Re: [PATCH] btrfs: Introduce new mount option to disable tree log replay

[Chandan Rajendra <chandan@linux.vnet.ibm.com>]

On Monday 07 Dec 2015 14:06:42 Qu Wenruo wrote:
> Introduce a new mount option "nologreplay" to co-operate with "ro" mount
> option to get real readonly mount, like "norecovery" in ext* and xfs.
> 
> Since the new parse_options() need to check new flags at remount time,
> so add a new parameter for parse_options().
>

Hello Qu,
The patch should add an entry into btrfs_show_options() for 'mount' command to
be able to display an entry corresponding to 'nologreplay' mount option.

Even after adding such an entry to btrfs_show_options(),
the following occurs,
# mount -o nologreplay,ro /dev/loop6 /mnt/
# mount | grep loop6
/dev/loop6 on /mnt type btrfs (ro,relatime,seclabel,nologreplay,space_cache,subvolid=5,subvol=/)
# mount -o remount,rw /dev/loop6 /mnt/
# mount | grep loop6
/dev/loop6 on /mnt type btrfs (rw,relatime,seclabel,nologreplay,space_cache,subvolid=5,subvol=/)

As can be seen from the last line, both 'rw' and 'nologreplay' options are set.

-- 
chandan