linux-kernel - Re: [PATCH] nfs: pnfs: use GFP

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Message-ID: <fd936b8622a9838070c58bc66e353f90e69347b1.camel@hammerspace.com>
Date:   Mon, 29 Jun 2020 12:04:55 +0000
From:   Trond Myklebust <trondmy@...merspace.com>
To:     "vulab@...as.ac.cn" <vulab@...as.ac.cn>,
        "linux-nfs@...r.kernel.org" <linux-nfs@...r.kernel.org>,
        "anna.schumaker@...app.com" <anna.schumaker@...app.com>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] nfs: pnfs: use GFP_ATOMIC under spin lock

On Mon, 2020-06-29 at 14:21 +0800, Xu Wang wrote:
> A spin lock is taken here so we should use GFP_ATOMIC.
> 
> Signed-off-by: Xu Wang <vulab@...as.ac.cn>
> ---
>  fs/nfs/pnfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index dd2e14f5875d..d84c1b7b71d2 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -2170,7 +2170,7 @@ _pnfs_grab_empty_layout(struct inode *ino,
> struct nfs_open_context *ctx)
>  	struct pnfs_layout_hdr *lo;
>  
>  	spin_lock(&ino->i_lock);
> -	lo = pnfs_find_alloc_layout(ino, ctx, GFP_KERNEL);
> +	lo = pnfs_find_alloc_layout(ino, ctx, GFP_ATOMIC);
>  	if (!lo)
>  		goto out_unlock;
>  	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))

NACK. Please read the code before sending yet another one of these
pointless patches.

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@...merspace.com