remount reiserfs hangs under heavy load 2.4.20pre5

remount reiserfs hangs under heavy load 2.4.20pre5

[Jeff Chua]

Whenever "mount -o remount -n -w /dev/hdax" is issued under disk
activities, the system would freezed, and had to be hard booted.

All disk on reiserfs, so don't know whether this only applies to reiserfs
or ext2 as well.

Linux 2.4.20-pre5, but hangs too on 2.4.1x


Jeff.

Re: remount reiserfs hangs under heavy load 2.4.20pre5

[Oleg Drokin]

Hello!

Thank you for report.

On Thu, Sep 05, 2002 at 08:43:36PM +0800, Jeff Chua wrote:

> Whenever "mount -o remount -n -w /dev/hdax" is issued under disk
> activities, the system would freezed, and had to be hard booted.

What kind of disk activies?
What was mount status of filesystems before that command was it readonly
mounted ?

> Linux 2.4.20-pre5, but hangs too on 2.4.1x

I cannot reproduce this behavior with 2.4.19, can you please describe in more
details how can we reproduce?

Thank you.

Bye,
    Oleg

Re: remount reiserfs hangs under heavy load 2.4.20pre5

[Jeff Chua]

On Fri, 6 Sep 2002, Oleg Drokin wrote:

> > Whenever "mount -o remount -n -w /dev/hdax" is issued under disk
> > activities, the system would freezed, and had to be hard booted.
>
> What kind of disk activies?

Activities such as compiling the kernel or rcp large files on /dev/hda3

> What was mount status of filesystems before that command was it readonly
> mounted ?

Yes, read-only on /dev/hda2, trying to change to read-write.

> I cannot reproduce this behavior with 2.4.19, can you please describe in more
> details how can we reproduce?

Using reiserfs on say /dev/hda2 200MB (/usr), mount initially as
read-only, another reiserfs /dev/hda3 800MB (/usr/src), mounted as
read-write, start compiling linux on /usr/src/linux, let it run for about
5 to 10 minutes, switch to another xterm and remount /usr as read-write
... then it may hang sometimes only. My PC is P3 1.13GHz, 650MB Ram, 30GB
hard disk. If the system is not heavily loaded enough, start rcp/cp large
amount of data from one partition to another or to another remote machine,
and remount /usr as read-only and it may hang.

Thanks,
Jeff.

Re: remount reiserfs hangs under heavy load 2.4.20pre5

[Oleg Drokin]

Hello!

On Fri, Sep 06, 2002 at 11:35:16PM +0800, Jeff Chua wrote:
> > > Whenever "mount -o remount -n -w /dev/hdax" is issued under disk
> > > activities, the system would freezed, and had to be hard booted.
> > What kind of disk activies?
> Activities such as compiling the kernel or rcp large files on /dev/hda3
> > What was mount status of filesystems before that command was it readonly
> > mounted ?
> Yes, read-only on /dev/hda2, trying to change to read-write.

Hm. Well, I have not found this same bug as you describe but a very similar
problem.
Can you please try patch below and see it it helps in your situation too?
It should apply to almost anything including 2.4.19 and 2.4.20-pre5.

Thank you.

Bye,
    Oleg


===== super.c 1.23 vs edited =====
--- 1.23/fs/reiserfs/super.c	Mon Sep  9 14:41:12 2002
+++ edited/super.c	Mon Sep  9 17:48:55 2002
@@ -664,7 +664,7 @@
   }
 
   if (*mount_flags & MS_RDONLY) {
-    /* remount rean-only */
+    /* remount read-only */
     if (s->s_flags & MS_RDONLY)
       /* it is read-only already */
       return 0;
@@ -680,6 +680,10 @@
     journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s));
     s->s_dirt = 0;
   } else {
+    /* remount read-write */
+    if (!(s->s_flags & MS_RDONLY))
+	return 0; /* We are read-write already */
+
     s->u.reiserfs_sb.s_mount_state = sb_state(rs) ;
     s->s_flags &= ~MS_RDONLY ; /* now it is safe to call journal_begin */
     journal_begin(&th, s, 10) ;

Re: remount reiserfs hangs under heavy load 2.4.20pre5

[Jeff Chua]

I upgraded to 2.4.20-pre7 and the problem seems to have gone away.


Thanks,
Jeff
[ jchua@fedex.com ]

On Mon, 9 Sep 2002, Oleg Drokin wrote:

> Hello!
>
> On Fri, Sep 06, 2002 at 11:35:16PM +0800, Jeff Chua wrote:
> > > > Whenever "mount -o remount -n -w /dev/hdax" is issued under disk
> > > > activities, the system would freezed, and had to be hard booted.
> > > What kind of disk activies?
> > Activities such as compiling the kernel or rcp large files on /dev/hda3
> > > What was mount status of filesystems before that command was it readonly
> > > mounted ?
> > Yes, read-only on /dev/hda2, trying to change to read-write.
>
> Hm. Well, I have not found this same bug as you describe but a very similar
> problem.
> Can you please try patch below and see it it helps in your situation too?
> It should apply to almost anything including 2.4.19 and 2.4.20-pre5.
>
> Thank you.
>
> Bye,
>     Oleg
>
>
> ===== super.c 1.23 vs edited =====
> --- 1.23/fs/reiserfs/super.c	Mon Sep  9 14:41:12 2002
> +++ edited/super.c	Mon Sep  9 17:48:55 2002
> @@ -664,7 +664,7 @@
>    }
>
>    if (*mount_flags & MS_RDONLY) {
> -    /* remount rean-only */
> +    /* remount read-only */
>      if (s->s_flags & MS_RDONLY)
>        /* it is read-only already */
>        return 0;
> @@ -680,6 +680,10 @@
>      journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s));
>      s->s_dirt = 0;
>    } else {
> +    /* remount read-write */
> +    if (!(s->s_flags & MS_RDONLY))
> +	return 0; /* We are read-write already */
> +
>      s->u.reiserfs_sb.s_mount_state = sb_state(rs) ;
>      s->s_flags &= ~MS_RDONLY ; /* now it is safe to call journal_begin */
>      journal_begin(&th, s, 10) ;
>