The following patch moves the BKL out of notify_change() and into the 
individual filesystems.  There was an attempt to remove the BKL from the 
function here:
http://groups.google.com/groups?hl=en&selm=20020118043308.B9A75B581%40smtp.transgeek.com.lucky.linux.kernel
However, it looks to me like Craig's I_ATTR_LOCK bit in i_state plus the 
inode_lock just about equals a semaphore.  If so, why not just use a 
semaphore?  Is space in the inode strucure THAT precious?

My patch adds a semaphore to the inode structure, removes the BKL from 
notify_change(), and shifts the BKL into the individual filesystems' 
setattr() functions.  I doubt that many of them actually need it, but I 
figure the FS maintainers can remove it.  The BKL use in notify_change() 
is replaced by the semaphore i_attr_lock.

-- 
Dave Hansen
haveblue@us.ibm.com