From patchwork Mon Oct 5 21:38:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Reichl X-Patchwork-Id: 11817795 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 3AF2413B2 for ; Mon, 5 Oct 2020 21:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09FDF2083B for ; Mon, 5 Oct 2020 21:39:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="geMSbw9T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726685AbgJEVjD (ORCPT ); Mon, 5 Oct 2020 17:39:03 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55839 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726693AbgJEVjD (ORCPT ); Mon, 5 Oct 2020 17:39:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601933940; 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=B2naLBIfpEWa5yk+wORMESIqi2vsca2gmo21A9qN4Cs=; b=geMSbw9Tyh5Ezy/F5HodgfRWF9tfpjQjD4Mn+Gyf9RrF6xWtHUriqkunttB/BsMstRgSzQ xurwUCJ/lqLyZA1PCbBCI/Z3JgliXEDZoFmr5iH2yY/J/+ko+Kya5Q5uO8japrVrZix0t9 BhKp4n7TrjDVO5eUDz2b7T5yjYecXK0= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-101-UHIInXFXO3-Gau_T2X1QAA-1; Mon, 05 Oct 2020 17:38:59 -0400 X-MC-Unique: UHIInXFXO3-Gau_T2X1QAA-1 Received: by mail-wm1-f69.google.com with SMTP id c204so328961wmd.5 for ; Mon, 05 Oct 2020 14:38:59 -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=B2naLBIfpEWa5yk+wORMESIqi2vsca2gmo21A9qN4Cs=; b=KCXuDYcYrh2BF/nSoR5tRpuaqzQeMr01FFrxDNvVmKYOI1dg+bgksK44CDt+6VLEok AwI+Hylp2Kjj2LEvZ34ZDcrvv22dOIRwznUogJ84uGibY1OS332Ht59aWPvYl9VWGXeP NwR4UQCwCwDzSb4BplCIxaTpJ4KeIH24n3paclcfct9hfilaUIO3cXtxcWaRa1ZwCMmE oR4YsDYIMZBTMmxVGtPDznmVGnq747Sq9Hd1KWPGEtblBdAY2jZopBQJZrIfNoLV2ptI 3NkwhC+eInpqjxIK0T+q9P/AwUhhdaH/cUCV1N/nMr5bHipZ/2iex1to8VTSJdjA4o3w 60TQ== X-Gm-Message-State: AOAM532Y8/MxjcpR1iNYZVMtNdvMPgr1Cw4Mn7RC2DFrPHP/rPsldnDc C0ILSJd3chh+Poq9j0iTrAlJHL4nO0IcTzdpJaKQCr0J+TSxq866zhnzmBDXNF7xFnwwl+hUmCs mx0Si2s9jQIRIPIB6akd+ X-Received: by 2002:adf:fac8:: with SMTP id a8mr1339113wrs.186.1601933937872; Mon, 05 Oct 2020 14:38:57 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx+V/t+fBS/a/MJ426wbuCAOK6SrbRvsgd7YHfVoATuC7GZZbAh6ETqPnft2mXLKfVIo9pWVg== X-Received: by 2002:adf:fac8:: with SMTP id a8mr1339096wrs.186.1601933937624; Mon, 05 Oct 2020 14:38:57 -0700 (PDT) Received: from localhost.localdomain.com ([84.19.91.81]) by smtp.gmail.com with ESMTPSA id r5sm1576499wrp.15.2020.10.05.14.38.56 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 05 Oct 2020 14:38:57 -0700 (PDT) From: Pavel Reichl To: linux-xfs@vger.kernel.org Subject: [PATCH v8 4/4] xfs: replace mrlock_t with rw_semaphores Date: Mon, 5 Oct 2020 23:38:52 +0200 Message-Id: <20201005213852.233004-5-preichl@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201005213852.233004-1-preichl@redhat.com> References: <20201005213852.233004-1-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 --- fs/xfs/libxfs/xfs_btree.c | 10 +++++ fs/xfs/mrlock.h | 78 --------------------------------------- fs/xfs/xfs_inode.c | 36 ++++++++++-------- 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, 37 insertions(+), 103 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..d798d288eed1 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -2816,6 +2816,7 @@ xfs_btree_split_worker( unsigned long pflags; unsigned long new_pflags = PF_MEMALLOC_NOFS; + 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 @@ -2832,6 +2833,7 @@ xfs_btree_split_worker( complete(args->done); current_restore_flags_nested(&pflags, new_pflags); + rwsem_release(&args->cur->bc_ino.ip->i_lock.dep_map, _THIS_IP_); } /* @@ -2863,8 +2865,16 @@ xfs_btree_split( args.done = &done; args.kswapd = current_is_kswapd(); INIT_WORK_ONSTACK(&args.work, xfs_btree_split_worker); + + /* Release the lock so it can be acquired in the kernel thread which + * executes the xfs_btree_split_worker. + */ + rwsem_release(&cur->bc_ino.ip->i_lock.dep_map, _THIS_IP_); queue_work(xfs_alloc_wq, &args.work); + wait_for_completion(&done); + /* Re-aqcquire the lock previously released for the work queue. */ + 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 49d296877494..dbc1b80629c5 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); @@ -385,11 +386,14 @@ xfs_isilocked( uint lock_flags) { 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)) { + ASSERT(!(lock_flags & + ~(XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED))); return __xfs_rwsem_islocked(&ip->i_mmaplock, (lock_flags >> XFS_MMAPLOCK_FLAG_SHIFT)); } diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index 77d5655191ab..02c98ecfe4c5 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); } /*