* [PATCH] nilfs2: fix very long mount time issue
@ 2013-01-12 15:34 Vyacheslav Dubeyko
2013-01-13 7:07 ` Ryusuke Konishi
0 siblings, 1 reply; 4+ messages in thread
From: Vyacheslav Dubeyko @ 2013-01-12 15:34 UTC (permalink / raw)
To: Сергей
Александров,
Ryusuke Konishi, linux-nilfs
Cc: linux-fsdevel, linux-kernel, Andrew Morton
From: Vyacheslav Dubeyko <slava@dubeyko.com>
Subject: [PATCH] nilfs2: fix very long mount time issue
DESCRIPTION:
It exists situation when GC can work in background alone without any other filesystem activity during significant time. The nilfs_clean_segments() method calls nilfs_segctor_construct() that updates superblocks in the case of NILFS_SC_SUPER_ROOT and THE_NILFS_DISCONTINUED flags are set. But when GC is working alone the nilfs_clean_segments() is called with unset THE_NILFS_DISCONTINUED flag. As a result, the update of superblocks doesn't occurred all this time and in the case of SPOR superblocks keep very old values of last super root placement.
SYMPTOMS:
Trying to mount a NILFS2 volume after SPOR in such environment ends with very long mounting time (it can achieve about several hours in some cases).
REPRODUCING PATH:
1. It needs to use external USB HDD, disable automount and doesn't make any additional filesystem activity on the NILFS2 volume.
2. Generate temporary file with size about 100 - 500 GB (for example, dd if=/dev/zero of=<file_name> bs=1073741824 count=200). The size of file defines duration of GC working.
3. Then it needs to delete file.
4. Start GC manually by means of command "nilfs-clean -p 0". When you start GC by means of such way then, at the end, superblocks is updated by once. So, for simulation of SPOR, it needs to wait sometime (15 - 40 minutes) and simply switch off USB HDD manually.
5. Switch on USB HDD again and try to mount NILFS2 volume. As a result, NILFS2 volume will mount during very long time.
REPRODUCIBILITY: 100%
FIX:
This patch adds checking that superblocks need to update and set THE_NILFS_DISCONTINUED flag before nilfs_clean_segments() call.
Reported-by: Sergey Alexandrov <splavgm@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
---
fs/nilfs2/ioctl.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index fdb1807..f385935 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -664,8 +664,11 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
if (ret < 0)
printk(KERN_ERR "NILFS: GC failed during preparation: "
"cannot read source blocks: err=%d\n", ret);
- else
+ else {
+ if (nilfs_sb_need_update(nilfs))
+ set_nilfs_discontinued(nilfs);
ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
+ }
nilfs_remove_all_gcinodes(nilfs);
clear_nilfs_gc_running(nilfs);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] nilfs2: fix very long mount time issue
2013-01-12 15:34 [PATCH] nilfs2: fix very long mount time issue Vyacheslav Dubeyko
@ 2013-01-13 7:07 ` Ryusuke Konishi
2013-01-14 23:00 ` Andrew Morton
0 siblings, 1 reply; 4+ messages in thread
From: Ryusuke Konishi @ 2013-01-13 7:07 UTC (permalink / raw)
To: slava, akpm; +Cc: splavgm, linux-nilfs, linux-fsdevel, linux-kernel
On Sat, 12 Jan 2013 19:34:48 +0400, Vyacheslav Dubeyko wrote:
> From: Vyacheslav Dubeyko <slava@dubeyko.com>
> Subject: [PATCH] nilfs2: fix very long mount time issue
>
> DESCRIPTION:
> It exists situation when GC can work in background alone without any other filesystem activity during significant time. The nilfs_clean_segments() method calls nilfs_segctor_construct() that updates superblocks in the case of NILFS_SC_SUPER_ROOT and THE_NILFS_DISCONTINUED flags are set. But when GC is working alone the nilfs_clean_segments() is called with unset THE_NILFS_DISCONTINUED flag. As a result, the update of superblocks doesn't occurred all this time and in the case of SPOR superblocks keep very old values of last super root placement.
>
> SYMPTOMS:
> Trying to mount a NILFS2 volume after SPOR in such environment ends with very long mounting time (it can achieve about several hours in some cases).
>
> REPRODUCING PATH:
> 1. It needs to use external USB HDD, disable automount and doesn't make any additional filesystem activity on the NILFS2 volume.
> 2. Generate temporary file with size about 100 - 500 GB (for example, dd if=/dev/zero of=<file_name> bs=1073741824 count=200). The size of file defines duration of GC working.
> 3. Then it needs to delete file.
> 4. Start GC manually by means of command "nilfs-clean -p 0". When you start GC by means of such way then, at the end, superblocks is updated by once. So, for simulation of SPOR, it needs to wait sometime (15 - 40 minutes) and simply switch off USB HDD manually.
> 5. Switch on USB HDD again and try to mount NILFS2 volume. As a result, NILFS2 volume will mount during very long time.
>
> REPRODUCIBILITY: 100%
>
> FIX:
> This patch adds checking that superblocks need to update and set THE_NILFS_DISCONTINUED flag before nilfs_clean_segments() call.
>
> Reported-by: Sergey Alexandrov <splavgm@gmail.com>
> Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
> Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Thanks, Vyacheslav. I confirmed the issue and could reproduce it.
Your patch fixed it.
Andrew, please apply.
Thanks,
Ryusuke Konishi
> ---
> fs/nilfs2/ioctl.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
> index fdb1807..f385935 100644
> --- a/fs/nilfs2/ioctl.c
> +++ b/fs/nilfs2/ioctl.c
> @@ -664,8 +664,11 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
> if (ret < 0)
> printk(KERN_ERR "NILFS: GC failed during preparation: "
> "cannot read source blocks: err=%d\n", ret);
> - else
> + else {
> + if (nilfs_sb_need_update(nilfs))
> + set_nilfs_discontinued(nilfs);
> ret = nilfs_clean_segments(inode->i_sb, argv, kbufs);
> + }
>
> nilfs_remove_all_gcinodes(nilfs);
> clear_nilfs_gc_running(nilfs);
> --
> 1.7.9.5
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] nilfs2: fix very long mount time issue
2013-01-13 7:07 ` Ryusuke Konishi
@ 2013-01-14 23:00 ` Andrew Morton
2013-01-14 23:38 ` Ryusuke Konishi
0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2013-01-14 23:00 UTC (permalink / raw)
To: Ryusuke Konishi; +Cc: slava, splavgm, linux-nilfs, linux-fsdevel, linux-kernel
On Sun, 13 Jan 2013 16:07:23 +0900 (JST)
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> wrote:
> On Sat, 12 Jan 2013 19:34:48 +0400, Vyacheslav Dubeyko wrote:
> > From: Vyacheslav Dubeyko <slava@dubeyko.com>
> > Subject: [PATCH] nilfs2: fix very long mount time issue
> >
> > DESCRIPTION:
> > It exists situation when GC can work in background alone without any other filesystem activity during significant time. The nilfs_clean_segments() method calls nilfs_segctor_construct() that updates superblocks in the case of NILFS_SC_SUPER_ROOT and THE_NILFS_DISCONTINUED flags are set. But when GC is working alone the nilfs_clean_segments() is called with unset THE_NILFS_DISCONTINUED flag. As a result, the update of superblocks doesn't occurred all this time and in the case of SPOR superblocks keep very old values of last super root placement.
> >
> > SYMPTOMS:
> > Trying to mount a NILFS2 volume after SPOR in such environment ends with very long mounting time (it can achieve about several hours in some cases).
> >
> > REPRODUCING PATH:
> > 1. It needs to use external USB HDD, disable automount and doesn't make any additional filesystem activity on the NILFS2 volume.
> > 2. Generate temporary file with size about 100 - 500 GB (for example, dd if=/dev/zero of=<file_name> bs=1073741824 count=200). The size of file defines duration of GC working.
> > 3. Then it needs to delete file.
> > 4. Start GC manually by means of command "nilfs-clean -p 0". When you start GC by means of such way then, at the end, superblocks is updated by once. So, for simulation of SPOR, it needs to wait sometime (15 - 40 minutes) and simply switch off USB HDD manually.
> > 5. Switch on USB HDD again and try to mount NILFS2 volume. As a result, NILFS2 volume will mount during very long time.
> >
> > REPRODUCIBILITY: 100%
> >
> > FIX:
> > This patch adds checking that superblocks need to update and set THE_NILFS_DISCONTINUED flag before nilfs_clean_segments() call.
> >
> > Reported-by: Sergey Alexandrov <splavgm@gmail.com>
> > Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
> > Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
>
> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
>
> Thanks, Vyacheslav. I confirmed the issue and could reproduce it.
> Your patch fixed it.
>
> Andrew, please apply.
I added a Cc:stable so the fix will be backported into earlier kernels.
40 minutes mount time is pretty bad!
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] nilfs2: fix very long mount time issue
2013-01-14 23:00 ` Andrew Morton
@ 2013-01-14 23:38 ` Ryusuke Konishi
0 siblings, 0 replies; 4+ messages in thread
From: Ryusuke Konishi @ 2013-01-14 23:38 UTC (permalink / raw)
To: Andrew Morton; +Cc: slava, splavgm, linux-nilfs, linux-fsdevel, linux-kernel
>On Sun, 13 Jan 2013 16:07:23 +0900 (JST)
>Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> wrote:
>
>> On Sat, 12 Jan 2013 19:34:48 +0400, Vyacheslav Dubeyko wrote:
>> > From: Vyacheslav Dubeyko <slava@dubeyko.com>
>> > Subject: [PATCH] nilfs2: fix very long mount time issue
>> >
>> > DESCRIPTION:
>> > It exists situation when GC can work in background alone without any other filesystem activity during significant
time. The nilfs_clean_segments() method calls nilfs_segctor_construct() that updates superblocks in the case of
NILFS_SC_SUPER_ROOT and THE_NILFS_DISCONTINUED flags are set. But when GC is working alone the nilfs_clean_segments() is
called with unset THE_NILFS_DISCONTINUED flag. As a result, the update of superblocks doesn't occurred all this time and
in the case of SPOR superblocks keep very old values of last super root placement.
>> >
>> > SYMPTOMS:
>> > Trying to mount a NILFS2 volume after SPOR in such environment ends with very long mounting time (it can achieve
about several hours in some cases).
>> >
>> > REPRODUCING PATH:
>> > 1. It needs to use external USB HDD, disable automount and doesn't make any additional filesystem activity on the
NILFS2 volume.
>> > 2. Generate temporary file with size about 100 - 500 GB (for example, dd if=/dev/zero of=<file_name> bs=1073741824
count=200). The size of file defines duration of GC working.
>> > 3. Then it needs to delete file.
>> > 4. Start GC manually by means of command "nilfs-clean -p 0". When you start GC by means of such way then, at the end,
superblocks is updated by once. So, for simulation of SPOR, it needs to wait sometime (15 - 40 minutes) and simply switch
off USB HDD manually.
>> > 5. Switch on USB HDD again and try to mount NILFS2 volume. As a result, NILFS2 volume will mount during very long
time.
>> >
>> > REPRODUCIBILITY: 100%
>> >
>> > FIX:
>> > This patch adds checking that superblocks need to update and set THE_NILFS_DISCONTINUED flag before
nilfs_clean_segments() call.
>> >
>> > Reported-by: Sergey Alexandrov <splavgm@gmail.com>
>> > Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
>> > Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
>>
>> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
>>
>> Thanks, Vyacheslav. I confirmed the issue and could reproduce it.
>> Your patch fixed it.
>>
>> Andrew, please apply.
>
>I added a Cc:stable so the fix will be backported into earlier kernels.
>40 minutes mount time is pretty bad!
Yup, I agree.
Thanks.
Ryusuke Konishi
^ permalink raw reply [flat|nested] 4+ messages in thread
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2013-01-13 7:07 ` Ryusuke Konishi
2013-01-14 23:00 ` Andrew Morton
2013-01-14 23:38 ` Ryusuke Konishi
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