[PATCH 4.19 110/170] ext4: fix EXT4_IOC_GROUP_ADD ioctl

From: Greg Kroah-Hartman
Date: Mon Jan 07 2019 - 07:56:15 EST

4.19-stable review patch. If anyone has any objections, please let me know.


From: ruippan (æç) <ruippan@xxxxxxxxxxx>

commit e647e29196b7f802f8242c39ecb7cc937f5ef217 upstream.

Commit e2b911c53584 ("ext4: clean up feature test macros with
predicate functions") broke the EXT4_IOC_GROUP_ADD ioctl. This was
not noticed since only very old versions of resize2fs (before
e2fsprogs 1.42) use this ioctl. However, using a new kernel with an
enterprise Linux userspace will cause attempts to use online resize to
fail with "No reserved GDT blocks".

Fixes: e2b911c53584 ("ext4: clean up feature test macros with predicate...")
Cc: stable@xxxxxxxxxx # v4.4
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: ruippan (æç) <ruippan@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

fs/ext4/resize.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1631,7 +1631,7 @@ int ext4_group_add(struct super_block *s

if (reserved_gdb || gdb_off == 0) {
- if (ext4_has_feature_resize_inode(sb) ||
+ if (!ext4_has_feature_resize_inode(sb) ||
!le16_to_cpu(es->s_reserved_gdt_blocks)) {
"No reserved GDT blocks, can't resize");