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From: ronnie sahlberg <ronniesahlberg@gmail.com>
To: "Aurélien Aptel" <aaptel@suse.com>
Cc: Steve French <smfrench@gmail.com>, CIFS <linux-cifs@vger.kernel.org>
Subject: Re: [RFC][SMB3][PATCH] Allow share to be mounted with "cache=ro" if immutable share
Date: Wed, 28 Aug 2019 20:27:32 +1000
Message-ID: <CAN05THSPmp3GtZifXK-mLtVntgQR0uwaYY-c5LS9Dhf_P78grA@mail.gmail.com> (raw)
In-Reply-To: <87k1axlhf8.fsf@suse.com>

On Wed, Aug 28, 2019 at 8:21 PM Aurélien Aptel <aaptel@suse.com> wrote:
>
> "Steve French" <smfrench@gmail.com> writes:
> > Increases performance a lot in cases where we know that the share is
> > not changing
>
> This is just adding the parsing of the option but it sounds like a good idea.

You also have the magic happening in:
-#define CIFS_CACHE_READ(cinode) (cinode->oplock & CIFS_CACHE_READ_FLG)
+#define CIFS_CACHE_READ(cinode) ((cinode->oplock &
CIFS_CACHE_READ_FLG) ||
(CIFS_SB(cinode->vfs_inode.i_sb)->mnt_cifs_flags &
CIFS_MOUNT_RO_CACHE))

which makes things work. Still I would want this to be driven by
whether the server returns "this share is WRITEABLE or  not" flag
instead of a mount option.
A mount option only invites people to "I use this because it makes
thing faster"  then "why do my files look corrupted sometimes" ?

>
> > +#define CIFS_MOUNT_RO_CACHE  0x20000000  /* assumes share will not change */
>
> This flag probably needs to be added to CIFS_MOUNT_MASK: if one cifs sb
> is using that flag, it should only be reused for new mounts that also
> require that flag.
>
> Cheers,
>
> --
> Aurélien Aptel / SUSE Labs Samba Team
> GPG: 1839 CB5F 9F5B FB9B AA97  8C99 03C8 A49B 521B D5D3
> SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg, DE
> GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 247165 (AG München)

  reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-28  5:02 Steve French
2019-08-28  6:11 ` ronnie sahlberg
2019-08-28 10:20 ` Aurélien Aptel
2019-08-28 10:27   ` ronnie sahlberg [this message]
2019-08-28 10:54     ` Aurélien Aptel
2019-08-28 22:17     ` Steve French

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