resize2fs: enforce restrictions if the kernel doesn't do meta_bg resizing

Enhance the online resizing code to be more nuanced about resizing
restrictions.  If the kernel supports meta_bg resizing, then we can
skip all of the restrictions.  If the kernel does not support meta_bg
resizing, check more carefully to make sure there are enough reserved
gdt blocks, so that the user gets a clearer error message.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
1 file changed