[LEDE-DEV] Ext4 resize fault

[Gerhard Bertelsmann]

Hi,

I want to distribute a small Lede image for BananaPi. This image
should be automatically expanded to the maximum size of the SD card
like the way Raspbian is doing it.

But resize2fs exits with a fault.

Here the steps I have done:

Before reboot:
root at Modellbahn-BPi:/# fdisk -l | egrep "Device|^/dev"
Device         Boot Start     End Sectors  Size Id Type
/dev/mmcblk0p1 *     2048   43007   40960   20M  c W95 FAT32 (LBA)
/dev/mmcblk0p2      45056 1093631 1048576  512M 83 Linux

Resized and booted:

root at Modellbahn-BPi:/# fdisk -l | egrep "Device|^/dev"
Device         Boot Start      End  Sectors  Size Id Type
/dev/mmcblk0p1 *     2048    43007    40960   20M  c W95 FAT32 (LBA)
/dev/mmcblk0p2      45056 15130623 15085568  7.2G 83 Linux

root at Modellbahn-BPi:/# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/root               504040     65256    428300  13% /
tmpfs                   515568        44    515524   0% /tmp
tmpfs                      512         0       512   0% /dev

And now try to resize:

root at Modellbahn-BPi:~# resize2fs /dev/mmcblk0p2
resize2fs 1.43.1 (08-Jun-2016)
Filesystem at /dev/mmcblk0p2 is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 1
resize2fs: Invalid argument While checking for on-line resizing support

which also shows following on the console:
[  120.846183] EXT4-fs (mmcblk0p2): resizing filesystem from 131072 to 
1885696 blocks
[  120.910386] EXT4-fs warning (device mmcblk0p2): 
reserve_backup_gdb:968: reserved block 32 not at offset 31
[  120.920136] EXT4-fs (mmcblk0p2): resized filesystem to 1885696
[  124.239447] EXT4-fs warning (device mmcblk0p2): 
ext4_group_extend:1730: can't shrink FS - resize aborted

  As far as I know (googled), the small GDT number is the problem. My 
slightly
  modified image (size 256M -> 512M and 12,000 -> 48,000 inodes) looks 
like:

% tune2fs -l lede-sunxi-root.ext4
tune2fs 1.42.9 (4-Feb-2014)
Filesystem volume name:   <none>
Last mounted on:          <not available>
Filesystem UUID:          57f8f4bc-abf4-655f-bf67-946fc0f9f25b
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
  Filesystem features:      has_journal ext_attr resize_inode filetype 
extent sparse_super large_file uninit_bg
Filesystem flags:         unsigned_directory_hash
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Remount read-only
Filesystem OS type:       Linux
Inode count:              48000
Block count:              131072
Reserved block count:     0
Free blocks:              109688
Free inodes:              40349
First block:              0
Block size:               4096
Fragment size:            4096
Reserved  ks:      31
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         12000
Inode blocks per group:   750
Last mount time:          n/a
Last write time:          Thu Jan  1 01:00:00 1970
Mount count:              0
Maximum mount count:      -1
Last checked:             Thu Jan  1 01:00:00 1970
Check interval:           0 (<none>)
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:              256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   tea
Journal backup:           inode blocks


I had a look at make_ext4fs.c but I don't get any clue how to increase
the amount of GDT entries created.

Does anybody know how I could influence the GDT number ?

Regards

Gerd