[PATCH 2/6] btrfs: use memdup_user()

Li Zefan
2009-04-08T07:06:33Z

Remove open-coded memdup_user().

Note this changes some GFP_NOFS to GFP_KERNEL, since copy_from_user() may
cause pagefault, it's pointless to pass GFP_NOFS to kmalloc().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/ioctl.c | 49 ++++++++++++-------------------------------------
fs/btrfs/super.c | 13 ++++---------
2 files changed, 16 insertions(+), 46 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7594bec..9f135e8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -461,15 +461,9 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

- vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
-
- if (!vol_args)
- return -ENOMEM;
-
- if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
- ret = -EFAULT;
- goto out;
- }
+ vol_args = memdup_user(arg, sizeof(*vol_args));
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);

vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
@@ -545,7 +539,6 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)

out_unlock:
mutex_unlock(&root->fs_info->volume_mutex);
-out:
kfree(vol_args);
return ret;
}
@@ -565,15 +558,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file,
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;

- vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
-
- if (!vol_args)
- return -ENOMEM;
-
- if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
- ret = -EFAULT;
- goto out;
- }
+ vol_args = memdup_user(arg, sizeof(*vol_args));
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);

vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
@@ -675,19 +662,13 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

- vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+ vol_args = memdup_user(arg, sizeof(*vol_args));
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);

- if (!vol_args)
- return -ENOMEM;
-
- if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
- ret = -EFAULT;
- goto out;
- }
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_init_new_device(root, vol_args->name);

-out:
kfree(vol_args);
return ret;
}
@@ -703,19 +684,13 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;

- vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
+ vol_args = memdup_user(arg, sizeof(*vol_args));
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);

- if (!vol_args)
- return -ENOMEM;
-
- if (copy_from_user(vol_args, arg, sizeof(*vol_args))) {
- ret = -EFAULT;
- goto out;
- }
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_rm_device(root, vol_args->name);

-out:
kfree(vol_args);
return ret;
}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 9744af9..a7acfe6 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -635,14 +635,9 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

- vol = kmalloc(sizeof(*vol), GFP_KERNEL);
- if (!vol)
- return -ENOMEM;
-
- if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
- ret = -EFAULT;
- goto out;
- }
+ vol = memdup_user((void __user *)arg, sizeof(*vol));
+ if (IS_ERR(vol))
+ return PTR_ERR(vol);

switch (cmd) {
case BTRFS_IOC_SCAN_DEV:
@@ -650,7 +645,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
&btrfs_fs_type, &fs_devices);
break;
}
-out:
+
kfree(vol);
return ret;
}
--
1.5.4.rc3