ext4: grow the s_flex_groups array as needed when resizing
Previously, we allocated the s_flex_groups array to the maximum size
that the file system could be resized. There was two problems with
this approach. First, it wasted memory in the common case where the
file system was not resized. Secondly, once we start allowing online
resizing using the meta_bg scheme, there is no maximum size that the
file system can be resized. So instead, we need to grow the
s_flex_groups at inline resize time.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 365d800..3f5c67b 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1503,6 +1503,10 @@
if (err)
goto out;
+ err = ext4_alloc_flex_bg_array(sb, input->group + 1);
+ if (err)
+ return err;
+
flex_gd.count = 1;
flex_gd.groups = input;
flex_gd.bg_flags = &bg_flags;
@@ -1662,7 +1666,7 @@
unsigned long n_desc_blocks;
unsigned long o_desc_blocks;
unsigned long desc_blocks;
- int err = 0, flexbg_size = 1;
+ int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex;
o_blocks_count = ext4_blocks_count(es);
@@ -1721,13 +1725,13 @@
goto out;
}
- if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
- es->s_log_groups_per_flex)
- flexbg_size = 1 << es->s_log_groups_per_flex;
-
if (ext4_blocks_count(es) == n_blocks_count)
goto out;
+ err = ext4_alloc_flex_bg_array(sb, n_group + 1);
+ if (err)
+ return err;
+
flex_gd = alloc_flex_gd(flexbg_size);
if (flex_gd == NULL) {
err = -ENOMEM;