On 04/10/2013 01:56 PM, Eric Sandeen wrote:
On 4/10/13 1:24 PM, Mark Tinguely wrote:
Reserve fields in new inode layout for parent pointer and
allocation policy.
----
The inode will hold the parent information for the first
link to a file. Information for the other links will be
held in extended attribute entries.
The "di_parino" is the inode of the parent directory. The
directory information for this entry is located the parent
directory with "di_paroff" offset.
The di_parino/di_paroff concept code is running.
----
The "di_allocpolicy" will be used to remember the allocation
policy associated with this inode.
can you say more about this allocation policy?
-Eric
No its super secret information. ;)
Its on my plate Eric, because Mark was making a change for parent ptrs,
I asked him to request space for allocation policies also.
I don't have all the details yet but here is a very high level concept.
Identify allocation groups by names (or numbers -- preferably using names
in user-visible areas), allowing many different areas. Placing the
allocation
policy outside of user programs is necessary for this to be successful.
Current thoughts on proposed a layered allocation policies:
Policy for the entire filesystem
Policy attached to a directory (whose policy would be inherited by
subdirectories when subdirectories are created)
Policy for a single file
The policy would define:
where to place file data
where to place metadata for the files.
a prefered allocation group for placing file data (for directories).
--Rich
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