Re: [PATCH 4.19 35/98] NFS: Fix regression whereby fscache errors are appearing on nofsc mounts

From: Pavel Machek
Date: Wed Aug 28 2019 - 03:11:25 EST


On Tue 2019-08-27 09:50:14, Greg Kroah-Hartman wrote:
> [ Upstream commit dea1bb35c5f35e0577cfc61f79261d80b8715221 ]
>
> People are reporing seeing fscache errors being reported concerning
> duplicate cookies even in cases where they are not setting up fscache
> at all. The rule needs to be that if fscache is not enabled, then it
> should have no side effects at all.
>
> To ensure this is the case, we disable fscache completely on all superblocks
> for which the 'fsc' mount option was not set. In order to avoid issues
> with '-oremount', we also disable the ability to turn fscache on via
> remount.

Actually, the code seems to suggest that you disable the ability to
turn fscache _off_ via remount, too.

Is that intentional?

Best regards,
Pavel

> @@ -2239,6 +2239,7 @@ nfs_compare_remount_data(struct nfs_server *nfss,
> data->acdirmin != nfss->acdirmin / HZ ||
> data->acdirmax != nfss->acdirmax / HZ ||
> data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
> + (data->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
> data->nfs_server.port != nfss->port ||
> data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
> !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,

--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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