afs: Fix large file support

By default s_maxbytes is set to MAX_NON_LFS, which limits the usable
file size to 2GB, enforced by the vfs.

Commit b9b1f8d5 ("AFS: write support fixes") added support for the
64-bit fetch and store server operations, but did not change this value.
As a result, attempts to write past the 2G mark result in EFBIG errors:

 $ dd if=/dev/zero of=foo bs=1M count=1 seek=2048
 dd: error writing 'foo': File too large

Set s_maxbytes to MAX_LFS_FILESIZE.

Fixes: b9b1f8d5 ("AFS: write support fixes")
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/afs/super.c

@@ -435,6 +435,7 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 	/* fill in the superblock */
 	sb->s_blocksize		= PAGE_SIZE;
 	sb->s_blocksize_bits	= PAGE_SHIFT;
+	sb->s_maxbytes		= MAX_LFS_FILESIZE;
 	sb->s_magic		= AFS_FS_MAGIC;
 	sb->s_op		= &afs_super_ops;
 	if (!as->dyn_root)