Re: [PATCH 00/28] blk_end_request: full I/O completion handler (take 3)
On Fri, Nov 30 2007, Kiyoshi Ueda wrote: Hello Jens, The following is the updated patch-set for blk_end_request(). Changes since the last version are only minor updates to catch up with the base kernel changes. Do you agree the implementation of blk_end_request()? If there's no problem, could you merge it to your tree? Or does it have to be merged to -mm tree first? Boaz, Could you review the newly added PATCH 27 which converts the bidi part, and give me your comments? It uses blk_end_request_callback() in PATCH 25, which was only for the tricky ide-cd driver. If bidi added a 'resid' member to struct request instead of reusing 'data_len' for the other purpose, it could use the standard blk_end_request() instead. -- Changes from the previous post - Changes between take2 and take3: o Rebased on top of 2.6.24-rc3-mm2 OK, so this means that I can't apply it unfortunately. It depends on other patches in -mm (bidi). SCSI sits on block, so the best approach imho is to base this patchset on mainline so I can include the block bits. -- Jens Axboe - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 00/28] blk_end_request: full I/O completion handler (take 3)
On Fri, Nov 30 2007, Kiyoshi Ueda wrote: Hello Jens, The following is the updated patch-set for blk_end_request(). Changes since the last version are only minor updates to catch up with the base kernel changes. Do you agree the implementation of blk_end_request()? If there's no problem, could you merge it to your tree? Or does it have to be merged to -mm tree first? Looks good to me now, I'll queue it up. Thanks! -- Jens Axboe - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 00/28] blk_end_request: full I/O completion handler (take 3)
On Tue, Dec 04 2007 at 14:16 +0200, Jens Axboe [EMAIL PROTECTED] wrote: On Fri, Nov 30 2007, Kiyoshi Ueda wrote: Hello Jens, The following is the updated patch-set for blk_end_request(). Changes since the last version are only minor updates to catch up with the base kernel changes. Do you agree the implementation of blk_end_request()? If there's no problem, could you merge it to your tree? Or does it have to be merged to -mm tree first? Boaz, Could you review the newly added PATCH 27 which converts the bidi part, and give me your comments? It uses blk_end_request_callback() in PATCH 25, which was only for the tricky ide-cd driver. If bidi added a 'resid' member to struct request instead of reusing 'data_len' for the other purpose, it could use the standard blk_end_request() instead. -- Changes from the previous post - Changes between take2 and take3: o Rebased on top of 2.6.24-rc3-mm2 OK, so this means that I can't apply it unfortunately. It depends on other patches in -mm (bidi). SCSI sits on block, so the best approach imho is to base this patchset on mainline so I can include the block bits. I was wishing that the bidi work can go into 2.6.25, I guess that's James to say. If so than it is not important what order they go in. Or the patchset can be submitted in two parts, with scsi and remove-of- old-API in a later stage. Or *rant* Boaz can just rebase his work again *rant*. Kiyoshi, It's OK, if you have a maintainer that is willing to accept your work then go head, My code can wait, no problem. Just resolve the resid issue in scsi_io_completion() (See my other mail) Thanks for doing this Boaz - To unsubscribe from this list: send the line unsubscribe linux-scsi in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 00/28] blk_end_request: full I/O completion handler (take 3)
Hello Jens,
The following is the updated patch-set for blk_end_request().
Changes since the last version are only minor updates to catch up
with the base kernel changes.
Do you agree the implementation of blk_end_request()?
If there's no problem, could you merge it to your tree?
Or does it have to be merged to -mm tree first?
Boaz,
Could you review the newly added PATCH 27 which converts the bidi part,
and give me your comments?
It uses blk_end_request_callback() in PATCH 25, which was only for
the tricky ide-cd driver.
If bidi added a 'resid' member to struct request instead of reusing
'data_len' for the other purpose, it could use the standard
blk_end_request() instead.
-- Changes from the previous post -
Changes between take2 and take3:
o Rebased on top of 2.6.24-rc3-mm2
o Added a bidi patch, which changes bidi to use blk_end_request()
(PATCH 27)
o Dropped blk_rq_size() which was to get size of entire request
because rq_byte_size() has been added to ll_rw_blk.c (PATCH 02)
o Removed 'dequeue' argument, which was added in 2.6.23-rc7-mm1,
from __end_request() (PATCH 03)
o Removed lguest patch because lguest has been changed not to use
end_that_request_{chunk/last} directly.
Changes between take1 and take2:
o Rebased on top of 2.6.23-rc4-mm1
o Don't pass the lock held information (PATCH 01)
o Removed sect2byte() macro (PATCH 02)
o fixed blk_rq_size() and blk_rq_cur_size() for blk_pc_requests (PATCH 02)
o Separated the patch for changes of end_that_request_* user (PATCH 03-26)
o Removed the patch which changes the role of rq-end_io()
from this patch-set because some more discussions are needed
about it.
---
Summary of each patch are below:
01/28: add new request completion interface, blk_end_request()
02/28: add some functions to get the size of request in bytes
03/28: convert to use blk_end_request() (core parts of block layer)
04/28: convert to use blk_end_request() (arm)
05/28: convert to use blk_end_request() (um)
06/28: convert to use blk_end_request() (DAC960)
07/28: convert to use blk_end_request() (floppy)
08/28: convert to use blk_end_request() (nbd)
09/28: convert to use blk_end_request() (ps3disk)
10/28: convert to use blk_end_request() (sunvdc)
11/28: convert to use blk_end_request() (sx8)
12/28: convert to use blk_end_request() (ub)
13/28: convert to use blk_end_request() (viodasd)
14/28: convert to use blk_end_request() (xen-blkfront)
15/28: convert to use blk_end_request() (viocd)
16/28: convert to use blk_end_request() (i2o_block)
17/28: convert to use blk_end_request() (mmc)
18/28: convert to use blk_end_request() (s390)
19/28: convert to use blk_end_request() (scsi mid-layer)
20/28: convert to use blk_end_request() (ide-scsi)
21/28: convert to use blk_end_request() (xsysace)
22/28: convert to use blk_end_request() (cciss)
23/28: convert to use blk_end_request() (cpqarray)
24/28: convert to use blk_end_request() (normal parts of ide)
25/28: add a valiant of blk_end_request() having callback feature
26/28: convert to use blk_end_request() (ide-cd, cdrom_newpc_intr())
27/28: convert to use blk_end_request() (scsi bidi)
28/28: remove/unexport no longer needed end_that_request_*
I have tested this patch-set on two machines,
IA64+QLA1280+QLA2200 box and x86_64+SATA+IDE-CDROM box.
Below is the explanation about needs and details of this patch-set.
SUMMARY
===
This set of patches changes request completion interface
between device drivers and block layer to 1 step procedure
from current 2 step procedures using end_that_request_{first/chunk}
and end_that_request_last().
This patch-set prepares for realizing another patch-set which changes
the role of rq-end_io(). It allows request-based multipath to hook
in before completing each chunk of request, check errors for it and
retry it using another path if error is detected.
BACKGROUND
==
The patch-set which changes the role of rq-end_io() is necessary
to allow device stacking at request level, that is request-based
device-mapper multipath.
Currently, device-mapper is implemented as a stacking block device
at BIO level. OTOH, request-based dm will stack at request level
to allow better multipathing decision.
To allow device stacking at request level, the completion procedure
need to provide a hook for it.
For example, dm-multipath has to check errors and retry with other
paths if necessary before returning the I/O result to upper layer.
struct request has 'end_io' hook currently. But it's called at
the very late stage of completion handling where the I/O result
is already returned to the upper layer.
So we need something here.
The first approach to hook in completion of each chunk of request
was adding a new rq-end_io_first() hook and calling it on the top
of __end_that_request_first().
-
