Btrfs: avoid stack bloat in btrfs_ioctl_fs_info()
The size of struct btrfs_ioctl_fs_info_args is as big as 1KB, so
don't declare the variable on stack.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ac37040..b793d11 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2054,29 +2054,34 @@
static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
{
- struct btrfs_ioctl_fs_info_args fi_args;
+ struct btrfs_ioctl_fs_info_args *fi_args;
struct btrfs_device *device;
struct btrfs_device *next;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+ int ret = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- fi_args.num_devices = fs_devices->num_devices;
- fi_args.max_id = 0;
- memcpy(&fi_args.fsid, root->fs_info->fsid, sizeof(fi_args.fsid));
+ fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
+ if (!fi_args)
+ return -ENOMEM;
+
+ fi_args->num_devices = fs_devices->num_devices;
+ memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
- if (device->devid > fi_args.max_id)
- fi_args.max_id = device->devid;
+ if (device->devid > fi_args->max_id)
+ fi_args->max_id = device->devid;
}
mutex_unlock(&fs_devices->device_list_mutex);
- if (copy_to_user(arg, &fi_args, sizeof(fi_args)))
- return -EFAULT;
+ if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
+ ret = -EFAULT;
- return 0;
+ kfree(fi_args);
+ return ret;
}
static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)