Re: [PATCH 0/2] pnfs/flexfiles: make DS connect application interrupt resistent

["Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>]

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Dear NFS fellows,

I will appreciate comments on this series, including the separate krb5i handshake patch.

Thanks in advance,
   Tigran.

----- Original Message -----
> From: "Tigran Mkrtchyan" <tigran.mkrtchyan@desy.de>
> To: "trondmy" <trondmy@kernel.org>, "anna" <anna@kernel.org>
> Cc: "linux-nfs" <linux-nfs@vger.kernel.org>, "Mike Snitzer" <snitzer@kernel.org>, "Tigran Mkrtchyan"
> <tigran.mkrtchyan@desy.de>
> Sent: Sunday, 11 October, 2026 00:18:37
> Subject: [PATCH 0/2] pnfs/flexfiles: make DS connect application interrupt resistent

> In our testing we hit a situation where the pNFS flexfiles client
> goes into an infinite loop. The application spawns one reader process
> per CPU core to read multiple files in parallel, and kills the readers
> once a fixed time budget expires. The killed processes never exit.
> 
> We have identified three issues:
> 
> - Concurrent connections to data servers are serialized in
>  nfs4_discover_server_trunking() (not addressed yet).
> 
> - Regardless of the configured security flavor, the client always
>  tries krb5i first, addressed in a separate patch:
>  https://lore.kernel.org/linux-nfs/20261009155802.540179-1-tigran.mkrtchyan@desy.de/T/#u
> 
> - ff_layout_pg_init_read() and ff_layout_pg_init_write() retry in a
>  loop with ssleep() when no data server is available. Since ssleep()
>  is uninterruptible and the loop does not check for fatal signals,
>  a task with SIGKILL pending never leaves the loop.
> 
> These two patches address the last issue.
> 
> The patches tested on 7.3-rc3 and RHEL 5.14.0-757 kernels (with
> backport).
> 
> Tigranve  Mkrtchyan (2):
>  pNFS/flexfiles: make pg_init retry loops killable
>  pNFS/flexfiles: don't report an interrupted DS connect as a DS error
> 
> fs/nfs/flexfilelayout/flexfilelayout.c    | 23 ++++++++++++++++++++---
> fs/nfs/flexfilelayout/flexfilelayoutdev.c |  5 +++++
> 2 files changed, 25 insertions(+), 3 deletions(-)
> 
> --
> 2.56.0

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