Re: [PATCH #upstream-fixes 2/4] libata: beef up iterators

[Jeff Garzik <jeff@garzik.org>]

Mark Lord wrote:
> Jeff Garzik wrote:
>> Tejun Heo wrote:
>>> There currently are the following loop constructs.
>>>
>>> * __ata_port_for_each_link() for all available links
>>> * ata_port_for_each_link() for edge links
>>> * ata_link_for_each_dev() for all devices
>>> * ata_link_for_each_dev_reverse() for all devices in reverse order
>>>
>>> Now there's a need for loop construct which is similar to
>>> __ata_port_for_each_link() but iterates over PMP links before the host
>>> link.  Instead of adding another one with long name, do the following
>>> cleanup.
>>>
>>> * Implement and export ata_link_next() and ata_dev_next() which take
>>>   @mode parameter and can be used to build custom loop.
>>> * Implement ata_for_each_link() and ata_for_each_dev() which take
>>>   looping mode explicitly.
>>>
>>> The following iteration modes are implemented.
>>>
>>> * ATA_LITER_EDGE        : loop over edge links
>>> * ATA_LITER_HOST_FIRST        : loop over all links, host link first
>>> * ATA_LITER_PMP_FIRST        : loop over all links, PMP links first
>>>
>>> * ATA_DITER_ENABLED        : loop over enabled devices
>>> * ATA_DITER_ENABLED_REVERSE    : loop over enabled devices in reverse 
>>> order
>>> * ATA_DITER_ALL            : loop over all devices
>>> * ATA_DITER_ALL_REVERSE        : loop over all devices in reverse order
>>>
>>> This change removes exlicit device enabledness checks from many loops
>>> and makes it clear which ones are iterated over in which direction.
>>>
>>> Signed-off-by: Tejun Heo <tj@kernel.org>
>>> ---
>>>  drivers/ata/ahci.c           |    8 -
>>>  drivers/ata/ata_generic.c    |    5 -
>>>  drivers/ata/libata-acpi.c    |   19 +---
>>>  drivers/ata/libata-core.c    |  183 
>>> ++++++++++++++++++++++++++++---------------
>>>  drivers/ata/libata-eh.c      |   84 ++++++++-----------
>>>  drivers/ata/libata-pmp.c     |   22 ++---
>>>  drivers/ata/libata-scsi.c    |   22 ++---
>>>  drivers/ata/pata_it821x.c    |   34 +++----
>>>  drivers/ata/pata_ixp4xx_cf.c |   14 +--
>>>  drivers/ata/pata_legacy.c    |   17 +--
>>>  drivers/ata/pata_pdc2027x.c  |   27 ++----
>>>  drivers/ata/pata_platform.c  |   14 +--
>>>  drivers/ata/pata_rz1000.c    |   16 +--
>>>  drivers/ata/sata_sil.c       |    2  include/linux/libata.h       
>>> |   50 +++++++----
>>>  15 files changed, 279 insertions(+), 238 deletions(-)
>>
>> ACK... for 2.6.29.  I think this is too much change for -rc2.  It's a 
>> good idea though.
>>
>> Also, it could use more documentation than just the commit message... 
>> something that programmers can easily refer to (header file comment?)
> ..
> 
> Yeah.  Especially a reminder of what "LITER" and "DITER" stand for!  :)

Well, DITER stands for device iteration, and LITER stands for an amount 
of petrol... <grin>

	Jeff