Re: JBD: ext2online wants too many credits (744 > 256)

On Mon, 7 May 2007 00:26:26 +0200 Frank van Maarseveen [off-list ref] wrote:

2.6.20.6, FC4:

I created a 91248k ext3 fs with 4k blocksize:

| mke2fs -j -b 4096 /dev/vol1/project 
| mke2fs 1.38 (30-Jun-2005)
| Filesystem label=
| OS type: Linux
| Block size=4096 (log=2)
| Fragment size=4096 (log=2)
| 23552 inodes, 23552 blocks
| 1177 blocks (5.00%) reserved for the super user
| First data block=0
| Maximum filesystem blocks=25165824
| 1 block group
| 32768 blocks per group, 32768 fragments per group
| 23552 inodes per group

Writing inode tables: done                            
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done

Next, I tried to resize it to about 3G using ext2online while mounted:

| # ext2online /dev/vol1/project 
| ext2online v1.1.18 - 2001/03/18 for EXT2FS 0.5b
| ext2online: ext2_ioctl: No space left on device
|
| ext2online: unable to resize /dev/mapper/vol1-project

At that time the kernel said:

|JBD: ext2online wants too many credits (744 > 256)

What is the limitation I should be aware of? Has it something to do with
the journal log size?

The size actually did increase a bit, to 128112k.


Steps to reproduce:
Create a 3G partition, say /dev/vol1/project
mke2fs -j -b 4096 /dev/vol1/project 22812
mount it
ext2online /dev/vol1/project said:

| ext2online v1.1.18 - 2001/03/18 for EXT2FS 0.5b
| ext2online: ext2_ioctl: No space left on device
| 
| ext2online: unable to resize /dev/mapper/vol1-project

kernel said:

| JBD: ext2online wants too many credits (721 > 256)

(added linux-ext4 to cc)