[15/21] lustre: obdclass: char obd_ioctl_getdata type.
diff mbox series

Message ID 154949781327.10620.2294752316778817915.stgit@noble.brown
State New
Headers show
Series
  • lustre: Assorted cleanups for obdclass
Related show

Commit Message

NeilBrown Feb. 7, 2019, 12:03 a.m. UTC
Instead of having obd_ioctl_getdata() return the allocated
data as a "char *", return it as it really is,
 struct obd_ioctl_data *

This avoids the need for extra variables and casts.

Signed-off-by: NeilBrown <neilb@suse.com>
---
 drivers/staging/lustre/lustre/include/obd_class.h  |    3 ++-
 drivers/staging/lustre/lustre/llite/dir.c          |   17 +++++------------
 drivers/staging/lustre/lustre/llite/llite_lib.c    |    8 +++-----
 drivers/staging/lustre/lustre/lov/lov_obd.c        |   15 ++++++---------
 drivers/staging/lustre/lustre/obdclass/class_obd.c |   18 ++++++++----------
 5 files changed, 24 insertions(+), 37 deletions(-)

Comments

Andreas Dilger Feb. 8, 2019, 5:56 a.m. UTC | #1
On Feb 6, 2019, at 17:03, NeilBrown <neilb@suse.com> wrote:
> 
> Instead of having obd_ioctl_getdata() return the allocated
> data as a "char *", return it as it really is,
> struct obd_ioctl_data *
> 
> This avoids the need for extra variables and casts.
> 
> Signed-off-by: NeilBrown <neilb@suse.com>

Most of the patch looks like a no-op, except at one part below:

> @@ -1651,18 +1647,16 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> 		return rc;
> 	}
> 	case LL_IOC_MIGRATE: {
> -		char *buf = NULL;
> 		const char *filename;
> 		int namelen = 0;
> 		int len;
> 		int rc;
> 		int mdtidx;
> 
> -		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
> +		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
> 		if (rc < 0)
> 			return rc;
> 
> -		data = (struct obd_ioctl_data *)buf;
> 		if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
> 		    !data->ioc_inllen1 || !data->ioc_inllen2) {
> 			rc = -EINVAL;
> @@ -1684,7 +1678,6 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> 
> 		rc = ll_migrate(inode, file, mdtidx, filename, namelen - 1);
> migrate_free:
> -		kvfree(buf);

This removes the call to kvfree(buf) but it isn't clear why, since the rest of
the patch is mostly variable renaming?

Cheers, Andreas
---
Andreas Dilger
Principal Lustre Architect
Whamcloud
NeilBrown Feb. 11, 2019, 12:52 a.m. UTC | #2
On Fri, Feb 08 2019, Andreas Dilger wrote:

> On Feb 6, 2019, at 17:03, NeilBrown <neilb@suse.com> wrote:
>> 
>> Instead of having obd_ioctl_getdata() return the allocated
>> data as a "char *", return it as it really is,
>> struct obd_ioctl_data *
>> 
>> This avoids the need for extra variables and casts.
>> 
>> Signed-off-by: NeilBrown <neilb@suse.com>
>
> Most of the patch looks like a no-op, except at one part below:
>
>> @@ -1651,18 +1647,16 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>> 		return rc;
>> 	}
>> 	case LL_IOC_MIGRATE: {
>> -		char *buf = NULL;
>> 		const char *filename;
>> 		int namelen = 0;
>> 		int len;
>> 		int rc;
>> 		int mdtidx;
>> 
>> -		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
>> +		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
>> 		if (rc < 0)
>> 			return rc;
>> 
>> -		data = (struct obd_ioctl_data *)buf;
>> 		if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
>> 		    !data->ioc_inllen1 || !data->ioc_inllen2) {
>> 			rc = -EINVAL;
>> @@ -1684,7 +1678,6 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>> 
>> 		rc = ll_migrate(inode, file, mdtidx, filename, namelen - 1);
>> migrate_free:
>> -		kvfree(buf);
>
> This removes the call to kvfree(buf) but it isn't clear why, since the rest of
> the patch is mostly variable renaming?

Thanks for catching that!  It should be:

 migrate_free:
-               kvfree(buf);
+               kvfree(data);
 
of course.  Fixed now.

NeilBrown
James Simmons Feb. 11, 2019, 4:03 a.m. UTC | #3
> Instead of having obd_ioctl_getdata() return the allocated
> data as a "char *", return it as it really is,
>  struct obd_ioctl_data *
> 
> This avoids the need for extra variables and casts.

I think this needs the fix Andreas pointed out.
 
> Signed-off-by: NeilBrown <neilb@suse.com>
> ---
>  drivers/staging/lustre/lustre/include/obd_class.h  |    3 ++-
>  drivers/staging/lustre/lustre/llite/dir.c          |   17 +++++------------
>  drivers/staging/lustre/lustre/llite/llite_lib.c    |    8 +++-----
>  drivers/staging/lustre/lustre/lov/lov_obd.c        |   15 ++++++---------
>  drivers/staging/lustre/lustre/obdclass/class_obd.c |   18 ++++++++----------
>  5 files changed, 24 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/include/obd_class.h b/drivers/staging/lustre/lustre/include/obd_class.h
> index 30b3e2c69f83..32d4ab6e78a0 100644
> --- a/drivers/staging/lustre/lustre/include/obd_class.h
> +++ b/drivers/staging/lustre/lustre/include/obd_class.h
> @@ -1697,6 +1697,7 @@ struct root_squash_info {
>  };
>  
>  /* linux-module.c */
> -int obd_ioctl_getdata(char **buf, int *len, void __user *arg);
> +struct obd_ioctl_data;
> +int obd_ioctl_getdata(struct obd_ioctl_data **data, int *len, void __user *arg);
>  
>  #endif /* __LINUX_OBD_CLASS_H */
> diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
> index fd1af4a5cdad..0c49244eaee8 100644
> --- a/drivers/staging/lustre/lustre/llite/dir.c
> +++ b/drivers/staging/lustre/lustre/llite/dir.c
> @@ -1130,13 +1130,11 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  	}
>  	case IOC_MDC_LOOKUP: {
>  		int namelen, len = 0;
> -		char *buf = NULL;
>  		char *filename;
>  
> -		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
> +		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
>  		if (rc)
>  			return rc;
> -		data = (void *)buf;
>  
>  		filename = data->ioc_inlbuf1;
>  		namelen = strlen(filename);
> @@ -1155,12 +1153,11 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  			goto out_free;
>  		}
>  out_free:
> -		kvfree(buf);
> +		kvfree(data);
>  		return rc;
>  	}
>  	case LL_IOC_LMV_SETSTRIPE: {
>  		struct lmv_user_md  *lum;
> -		char *buf = NULL;
>  		char *filename;
>  		int namelen = 0;
>  		int lumlen = 0;
> @@ -1168,11 +1165,10 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  		int len;
>  		int rc;
>  
> -		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
> +		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
>  		if (rc)
>  			return rc;
>  
> -		data = (void *)buf;
>  		if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
>  		    data->ioc_inllen1 == 0 || data->ioc_inllen2 == 0) {
>  			rc = -EINVAL;
> @@ -1205,7 +1201,7 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  #endif
>  		rc = ll_dir_setdirstripe(dentry, lum, filename, mode);
>  lmv_out_free:
> -		kvfree(buf);
> +		kvfree(data);
>  		return rc;
>  	}
>  	case LL_IOC_LMV_SET_DEFAULT_STRIPE: {
> @@ -1651,18 +1647,16 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  		return rc;
>  	}
>  	case LL_IOC_MIGRATE: {
> -		char *buf = NULL;
>  		const char *filename;
>  		int namelen = 0;
>  		int len;
>  		int rc;
>  		int mdtidx;
>  
> -		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
> +		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
>  		if (rc < 0)
>  			return rc;
>  
> -		data = (struct obd_ioctl_data *)buf;
>  		if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
>  		    !data->ioc_inllen1 || !data->ioc_inllen2) {
>  			rc = -EINVAL;
> @@ -1684,7 +1678,6 @@ static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  
>  		rc = ll_migrate(inode, file, mdtidx, filename, namelen - 1);
>  migrate_free:
> -		kvfree(buf);
>  
>  		return rc;
>  	}
> diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
> index 8e09fdd7a96e..e2417cd5aaed 100644
> --- a/drivers/staging/lustre/lustre/llite/llite_lib.c
> +++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
> @@ -2295,7 +2295,6 @@ int ll_obd_statfs(struct inode *inode, void __user *arg)
>  {
>  	struct ll_sb_info *sbi = NULL;
>  	struct obd_export *exp;
> -	char *buf = NULL;
>  	struct obd_ioctl_data *data = NULL;
>  	u32 type;
>  	int len = 0, rc;
> @@ -2311,11 +2310,10 @@ int ll_obd_statfs(struct inode *inode, void __user *arg)
>  		goto out_statfs;
>  	}
>  
> -	rc = obd_ioctl_getdata(&buf, &len, arg);
> +	rc = obd_ioctl_getdata(&data, &len, arg);
>  	if (rc)
>  		goto out_statfs;
>  
> -	data = (void *)buf;
>  	if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
>  	    !data->ioc_pbuf1 || !data->ioc_pbuf2) {
>  		rc = -EINVAL;
> @@ -2340,11 +2338,11 @@ int ll_obd_statfs(struct inode *inode, void __user *arg)
>  		goto out_statfs;
>  	}
>  
> -	rc = obd_iocontrol(IOC_OBD_STATFS, exp, len, buf, NULL);
> +	rc = obd_iocontrol(IOC_OBD_STATFS, exp, len, data, NULL);
>  	if (rc)
>  		goto out_statfs;
>  out_statfs:
> -	kvfree(buf);
> +	kvfree(data);
>  	return rc;
>  }
>  
> diff --git a/drivers/staging/lustre/lustre/lov/lov_obd.c b/drivers/staging/lustre/lustre/lov/lov_obd.c
> index 04d0a9ed1d05..fd769c39b482 100644
> --- a/drivers/staging/lustre/lustre/lov/lov_obd.c
> +++ b/drivers/staging/lustre/lustre/lov/lov_obd.c
> @@ -1039,27 +1039,24 @@ static int lov_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
>  	case OBD_IOC_LOV_GET_CONFIG: {
>  		struct obd_ioctl_data *data;
>  		struct lov_desc *desc;
> -		char *buf = NULL;
>  		u32 *genp;
>  
>  		len = 0;
> -		if (obd_ioctl_getdata(&buf, &len, uarg))
> +		if (obd_ioctl_getdata(&data, &len, uarg))
>  			return -EINVAL;
>  
> -		data = (struct obd_ioctl_data *)buf;
> -
>  		if (sizeof(*desc) > data->ioc_inllen1) {
> -			kvfree(buf);
> +			kvfree(data);
>  			return -EINVAL;
>  		}
>  
>  		if (sizeof(uuidp->uuid) * count > data->ioc_inllen2) {
> -			kvfree(buf);
> +			kvfree(data);
>  			return -EINVAL;
>  		}
>  
>  		if (sizeof(u32) * count > data->ioc_inllen3) {
> -			kvfree(buf);
> +			kvfree(data);
>  			return -EINVAL;
>  		}
>  
> @@ -1076,9 +1073,9 @@ static int lov_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
>  			*genp = lov->lov_tgts[i]->ltd_gen;
>  		}
>  
> -		if (copy_to_user(uarg, buf, len))
> +		if (copy_to_user(uarg, data, len))
>  			rc = -EFAULT;
> -		kvfree(buf);
> +		kvfree(data);
>  		break;
>  	}
>  	case OBD_IOC_QUOTACTL: {
> diff --git a/drivers/staging/lustre/lustre/obdclass/class_obd.c b/drivers/staging/lustre/lustre/obdclass/class_obd.c
> index b859ab19b9f6..2ef4fd41cdd0 100644
> --- a/drivers/staging/lustre/lustre/obdclass/class_obd.c
> +++ b/drivers/staging/lustre/lustre/obdclass/class_obd.c
> @@ -230,7 +230,7 @@ static int obd_ioctl_is_invalid(struct obd_ioctl_data *data)
>  }
>  
>  /* buffer MUST be at least the size of obd_ioctl_hdr */
> -int obd_ioctl_getdata(char **buf, int *len, void __user *arg)
> +int obd_ioctl_getdata(struct obd_ioctl_data **datap, int *len, void __user *arg)
>  {
>  	struct obd_ioctl_data *data;
>  	struct obd_ioctl_hdr hdr;
> @@ -262,16 +262,16 @@ int obd_ioctl_getdata(char **buf, int *len, void __user *arg)
>  	 * obdfilter-survey is an example, which relies on ioctl. So we'd
>  	 * better avoid vmalloc on ioctl path. LU-66
>  	 */
> -	*buf = kvzalloc(hdr.ioc_len, GFP_KERNEL);
> -	if (!*buf) {
> +	data = kvzalloc(hdr.ioc_len, GFP_KERNEL);
> +	if (!data) {
>  		CERROR("Cannot allocate control buffer of len %d\n",
>  		       hdr.ioc_len);
>  		return -EINVAL;
>  	}
>  	*len = hdr.ioc_len;
> -	data = (struct obd_ioctl_data *)*buf;
> +	*datap = data;
>  
> -	if (copy_from_user(*buf, arg, hdr.ioc_len)) {
> +	if (copy_from_user(data, arg, hdr.ioc_len)) {
>  		err = -EFAULT;
>  		goto free_buf;
>  	}
> @@ -308,14 +308,13 @@ int obd_ioctl_getdata(char **buf, int *len, void __user *arg)
>  	return 0;
>  
>  free_buf:
> -	kvfree(*buf);
> +	kvfree(data);
>  	return err;
>  }
>  EXPORT_SYMBOL(obd_ioctl_getdata);
>  
>  int class_handle_ioctl(unsigned int cmd, unsigned long arg)
>  {
> -	char *buf = NULL;
>  	struct obd_ioctl_data *data;
>  	struct libcfs_debug_ioctl_data *debug_data;
>  	struct obd_device *obd = NULL;
> @@ -330,11 +329,10 @@ int class_handle_ioctl(unsigned int cmd, unsigned long arg)
>  	}
>  
>  	CDEBUG(D_IOCTL, "cmd = %x\n", cmd);
> -	if (obd_ioctl_getdata(&buf, &len, (void __user *)arg)) {
> +	if (obd_ioctl_getdata(&data, &len, (void __user *)arg)) {
>  		CERROR("OBD ioctl: data error\n");
>  		return -EINVAL;
>  	}
> -	data = (struct obd_ioctl_data *)buf;
>  
>  	switch (cmd) {
>  	case OBD_IOC_PROCESS_CFG: {
> @@ -545,7 +543,7 @@ int class_handle_ioctl(unsigned int cmd, unsigned long arg)
>  	}
>  
>   out:
> -	kvfree(buf);
> +	kvfree(data);
>  	return err;
>  } /* class_handle_ioctl */
>  
> 
> 
>

Patch
diff mbox series

diff --git a/drivers/staging/lustre/lustre/include/obd_class.h b/drivers/staging/lustre/lustre/include/obd_class.h
index 30b3e2c69f83..32d4ab6e78a0 100644
--- a/drivers/staging/lustre/lustre/include/obd_class.h
+++ b/drivers/staging/lustre/lustre/include/obd_class.h
@@ -1697,6 +1697,7 @@  struct root_squash_info {
 };
 
 /* linux-module.c */
-int obd_ioctl_getdata(char **buf, int *len, void __user *arg);
+struct obd_ioctl_data;
+int obd_ioctl_getdata(struct obd_ioctl_data **data, int *len, void __user *arg);
 
 #endif /* __LINUX_OBD_CLASS_H */
diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index fd1af4a5cdad..0c49244eaee8 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -1130,13 +1130,11 @@  static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	}
 	case IOC_MDC_LOOKUP: {
 		int namelen, len = 0;
-		char *buf = NULL;
 		char *filename;
 
-		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
+		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
 		if (rc)
 			return rc;
-		data = (void *)buf;
 
 		filename = data->ioc_inlbuf1;
 		namelen = strlen(filename);
@@ -1155,12 +1153,11 @@  static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			goto out_free;
 		}
 out_free:
-		kvfree(buf);
+		kvfree(data);
 		return rc;
 	}
 	case LL_IOC_LMV_SETSTRIPE: {
 		struct lmv_user_md  *lum;
-		char *buf = NULL;
 		char *filename;
 		int namelen = 0;
 		int lumlen = 0;
@@ -1168,11 +1165,10 @@  static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		int len;
 		int rc;
 
-		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
+		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
 		if (rc)
 			return rc;
 
-		data = (void *)buf;
 		if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
 		    data->ioc_inllen1 == 0 || data->ioc_inllen2 == 0) {
 			rc = -EINVAL;
@@ -1205,7 +1201,7 @@  static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 #endif
 		rc = ll_dir_setdirstripe(dentry, lum, filename, mode);
 lmv_out_free:
-		kvfree(buf);
+		kvfree(data);
 		return rc;
 	}
 	case LL_IOC_LMV_SET_DEFAULT_STRIPE: {
@@ -1651,18 +1647,16 @@  static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		return rc;
 	}
 	case LL_IOC_MIGRATE: {
-		char *buf = NULL;
 		const char *filename;
 		int namelen = 0;
 		int len;
 		int rc;
 		int mdtidx;
 
-		rc = obd_ioctl_getdata(&buf, &len, (void __user *)arg);
+		rc = obd_ioctl_getdata(&data, &len, (void __user *)arg);
 		if (rc < 0)
 			return rc;
 
-		data = (struct obd_ioctl_data *)buf;
 		if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
 		    !data->ioc_inllen1 || !data->ioc_inllen2) {
 			rc = -EINVAL;
@@ -1684,7 +1678,6 @@  static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 		rc = ll_migrate(inode, file, mdtidx, filename, namelen - 1);
 migrate_free:
-		kvfree(buf);
 
 		return rc;
 	}
diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index 8e09fdd7a96e..e2417cd5aaed 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -2295,7 +2295,6 @@  int ll_obd_statfs(struct inode *inode, void __user *arg)
 {
 	struct ll_sb_info *sbi = NULL;
 	struct obd_export *exp;
-	char *buf = NULL;
 	struct obd_ioctl_data *data = NULL;
 	u32 type;
 	int len = 0, rc;
@@ -2311,11 +2310,10 @@  int ll_obd_statfs(struct inode *inode, void __user *arg)
 		goto out_statfs;
 	}
 
-	rc = obd_ioctl_getdata(&buf, &len, arg);
+	rc = obd_ioctl_getdata(&data, &len, arg);
 	if (rc)
 		goto out_statfs;
 
-	data = (void *)buf;
 	if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2 ||
 	    !data->ioc_pbuf1 || !data->ioc_pbuf2) {
 		rc = -EINVAL;
@@ -2340,11 +2338,11 @@  int ll_obd_statfs(struct inode *inode, void __user *arg)
 		goto out_statfs;
 	}
 
-	rc = obd_iocontrol(IOC_OBD_STATFS, exp, len, buf, NULL);
+	rc = obd_iocontrol(IOC_OBD_STATFS, exp, len, data, NULL);
 	if (rc)
 		goto out_statfs;
 out_statfs:
-	kvfree(buf);
+	kvfree(data);
 	return rc;
 }
 
diff --git a/drivers/staging/lustre/lustre/lov/lov_obd.c b/drivers/staging/lustre/lustre/lov/lov_obd.c
index 04d0a9ed1d05..fd769c39b482 100644
--- a/drivers/staging/lustre/lustre/lov/lov_obd.c
+++ b/drivers/staging/lustre/lustre/lov/lov_obd.c
@@ -1039,27 +1039,24 @@  static int lov_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
 	case OBD_IOC_LOV_GET_CONFIG: {
 		struct obd_ioctl_data *data;
 		struct lov_desc *desc;
-		char *buf = NULL;
 		u32 *genp;
 
 		len = 0;
-		if (obd_ioctl_getdata(&buf, &len, uarg))
+		if (obd_ioctl_getdata(&data, &len, uarg))
 			return -EINVAL;
 
-		data = (struct obd_ioctl_data *)buf;
-
 		if (sizeof(*desc) > data->ioc_inllen1) {
-			kvfree(buf);
+			kvfree(data);
 			return -EINVAL;
 		}
 
 		if (sizeof(uuidp->uuid) * count > data->ioc_inllen2) {
-			kvfree(buf);
+			kvfree(data);
 			return -EINVAL;
 		}
 
 		if (sizeof(u32) * count > data->ioc_inllen3) {
-			kvfree(buf);
+			kvfree(data);
 			return -EINVAL;
 		}
 
@@ -1076,9 +1073,9 @@  static int lov_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
 			*genp = lov->lov_tgts[i]->ltd_gen;
 		}
 
-		if (copy_to_user(uarg, buf, len))
+		if (copy_to_user(uarg, data, len))
 			rc = -EFAULT;
-		kvfree(buf);
+		kvfree(data);
 		break;
 	}
 	case OBD_IOC_QUOTACTL: {
diff --git a/drivers/staging/lustre/lustre/obdclass/class_obd.c b/drivers/staging/lustre/lustre/obdclass/class_obd.c
index b859ab19b9f6..2ef4fd41cdd0 100644
--- a/drivers/staging/lustre/lustre/obdclass/class_obd.c
+++ b/drivers/staging/lustre/lustre/obdclass/class_obd.c
@@ -230,7 +230,7 @@  static int obd_ioctl_is_invalid(struct obd_ioctl_data *data)
 }
 
 /* buffer MUST be at least the size of obd_ioctl_hdr */
-int obd_ioctl_getdata(char **buf, int *len, void __user *arg)
+int obd_ioctl_getdata(struct obd_ioctl_data **datap, int *len, void __user *arg)
 {
 	struct obd_ioctl_data *data;
 	struct obd_ioctl_hdr hdr;
@@ -262,16 +262,16 @@  int obd_ioctl_getdata(char **buf, int *len, void __user *arg)
 	 * obdfilter-survey is an example, which relies on ioctl. So we'd
 	 * better avoid vmalloc on ioctl path. LU-66
 	 */
-	*buf = kvzalloc(hdr.ioc_len, GFP_KERNEL);
-	if (!*buf) {
+	data = kvzalloc(hdr.ioc_len, GFP_KERNEL);
+	if (!data) {
 		CERROR("Cannot allocate control buffer of len %d\n",
 		       hdr.ioc_len);
 		return -EINVAL;
 	}
 	*len = hdr.ioc_len;
-	data = (struct obd_ioctl_data *)*buf;
+	*datap = data;
 
-	if (copy_from_user(*buf, arg, hdr.ioc_len)) {
+	if (copy_from_user(data, arg, hdr.ioc_len)) {
 		err = -EFAULT;
 		goto free_buf;
 	}
@@ -308,14 +308,13 @@  int obd_ioctl_getdata(char **buf, int *len, void __user *arg)
 	return 0;
 
 free_buf:
-	kvfree(*buf);
+	kvfree(data);
 	return err;
 }
 EXPORT_SYMBOL(obd_ioctl_getdata);
 
 int class_handle_ioctl(unsigned int cmd, unsigned long arg)
 {
-	char *buf = NULL;
 	struct obd_ioctl_data *data;
 	struct libcfs_debug_ioctl_data *debug_data;
 	struct obd_device *obd = NULL;
@@ -330,11 +329,10 @@  int class_handle_ioctl(unsigned int cmd, unsigned long arg)
 	}
 
 	CDEBUG(D_IOCTL, "cmd = %x\n", cmd);
-	if (obd_ioctl_getdata(&buf, &len, (void __user *)arg)) {
+	if (obd_ioctl_getdata(&data, &len, (void __user *)arg)) {
 		CERROR("OBD ioctl: data error\n");
 		return -EINVAL;
 	}
-	data = (struct obd_ioctl_data *)buf;
 
 	switch (cmd) {
 	case OBD_IOC_PROCESS_CFG: {
@@ -545,7 +543,7 @@  int class_handle_ioctl(unsigned int cmd, unsigned long arg)
 	}
 
  out:
-	kvfree(buf);
+	kvfree(data);
 	return err;
 } /* class_handle_ioctl */