* do we support using a file as logdev?
@ 2010-04-20 14:36 Wengang Wang
2010-04-20 15:27 ` Iustin Pop
2010-04-20 17:01 ` Eric Sandeen
0 siblings, 2 replies; 5+ messages in thread
From: Wengang Wang @ 2010-04-20 14:36 UTC (permalink / raw)
To: xfs; +Cc: greg.marsden, joe.jin, wen.gang.wang
Hi experts,
Do we support using a file as log device?
If no, it's strange that we support running xfs on a file but don't support log
file.
If yes, it fails at mount.
[root@desk test-xfsprogs]# mkfs.xfs
-llogdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile,size=32768b
/dev/sda10 -f
meta-data=/dev/sda10 isize=256 agcount=4, agsize=1250558
blks
= sectsz=512 attr=2
data = bsize=4096 blocks=5002231, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =/root/test-xfsprogs/test-xfsprogs-tmp/imagefile bsize=4096
blocks=32768, version=2
= sectsz=512 sunit=0 blks, lazy-count=0
realtime =none extsz=4096 blocks=0, rtextents=0
[root@desk test-xfsprogs]# mount
-ologdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile /dev/sda10 /xfs
mount: the kernel does not recognize /dev/sda10 as a block device
(maybe `insmod driver'?)
regards,
wengang.
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: do we support using a file as logdev?
2010-04-20 14:36 do we support using a file as logdev? Wengang Wang
@ 2010-04-20 15:27 ` Iustin Pop
2010-04-20 16:09 ` Wengang Wang
2010-04-20 17:01 ` Eric Sandeen
1 sibling, 1 reply; 5+ messages in thread
From: Iustin Pop @ 2010-04-20 15:27 UTC (permalink / raw)
To: Wengang Wang; +Cc: greg.marsden, joe.jin, xfs
On Tue, Apr 20, 2010 at 10:36:56PM +0800, Wengang Wang wrote:
> Hi experts,
>
> Do we support using a file as log device?
> If no, it's strange that we support running xfs on a file but don't support log
> file.
Have you tried using losetup and passing the loop device instead?
regards,
iustin
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: do we support using a file as logdev?
2010-04-20 15:27 ` Iustin Pop
@ 2010-04-20 16:09 ` Wengang Wang
0 siblings, 0 replies; 5+ messages in thread
From: Wengang Wang @ 2010-04-20 16:09 UTC (permalink / raw)
To: Wengang Wang, xfs, greg.marsden, joe.jin
On 10-04-20 17:27, Iustin Pop wrote:
> On Tue, Apr 20, 2010 at 10:36:56PM +0800, Wengang Wang wrote:
> > Hi experts,
> >
> > Do we support using a file as log device?
> > If no, it's strange that we support running xfs on a file but don't support log
> > file.
>
> Have you tried using losetup and passing the loop device instead?
Yes, that's a workaround.
regards,
wengang.
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: do we support using a file as logdev?
2010-04-20 14:36 do we support using a file as logdev? Wengang Wang
2010-04-20 15:27 ` Iustin Pop
@ 2010-04-20 17:01 ` Eric Sandeen
2010-04-21 3:03 ` Wengang Wang
1 sibling, 1 reply; 5+ messages in thread
From: Eric Sandeen @ 2010-04-20 17:01 UTC (permalink / raw)
To: Wengang Wang; +Cc: greg.marsden, joe.jin, xfs
On 04/20/2010 09:36 AM, Wengang Wang wrote:
> Hi experts,
>
> Do we support using a file as log device?
> If no, it's strange that we support running xfs on a file but don't support log
> file.
> If yes, it fails at mount.
>
> [root@desk test-xfsprogs]# mkfs.xfs
> -llogdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile,size=32768b
> /dev/sda10 -f
> meta-data=/dev/sda10 isize=256 agcount=4, agsize=1250558
> blks
> = sectsz=512 attr=2
> data = bsize=4096 blocks=5002231, imaxpct=25
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=4096 ascii-ci=0
> log =/root/test-xfsprogs/test-xfsprogs-tmp/imagefile bsize=4096
> blocks=32768, version=2
> = sectsz=512 sunit=0 blks, lazy-count=0
> realtime =none extsz=4096 blocks=0, rtextents=0
> [root@desk test-xfsprogs]# mount
> -ologdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile /dev/sda10 /xfs
> mount: the kernel does not recognize /dev/sda10 as a block device
> (maybe `insmod driver'?)
Well, -o logdev=$BLAH sets up m_logname with that value in the mount
point, and xfs_open_devices() then tries:
if (mp->m_logname) {
error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
which eventually does
open_bdev_exclusive(name, FMODE_READ|FMODE_WRITE, mp);
/**
* open_bdev_exclusive - open a block device by name and set it up for use
*
* @path: special file representing the block device
* @mode: FMODE_... combination to pass be used
* @holder: owner for exclusion
*
* Open the blockdevice described by the special file at @path, claim it
* for the @holder.
*/
... this is all in kernelspace, which has no notion of what
/root/test-xfsprogs/test-xfsprogs-tmp/imagefile might be. You'll need
to use a devicename that open_bdev_exclusive() can understand (like
/dev/loop0, as suggested)
-Eric
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: do we support using a file as logdev?
2010-04-20 17:01 ` Eric Sandeen
@ 2010-04-21 3:03 ` Wengang Wang
0 siblings, 0 replies; 5+ messages in thread
From: Wengang Wang @ 2010-04-21 3:03 UTC (permalink / raw)
To: Eric Sandeen; +Cc: xfs, joe.jin, greg.marsden, Wengang Wang
On 10-04-20 12:01, Eric Sandeen wrote:
> On 04/20/2010 09:36 AM, Wengang Wang wrote:
> > Hi experts,
> >
> > Do we support using a file as log device?
> > If no, it's strange that we support running xfs on a file but don't support log
> > file.
> > If yes, it fails at mount.
> >
> > [root@desk test-xfsprogs]# mkfs.xfs
> > -llogdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile,size=32768b
> > /dev/sda10 -f
> > meta-data=/dev/sda10 isize=256 agcount=4, agsize=1250558
> > blks
> > = sectsz=512 attr=2
> > data = bsize=4096 blocks=5002231, imaxpct=25
> > = sunit=0 swidth=0 blks
> > naming =version 2 bsize=4096 ascii-ci=0
> > log =/root/test-xfsprogs/test-xfsprogs-tmp/imagefile bsize=4096
> > blocks=32768, version=2
> > = sectsz=512 sunit=0 blks, lazy-count=0
> > realtime =none extsz=4096 blocks=0, rtextents=0
> > [root@desk test-xfsprogs]# mount
> > -ologdev=/root/test-xfsprogs/test-xfsprogs-tmp/imagefile /dev/sda10 /xfs
> > mount: the kernel does not recognize /dev/sda10 as a block device
> > (maybe `insmod driver'?)
>
> Well, -o logdev=$BLAH sets up m_logname with that value in the mount
> point, and xfs_open_devices() then tries:
>
> if (mp->m_logname) {
> error = xfs_blkdev_get(mp, mp->m_logname, &logdev);
>
> which eventually does
>
> open_bdev_exclusive(name, FMODE_READ|FMODE_WRITE, mp);
> /**
> * open_bdev_exclusive - open a block device by name and set it up for use
> *
> * @path: special file representing the block device
> * @mode: FMODE_... combination to pass be used
> * @holder: owner for exclusion
> *
> * Open the blockdevice described by the special file at @path, claim it
> * for the @holder.
> */
>
> ... this is all in kernelspace, which has no notion of what
> /root/test-xfsprogs/test-xfsprogs-tmp/imagefile might be. You'll need
> to use a devicename that open_bdev_exclusive() can understand (like
> /dev/loop0, as suggested)
I see.
Thanks Eric for your detailed explanation!
regards,
wengang.
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^ permalink raw reply [flat|nested] 5+ messages in thread
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2010-04-20 14:36 do we support using a file as logdev? Wengang Wang
2010-04-20 15:27 ` Iustin Pop
2010-04-20 16:09 ` Wengang Wang
2010-04-20 17:01 ` Eric Sandeen
2010-04-21 3:03 ` Wengang Wang
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