REPRIORITIZE 801063 - mkfs.xfs after having ext2 mounted on a device can fail

[pv@xxxxxxxxxxxxx (nathans@xxxxxxxxxxxx)]

View Incident: 
http://co-op.engr.sgi.com/BugWorks/code/bwxquery.cgi?search=Search&wlong=1&view_type=Bug&wi=801063

 Status : open                        *Priority : 4                         
 Assigned Engineer : nathans           Submitter : lord                     
 Opened Date : 09/06/00               *Severity : 3                         
*Modified User : nathans              *Modified User Domain : engr          
*Description :
Running mkfs to build an xfs filesystem after a partition has
been mounted as ext2 has periodically failed for me. The failure
is usually this:

[root@lord /]# mkfs -t xfs -f -l size=16000b /dev/sda4
meta-data=/dev/sda4              isize=256    agcount=8, agsize=149104 blks
data     =                       bsize=4096   blocks=1192826, imaxpct=25
         =                       sunit=0      swidth=0 blks, unwritten=0
naming   =version 2              bsize=4096  
log      =internal log           bsize=4096   blocks=16000

.....


==========================
ADDITIONAL INFORMATION (REPRIORITIZE)
From: nathans@engr (BugWorks)
Date: Sep 11 2000 09:19:19PM
==========================

Been asked to prioritise this down as it does not need immediate
attention before beta - with the initial change to mkfs, we are
no longer at immediate risk.

WRT the external log case from yesterday, this does not fail because
the size of the log must be a multiple of the filesystem blocksize
(mkfs enforces this), so we never attempt a write in the last sub-4K
part of the device, so never hit the out-of-space condition.

I imagine this will become a problem when attempting to mkfs an xfs
filesystem using a block size of less than 4Kb, however - that puts
our writes us back into the <4K window at the end of the device.