From patchwork Wed Jan 13 11:17:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 12016551 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87236C433E9 for ; Wed, 13 Jan 2021 11:18:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3ABE62333F for ; Wed, 13 Jan 2021 11:18:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727180AbhAMLR4 (ORCPT ); Wed, 13 Jan 2021 06:17:56 -0500 Received: from mx2.suse.de ([195.135.220.15]:35950 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728293AbhAMLRz (ORCPT ); Wed, 13 Jan 2021 06:17:55 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1610536629; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FZdTwyKkf0cyWEtrVipKEpgR3vbT1AfRNaFwxyyVy74=; b=QNA2b1hpDM6QbEu3KrMs1jg1TIaaoFuzwcA2neOLiaA3xBRIgXwE4+5HgjvVa0bLBgFCwF N3Ike1VCdE+yNsW3Tmrg3M8oNUs36tYSuezeScNbvKLtUrqHFWhnE2EVcMRyn4CVLBQ0Zn QLEoOtTDwKKelfdz+cyC51HmsjSeEy0= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 4F953AEE0; Wed, 13 Jan 2021 11:17:09 +0000 (UTC) From: Nikolay Borisov To: linux-xfs@vger.kernel.org Cc: david@fromorbit.com, Nikolay Borisov Subject: [RFC PATCH 1/3] xfs: Add is_rwsem_write_locked function Date: Wed, 13 Jan 2021 13:17:04 +0200 Message-Id: <20210113111707.756662-2-nborisov@suse.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210113111707.756662-1-nborisov@suse.com> References: <20210113111707.756662-1-nborisov@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org This is going to be used to check if an rwsem is held for write. Mimicking what current mrlock->mr_writer variable provides but using the generic rwsem infrastructure. One might argue that redefining the locked bit is a layering violation since RWSEM_WRITE_LOCKED is not exposed, however I'd argue back that this is only used in a debugging scenario and the physical layout of the rwsem is unlikely to change. Signed-off-by: Nikolay Borisov --- fs/xfs/xfs_inode.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index b7352bc4c815..499e63da935c 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -345,6 +345,13 @@ xfs_ilock_demote( } #if defined(DEBUG) || defined(XFS_WARN) +static bool is_rwsem_write_locked(struct rw_semaphore *rwsem) +{ + /* Copy of RWSEM_WRITE_LOCKED from rwsem.c */ +#define LOCK_BIT (1UL << 0) + return atomic_long_read(&rwsem->count) & LOCK_BIT; +} + int xfs_isilocked( xfs_inode_t *ip, From patchwork Wed Jan 13 11:17:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 12016553 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6363EC433E6 for ; Wed, 13 Jan 2021 11:18:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1591423383 for ; Wed, 13 Jan 2021 11:18:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728165AbhAMLR4 (ORCPT ); Wed, 13 Jan 2021 06:17:56 -0500 Received: from mx2.suse.de ([195.135.220.15]:35968 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727180AbhAMLRz (ORCPT ); Wed, 13 Jan 2021 06:17:55 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1610536629; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U3S1pgfzzSSK2BfaixGQgUpSLnPwufqN9+OijQeJQ/4=; b=BEGipiN0z+n0Qb1CkHSrQKrH4ooyY45ST+Hth6NWF7gt+zcSDFJrB3/TRpWI7axLMm+kzz uO0L+qUIyytiK9rVRli3YQHh7NXRIEUp054VoQZXhq6d6A/ZbJ8dbGdn8eWcSomi3y0l61 yLcr5CZgfohOMuv3UwMPbOq9iHVEi8o= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9348DAF16; Wed, 13 Jan 2021 11:17:09 +0000 (UTC) From: Nikolay Borisov To: linux-xfs@vger.kernel.org Cc: david@fromorbit.com, Nikolay Borisov Subject: [RFC PATCH 2/3] xfs: Convert i_lock/i_mmaplock to rw_semaphore Date: Wed, 13 Jan 2021 13:17:05 +0200 Message-Id: <20210113111707.756662-3-nborisov@suse.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210113111707.756662-1-nborisov@suse.com> References: <20210113111707.756662-1-nborisov@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Having the mrlock_t doesn't provide any benefit since rwsem is perfectly equipped to answer the question whether a rwsem is held for write or not. Exploit this fact to convert the i_lock/i_mmaplock to direct semaphores, thus making mrlock unused. This removes a level of indirection internal to xfs but also paves the way to lifting i_mmaplock to VFS in the future. Signed-off-by: Nikolay Borisov --- fs/xfs/xfs_inode.c | 41 +++++++++++++++++++++-------------------- fs/xfs/xfs_inode.h | 6 +++--- fs/xfs/xfs_super.c | 7 ++----- 3 files changed, 26 insertions(+), 28 deletions(-) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 499e63da935c..dcf216eb7505 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -4,6 +4,7 @@ * All Rights Reserved. */ #include +#include #include "xfs.h" #include "xfs_fs.h" @@ -191,14 +192,14 @@ 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); @@ -359,14 +360,14 @@ xfs_isilocked( { 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); + return is_rwsem_write_locked(&ip->i_lock); + return rwsem_is_locked(&ip->i_lock); } 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); + return is_rwsem_write_locked(&ip->i_mmaplock); + return rwsem_is_locked(&ip->i_mmaplock); } if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) { diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h index eca333f5f715..dd1d81afc4ce 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 */ /* @@ -310,7 +310,7 @@ static inline bool xfs_inode_has_bigtime(struct xfs_inode *ip) * 5 PARENT subclass (not nestable) * 6 RTBITMAP subclass (not nestable) * 7 RTSUM subclass (not nestable) - * + * */ #define XFS_IOLOCK_SHIFT 16 #define XFS_IOLOCK_MAX_SUBCLASS 3 diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 813be879a5e5..7646001324c3 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -709,11 +709,8 @@ xfs_fs_inode_init_once( /* xfs inode */ 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); } /* From patchwork Wed Jan 13 11:17:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 12016549 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CF1DC43381 for ; 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Wed, 13 Jan 2021 11:17:10 +0000 (UTC) From: Nikolay Borisov To: linux-xfs@vger.kernel.org Cc: david@fromorbit.com, Nikolay Borisov Subject: [RFC PATCH 3/3] xfs: Remove mrlock Date: Wed, 13 Jan 2021 13:17:07 +0200 Message-Id: <20210113111707.756662-5-nborisov@suse.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210113111707.756662-1-nborisov@suse.com> References: <20210113111707.756662-1-nborisov@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org It's no longer used so let's put the final nail in its coffin. Signed-off-by: Nikolay Borisov --- fs/xfs/mrlock.h | 78 ---------------------------------------- fs/xfs/xfs_linux.h | 1 - fs/xfs/xfs_qm_syscalls.c | 2 +- 3 files changed, 1 insertion(+), 80 deletions(-) delete mode 100644 fs/xfs/mrlock.h 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_linux.h b/fs/xfs/xfs_linux.h index 5b7a1e201559..fa57f2f060ca 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 diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c index ca1b57d291dc..1a582f21c619 100644 --- a/fs/xfs/xfs_qm_syscalls.c +++ b/fs/xfs/xfs_qm_syscalls.c @@ -206,7 +206,7 @@ xfs_qm_scall_quotaoff( /* * Next we make the changes in the quota flag in the mount struct. * This isn't protected by a particular lock directly, because we - * don't want to take a mrlock every time we depend on quotas being on. + * don't want to take a rwsem every time we depend on quotas being on. */ mp->m_qflags &= ~flags;