From: Dave Chinner <david@fromorbit.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-nvdimm@lists.01.org, linux-api@vger.kernel.org,
Trond Myklebust <trond.myklebust@primarydata.com>,
linux-kernel@vger.kernel.org,
Anna Schumaker <anna.schumaker@netapp.com>,
linux-xfs@vger.kernel.org, linux-mm@kvack.org, luto@kernel.org,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
darrick.wong@oracle.com
Subject: Re: [PATCH v3 6/6] mm, xfs: protect swapfile contents with immutable + unwritten extents
Date: Sat, 12 Aug 2017 09:33:24 +1000 [thread overview]
Message-ID: <20170811233323.GU21024@dastard> (raw)
In-Reply-To: <150243358949.8777.17308615269167142735.stgit@dwillia2-desk3.amr.corp.intel.com>
On Thu, Aug 10, 2017 at 11:39:49PM -0700, Dan Williams wrote:
> ifp = XFS_IFORK_PTR(ip, whichfork);
> diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
> index 851982a5dfbc..a0f099289520 100644
> --- a/fs/xfs/libxfs/xfs_bmap.h
> +++ b/fs/xfs/libxfs/xfs_bmap.h
> @@ -113,6 +113,15 @@ struct xfs_extent_free_item
> /* Only convert delalloc space, don't allocate entirely new extents */
> #define XFS_BMAPI_DELALLOC 0x400
>
> +/*
> + * Permit extent manipulations even if S_IOMAP_IMMUTABLE is set on the
> + * inode. This is only expected to be used in the swapfile activation
> + * case where we want to mark all swap space as unwritten so that reads
> + * return zero and writes fail with ETXTBSY. Storage access in this
> + * state can only occur via swap operations.
> + */
> +#define XFS_BMAPI_FORCE 0x800
Urk. No. Immutable means immutable.
And, as a matter of policy, we should not be changing the on disk
layout of the swapfile that is provided inside the kernel. If the
swap file is already allocated as unwritten, great. If not, we
should not force it to be unwritten to be because then if the user
downgrades their kernel the swapfile suddenly can not be used by the
older kernel.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: darrick.wong@oracle.com, linux-nvdimm@lists.01.org,
linux-api@vger.kernel.org,
Trond Myklebust <trond.myklebust@primarydata.com>,
linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-mm@kvack.org, luto@kernel.org,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Anna Schumaker <anna.schumaker@netapp.com>
Subject: Re: [PATCH v3 6/6] mm, xfs: protect swapfile contents with immutable + unwritten extents
Date: Sat, 12 Aug 2017 09:33:24 +1000 [thread overview]
Message-ID: <20170811233323.GU21024@dastard> (raw)
In-Reply-To: <150243358949.8777.17308615269167142735.stgit@dwillia2-desk3.amr.corp.intel.com>
On Thu, Aug 10, 2017 at 11:39:49PM -0700, Dan Williams wrote:
> ifp = XFS_IFORK_PTR(ip, whichfork);
> diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
> index 851982a5dfbc..a0f099289520 100644
> --- a/fs/xfs/libxfs/xfs_bmap.h
> +++ b/fs/xfs/libxfs/xfs_bmap.h
> @@ -113,6 +113,15 @@ struct xfs_extent_free_item
> /* Only convert delalloc space, don't allocate entirely new extents */
> #define XFS_BMAPI_DELALLOC 0x400
>
> +/*
> + * Permit extent manipulations even if S_IOMAP_IMMUTABLE is set on the
> + * inode. This is only expected to be used in the swapfile activation
> + * case where we want to mark all swap space as unwritten so that reads
> + * return zero and writes fail with ETXTBSY. Storage access in this
> + * state can only occur via swap operations.
> + */
> +#define XFS_BMAPI_FORCE 0x800
Urk. No. Immutable means immutable.
And, as a matter of policy, we should not be changing the on disk
layout of the swapfile that is provided inside the kernel. If the
swap file is already allocated as unwritten, great. If not, we
should not force it to be unwritten to be because then if the user
downgrades their kernel the swapfile suddenly can not be used by the
older kernel.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: darrick.wong@oracle.com, linux-nvdimm@lists.01.org,
linux-api@vger.kernel.org,
Trond Myklebust <trond.myklebust@primarydata.com>,
linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-mm@kvack.org, luto@kernel.org,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Anna Schumaker <anna.schumaker@netapp.com>
Subject: Re: [PATCH v3 6/6] mm, xfs: protect swapfile contents with immutable + unwritten extents
Date: Sat, 12 Aug 2017 09:33:24 +1000 [thread overview]
Message-ID: <20170811233323.GU21024@dastard> (raw)
In-Reply-To: <150243358949.8777.17308615269167142735.stgit@dwillia2-desk3.amr.corp.intel.com>
On Thu, Aug 10, 2017 at 11:39:49PM -0700, Dan Williams wrote:
> ifp = XFS_IFORK_PTR(ip, whichfork);
> diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
> index 851982a5dfbc..a0f099289520 100644
> --- a/fs/xfs/libxfs/xfs_bmap.h
> +++ b/fs/xfs/libxfs/xfs_bmap.h
> @@ -113,6 +113,15 @@ struct xfs_extent_free_item
> /* Only convert delalloc space, don't allocate entirely new extents */
> #define XFS_BMAPI_DELALLOC 0x400
>
> +/*
> + * Permit extent manipulations even if S_IOMAP_IMMUTABLE is set on the
> + * inode. This is only expected to be used in the swapfile activation
> + * case where we want to mark all swap space as unwritten so that reads
> + * return zero and writes fail with ETXTBSY. Storage access in this
> + * state can only occur via swap operations.
> + */
> +#define XFS_BMAPI_FORCE 0x800
Urk. No. Immutable means immutable.
And, as a matter of policy, we should not be changing the on disk
layout of the swapfile that is provided inside the kernel. If the
swap file is already allocated as unwritten, great. If not, we
should not force it to be unwritten to be because then if the user
downgrades their kernel the swapfile suddenly can not be used by the
older kernel.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
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WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>
To: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Trond Myklebust
<trond.myklebust-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Anna Schumaker
<anna.schumaker-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org>,
linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org
Subject: Re: [PATCH v3 6/6] mm, xfs: protect swapfile contents with immutable + unwritten extents
Date: Sat, 12 Aug 2017 09:33:24 +1000 [thread overview]
Message-ID: <20170811233323.GU21024@dastard> (raw)
In-Reply-To: <150243358949.8777.17308615269167142735.stgit-p8uTFz9XbKj2zm6wflaqv1nYeNYlB/vhral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
On Thu, Aug 10, 2017 at 11:39:49PM -0700, Dan Williams wrote:
> ifp = XFS_IFORK_PTR(ip, whichfork);
> diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
> index 851982a5dfbc..a0f099289520 100644
> --- a/fs/xfs/libxfs/xfs_bmap.h
> +++ b/fs/xfs/libxfs/xfs_bmap.h
> @@ -113,6 +113,15 @@ struct xfs_extent_free_item
> /* Only convert delalloc space, don't allocate entirely new extents */
> #define XFS_BMAPI_DELALLOC 0x400
>
> +/*
> + * Permit extent manipulations even if S_IOMAP_IMMUTABLE is set on the
> + * inode. This is only expected to be used in the swapfile activation
> + * case where we want to mark all swap space as unwritten so that reads
> + * return zero and writes fail with ETXTBSY. Storage access in this
> + * state can only occur via swap operations.
> + */
> +#define XFS_BMAPI_FORCE 0x800
Urk. No. Immutable means immutable.
And, as a matter of policy, we should not be changing the on disk
layout of the swapfile that is provided inside the kernel. If the
swap file is already allocated as unwritten, great. If not, we
should not force it to be unwritten to be because then if the user
downgrades their kernel the swapfile suddenly can not be used by the
older kernel.
Cheers,
Dave.
--
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org
next prev parent reply other threads:[~2017-08-11 23:31 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-11 6:39 [PATCH v3 0/6] fs, xfs: block map immutable files Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` [PATCH v3 1/6] fs, xfs: introduce S_IOMAP_IMMUTABLE Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` [PATCH v3 2/6] fs, xfs: introduce FALLOC_FL_SEAL_BLOCK_MAP Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 23:27 ` Dave Chinner
2017-08-11 23:27 ` Dave Chinner
2017-08-11 23:27 ` Dave Chinner
2017-08-11 23:42 ` Dan Williams
2017-08-11 23:42 ` Dan Williams
2017-08-11 23:42 ` Dan Williams
2017-08-12 0:30 ` Dave Chinner
2017-08-12 0:30 ` Dave Chinner
2017-08-12 0:30 ` Dave Chinner
2017-08-12 2:31 ` Darrick J. Wong
2017-08-12 2:31 ` Darrick J. Wong
2017-08-12 2:31 ` Darrick J. Wong
2017-08-12 4:06 ` Dave Chinner
2017-08-12 4:06 ` Dave Chinner
2017-08-11 6:39 ` [PATCH v3 3/6] fs, xfs: introduce FALLOC_FL_UNSEAL_BLOCK_MAP Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` [PATCH v3 4/6] xfs: introduce XFS_DIFLAG2_IOMAP_IMMUTABLE Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` [PATCH v3 5/6] xfs: toggle XFS_DIFLAG2_IOMAP_IMMUTABLE in response to fallocate Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` [PATCH v3 6/6] mm, xfs: protect swapfile contents with immutable + unwritten extents Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 6:39 ` Dan Williams
2017-08-11 23:33 ` Dave Chinner [this message]
2017-08-11 23:33 ` Dave Chinner
2017-08-11 23:33 ` Dave Chinner
2017-08-11 23:33 ` Dave Chinner
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