From patchwork Tue Nov 3 13:17:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 11877455 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C7BED6A2 for ; Tue, 3 Nov 2020 13:18:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D3212224E for ; Tue, 3 Nov 2020 13:18:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="U4Sq0WIh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728245AbgKCNS1 (ORCPT ); Tue, 3 Nov 2020 08:18:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729183AbgKCNS0 (ORCPT ); Tue, 3 Nov 2020 08:18:26 -0500 Received: from mail-oi1-x241.google.com (mail-oi1-x241.google.com [IPv6:2607:f8b0:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA251C0613D1; Tue, 3 Nov 2020 05:18:26 -0800 (PST) Received: by mail-oi1-x241.google.com with SMTP id t16so957206oie.11; Tue, 03 Nov 2020 05:18:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=wcewLsncu9ZYLAdf8Dj+b3i3xIrhlEzCNXPbs1EqjSc=; b=U4Sq0WIhR9xhMN9zPWhvg/zls9REX7I5XS/eUk2Dmrg1PTGMlH1hqkaQhkJsZW4aFs HrzLLXJxQx4kGNkUK94cTwvSumfEUW+OSbdZYyoZx3Qqee+1b7NjQowPXNXKtQlMcqqs iIwgdq+MNQBS+u0Kn4Wn/U+aAR5ZdkGh1ICGYhD3fNGn8gb9XE2GKYGBV8WcpbRtaw/c htJYPkbAEBUYmJK0SGX2FdKMPK33YSZtRS1HdZ836qNuvDSdrIw2S1FOvdcd053EIuuK 6A+2buP86nqP0qO5t2ucS15ZhxZM9yku26PMyApS3/c48JLNnV9oo4FYG8a1AhbrcZwm UGtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=wcewLsncu9ZYLAdf8Dj+b3i3xIrhlEzCNXPbs1EqjSc=; b=KjEgh4d7UfB0ycaOsIZSjUv6W2Ru0Io8N2GdvjzpYhKvqh6zDmpRuHp0+5+nGaplLo /Fyf2+S1vaSW1NvFRYS9410Qp6iz7j4X6nkEa+PkKxFEZY1kn0X4fc1e4yYl34Vv7VnU BbquqQQysV3hpAXAYU/KeGzU2v4HWh7sYDcqTbQICh9Th8CfIJjFzKeMto4Sntf8tK+R tKZrKGpVsyu9zP/ALPbD8juxDsYbEtJ3YJncKULsX8WCcXtz4S+ypJYGMwwlKgdN2wM6 3rjz1n85ATmhhoFm8y3Cpf51lDvGV7aFbjIiwsCQYLWKPOr+I6gcyd6efCpVqpdKQFH0 A1kg== X-Gm-Message-State: AOAM530hPtbKdfgva52q7NGs2UX3MH+hwfT6l+3kW3UXgygmjYKqh3Ba WiLJQFSn8LvGEs4YFQUEe4g= X-Google-Smtp-Source: ABdhPJxxY1oARG/kzprtfN6LQpvSv/dkZkBdU/f6ENapc5lPESBoit+o9PJKuZzR/35lv0PKgZQ8Aw== X-Received: by 2002:aca:1e08:: with SMTP id m8mr1763659oic.168.1604409506161; Tue, 03 Nov 2020 05:18:26 -0800 (PST) Received: from localhost.localdomain ([50.236.19.102]) by smtp.gmail.com with ESMTPSA id f18sm4396138otf.55.2020.11.03.05.18.22 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Nov 2020 05:18:25 -0800 (PST) From: Yafang Shao To: akpm@linux-foundation.org Cc: david@fromorbit.com, hch@infradead.org, darrick.wong@oracle.com, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, Yafang Shao Subject: [PATCH v8 resend 1/2] mm: Add become_kswapd and restore_kswapd Date: Tue, 3 Nov 2020 21:17:53 +0800 Message-Id: <20201103131754.94949-2-laoar.shao@gmail.com> X-Mailer: git-send-email 2.17.2 (Apple Git-113) In-Reply-To: <20201103131754.94949-1-laoar.shao@gmail.com> References: <20201103131754.94949-1-laoar.shao@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: "Matthew Wilcox (Oracle)" Since XFS needs to pretend to be kswapd in some of its worker threads, create methods to save & restore kswapd state. Don't bother restoring kswapd state in kswapd -- the only time we reach this code is when we're exiting and the task_struct is about to be destroyed anyway. Cc: Dave Chinner Acked-by: Michal Hocko Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Yafang Shao --- fs/xfs/libxfs/xfs_btree.c | 14 ++++++++------ include/linux/sched/mm.h | 23 +++++++++++++++++++++++ mm/vmscan.c | 16 +--------------- 3 files changed, 32 insertions(+), 21 deletions(-) diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index 2d25bab..a04a442 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -2813,8 +2813,9 @@ struct xfs_btree_split_args { { struct xfs_btree_split_args *args = container_of(work, struct xfs_btree_split_args, work); + bool is_kswapd = args->kswapd; unsigned long pflags; - unsigned long new_pflags = PF_MEMALLOC_NOFS; + int memalloc_nofs; /* * we are in a transaction context here, but may also be doing work @@ -2822,16 +2823,17 @@ struct xfs_btree_split_args { * temporarily to ensure that we don't block waiting for memory reclaim * in any way. */ - if (args->kswapd) - new_pflags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD; - - current_set_flags_nested(&pflags, new_pflags); + if (is_kswapd) + pflags = become_kswapd(); + memalloc_nofs = memalloc_nofs_save(); args->result = __xfs_btree_split(args->cur, args->level, args->ptrp, args->key, args->curp, args->stat); complete(args->done); - current_restore_flags_nested(&pflags, new_pflags); + memalloc_nofs_restore(memalloc_nofs); + if (is_kswapd) + restore_kswapd(pflags); } /* diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index d5ece7a..2faf03e 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -278,6 +278,29 @@ static inline void memalloc_nocma_restore(unsigned int flags) } #endif +/* + * Tell the memory management code that this thread is working on behalf + * of background memory reclaim (like kswapd). That means that it will + * get access to memory reserves should it need to allocate memory in + * order to make forward progress. With this great power comes great + * responsibility to not exhaust those reserves. + */ +#define KSWAPD_PF_FLAGS (PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD) + +static inline unsigned long become_kswapd(void) +{ + unsigned long flags = current->flags & KSWAPD_PF_FLAGS; + + current->flags |= KSWAPD_PF_FLAGS; + + return flags; +} + +static inline void restore_kswapd(unsigned long flags) +{ + current->flags &= ~(flags ^ KSWAPD_PF_FLAGS); +} + #ifdef CONFIG_MEMCG DECLARE_PER_CPU(struct mem_cgroup *, int_active_memcg); /** diff --git a/mm/vmscan.c b/mm/vmscan.c index 1b8f0e0..77bc1dd 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3869,19 +3869,7 @@ static int kswapd(void *p) if (!cpumask_empty(cpumask)) set_cpus_allowed_ptr(tsk, cpumask); - /* - * Tell the memory management that we're a "memory allocator", - * and that if we need more memory we should get access to it - * regardless (see "__alloc_pages()"). "kswapd" should - * never get caught in the normal page freeing logic. - * - * (Kswapd normally doesn't need memory anyway, but sometimes - * you need a small amount of memory in order to be able to - * page out something else, and this flag essentially protects - * us from recursively trying to free more memory as we're - * trying to free the first piece of memory in the first place). - */ - tsk->flags |= PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD; + become_kswapd(); set_freezable(); WRITE_ONCE(pgdat->kswapd_order, 0); @@ -3931,8 +3919,6 @@ static int kswapd(void *p) goto kswapd_try_sleep; } - tsk->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE | PF_KSWAPD); - return 0; } From patchwork Tue Nov 3 13:17:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 11877461 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 15B966A2 for ; Tue, 3 Nov 2020 13:18:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFB9C22243 for ; Tue, 3 Nov 2020 13:18:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nLL1uzXC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729183AbgKCNSd (ORCPT ); Tue, 3 Nov 2020 08:18:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729161AbgKCNSd (ORCPT ); Tue, 3 Nov 2020 08:18:33 -0500 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F31A7C0613D1; Tue, 3 Nov 2020 05:18:32 -0800 (PST) Received: by mail-ot1-x341.google.com with SMTP id h62so15865726oth.9; Tue, 03 Nov 2020 05:18:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Qv1wGdsij+9w5z85zBACLm0WGUMqCz1dz7LNa3UTDtk=; b=nLL1uzXCYA1FaoNOMbGrHfODfoC31v1Tm0VUBWwPlAjqM5N7X4FEuuaqNMkVlzqdV6 +ICaG0vi2MvwTlbA2/ErhlMIAuD3CDu0IELcctFzBMhETIiKqwTVyVNDQqHgPsn2cDi+ 7/w+v42iu1bGbtA+1vHMETVIiPA0vJMqxtd5R8QdOBxpBKfnhIrFBj4X/PmMyGoxBMou rbzy/2m+ag5FWc4IV2LbPnYeneq2dBZzXvUgzFkA7Q78PhPoP49zXPJ29/co+ASfwt99 TESDvAhHJWWxe7GlUU9J/Qegb23xy4RUltF/4ow00JzI9495kDNre72fqsdbVKF6Iqqr C7Mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Qv1wGdsij+9w5z85zBACLm0WGUMqCz1dz7LNa3UTDtk=; b=WDEGQlAsgbiv7JGDbZojnPwrr4a1a95x44ol3Sjtyp46BQlQDa6fsDdWu3YJxasN+D fu/rI9qmATNFaRB3hpNEazFJeIskNZvpTvCObMdrEfy05DUlt2euo8wwrzA7ilPkfNcW /YjIL5dCaJHF2li/im1G9txN2xvYfgJgDH7nlnOqPfrU9gSogxPR3FhP5Zysl4AAiL4q V/KF1OUdwwGfGkEEh/k+dcW9k9s+8If1nW4g6NDnNXWFGr53CcRTIwOYDC4wx6TJG6G9 4VHwTEu2LJYsXOnLqJsRxl+4PV87oaHjvok1f5WyuxuZjUybsOOipQAmBoJ0GSV1pjCX b2VQ== X-Gm-Message-State: AOAM530PJQaPn11f6I8wqFm8xsUgPjocsZJO9isRsGuA4nrDJ+l/IvIa zNXsQ8P/wI1BWX3yZDwuBO8= X-Google-Smtp-Source: ABdhPJyXf4V3twjJit4yagiweFA1fx+ddVWP5CNLhVwvuGxduXs0ohrKBigLkgLPtmMkz8WCmOBXuw== X-Received: by 2002:a9d:7419:: with SMTP id n25mr15724612otk.183.1604409512309; Tue, 03 Nov 2020 05:18:32 -0800 (PST) Received: from localhost.localdomain ([50.236.19.102]) by smtp.gmail.com with ESMTPSA id f18sm4396138otf.55.2020.11.03.05.18.26 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Nov 2020 05:18:31 -0800 (PST) From: Yafang Shao To: akpm@linux-foundation.org Cc: david@fromorbit.com, hch@infradead.org, darrick.wong@oracle.com, willy@infradead.org, mhocko@kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, Yafang Shao Subject: [PATCH v8 resend 2/2] xfs: avoid transaction reservation recursion Date: Tue, 3 Nov 2020 21:17:54 +0800 Message-Id: <20201103131754.94949-3-laoar.shao@gmail.com> X-Mailer: git-send-email 2.17.2 (Apple Git-113) In-Reply-To: <20201103131754.94949-1-laoar.shao@gmail.com> References: <20201103131754.94949-1-laoar.shao@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org PF_FSTRANS which is used to avoid transaction reservation recursion, is dropped since commit 9070733b4efa ("xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS") and commit 7dea19f9ee63 ("mm: introduce memalloc_nofs_{save,restore} API") and replaced by PF_MEMALLOC_NOFS which means to avoid filesystem reclaim recursion. That change is subtle. Let's take the exmple of the check of WARN_ON_ONCE(current->flags & PF_MEMALLOC_NOFS)) to explain why this abstraction from PF_FSTRANS to PF_MEMALLOC_NOFS is not proper. Below comment is quoted from Dave, > It wasn't for memory allocation recursion protection in XFS - it was for > transaction reservation recursion protection by something trying to flush > data pages while holding a transaction reservation. Doing > this could deadlock the journal because the existing reservation > could prevent the nested reservation for being able to reserve space > in the journal and that is a self-deadlock vector. > IOWs, this check is not protecting against memory reclaim recursion > bugs at all (that's the previous check [1]). This check is > protecting against the filesystem calling writepages directly from a > context where it can self-deadlock. > So what we are seeing here is that the PF_FSTRANS -> > PF_MEMALLOC_NOFS abstraction lost all the actual useful information > about what type of error this check was protecting against. As a result, we should reintroduce PF_FSTRANS. As current->journal_info isn't used in XFS, we can reuse it to indicate whehter the task is in fstrans or not, Per Willy. To achieve that, four new helpers are introduce in this patch, per Dave: - xfs_trans_context_set() Used in xfs_trans_alloc() - xfs_trans_context_clear() Used in xfs_trans_commit() and xfs_trans_cancel() - xfs_trans_context_update() Used in xfs_trans_roll() - xfs_trans_context_active() To check whehter current is in fs transcation or not [1]. Below check is to avoid memory reclaim recursion. if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == PF_MEMALLOC)) goto redirty; Signed-off-by: Yafang Shao Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Cc: Dave Chinner Cc: Michal Hocko --- fs/iomap/buffered-io.c | 7 ------- fs/xfs/xfs_aops.c | 23 +++++++++++++++++++++-- fs/xfs/xfs_linux.h | 4 ---- fs/xfs/xfs_trans.c | 19 +++++++++---------- fs/xfs/xfs_trans.h | 30 ++++++++++++++++++++++++++++++ 5 files changed, 60 insertions(+), 23 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 8180061..2f090b6 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1469,13 +1469,6 @@ static void iomap_writepage_end_bio(struct bio *bio) goto redirty; /* - * Given that we do not allow direct reclaim to call us, we should - * never be called in a recursive filesystem reclaim context. - */ - if (WARN_ON_ONCE(current->flags & PF_MEMALLOC_NOFS)) - goto redirty; - - /* * Is this page beyond the end of the file? * * The page index is less than the end_index, adjust the end_offset diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 55d126d..b25196a 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -62,7 +62,8 @@ static inline bool xfs_ioend_is_append(struct iomap_ioend *ioend) * We hand off the transaction to the completion thread now, so * clear the flag here. */ - current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); + xfs_trans_context_clear(tp); + return 0; } @@ -125,7 +126,7 @@ static inline bool xfs_ioend_is_append(struct iomap_ioend *ioend) * thus we need to mark ourselves as being in a transaction manually. * Similarly for freeze protection. */ - current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); + xfs_trans_context_set(tp); __sb_writers_acquired(VFS_I(ip)->i_sb, SB_FREEZE_FS); /* we abort the update if there was an IO error */ @@ -564,6 +565,16 @@ static inline bool xfs_ioend_needs_workqueue(struct iomap_ioend *ioend) { struct xfs_writepage_ctx wpc = { }; + /* + * Given that we do not allow direct reclaim to call us, we should + * never be called while in a filesystem transaction. + */ + if (xfs_trans_context_active()) { + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return 0; + } + return iomap_writepage(page, wbc, &wpc.ctx, &xfs_writeback_ops); } @@ -575,6 +586,14 @@ static inline bool xfs_ioend_needs_workqueue(struct iomap_ioend *ioend) struct xfs_writepage_ctx wpc = { }; xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED); + + /* + * Given that we do not allow direct reclaim to call us, we should + * never be called while in a filesystem transaction. + */ + if (xfs_trans_context_active()) + return 0; + return iomap_writepages(mapping, wbc, &wpc.ctx, &xfs_writeback_ops); } diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h index 5b7a1e2..6ab0f80 100644 --- a/fs/xfs/xfs_linux.h +++ b/fs/xfs/xfs_linux.h @@ -102,10 +102,6 @@ #define xfs_cowb_secs xfs_params.cowb_timer.val #define current_cpu() (raw_smp_processor_id()) -#define current_set_flags_nested(sp, f) \ - (*(sp) = current->flags, current->flags |= (f)) -#define current_restore_flags_nested(sp, f) \ - (current->flags = ((current->flags & ~(f)) | (*(sp) & (f)))) #define NBBY 8 /* number of bits per byte */ diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index c94e71f..b272d07 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -153,8 +153,6 @@ int error = 0; bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0; - /* Mark this thread as being in a transaction */ - current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); /* * Attempt to reserve the needed disk blocks by decrementing @@ -163,10 +161,8 @@ */ if (blocks > 0) { error = xfs_mod_fdblocks(mp, -((int64_t)blocks), rsvd); - if (error != 0) { - current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); + if (error != 0) return -ENOSPC; - } tp->t_blk_res += blocks; } @@ -241,8 +237,6 @@ tp->t_blk_res = 0; } - current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); - return error; } @@ -284,6 +278,8 @@ INIT_LIST_HEAD(&tp->t_dfops); tp->t_firstblock = NULLFSBLOCK; + /* Mark this thread as being in a transaction */ + xfs_trans_context_set(tp); error = xfs_trans_reserve(tp, resp, blocks, rtextents); if (error) { xfs_trans_cancel(tp); @@ -878,7 +874,8 @@ xfs_log_commit_cil(mp, tp, &commit_lsn, regrant); - current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); + if (!regrant) + xfs_trans_context_clear(tp); xfs_trans_free(tp); /* @@ -910,7 +907,8 @@ xfs_log_ticket_ungrant(mp->m_log, tp->t_ticket); tp->t_ticket = NULL; } - current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); + + xfs_trans_context_clear(tp); xfs_trans_free_items(tp, !!error); xfs_trans_free(tp); @@ -971,7 +969,7 @@ } /* mark this thread as no longer being in a transaction */ - current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); + xfs_trans_context_clear(tp); xfs_trans_free_items(tp, dirty); xfs_trans_free(tp); @@ -1013,6 +1011,7 @@ if (error) return error; + xfs_trans_context_update(trans, *tpp); /* * Reserve space in the log for the next transaction. * This also pushes items in the "AIL", the list of logged items, diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h index 0846589..c4877afc 100644 --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -268,4 +268,34 @@ void xfs_trans_buf_copy_type(struct xfs_buf *dst_bp, return lip->li_ops->iop_relog(lip, tp); } +static inline void +xfs_trans_context_set(struct xfs_trans *tp) +{ + ASSERT(!current->journal_info); + current->journal_info = tp; + tp->t_pflags = memalloc_nofs_save(); +} + +static inline void +xfs_trans_context_update(struct xfs_trans *old, struct xfs_trans *new) +{ + ASSERT(current->journal_info == old); + current->journal_info = new; +} + +static inline void +xfs_trans_context_clear(struct xfs_trans *tp) +{ + ASSERT(current->journal_info == tp); + current->journal_info = NULL; + memalloc_nofs_restore(tp->t_pflags); +} + +static inline bool +xfs_trans_context_active(void) +{ + /* Use journal_info to indicate current is in a transaction */ + return current->journal_info != NULL; +} + #endif /* __XFS_TRANS_H__ */