Re: [PATCH 1/3] new_inode_autonum: add per-sb lastino counter and add new_inode_autonum function that guarantees i_ino uniqueness

[Eric Sandeen <sandeen@sandeen.net>]

Jeff Layton wrote:
> - add a new per superblock s_nextino counter and change iunique to use it
>   instead of its global inode counter
> - make the size of the counter conditional on CONFIG_COMPAT. This is to try
>   prevent userspace EOVERFLOWs when 32-bit programs not compiled with large
>   offsets are run on 64-bit kernels
> - add new_inode_autonum which guarantees that i_ino is assigned a unique val
>   on the filesystem.
> - Change new_inode to assign i_ino to 0 to catch filesystems that use it and
>   don't reset it to a unique value.

I like the general approach.  A few tidbits...

- the comment for __new_inode isn't accurate, there is no @autonum
parameter added.

- I'm not sure what the point of wrapping __new_inode() in new_inode()
is.  Why not just remove the i_ino setting from new_inode, (or
initialize it to 0*), and let new_inode_autonum() call new_inode();
iunique() ?  Less indirection IMHO....

- *does setting the new i_ino to 0 really help catch anything?  And if
it does, perhaps just setting it in alloc_inode() with all the other
field initializations would be more consistent.

- the comment for the s_nextino field is a bit misleading, it is
actually not used in new_inode(), only in iunique().

-Eric