From patchwork Fri Oct 16 02:10:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Reichl X-Patchwork-Id: 11840479 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 7FFD761C for ; Fri, 16 Oct 2020 02:10:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C63920897 for ; Fri, 16 Oct 2020 02:10:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Yue9XRne" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393387AbgJPCKX (ORCPT ); Thu, 15 Oct 2020 22:10:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:29028 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393379AbgJPCKX (ORCPT ); Thu, 15 Oct 2020 22:10:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602814220; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HbJrU8J3wxNI/dXi+6MkhN2CIyrhigjNuq3VoDFiDTA=; b=Yue9XRnexQ2QBqOcYLGiFm/Ck+rRqOTD8yRbpbfw8HQe546ZHQ1JWWikgAbK/r5O4HzOx7 3Gqnwc59mxtpt/hDsysauwFwhpwZZzoSzZk82uXXrwhJpdgZj/+SllVX5S4HcQCcYhOEkp rWFZLLWWJLrizm5YGAkf5Ucctku44f0= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-122-SPFCNBq5M4SwC2w_jDySUw-1; Thu, 15 Oct 2020 22:10:12 -0400 X-MC-Unique: SPFCNBq5M4SwC2w_jDySUw-1 Received: by mail-wm1-f71.google.com with SMTP id u5so167930wme.3 for ; Thu, 15 Oct 2020 19:10:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=HbJrU8J3wxNI/dXi+6MkhN2CIyrhigjNuq3VoDFiDTA=; b=oEhtOlqwuv6XyuT2aWKOg8tkLOeNrPgiMiZD3hvxa2KcHMsw2iULEYuesQZ50BJdTE 3OitPMdQuIrIP146NvQRIs28SEfmsRnRwcnx8gILJ5I5ZV1rp8s7cNh8151oGfRb6fE1 DUpyLR55jeRKMwbEHefR2KU0NdDDeYJ2cmePm6HEzc/8da7MX7caTA5RPcaQ4eUCXWq0 99X8MjfLrhjr1sft1G1buIIbrgs1PrVdFMAZWH9x7nIcPQoRsmOQU8qbLMqEQTdMtVgA IsXGJ/Wy9/KokMIUjEv3MvE2XmE05+TAfZmAruZshD4jwnOCCI9KFM632LtpGRT6q/2Z Lx3A== X-Gm-Message-State: AOAM531NoABrejfwNUk19xgGhSu7h539bdg9hEuRjw4og0K4AIBFrwRo c6VfWTIiO/3Ae97E862LfgKpIvDa9Doqi/f5K/GvSPLjz/Itb99loLllKYZYS2xM5yzjV67rSTS srKkuvLZux+apJ2IStRVV X-Received: by 2002:a7b:cc09:: with SMTP id f9mr1285756wmh.93.1602814211024; Thu, 15 Oct 2020 19:10:11 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwQYVWFwh59BkuhxNaWJzKi2oX0z3WgNMdOMsPpweQcNsihLQZK+ZaouJKk75+2C+IF/JCItg== X-Received: by 2002:a7b:cc09:: with SMTP id f9mr1285741wmh.93.1602814210755; Thu, 15 Oct 2020 19:10:10 -0700 (PDT) Received: from localhost.localdomain.com ([84.19.91.81]) by smtp.gmail.com with ESMTPSA id v3sm1420685wre.17.2020.10.15.19.10.10 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Oct 2020 19:10:10 -0700 (PDT) From: Pavel Reichl To: linux-xfs@vger.kernel.org Subject: [PATCH v12 4/4] xfs: replace mrlock_t with rw_semaphores Date: Fri, 16 Oct 2020 04:10:05 +0200 Message-Id: <20201016021005.548850-5-preichl@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201016021005.548850-1-preichl@redhat.com> References: <20201016021005.548850-1-preichl@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Remove mrlock_t as it does not provide any extra value over rw_semaphores. Make i_lock and i_mmaplock native rw_semaphores and replace mr*() functions with native rwsem calls. Release the lock in xfs_btree_split() just before the work-queue executing xfs_btree_split_worker() is scheduled and make xfs_btree_split_worker() to acquire the lock as a first thing and release it just before returning from the function. This it done so the ownership of the lock is transfered between kernel threads and thus lockdep won't complain about lock being held by a different kernel thread. Signed-off-by: Pavel Reichl Reviewed-by: Christoph Hellwig Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_btree.c | 25 +++++++++++++ fs/xfs/mrlock.h | 78 --------------------------------------- fs/xfs/xfs_inode.c | 52 ++++++++++++++------------ fs/xfs/xfs_inode.h | 4 +- fs/xfs/xfs_iops.c | 4 +- fs/xfs/xfs_linux.h | 2 +- fs/xfs/xfs_super.c | 6 +-- 7 files changed, 60 insertions(+), 111 deletions(-) delete mode 100644 fs/xfs/mrlock.h diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index 2d25bab68764..5ec2098c271c 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -2816,6 +2816,12 @@ xfs_btree_split_worker( unsigned long pflags; unsigned long new_pflags = PF_MEMALLOC_NOFS; + /* + * Update lockdep's lock ownership information to point to + * this thread as the thread that scheduled this worker is waiting + * for its completion. + */ + rwsem_acquire(&args->cur->bc_ino.ip->i_lock.dep_map, 0, 0, _RET_IP_); /* * we are in a transaction context here, but may also be doing work * in kswapd context, and hence we may need to inherit that state @@ -2829,6 +2835,12 @@ xfs_btree_split_worker( args->result = __xfs_btree_split(args->cur, args->level, args->ptrp, args->key, args->curp, args->stat); + /* + * Update lockdep's lock ownership information to reflect that we will + * be transferring the ilock from this worker back to the scheduling + * thread. + */ + rwsem_release(&args->cur->bc_ino.ip->i_lock.dep_map, _THIS_IP_); complete(args->done); current_restore_flags_nested(&pflags, new_pflags); @@ -2863,8 +2875,21 @@ xfs_btree_split( args.done = &done; args.kswapd = current_is_kswapd(); INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker); + /* + * Update lockdep's ownership information to reflect transfer of the + * ilock from the current task to the worker. Otherwise assertions that + * the lock is held (such as when logging the inode) might fail due to + * incorrect task owner state. + */ + rwsem_release(&cur->bc_ino.ip->i_lock.dep_map, _THIS_IP_); queue_work(xfs_alloc_wq, &args.work); wait_for_completion(&done); + /* + * Update lockdep's lock ownership information to point to + * this thread as the lock owner now that the worker item is + * done. + */ + rwsem_acquire(&cur->bc_ino.ip->i_lock.dep_map, 0, 0, _RET_IP_); destroy_work_on_stack(&args.work); return args.result; } diff --git a/fs/xfs/mrlock.h b/fs/xfs/mrlock.h deleted file mode 100644 index 79155eec341b..000000000000 --- a/fs/xfs/mrlock.h +++ /dev/null @@ -1,78 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (c) 2000-2006 Silicon Graphics, Inc. - * All Rights Reserved. - */ -#ifndef __XFS_SUPPORT_MRLOCK_H__ -#define __XFS_SUPPORT_MRLOCK_H__ - -#include - -typedef struct { - struct rw_semaphore mr_lock; -#if defined(DEBUG) || defined(XFS_WARN) - int mr_writer; -#endif -} mrlock_t; - -#if defined(DEBUG) || defined(XFS_WARN) -#define mrinit(mrp, name) \ - do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0) -#else -#define mrinit(mrp, name) \ - do { init_rwsem(&(mrp)->mr_lock); } while (0) -#endif - -#define mrlock_init(mrp, t,n,s) mrinit(mrp, n) -#define mrfree(mrp) do { } while (0) - -static inline void mraccess_nested(mrlock_t *mrp, int subclass) -{ - down_read_nested(&mrp->mr_lock, subclass); -} - -static inline void mrupdate_nested(mrlock_t *mrp, int subclass) -{ - down_write_nested(&mrp->mr_lock, subclass); -#if defined(DEBUG) || defined(XFS_WARN) - mrp->mr_writer = 1; -#endif -} - -static inline int mrtryaccess(mrlock_t *mrp) -{ - return down_read_trylock(&mrp->mr_lock); -} - -static inline int mrtryupdate(mrlock_t *mrp) -{ - if (!down_write_trylock(&mrp->mr_lock)) - return 0; -#if defined(DEBUG) || defined(XFS_WARN) - mrp->mr_writer = 1; -#endif - return 1; -} - -static inline void mrunlock_excl(mrlock_t *mrp) -{ -#if defined(DEBUG) || defined(XFS_WARN) - mrp->mr_writer = 0; -#endif - up_write(&mrp->mr_lock); -} - -static inline void mrunlock_shared(mrlock_t *mrp) -{ - up_read(&mrp->mr_lock); -} - -static inline void mrdemote(mrlock_t *mrp) -{ -#if defined(DEBUG) || defined(XFS_WARN) - mrp->mr_writer = 0; -#endif - downgrade_write(&mrp->mr_lock); -} - -#endif /* __XFS_SUPPORT_MRLOCK_H__ */ diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 085927700530..f47202c487e0 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -191,14 +191,15 @@ xfs_ilock( } if (lock_flags & XFS_MMAPLOCK_EXCL) - mrupdate_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); + down_write_nested(&ip->i_mmaplock, + XFS_MMAPLOCK_DEP(lock_flags)); else if (lock_flags & XFS_MMAPLOCK_SHARED) - mraccess_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); + down_read_nested(&ip->i_mmaplock, XFS_MMAPLOCK_DEP(lock_flags)); if (lock_flags & XFS_ILOCK_EXCL) - mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); + down_write_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); else if (lock_flags & XFS_ILOCK_SHARED) - mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); + down_read_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags)); } /* @@ -242,27 +243,27 @@ xfs_ilock_nowait( } if (lock_flags & XFS_MMAPLOCK_EXCL) { - if (!mrtryupdate(&ip->i_mmaplock)) + if (!down_write_trylock(&ip->i_mmaplock)) goto out_undo_iolock; } else if (lock_flags & XFS_MMAPLOCK_SHARED) { - if (!mrtryaccess(&ip->i_mmaplock)) + if (!down_read_trylock(&ip->i_mmaplock)) goto out_undo_iolock; } if (lock_flags & XFS_ILOCK_EXCL) { - if (!mrtryupdate(&ip->i_lock)) + if (!down_write_trylock(&ip->i_lock)) goto out_undo_mmaplock; } else if (lock_flags & XFS_ILOCK_SHARED) { - if (!mrtryaccess(&ip->i_lock)) + if (!down_read_trylock(&ip->i_lock)) goto out_undo_mmaplock; } return 1; out_undo_mmaplock: if (lock_flags & XFS_MMAPLOCK_EXCL) - mrunlock_excl(&ip->i_mmaplock); + up_write(&ip->i_mmaplock); else if (lock_flags & XFS_MMAPLOCK_SHARED) - mrunlock_shared(&ip->i_mmaplock); + up_read(&ip->i_mmaplock); out_undo_iolock: if (lock_flags & XFS_IOLOCK_EXCL) up_write(&VFS_I(ip)->i_rwsem); @@ -309,14 +310,14 @@ xfs_iunlock( up_read(&VFS_I(ip)->i_rwsem); if (lock_flags & XFS_MMAPLOCK_EXCL) - mrunlock_excl(&ip->i_mmaplock); + up_write(&ip->i_mmaplock); else if (lock_flags & XFS_MMAPLOCK_SHARED) - mrunlock_shared(&ip->i_mmaplock); + up_read(&ip->i_mmaplock); if (lock_flags & XFS_ILOCK_EXCL) - mrunlock_excl(&ip->i_lock); + up_write(&ip->i_lock); else if (lock_flags & XFS_ILOCK_SHARED) - mrunlock_shared(&ip->i_lock); + up_read(&ip->i_lock); trace_xfs_iunlock(ip, lock_flags, _RET_IP_); } @@ -335,9 +336,9 @@ xfs_ilock_demote( ~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); if (lock_flags & XFS_ILOCK_EXCL) - mrdemote(&ip->i_lock); + downgrade_write(&ip->i_lock); if (lock_flags & XFS_MMAPLOCK_EXCL) - mrdemote(&ip->i_mmaplock); + downgrade_write(&ip->i_mmaplock); if (lock_flags & XFS_IOLOCK_EXCL) downgrade_write(&VFS_I(ip)->i_rwsem); @@ -375,19 +376,22 @@ xfs_isilocked( struct xfs_inode *ip, uint lock_flags) { - if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) { - if (!(lock_flags & XFS_ILOCK_SHARED)) - return !!ip->i_lock.mr_writer; - return rwsem_is_locked(&ip->i_lock.mr_lock); + if (lock_flags & (XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)) { + ASSERT(!(lock_flags & ~(XFS_ILOCK_EXCL | XFS_ILOCK_SHARED))); + return __xfs_rwsem_islocked(&ip->i_lock, lock_flags, + XFS_ILOCK_FLAG_SHIFT); } - if (lock_flags & (XFS_MMAPLOCK_EXCL|XFS_MMAPLOCK_SHARED)) { - if (!(lock_flags & XFS_MMAPLOCK_SHARED)) - return !!ip->i_mmaplock.mr_writer; - return rwsem_is_locked(&ip->i_mmaplock.mr_lock); + if (lock_flags & (XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED)) { + ASSERT(!(lock_flags & + ~(XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED))); + return __xfs_rwsem_islocked(&ip->i_mmaplock, lock_flags, + XFS_MMAPLOCK_FLAG_SHIFT); } if (lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) { + ASSERT(!(lock_flags & + ~(XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED))); return __xfs_rwsem_islocked(&VFS_I(ip)->i_rwsem, lock_flags, XFS_IOLOCK_FLAG_SHIFT); } diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 9cecd6c9c90c..413998972b35 100644 --- a/fs/xfs/xfs_inode.h +++ b/fs/xfs/xfs_inode.h @@ -39,8 +39,8 @@ typedef struct xfs_inode { /* Transaction and locking information. */ struct xfs_inode_log_item *i_itemp; /* logging information */ - mrlock_t i_lock; /* inode lock */ - mrlock_t i_mmaplock; /* inode mmap IO lock */ + struct rw_semaphore i_lock; /* inode lock */ + struct rw_semaphore i_mmaplock; /* inode mmap IO lock */ atomic_t i_pincount; /* inode pin count */ /* diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index 80a13c8561d8..66cca3e599c7 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -1336,9 +1336,9 @@ xfs_setup_inode( */ lockdep_set_class(&inode->i_rwsem, &inode->i_sb->s_type->i_mutex_dir_key); - lockdep_set_class(&ip->i_lock.mr_lock, &xfs_dir_ilock_class); + lockdep_set_class(&ip->i_lock, &xfs_dir_ilock_class); } else { - lockdep_set_class(&ip->i_lock.mr_lock, &xfs_nondir_ilock_class); + lockdep_set_class(&ip->i_lock, &xfs_nondir_ilock_class); } /* diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h index ab737fed7b12..ba37217f86d2 100644 --- a/fs/xfs/xfs_linux.h +++ b/fs/xfs/xfs_linux.h @@ -22,7 +22,6 @@ typedef __u32 xfs_nlink_t; #include "xfs_types.h" #include "kmem.h" -#include "mrlock.h" #include #include @@ -61,6 +60,7 @@ typedef __u32 xfs_nlink_t; #include #include #include +#include #include #include diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 71ac6c1cdc36..00be9cfa29fa 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -708,10 +708,8 @@ xfs_fs_inode_init_once( atomic_set(&ip->i_pincount, 0); spin_lock_init(&ip->i_flags_lock); - mrlock_init(&ip->i_mmaplock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, - "xfsino", ip->i_ino); - mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER, - "xfsino", ip->i_ino); + init_rwsem(&ip->i_mmaplock); + init_rwsem(&ip->i_lock); } /*