c
  *
  * Copyright (C) 2006 Herbert Poetzl
  * adapted from Remy Card's ext2/ioctl.c
  */

 #include <linux/fs.h>
 #include <linux/mount.h>
 #include <linux/compat.h>

 #include <cluster/masklog.h>

 #include "ocfs2.h"
 #include "alloc.h"
 #include "dlmglue.h"
 #include "file.h"
 #include "inode.h"
 #include "journal.h"

 #include "ocfs2_fs.h"
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"

 #include <linux/ext2_fs.h>

 #define o2info_from_user(a, b)	\
 		copy_from_user(&(a), (b), sizeof(a))
 #define o2info_to_user(a, b)	\
 		copy_to_user((typeof(a) __user *)b, &(a), sizeof(a))

 /*
  * This call is void because we are already reporting an error that may
  * be -EFAULT.  The error will be returned from the ioctl(2) call.  It's
  * just a best-effort to tell userspace that this request caused the error.
  */
 static inline void __o2info_set_request_error(struct ocfs2_info_request *kreq,
 					struct ocfs2_info_request __user *req)
 {
 	kreq->ir_flags |= OCFS2_INFO_FL_ERROR;
 	(void)put_user(kreq->ir_flags, (__u32 __user *)&(req->ir_flags));
 }

 #define o2info_set_request_error(a, b) \
 		__o2info_set_request_error((struct ocfs2_info_request *)&(a), b)

 static inline void __o2info_set_request_filled(struct ocfs2_info_request *req)
 {
 	req->ir_flags |= OCFS2_INFO_FL_FILLED;
 }

 #define o2info_set_request_filled(a) \
 		__o2info_set_request_filled((struct ocfs2_info_request *)&(a))

 static inline void __o2info_clear_request_filled(struct ocfs2_info_request *req)
 {
 	req->ir_flags &= ~OCFS2_INFO_FL_FILLED;
 }

 #define o2info_clear_request_filled(a) \
 		__o2info_clear_request_filled((struct ocfs2_info_request *)&(a))

 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {
 	int status;

 	status = ocfs2_inode_lock(inode, NULL, 0);
 	if (status < 0) {
 		mlog_errno(status);
 		return status;
 	}
 	ocfs2_get_inode_flags(OCFS2_I(inode));
 	*flags = OCFS2_I(inode)->ip_attr;
 	ocfs2_inode_unlock(inode, 0);

 	return status;
 }

 static int ocfs2_set_inode_attr(struct inode *inode, unsigned flags,
 				unsigned mask)
 {
 	struct ocfs2_inode_info *ocfs2_inode = OCFS2_I(inode);
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 	handle_t *handle = NULL;
 	struct buffer_head *bh = NULL;
 	unsigned oldflags;
 	int status;

 	mutex_lock(&inode->i_mutex);

 	status = ocfs2_inode_lock(inode, &bh, 1);
 	if (status < 0) {
 		mlog_errno(status);
 		goto bail;
 	}

 	status = -EACCES;
 	if (!inode_owner_or_capable(inode))
 		goto bail_unlock;

 	if (!S_ISDIR(inode->i_mode))
 		flags &= ~OCFS2_DIRSYNC_FL;

 	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
 	if (IS_ERR(handle)) {
 		status = PTR_ERR(handle);
 		mlog_errno(status);
 		goto bail_unlock;
 	}

 	oldflags = ocfs2_inode->ip_attr;
 	flags = flags & mask;
 	flags |= oldflags & ~mask;

 	/*
 	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 	 * the relevant capability.
 	 */
 	status = -EPERM;
 	if ((oldflags & OCFS2_IMMUTABLE_FL) || ((flags ^ oldflags) &
 		(OCFS2_APPEND_FL | OCFS2_IMMUTABLE_FL))) {
 		if (!capable(CAP_LINUX_IMMUTABLE))
 			goto bail_unlock;
 	}

 	ocfs2_inode->ip_attr = flags;
 	ocfs2_set_inode_flags(inode);

 	status = ocfs2_mark_inode_dirty(handle, inode, bh);
 	if (status < 0)
 		mlog_errno(status);

 	ocfs2_commit_trans(osb, handle);
 bail_unlock:
 	ocfs2_inode_unlock(inode, 1);
 bail:
 	mutex_unlock(&inode->i_mutex);

 	brelse(bh);

 	return status;
 }

 int ocfs2_info_handle_blocksize(struct inode *inode,
 				struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_blocksize oib;

 	if (o2info_from_user(oib, req))
 		goto bail;

 	oib.ib_blocksize = inode->i_sb->s_blocksize;

 	o2info_set_request_filled(oib);

 	if (o2info_to_user(oib, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oib, req);

 	return status;
 }

 int ocfs2_info_handle_clustersize(struct inode *inode,
 				  struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_clustersize oic;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

 	if (o2info_from_user(oic, req))
 		goto bail;

 	oic.ic_clustersize = osb->s_clustersize;

 	o2info_set_request_filled(oic);

 	if (o2info_to_user(oic, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oic, req);

 	return status;
 }

 int ocfs2_info_handle_maxslots(struct inode *inode,
 			       struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_maxslots oim;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

 	if (o2info_from_user(oim, req))
 		goto bail;

 	oim.im_max_slots = osb->max_slots;

 	o2info_set_request_filled(oim);

 	if (o2info_to_user(oim, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oim, req);

 	return status;
 }

 int ocfs2_info_handle_label(struct inode *inode,
 			    struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_label oil;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

 	if (o2info_from_user(oil, req))
 		goto bail;

 	memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);

 	o2info_set_request_filled(oil);

 	if (o2info_to_user(oil, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oil, req);

 	return status;
 }

 int ocfs2_info_handle_uuid(struct inode *inode,
 			   struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_uuid oiu;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

 	if (o2info_from_user(oiu, req))
 		goto bail;

 	memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_TEXT_UUID_LEN + 1);

 	o2info_set_request_filled(oiu);

 	if (o2info_to_user(oiu, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oiu, req);

 	return status;
 }

 int ocfs2_info_handle_fs_features(struct inode *inode,
 				  struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_fs_features oif;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

 	if (o2info_from_user(oif, req))
 		goto bail;

 	oif.if_compat_features = osb->s_feature_compat;
 	oif.if_incompat_features = osb->s_feature_incompat;
 	oif.if_ro_compat_features = osb->s_feature_ro_compat;

 	o2info_set_request_filled(oif);

 	if (o2info_to_user(oif, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oif, req);

 	return status;
 }

 int ocfs2_info_handle_journal_size(struct inode *inode,
 				   struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_journal_size oij;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

 	if (o2info_from_user(oij, req))
 		goto bail;

 	oij.ij_journal_size = osb->journal->j_inode->i_size;

 	o2info_set_request_filled(oij);

 	if (o2info_to_user(oij, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oij, req);

 	return status;
 }

 int ocfs2_info_handle_unknown(struct inode *inode,
 			      struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_request oir;

 	if (o2info_from_user(oir, req))
 		goto bail;

 	o2info_clear_request_filled(oir);

 	if (o2info_to_user(oir, req))
 		goto bail;

 	status = 0;
 bail:
 	if (status)
 		o2info_set_request_error(oir, req);

 	return status;
 }

 /*
  * Validate and distinguish OCFS2_IOC_INFO requests.
  *
  * - validate the magic number.
  * - distinguish different requests.
  * - validate size of different requests.
  */
 int ocfs2_info_handle_request(struct inode *inode,
 			      struct ocfs2_info_request __user *req)
 {
 	int status = -EFAULT;
 	struct ocfs2_info_request oir;

 	if (o2info_from_user(oir, req))
 		goto bail;

 	status = -EINVAL;
 	if (oir.ir_magic != OCFS2_INFO_MAGIC)
 		goto bail;

 	switch (oir.ir_code) {
 	case OCFS2_INFO_BLOCKSIZE:
 		if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
 			status = ocfs2_info_handle_blocksize(inode, req);
 		break;
 	case OCFS2_INFO_CLUSTERSIZE:
 		if (oir.ir_size == sizeof(struct ocfs2_info_clustersize))
 			status = ocfs2_info_handle_clustersize(inode, req);
 		break;
 	case OCFS2_INFO_MAXSLOTS:
 		if (oir.ir_size == sizeof(struct ocfs2_info_maxslots))
 			status = ocfs2_info_handle_maxslots(inode, req);
 		break;
 	case OCFS2_INFO_LABEL:
 		if (oir.ir_size == sizeof(struct ocfs2_info_label))
 			status = ocfs2_info_handle_label(inode, req);
 		break;
 	case OCFS2_INFO_UUID:
 		if (oir.ir_size == sizeof(struct ocfs2_info_uuid))
 			status = ocfs2_info_handle_uuid(inode, req);
 		break;
 	case OCFS2_INFO_FS_FEATURES:
 		if (oir.ir_size == sizeof(struct ocfs2_info_fs_features))
 			status = ocfs2_info_handle_fs_features(inode, req);
 		break;
 	case OCFS2_INFO_JOURNAL_SIZE:
 		if (oir.ir_size == sizeof(struct ocfs2_info_journal_size))
 			status = ocfs2_info_handle_journal_size(inode, req);
 		break;
 	default:
 		status = ocfs2_info_handle_unknown(inode, req);
 		break;
 	}

 bail:
 	return status;
 }

 int ocfs2_get_request_ptr(struct ocfs2_info *info, int idx,
 			  u64 *req_addr, int compat_flag)
 {
 	int status = -EFAULT;
 	u64 __user *bp = NULL;

 	if (compat_flag) {
 #ifdef CONFIG_COMPAT
 		/*
 		 * pointer bp stores the base address of a pointers array,
 		 * which collects all addresses of separate request.
 		 */
 		bp = (u64 __user *)(unsigned long)compat_ptr(info->oi_requests);
 #else
 		BUG();
 #endif
 	} else
 		bp = (u64 __user *)(unsigned long)(info->oi_requests);

 	if (o2info_from_user(*req_addr, bp + idx))
 		goto bail;

 	status = 0;
 bail:
 	return status;
 }

 /*
  * OCFS2_IOC_INFO handles an array of requests passed from userspace.
  *
  * ocfs2_info_handle() recevies a large info aggregation, grab and
  * validate the request count from header, then break it into small
  * pieces, later specific handlers can handle them one by one.
  *
  * Idea here is to make each separate request small enough to ensure
  * a better backward&forward compatibility, since a small piece of
  * request will be less likely to be broken if disk layout get changed.
  */
 int ocfs2_info_handle(struct inode *inode, struct ocfs2_info *info,
 		      int compat_flag)
 {
 	int i, status = 0;
 	u64 req_addr;
 	struct ocfs2_info_request __user *reqp;

 	if ((info->oi_count > OCFS2_INFO_MAX_REQUEST) ||
 	    (!info->oi_requests)) {
 		status = -EINVAL;
 		goto bail;
 	}

 	for (i = 0; i < info->oi_count; i++) {

 		status = ocfs2_get_request_ptr(info, i, &req_addr, compat_flag);
 		if (status)
 			break;

 		reqp = (struct ocfs2_info_request *)(unsigned long)req_addr;
 		if (!reqp) {
 			status = -EINVAL;
 			goto bail;
 		}

 		status = ocfs2_info_handle_request(inode, reqp);
 		if (status)
 			break;
 	}

 bail:
 	return status;
 }

 long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	unsigned int flags;
 	int new_clusters;
 	int status;
 	struct ocfs2_space_resv sr;
 	struct ocfs2_new_group_input input;
 	struct reflink_arguments args;
 	const char *old_path, *new_path;
 	bool preserve;
 	struct ocfs2_info info;

 	switch (cmd) {
 	case OCFS2_IOC_GETFLAGS:
 		status = ocfs2_get_inode_attr(inode, &flags);
 		if (status < 0)
 			return status;

 		flags &= OCFS2_FL_VISIBLE;
 		return put_user(flags, (int __user *) arg);
 	case OCFS2_IOC_SETFLAGS:
 		if (get_user(flags, (int __user *) arg))
 			return -EFAULT;

 		status = mnt_want_write(filp->f_path.mnt);
 		if (status)
 			return status;
 		status = ocfs2_set_inode_attr(inode, flags,
 			OCFS2_FL_MODIFIABLE);
 		mnt_drop_write(filp->f_path.mnt);
 		return status;
 	case OCFS2_IOC_RESVSP:
 	case OCFS2_IOC_RESVSP64:
 	case OCFS2_IOC_UNRESVSP:
 	case OCFS2_IOC_UNRESVSP64:
 		if (copy_from_user(&sr, (int __user *) arg, sizeof(sr)))
 			return -EFAULT;

 		return ocfs2_change_file_space(filp, cmd, &sr);
 	case OCFS2_IOC_GROUP_EXTEND:
 		if (!capable(CAP_SYS_RESOURCE))
 			return -EPERM;

 		if (get_user(new_clusters, (int __user *)arg))
 			return -EFAULT;

 		return ocfs2_group_extend(inode, new_clusters);
 	case OCFS2_IOC_GROUP_ADD:
 	case OCFS2_IOC_GROUP_ADD64:
 		if (!capable(CAP_SYS_RESOURCE))
 			return -EPERM;

 		if (copy_from_user(&input, (int __user *) arg, sizeof(input)))
 			return -EFAULT;

 		return ocfs2_group_add(inode, &input);
 	case OCFS2_IOC_REFLINK:
 		if (copy_from_user(&args, (struct reflink_arguments *)arg,
 				   sizeof(args)))
 			return -EFAULT;
 		old_path = (const char *)(unsigned long)args.old_path;
 		new_path = (const char *)(unsigned long)args.new_path;
 		preserve = (args.preserve != 0);

 		return ocfs2_reflink_ioctl(inode, old_path, new_path, preserve);
 	case OCFS2_IOC_INFO:
 		if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
 				   sizeof(struct ocfs2_info)))
 			return -EFAULT;

 		return ocfs2_info_handle(inode, &info, 0);
 	default:
 		return -ENOTTY;
 	}
 }

 #ifdef CONFIG_COMPAT
 long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
 	bool preserve;
 	struct reflink_arguments args;
 	struct inode *inode = file->f_path.dentry->d_inode;
 	struct ocfs2_info info;

 	switch (cmd) {
 	case OCFS2_IOC32_GETFLAGS:
 		cmd = OCFS2_IOC_GETFLAGS;
 		break;
 	case OCFS2_IOC32_SETFLAGS:
 		cmd = OCFS2_IOC_SETFLAGS;
 		break;
 	case OCFS2_IOC_RESVSP:
 	case OCFS2_IOC_RESVSP64:
 	case OCFS2_IOC_UNRESVSP:
 	case OCFS2_IOC_UNRESVSP64:
 	case OCFS2_IOC_GROUP_EXTEND:
 	case OCFS2_IOC_GROUP_ADD:
 	case OCFS2_IOC_GROUP_ADD64:
 		break;
 	case OCFS2_IOC_REFLINK:
 		if (copy_from_user(&args, (struct reflink_arguments *)arg,
 				   sizeof(args)))
 			return -EFAULT;
 		preserve = (args.preserve != 0);

 		return ocfs2_reflink_ioctl(inode, compat_ptr(args.old_path),
 					   compat_ptr(args.new_path), preserve);
 	case OCFS2_IOC_INFO:
 		if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
 				   sizeof(struct ocfs2_info)))
 			return -EFAULT;

 		return ocfs2_info_handle(inode, &info, 1);
 	default:
 		return -ENOIOCTLCMD;
 	}

 	return ocfs2_ioctl(file, cmd, arg);
 }
 #endif
	/*
	* linux/fs/ocfs2/ioctl.c
	*
	* Copyright (C) 2006 Herbert Poetzl
	* adapted from Remy Card's ext2/ioctl.c
	*/

	#include <linux/fs.h>
	#include <linux/mount.h>
	#include <linux/compat.h>

	#include <cluster/masklog.h>

	#include "ocfs2.h"
	#include "alloc.h"
	#include "dlmglue.h"
	#include "file.h"
	#include "inode.h"
	#include "journal.h"

	#include "ocfs2_fs.h"
	#include "ioctl.h"
	#include "resize.h"
	#include "refcounttree.h"

	#include <linux/ext2_fs.h>

	#define o2info_from_user(a, b) \
	copy_from_user(&(a), (b), sizeof(a))
	#define o2info_to_user(a, b) \
	copy_to_user((typeof(a) __user *)b, &(a), sizeof(a))

	/*
	* This call is void because we are already reporting an error that may
	* be -EFAULT. The error will be returned from the ioctl(2) call. It's
	* just a best-effort to tell userspace that this request caused the error.
	*/
	static inline void __o2info_set_request_error(struct ocfs2_info_request *kreq,
	struct ocfs2_info_request __user *req)
	{
	kreq->ir_flags \|= OCFS2_INFO_FL_ERROR;
	(void)put_user(kreq->ir_flags, (__u32 __user *)&(req->ir_flags));
	}

	#define o2info_set_request_error(a, b) \
	__o2info_set_request_error((struct ocfs2_info_request *)&(a), b)

	static inline void __o2info_set_request_filled(struct ocfs2_info_request *req)
	{
	req->ir_flags \|= OCFS2_INFO_FL_FILLED;
	}

	#define o2info_set_request_filled(a) \
	__o2info_set_request_filled((struct ocfs2_info_request *)&(a))

	static inline void __o2info_clear_request_filled(struct ocfs2_info_request *req)
	{
	req->ir_flags &= ~OCFS2_INFO_FL_FILLED;
	}

	#define o2info_clear_request_filled(a) \
	__o2info_clear_request_filled((struct ocfs2_info_request *)&(a))

	static int ocfs2_get_inode_attr(struct inode inode, unsigned flags)
	{
	int status;

	status = ocfs2_inode_lock(inode, NULL, 0);
	if (status < 0) {
	mlog_errno(status);
	return status;
	}
	ocfs2_get_inode_flags(OCFS2_I(inode));
	*flags = OCFS2_I(inode)->ip_attr;
	ocfs2_inode_unlock(inode, 0);

	return status;
	}

	static int ocfs2_set_inode_attr(struct inode *inode, unsigned flags,
	unsigned mask)
	{
	struct ocfs2_inode_info *ocfs2_inode = OCFS2_I(inode);
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	handle_t *handle = NULL;
	struct buffer_head *bh = NULL;
	unsigned oldflags;
	int status;

	mutex_lock(&inode->i_mutex);

	status = ocfs2_inode_lock(inode, &bh, 1);
	if (status < 0) {
	mlog_errno(status);
	goto bail;
	}

	status = -EACCES;
	if (!inode_owner_or_capable(inode))
	goto bail_unlock;

	if (!S_ISDIR(inode->i_mode))
	flags &= ~OCFS2_DIRSYNC_FL;

	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
	if (IS_ERR(handle)) {
	status = PTR_ERR(handle);
	mlog_errno(status);
	goto bail_unlock;
	}

	oldflags = ocfs2_inode->ip_attr;
	flags = flags & mask;
	flags \|= oldflags & ~mask;

	/*
	* The IMMUTABLE and APPEND_ONLY flags can only be changed by
	* the relevant capability.
	*/
	status = -EPERM;
	if ((oldflags & OCFS2_IMMUTABLE_FL) \|\| ((flags ^ oldflags) &
	(OCFS2_APPEND_FL \| OCFS2_IMMUTABLE_FL))) {
	if (!capable(CAP_LINUX_IMMUTABLE))
	goto bail_unlock;
	}

	ocfs2_inode->ip_attr = flags;
	ocfs2_set_inode_flags(inode);

	status = ocfs2_mark_inode_dirty(handle, inode, bh);
	if (status < 0)
	mlog_errno(status);

	ocfs2_commit_trans(osb, handle);
	bail_unlock:
	ocfs2_inode_unlock(inode, 1);
	bail:
	mutex_unlock(&inode->i_mutex);

	brelse(bh);

	return status;
	}

	int ocfs2_info_handle_blocksize(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_blocksize oib;

	if (o2info_from_user(oib, req))
	goto bail;

	oib.ib_blocksize = inode->i_sb->s_blocksize;

	o2info_set_request_filled(oib);

	if (o2info_to_user(oib, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oib, req);

	return status;
	}

	int ocfs2_info_handle_clustersize(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_clustersize oic;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oic, req))
	goto bail;

	oic.ic_clustersize = osb->s_clustersize;

	o2info_set_request_filled(oic);

	if (o2info_to_user(oic, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oic, req);

	return status;
	}

	int ocfs2_info_handle_maxslots(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_maxslots oim;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oim, req))
	goto bail;

	oim.im_max_slots = osb->max_slots;

	o2info_set_request_filled(oim);

	if (o2info_to_user(oim, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oim, req);

	return status;
	}

	int ocfs2_info_handle_label(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_label oil;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oil, req))
	goto bail;

	memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);

	o2info_set_request_filled(oil);

	if (o2info_to_user(oil, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oil, req);

	return status;
	}

	int ocfs2_info_handle_uuid(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_uuid oiu;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oiu, req))
	goto bail;

	memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_TEXT_UUID_LEN + 1);

	o2info_set_request_filled(oiu);

	if (o2info_to_user(oiu, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oiu, req);

	return status;
	}

	int ocfs2_info_handle_fs_features(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_fs_features oif;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oif, req))
	goto bail;

	oif.if_compat_features = osb->s_feature_compat;
	oif.if_incompat_features = osb->s_feature_incompat;
	oif.if_ro_compat_features = osb->s_feature_ro_compat;

	o2info_set_request_filled(oif);

	if (o2info_to_user(oif, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oif, req);

	return status;
	}

	int ocfs2_info_handle_journal_size(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_journal_size oij;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	if (o2info_from_user(oij, req))
	goto bail;

	oij.ij_journal_size = osb->journal->j_inode->i_size;

	o2info_set_request_filled(oij);

	if (o2info_to_user(oij, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oij, req);

	return status;
	}

	int ocfs2_info_handle_unknown(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_request oir;

	if (o2info_from_user(oir, req))
	goto bail;

	o2info_clear_request_filled(oir);

	if (o2info_to_user(oir, req))
	goto bail;

	status = 0;
	bail:
	if (status)
	o2info_set_request_error(oir, req);

	return status;
	}

	/*
	* Validate and distinguish OCFS2_IOC_INFO requests.
	*
	* - validate the magic number.
	* - distinguish different requests.
	* - validate size of different requests.
	*/
	int ocfs2_info_handle_request(struct inode *inode,
	struct ocfs2_info_request __user *req)
	{
	int status = -EFAULT;
	struct ocfs2_info_request oir;

	if (o2info_from_user(oir, req))
	goto bail;

	status = -EINVAL;
	if (oir.ir_magic != OCFS2_INFO_MAGIC)
	goto bail;

	switch (oir.ir_code) {
	case OCFS2_INFO_BLOCKSIZE:
	if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
	status = ocfs2_info_handle_blocksize(inode, req);
	break;
	case OCFS2_INFO_CLUSTERSIZE:
	if (oir.ir_size == sizeof(struct ocfs2_info_clustersize))
	status = ocfs2_info_handle_clustersize(inode, req);
	break;
	case OCFS2_INFO_MAXSLOTS:
	if (oir.ir_size == sizeof(struct ocfs2_info_maxslots))
	status = ocfs2_info_handle_maxslots(inode, req);
	break;
	case OCFS2_INFO_LABEL:
	if (oir.ir_size == sizeof(struct ocfs2_info_label))
	status = ocfs2_info_handle_label(inode, req);
	break;
	case OCFS2_INFO_UUID:
	if (oir.ir_size == sizeof(struct ocfs2_info_uuid))
	status = ocfs2_info_handle_uuid(inode, req);
	break;
	case OCFS2_INFO_FS_FEATURES:
	if (oir.ir_size == sizeof(struct ocfs2_info_fs_features))
	status = ocfs2_info_handle_fs_features(inode, req);
	break;
	case OCFS2_INFO_JOURNAL_SIZE:
	if (oir.ir_size == sizeof(struct ocfs2_info_journal_size))
	status = ocfs2_info_handle_journal_size(inode, req);
	break;
	default:
	status = ocfs2_info_handle_unknown(inode, req);
	break;
	}

	bail:
	return status;
	}

	int ocfs2_get_request_ptr(struct ocfs2_info *info, int idx,
	u64 *req_addr, int compat_flag)
	{
	int status = -EFAULT;
	u64 __user *bp = NULL;

	if (compat_flag) {
	#ifdef CONFIG_COMPAT
	/*
	* pointer bp stores the base address of a pointers array,
	* which collects all addresses of separate request.
	*/
	bp = (u64 __user *)(unsigned long)compat_ptr(info->oi_requests);
	#else
	BUG();
	#endif
	} else
	bp = (u64 __user *)(unsigned long)(info->oi_requests);

	if (o2info_from_user(*req_addr, bp + idx))
	goto bail;

	status = 0;
	bail:
	return status;
	}

	/*
	* OCFS2_IOC_INFO handles an array of requests passed from userspace.
	*
	* ocfs2_info_handle() recevies a large info aggregation, grab and
	* validate the request count from header, then break it into small
	* pieces, later specific handlers can handle them one by one.
	*
	* Idea here is to make each separate request small enough to ensure
	* a better backward&forward compatibility, since a small piece of
	* request will be less likely to be broken if disk layout get changed.
	*/
	int ocfs2_info_handle(struct inode inode, struct ocfs2_info info,
	int compat_flag)
	{
	int i, status = 0;
	u64 req_addr;
	struct ocfs2_info_request __user *reqp;

	if ((info->oi_count > OCFS2_INFO_MAX_REQUEST) \|\|
	(!info->oi_requests)) {
	status = -EINVAL;
	goto bail;
	}

	for (i = 0; i < info->oi_count; i++) {

	status = ocfs2_get_request_ptr(info, i, &req_addr, compat_flag);
	if (status)
	break;

	reqp = (struct ocfs2_info_request *)(unsigned long)req_addr;
	if (!reqp) {
	status = -EINVAL;
	goto bail;
	}

	status = ocfs2_info_handle_request(inode, reqp);
	if (status)
	break;
	}

	bail:
	return status;
	}

	long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = filp->f_path.dentry->d_inode;
	unsigned int flags;
	int new_clusters;
	int status;
	struct ocfs2_space_resv sr;
	struct ocfs2_new_group_input input;
	struct reflink_arguments args;
	const char old_path, new_path;
	bool preserve;
	struct ocfs2_info info;

	switch (cmd) {
	case OCFS2_IOC_GETFLAGS:
	status = ocfs2_get_inode_attr(inode, &flags);
	if (status < 0)
	return status;

	flags &= OCFS2_FL_VISIBLE;
	return put_user(flags, (int __user *) arg);
	case OCFS2_IOC_SETFLAGS:
	if (get_user(flags, (int __user *) arg))
	return -EFAULT;

	status = mnt_want_write(filp->f_path.mnt);
	if (status)
	return status;
	status = ocfs2_set_inode_attr(inode, flags,
	OCFS2_FL_MODIFIABLE);
	mnt_drop_write(filp->f_path.mnt);
	return status;
	case OCFS2_IOC_RESVSP:
	case OCFS2_IOC_RESVSP64:
	case OCFS2_IOC_UNRESVSP:
	case OCFS2_IOC_UNRESVSP64:
	if (copy_from_user(&sr, (int __user *) arg, sizeof(sr)))
	return -EFAULT;

	return ocfs2_change_file_space(filp, cmd, &sr);
	case OCFS2_IOC_GROUP_EXTEND:
	if (!capable(CAP_SYS_RESOURCE))
	return -EPERM;

	if (get_user(new_clusters, (int __user *)arg))
	return -EFAULT;

	return ocfs2_group_extend(inode, new_clusters);
	case OCFS2_IOC_GROUP_ADD:
	case OCFS2_IOC_GROUP_ADD64:
	if (!capable(CAP_SYS_RESOURCE))
	return -EPERM;

	if (copy_from_user(&input, (int __user *) arg, sizeof(input)))
	return -EFAULT;

	return ocfs2_group_add(inode, &input);
	case OCFS2_IOC_REFLINK:
	if (copy_from_user(&args, (struct reflink_arguments *)arg,
	sizeof(args)))
	return -EFAULT;
	old_path = (const char *)(unsigned long)args.old_path;
	new_path = (const char *)(unsigned long)args.new_path;
	preserve = (args.preserve != 0);

	return ocfs2_reflink_ioctl(inode, old_path, new_path, preserve);
	case OCFS2_IOC_INFO:
	if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
	sizeof(struct ocfs2_info)))
	return -EFAULT;

	return ocfs2_info_handle(inode, &info, 0);
	default:
	return -ENOTTY;
	}
	}

	#ifdef CONFIG_COMPAT
	long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
	{
	bool preserve;
	struct reflink_arguments args;
	struct inode *inode = file->f_path.dentry->d_inode;
	struct ocfs2_info info;

	switch (cmd) {
	case OCFS2_IOC32_GETFLAGS:
	cmd = OCFS2_IOC_GETFLAGS;
	break;
	case OCFS2_IOC32_SETFLAGS:
	cmd = OCFS2_IOC_SETFLAGS;
	break;
	case OCFS2_IOC_RESVSP:
	case OCFS2_IOC_RESVSP64:
	case OCFS2_IOC_UNRESVSP:
	case OCFS2_IOC_UNRESVSP64:
	case OCFS2_IOC_GROUP_EXTEND:
	case OCFS2_IOC_GROUP_ADD:
	case OCFS2_IOC_GROUP_ADD64:
	break;
	case OCFS2_IOC_REFLINK:
	if (copy_from_user(&args, (struct reflink_arguments *)arg,
	sizeof(args)))
	return -EFAULT;
	preserve = (args.preserve != 0);

	return ocfs2_reflink_ioctl(inode, compat_ptr(args.old_path),
	compat_ptr(args.new_path), preserve);
	case OCFS2_IOC_INFO:
	if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
	sizeof(struct ocfs2_info)))
	return -EFAULT;

	return ocfs2_info_handle(inode, &info, 1);
	default:
	return -ENOIOCTLCMD;
	}

	return ocfs2_ioctl(file, cmd, arg);
	}
	#endif