bug#45887: closed (buffer cache flushed after excute 'parted -s print' command)

[GNU bug Tracking System]

Your message dated Fri, 15 Jan 2021 09:37:59 -0800
with message-id <YAHS92IIDH/qj0Ne@ohop.brianlane.com>
and subject line Re: bug#45887: buffer cache flushed after excute 'parted -s 
print' command
has caused the debbugs.gnu.org bug report #45887,
regarding buffer cache flushed after excute 'parted -s print' command
to be marked as done.

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45887: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=45887
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--- Begin Message --- Subject: buffer cache flushed after excute 'parted -s print' command Date: Fri, 15 Jan 2021 12:32:42 +0900

Hi, 

I have a strange issue with parted.

After execute parted command, buffer cache flushed and I don't know why.

I have nvme device to set bcache and HDD device for backing block device of bcache and writeback mode.

System informations:

 - OS: CentOS Linux release 7.4.1708 (Core)

 - Kernel version: 4.18.16-1.el7.elrepo.x86_64

 - parted version: parted (GNU parted) 3.1

Reproduce:

 - create nvme partition 

 - make bcache

 - execute parted command

Test:

$ free ; parted /dev/nvme0n1p10 -s print;free
              total        used        free      shared  buff/cache   available
Mem:      131463788    27276308    74617372        3064    29570108   102167828
Swap:       4194300           0     4194300
Error: /dev/nvme0n1p10: unrecognised disk label
Model: Unknown (unknown)
Disk /dev/nvme0n1p10: 50.0GB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:
              total        used        free      shared  buff/cache   available
Mem:      131463788    27276784    75484216        3064    28702788   102167836
Swap:       4194300           0     4194300

$ free ; parted /dev/nvme0n1p11 -s print;free
              total        used        free      shared  buff/cache   available
Mem:      131463788    27324028    75436544        3128    28703216   102119460
Swap:       4194300           0     4194300
Error: /dev/nvme0n1p11: unrecognised disk label
Model: Unknown (unknown)
Disk /dev/nvme0n1p11: 50.0GB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:
              total        used        free      shared  buff/cache   available
Mem:      131463788    27321968    76610612        3128    27531208   102121764
Swap:       4194300           0     4194300

gdisk and fdisk does not flush buffer cache with execute command.

Is this a bug or normal?

thank you in advance.

--- End Message ---

> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#45887: buffer cache flushed after excute 'parted -s print' command
>
>
>
>
> Date: 
>
> Fri, 15 Jan 2021 09:37:59 -0800
>
>
>
>
> On Fri, Jan 15, 2021 at 12:32:42PM +0900, Hyun Ha wrote:
> > Hi,
> > I have a strange issue with parted.
> > After execute parted command, buffer cache flushed and I don't know why.
> > I have nvme device to set bcache and HDD device for backing block device of
> > bcache and writeback mode.
>
> Yes, parted calls fsync when it is done with the device. It always opens
> the device in RW mode and always fsync's it when closing it to make sure
> any changes make it to disk.
>
> Brian
>
> -- 
> Brian C. Lane (PST8PDT) - weldr.io - lorax - parted - pykickstart
>
>
>
> --- End Message ---