From: Mingming Cao <cmm@us.ibm.com>
To: suparna@in.ibm.com
Cc: Andrew Morton <akpm@osdl.org>,
"Stephen C. Tweedie" <sct@redhat.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
ext2-devel <ext2-devel@lists.sourceforge.net>,
linux-fsdevel@vger.kernel.org
Subject: Re: [Ext2-devel] [RFC] Adding multiple block allocation
Date: Fri, 29 Apr 2005 12:42:44 -0700 [thread overview]
Message-ID: <1114803764.10473.46.camel@localhost.localdomain> (raw)
In-Reply-To: <1114794608.10473.18.camel@localhost.localdomain>
On Fri, 2005-04-29 at 10:10 -0700, Mingming Cao wrote:
> But if it try to allocating blocks in the hole (with direct IO), blocks
> are allocated one by one. I am looking at it right now.
>
Hi Andrew, Badari,
If we do direct write(block allocation) to a hole, I found that the
"create" flag passed to ext3_direct_io_get_blocks() is 0 if we are
trying to _write_ to a file hole. Is this expected?
This is what happened on mainline 2.6.12-rc2(and with my patch). To simplify, here is the problem description on mainline:
If we do 30 blocks write to a new file at offset 800k, fine, create flag is all 1.
Then if seek back to offset 400k, write another 30 blocks, create flag is 0
-bash-2.05b# mount -t ext3 /dev/ubdc /mnt/ext3
-bash-2.05b# cd /mnt/ext3
-bash-2.05b# touch a
-bash-2.05b# /root/filetst -o 819200 -b 122880 -c 1 -w -d -f a
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 30, iblock = 200, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 29, iblock = 201, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 28, iblock = 202, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 27, iblock = 203, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 26, iblock = 204, create = 1
...................
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 5, iblock = 225, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 4, iblock = 226, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 3, iblock = 227, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 2, iblock = 228, create = 1
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 1, iblock = 229, create = 1
-bash-2.05b# /root/filetst -o 409600 -b 122880 -c 1 -w -d -f a
Calling ext3_get_block_handle from ext3_direct_io_get_blocks: maxblocks = 30, iblock = 100, create = 0
Because of create flag is 0, ext3_get_block will not do block allocation
and return immediately after look up failed. Then ext3_get_block_handle
() is called from other path(I am not sure where) other than
ext3_direct_io_get_blocks to allocate the desired 30 blocks.(thus, when
apply ext3_get_blocks patch, ext3_get_blocks is not called)
Could you clarify?
Thanks,
Mingming
next prev parent reply other threads:[~2005-04-29 19:42 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-04-05 3:51 ext3 allocate-with-reservation latencies Lee Revell
2005-04-05 4:13 ` Ingo Molnar
2005-04-05 6:10 ` Mingming Cao
2005-04-05 16:38 ` Lee Revell
2005-04-06 5:35 ` Mingming Cao
2005-04-06 9:51 ` Stephen C. Tweedie
2005-04-06 16:53 ` Mingming Cao
2005-04-06 18:22 ` Stephen C. Tweedie
2005-04-06 19:03 ` Mingming Cao
2005-04-07 8:14 ` Ingo Molnar
2005-04-07 13:08 ` Stephen C. Tweedie
2005-04-07 19:16 ` Mingming Cao
2005-04-07 23:37 ` Mingming Cao
2005-04-08 14:40 ` Stephen C. Tweedie
2005-04-08 16:06 ` Arjan van de Ven
2005-04-08 18:10 ` Mingming Cao
2005-04-08 18:12 ` Lee Revell
2005-04-11 11:48 ` Stephen C. Tweedie
2005-04-11 18:38 ` Mingming Cao
2005-04-11 19:12 ` Lee Revell
2005-04-11 19:22 ` Lee Revell
2005-04-11 19:57 ` Stephen C. Tweedie
2005-04-12 6:41 ` Mingming Cao
2005-04-12 11:18 ` Stephen C. Tweedie
2005-04-12 23:27 ` Mingming Cao
2005-04-13 10:29 ` Stephen C. Tweedie
[not found] ` <1113597161.3899.80.camel@localhost.localdomain>
2005-04-18 18:00 ` Stephen C. Tweedie
2005-04-18 21:56 ` [Ext2-devel] " Mingming Cao
2005-04-22 22:10 ` [RFC][PATCH] Reduce ext3 allocate-with-reservation lock latencies Mingming Cao
2005-04-28 3:45 ` Lee Revell
2005-04-28 7:37 ` Mingming Cao
2005-04-28 16:12 ` Lee Revell
2005-04-28 18:34 ` Mingming Cao
2005-04-29 6:18 ` Mingming Cao
2005-04-28 19:14 ` [RFC] Adding multiple block allocation to current ext3 Mingming Cao
2005-04-29 13:52 ` [Ext2-devel] [RFC] Adding multiple block allocation Suparna Bhattacharya
2005-04-29 17:10 ` Mingming Cao
2005-04-29 19:42 ` Mingming Cao [this message]
2005-04-29 20:57 ` Andrew Morton
2005-04-29 21:12 ` Mingming Cao
2005-04-29 21:34 ` Andrew Morton
2005-04-30 16:00 ` Suparna Bhattacharya
2005-04-29 18:45 ` Badari Pulavarty
2005-04-29 23:22 ` Mingming Cao
2005-04-30 16:10 ` Suparna Bhattacharya
2005-04-30 17:11 ` Suparna Bhattacharya
2005-04-30 18:07 ` Mingming Cao
2005-05-02 4:46 ` Suparna Bhattacharya
2005-04-30 16:52 ` Suparna Bhattacharya
2005-04-30 0:33 ` Mingming Cao
2005-04-30 0:44 ` Mingming Cao
2005-04-30 17:03 ` Suparna Bhattacharya
2006-01-10 23:26 ` [PATCH 0/5] multiple block allocation to current ext3 Mingming Cao
2006-01-11 5:25 ` Andrew Morton
2006-01-11 19:17 ` Mingming Cao
2006-01-11 19:43 ` Andrew Morton
2006-01-11 21:31 ` Mingming Cao
2006-01-14 1:12 ` Fall back io scheduler for 2.6.15? Mingming Cao
2006-01-14 1:49 ` Andrew Morton
2006-01-14 5:22 ` Dave Jones
2006-01-16 8:43 ` Jens Axboe
2006-01-16 19:45 ` [PATCH] Fall back io scheduler ( Re: [Ext2-devel] Re: Fall back io scheduler for 2.6.15?) Mingming Cao
2006-01-16 19:49 ` Jens Axboe
2006-01-16 19:57 ` Mingming Cao
2006-01-19 19:37 ` Fall back io scheduler for 2.6.15? Nate Diller
2006-01-20 8:10 ` Jens Axboe
2006-01-16 19:38 ` [Ext2-devel] " Mingming Cao
2005-04-29 6:28 ` [PATCH] Reduce ext3 allocate-with-reservation lock latencies Mingming Cao
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