[PATCH 0/3] ext4: remove use of d_alloc()

[NeilBrown <neilb@ownmail.net>]

This is a revised version of the ext4 patches from my recent patchset
for revising directory locking.  My particular interest in changing ext4
is to remove the use of d_alloc().  I will want to deprecate d_alloc()
as it doesn't fit the new model well.

The use of d_alloc() in ext4 is incidental to the actual task at hand.
The code really wants to pass around a parent directory and a name, and
only uses the dentry because that seems convenient.  As these patches
show the code actually becomes simpler when we avoid the dentry.

The second patch here isn't needed.  I thought it would be, wrote it,
then found it didn't directly help.  However I think it is still a nice
simplification so I left it.  If you don't want it, please drop it.

Thanks to Jan Kara for his initial review which helpped me see some
problems with my initial attempt more clearly.

NeilBrown

Note: these patches are quite independant of the rest of that big
patchset, except for the late removal of d_alloc().  They can safely
land indepenantly if you would like to take them now in the ext4 tree.

 [PATCH 1/3] ext4: split __ext4_add_entry() out of ext4_add_entry()
 [PATCH 2/3] ext4: add ext4_fc_eligible()
 [PATCH 3/3] ext4: move dcache manipulation out of __ext4_link()