xfs: clean up the XFS_IOC_{GS}ET_RESBLKS handler

The XFS_IOC_GET_RESBLKS and XFS_IOC_SET_RESBLKS already share a fair
amount of code, and will share even more soon.  Move the logic for both
of them out of the main xfs_file_ioctl function into a
xfs_ioctl_getset_resblocks helper to share the code and prepare for
additional changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 6c3919687ea6b306585ea2f32f125c59a4b53a60..7edc1d892f0c8873f48057d7fc7e873a9feecdc0 100644 (file)
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1872,6 +1872,46 @@ xfs_fs_eofblocks_from_user(
        return 0;
 }
 
+static int
+xfs_ioctl_getset_resblocks(
+       struct file             *filp,
+       unsigned int            cmd,
+       void __user             *arg)
+{
+       struct xfs_mount        *mp = XFS_I(file_inode(filp))->i_mount;
+       struct xfs_fsop_resblks fsop = { };
+       int                     error;
+       uint64_t                in;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (cmd == XFS_IOC_SET_RESBLKS) {
+               if (xfs_is_readonly(mp))
+                       return -EROFS;
+
+               if (copy_from_user(&fsop, arg, sizeof(fsop)))
+                       return -EFAULT;
+
+               error = mnt_want_write_file(filp);
+               if (error)
+                       return error;
+               in = fsop.resblks;
+               error = xfs_reserve_blocks(mp, &in, &fsop);
+               mnt_drop_write_file(filp);
+               if (error)
+                       return error;
+       } else {
+               error = xfs_reserve_blocks(mp, NULL, &fsop);
+               if (error)
+                       return error;
+       }
+
+       if (copy_to_user(arg, &fsop, sizeof(fsop)))
+               return -EFAULT;
+       return 0;
+}
+
 /*
  * These long-unused ioctls were removed from the official ioctl API in 5.17,
  * but retain these definitions so that we can log warnings about them.
@@ -2018,50 +2058,9 @@ xfs_file_ioctl(
                return 0;
        }
 
-       case XFS_IOC_SET_RESBLKS: {
-               xfs_fsop_resblks_t inout;
-               uint64_t           in;
-
-               if (!capable(CAP_SYS_ADMIN))
-                       return -EPERM;
-
-               if (xfs_is_readonly(mp))
-                       return -EROFS;
-
-               if (copy_from_user(&inout, arg, sizeof(inout)))
-                       return -EFAULT;
-
-               error = mnt_want_write_file(filp);
-               if (error)
-                       return error;
-
-               /* input parameter is passed in resblks field of structure */
-               in = inout.resblks;
-               error = xfs_reserve_blocks(mp, &in, &inout);
-               mnt_drop_write_file(filp);
-               if (error)
-                       return error;
-
-               if (copy_to_user(arg, &inout, sizeof(inout)))
-                       return -EFAULT;
-               return 0;
-       }
-
-       case XFS_IOC_GET_RESBLKS: {
-               xfs_fsop_resblks_t out;
-
-               if (!capable(CAP_SYS_ADMIN))
-                       return -EPERM;
-
-               error = xfs_reserve_blocks(mp, NULL, &out);
-               if (error)
-                       return error;
-
-               if (copy_to_user(arg, &out, sizeof(out)))
-                       return -EFAULT;
-
-               return 0;
-       }
+       case XFS_IOC_SET_RESBLKS:
+       case XFS_IOC_GET_RESBLKS:
+               return xfs_ioctl_getset_resblocks(filp, cmd, arg);
 
        case XFS_IOC_FSGROWFSDATA: {
                struct xfs_growfs_data in;