Messages in this thread | | | Date | Tue, 27 Mar 2018 16:15:29 -0700 | From | Andrew Morton <> | Subject | Re: [V9fs-developer] [PATCH] fs/9p: don't set SB_NOATIME by default |
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On Tue, 27 Mar 2018 09:50:47 +0800 jiangyiwen <jiangyiwen@huawei.com> wrote:
> User use some syscall, for example mmap(v9fs_file_mmap), it will not > update atime even if user's mnt_flags without MNT_NOATIME, because > v9fs default set SB_NOATIME in v9fs_set_super. > > For supporting access time is updated when user mount with relatime, > we should not set SB_NOATIME by default. > > ... > > --- a/fs/9p/vfs_super.c > +++ b/fs/9p/vfs_super.c > @@ -94,7 +94,7 @@ static int v9fs_set_super(struct super_block *s, void *data) > if (v9ses->cache) > sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024)/PAGE_SIZE; > > - sb->s_flags |= SB_ACTIVE | SB_DIRSYNC | SB_NOATIME; > + sb->s_flags |= SB_ACTIVE | SB_DIRSYNC; > if (!v9ses->cache) > sb->s_flags |= SB_SYNCHRONOUS; >
So strictly speaking, this is a non-backward-compatible change, yes?
Please describe the circumstances under which an existing user might be harmed by this. I *think* such harm will occur if the user was already using 'mount -o relatime', yes? They previously weren't getting relatime treatment, but now they will, and things will be a little slower.
If correct, that sounds acceptable.
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