Btrfs: kill max_extent mount option

As Yan pointed out, theres not much reason for all this complicated math to
account for file extents being split up into max_extent chunks, since they are
likely to all end up in the same leaf anyway.  Since there isn't much reason to
use max_extent, just remove the option altogether so we have one less thing we
need to test.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 9ac612e..d11b12f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -64,10 +64,9 @@
 
 enum {
 	Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
-	Opt_nodatacow, Opt_max_extent, Opt_max_inline, Opt_alloc_start,
-	Opt_nobarrier, Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool,
-	Opt_noacl, Opt_compress, Opt_compress_force, Opt_notreelog, Opt_ratio,
-	Opt_flushoncommit,
+	Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
+	Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
+	Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
 	Opt_discard, Opt_err,
 };
 
@@ -79,7 +78,6 @@
 	{Opt_nodatasum, "nodatasum"},
 	{Opt_nodatacow, "nodatacow"},
 	{Opt_nobarrier, "nobarrier"},
-	{Opt_max_extent, "max_extent=%s"},
 	{Opt_max_inline, "max_inline=%s"},
 	{Opt_alloc_start, "alloc_start=%s"},
 	{Opt_thread_pool, "thread_pool=%d"},
@@ -188,18 +186,6 @@
 				       info->thread_pool_size);
 			}
 			break;
-		case Opt_max_extent:
-			num = match_strdup(&args[0]);
-			if (num) {
-				info->max_extent = memparse(num, NULL);
-				kfree(num);
-
-				info->max_extent = max_t(u64,
-					info->max_extent, root->sectorsize);
-				printk(KERN_INFO "btrfs: max_extent at %llu\n",
-				       (unsigned long long)info->max_extent);
-			}
-			break;
 		case Opt_max_inline:
 			num = match_strdup(&args[0]);
 			if (num) {
@@ -529,9 +515,6 @@
 		seq_puts(seq, ",nodatacow");
 	if (btrfs_test_opt(root, NOBARRIER))
 		seq_puts(seq, ",nobarrier");
-	if (info->max_extent != (u64)-1)
-		seq_printf(seq, ",max_extent=%llu",
-			   (unsigned long long)info->max_extent);
 	if (info->max_inline != 8192 * 1024)
 		seq_printf(seq, ",max_inline=%llu",
 			   (unsigned long long)info->max_inline);