btrfs: filter invalid arg for btrfs resize

Originally following cmds will work:
	# btrfs fi resize -10A  <mnt>
	# btrfs fi resize -10Gaha <mnt>
Filter the arg by checking the return pointer of memparse.

Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 59622366c613..05f8df866e4c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1472,6 +1472,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
         struct btrfs_trans_handle *trans;
         struct btrfs_device *device = NULL;
         char *sizestr;
+        char *retptr;
         char *devstr = NULL;
         int ret = 0;
         int mod = 0;
@@ -1539,8 +1540,8 @@ static noinline int btrfs_ioctl_resize(struct file *file,
                         mod = 1;
                         sizestr++;
                 }
-                new_size = memparse(sizestr, NULL);
-                if (new_size == 0) {
+                new_size = memparse(sizestr, &retptr);
+                if (*retptr != '\0' || new_size == 0) {
                         ret = -EINVAL;
                         goto out_free;
                 }