From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99E383C73F9; Thu, 19 Mar 2026 11:13:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773918817; cv=none; b=ujPswF/HojjuzWQS7WW/rBnf25DWAxbAzntAMpyQ5yUnVfwV9zMV1cC9y7NxAHQtheIjZvAm0MKiHFPFzVWl1a2pFKDFDBEy4HvfA+HJJtddrnFH3acH99+iTj8Krim1pExIiQ05zBsacIEk0IwZ7p1iDeYeg4IYsDwn7kH4SSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773918817; c=relaxed/simple; bh=6beKDERkuTDR2mjmfUbAvd+YsuHGYv8cQ3gCS0jJuWQ=; h=Subject:To:Cc:From:Date:In-Reply-To:Message-ID:MIME-Version: Content-Type; b=oCBuXxGqFLPDPDrKfRc4MVifN0EDSVbiGM/YfzlZsGU6chM4vWZ6n3D0pr/QUAOmcHNzjnBbTO/T+8VfN9A5qjHo+2iMRH+qq+Df2pQnM7NgtQWh+ef7DscyBOkDj1iilbhau/Xpq3i7jVxgV6TQvW0e0c/TNFsyf8ZpOu1YF9M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zRWHzgf7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zRWHzgf7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94169C19424; Thu, 19 Mar 2026 11:13:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773918817; bh=6beKDERkuTDR2mjmfUbAvd+YsuHGYv8cQ3gCS0jJuWQ=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=zRWHzgf75n6GiFCdgVQie8ogfZPRiRopmr2AChlOwFAEUb3QY7jioPRIDLjlaVsgq RR6HfWH2mIHI8kCp6hYxmdYYGh4uMcugLeF7as54z3SPLFHRux/4H9931Fz6Fe7UGO s5Ci7p8NUlkGalEei6yrhmnAEkrL8l9A2efhrvo0= Subject: Patch "NFS: Fix a deadlock involving nfs_release_folio()" has been added to the 6.6-stable tree To: 1468888505@139.com,anna@kernel.org,gregkh@linuxfoundation.org,patches@lists.linux.dev,trond.myklebust@hammerspace.com,wangzhaolong@huaweicloud.com Cc: From: Date: Thu, 19 Mar 2026 12:12:52 +0100 In-Reply-To: <20260224070237.2933965-1-1468888505@139.com> Message-ID: <2026031952-erupt-scoff-c087@gregkh> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore This is a note to let you know that I've just added the patch titled NFS: Fix a deadlock involving nfs_release_folio() to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfs-fix-a-deadlock-involving-nfs_release_folio.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From stable+bounces-217867-greg=kroah.com@vger.kernel.org Tue Feb 24 08:02:54 2026 From: Li hongliang <1468888505@139.com> Date: Tue, 24 Feb 2026 15:02:37 +0800 Subject: NFS: Fix a deadlock involving nfs_release_folio() To: gregkh@linuxfoundation.org, stable@vger.kernel.org, trond.myklebust@hammerspace.com Cc: patches@lists.linux.dev, linux-kernel@vger.kernel.org, anna@kernel.org, linux-nfs@vger.kernel.org, wangzhaolong@huaweicloud.com Message-ID: <20260224070237.2933965-1-1468888505@139.com> From: Trond Myklebust [ Upstream commit cce0be6eb4971456b703aaeafd571650d314bcca ] Wang Zhaolong reports a deadlock involving NFSv4.1 state recovery waiting on kthreadd, which is attempting to reclaim memory by calling nfs_release_folio(). The latter cannot make progress due to state recovery being needed. It seems that the only safe thing to do here is to kick off a writeback of the folio, without waiting for completion, or else kicking off an asynchronous commit. Reported-by: Wang Zhaolong Fixes: 96780ca55e3c ("NFS: fix up nfs_release_folio() to try to release the page") Signed-off-by: Trond Myklebust [ Minor conflict resolved. ] Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Greg Kroah-Hartman --- fs/nfs/file.c | 3 ++- fs/nfs/nfstrace.h | 3 +++ fs/nfs/write.c | 33 +++++++++++++++++++++++++++++++++ include/linux/nfs_fs.h | 1 + 4 files changed, 39 insertions(+), 1 deletion(-) --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -459,7 +459,8 @@ static bool nfs_release_folio(struct fol if ((current_gfp_context(gfp) & GFP_KERNEL) != GFP_KERNEL || current_is_kswapd() || current_is_kcompactd()) return false; - if (nfs_wb_folio(folio_file_mapping(folio)->host, folio) < 0) + if (nfs_wb_folio_reclaim(folio_file_mapping(folio)->host, folio) < 0 || + folio_test_private(folio)) return false; } return nfs_fscache_release_folio(folio, gfp); --- a/fs/nfs/nfstrace.h +++ b/fs/nfs/nfstrace.h @@ -1033,6 +1033,9 @@ DECLARE_EVENT_CLASS(nfs_folio_event_done DEFINE_NFS_FOLIO_EVENT(nfs_aop_readpage); DEFINE_NFS_FOLIO_EVENT_DONE(nfs_aop_readpage_done); +DEFINE_NFS_FOLIO_EVENT(nfs_writeback_folio_reclaim); +DEFINE_NFS_FOLIO_EVENT_DONE(nfs_writeback_folio_reclaim_done); + DEFINE_NFS_FOLIO_EVENT(nfs_writeback_folio); DEFINE_NFS_FOLIO_EVENT_DONE(nfs_writeback_folio_done); --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -2122,6 +2122,39 @@ int nfs_wb_folio_cancel(struct inode *in } /** + * nfs_wb_folio_reclaim - Write back all requests on one page + * @inode: pointer to page + * @folio: pointer to folio + * + * Assumes that the folio has been locked by the caller + */ +int nfs_wb_folio_reclaim(struct inode *inode, struct folio *folio) +{ + loff_t range_start = folio_pos(folio); + size_t len = folio_size(folio); + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .nr_to_write = 0, + .range_start = range_start, + .range_end = range_start + len - 1, + .for_sync = 1, + }; + int ret; + + if (folio_test_writeback(folio)) + return -EBUSY; + if (folio_clear_dirty_for_io(folio)) { + trace_nfs_writeback_folio_reclaim(inode, range_start, len); + ret = nfs_writepage_locked(folio, &wbc); + trace_nfs_writeback_folio_reclaim_done(inode, range_start, len, + ret); + return ret; + } + nfs_commit_inode(inode, 0); + return 0; +} + +/** * nfs_wb_folio - Write back all requests on one page * @inode: pointer to page * @folio: pointer to folio --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -608,6 +608,7 @@ extern int nfs_update_folio(struct file extern int nfs_sync_inode(struct inode *inode); extern int nfs_wb_all(struct inode *inode); extern int nfs_wb_folio(struct inode *inode, struct folio *folio); +extern int nfs_wb_folio_reclaim(struct inode *inode, struct folio *folio); int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio); extern int nfs_commit_inode(struct inode *, int); extern struct nfs_commit_data *nfs_commitdata_alloc(void); Patches currently in stable-queue which might be from 1468888505@139.com are queue-6.6/pnfs-fix-a-deadlock-when-returning-a-delegation-during-open.patch queue-6.6/nfs-pass-explicit-offset-count-to-trace-events.patch queue-6.6/nfs-fix-a-deadlock-involving-nfs_release_folio.patch