From patchwork Thu Oct 15 07:21:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 11838693 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 A1D5261C for ; Thu, 15 Oct 2020 07:22:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 884372224A for ; Thu, 15 Oct 2020 07:22:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728691AbgJOHWJ (ORCPT ); Thu, 15 Oct 2020 03:22:09 -0400 Received: from mail104.syd.optusnet.com.au ([211.29.132.246]:34910 "EHLO mail104.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728911AbgJOHWE (ORCPT ); Thu, 15 Oct 2020 03:22:04 -0400 Received: from dread.disaster.area (pa49-179-6-140.pa.nsw.optusnet.com.au [49.179.6.140]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id 166D758C4D7 for ; Thu, 15 Oct 2020 18:21:57 +1100 (AEDT) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1kSxaG-000hvS-Ji for linux-xfs@vger.kernel.org; Thu, 15 Oct 2020 18:21:56 +1100 Received: from dave by discord.disaster.area with local (Exim 4.94) (envelope-from ) id 1kSxaG-006qLj-CG for linux-xfs@vger.kernel.org; Thu, 15 Oct 2020 18:21:56 +1100 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH 08/27] libxfs: add spinlock_t wrapper Date: Thu, 15 Oct 2020 18:21:36 +1100 Message-Id: <20201015072155.1631135-9-david@fromorbit.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201015072155.1631135-1-david@fromorbit.com> References: <20201015072155.1631135-1-david@fromorbit.com> MIME-Version: 1.0 X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=Ubgvt5aN c=1 sm=1 tr=0 cx=a_idp_d a=uDU3YIYVKEaHT0eX+MXYOQ==:117 a=uDU3YIYVKEaHT0eX+MXYOQ==:17 a=afefHYAZSVUA:10 a=20KFwNOVAAAA:8 a=Ab2Hbm8BP3q4J0kLDiQA:9 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner These provide the kernel spinlock_t interface, but are *not* spinlocks. Spinlocks cannot be used by general purpose userspace processes due to the fact they cannot control task preemption and scheduling reliability. Hence these are implemented as a pthread_mutex_t, similar to the way the kernel RT build implements spinlock_t as a kernel mutex. Because the current libxfs spinlock "implementation" just makes spinlocks go away, we have to also add initialisation to spinlocks that libxfs uses that are missing from the userspace implementation. Signed-off-by: Dave Chinner --- include/Makefile | 1 + include/libxfs.h | 1 + include/spinlock.h | 25 +++++++++++++++++++++++++ include/xfs_inode.h | 1 + include/xfs_mount.h | 2 ++ include/xfs_trans.h | 1 + libxfs/init.c | 4 +++- libxfs/libxfs_priv.h | 4 +--- libxfs/rdwr.c | 2 ++ 9 files changed, 37 insertions(+), 4 deletions(-) create mode 100644 include/spinlock.h diff --git a/include/Makefile b/include/Makefile index 632b819fcded..f7c40a5ce1a1 100644 --- a/include/Makefile +++ b/include/Makefile @@ -16,6 +16,7 @@ LIBHFILES = libxfs.h \ kmem.h \ list.h \ parent.h \ + spinlock.h \ xfs_inode.h \ xfs_log_recover.h \ xfs_metadump.h \ diff --git a/include/libxfs.h b/include/libxfs.h index eb2db7f9647d..caf4a5139469 100644 --- a/include/libxfs.h +++ b/include/libxfs.h @@ -18,6 +18,7 @@ #include "kmem.h" #include "libfrog/radix-tree.h" #include "atomic.h" +#include "spinlock.h" #include "xfs_types.h" #include "xfs_fs.h" diff --git a/include/spinlock.h b/include/spinlock.h new file mode 100644 index 000000000000..8da2325cc8f5 --- /dev/null +++ b/include/spinlock.h @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2019-20 RedHat, Inc. + * All Rights Reserved. + */ +#ifndef __LIBXFS_SPINLOCK_H__ +#define __LIBXFS_SPINLOCK_H__ + +/* + * This implements kernel compatible spinlock exclusion semantics. These, + * however, are not spinlocks, as spinlocks cannot be reliably implemented in + * userspace without using realtime scheduling task contexts. Hence this + * interface is implemented with pthread mutexes and so can block, but this is + * no different to the kernel RT build which replaces spinlocks with mutexes. + * Hence we know it works. + */ + +typedef pthread_mutex_t spinlock_t; + +#define spin_lock_init(l) pthread_mutex_init(l, NULL) +#define spin_lock(l) pthread_mutex_lock(l) +#define spin_trylock(l) (pthread_mutex_trylock(l) != EBUSY) +#define spin_unlock(l) pthread_mutex_unlock(l) + +#endif /* __LIBXFS_SPINLOCK_H__ */ diff --git a/include/xfs_inode.h b/include/xfs_inode.h index 588d8c7258f4..29086a7d5e2e 100644 --- a/include/xfs_inode.h +++ b/include/xfs_inode.h @@ -42,6 +42,7 @@ struct inode { struct timespec i_atime; struct timespec i_mtime; struct timespec i_ctime; + spinlock_t i_lock; }; static inline uint32_t i_uid_read(struct inode *inode) diff --git a/include/xfs_mount.h b/include/xfs_mount.h index 20c8bfaf4fa8..d78c4cdc4f78 100644 --- a/include/xfs_mount.h +++ b/include/xfs_mount.h @@ -20,6 +20,7 @@ typedef struct xfs_mount { #define m_icount m_sb.sb_icount #define m_ifree m_sb.sb_ifree #define m_fdblocks m_sb.sb_fdblocks + spinlock_t m_sb_lock; /* * Bitsets of per-fs metadata that have been checked and/or are sick. @@ -30,6 +31,7 @@ typedef struct xfs_mount { char *m_fsname; /* filesystem name */ int m_bsize; /* fs logical block size */ + spinlock_t m_agirotor_lock; xfs_agnumber_t m_agfrotor; /* last ag where space found */ xfs_agnumber_t m_agirotor; /* last ag dir inode alloced */ xfs_agnumber_t m_maxagi; /* highest inode alloc group */ diff --git a/include/xfs_trans.h b/include/xfs_trans.h index 1f087672a2a8..9e6eae9ff483 100644 --- a/include/xfs_trans.h +++ b/include/xfs_trans.h @@ -35,6 +35,7 @@ struct xfs_inode_log_item { unsigned int ili_last_fields; /* fields when flushed*/ unsigned int ili_fields; /* fields to be logged */ unsigned int ili_fsync_fields; /* ignored by userspace */ + spinlock_t ili_lock; }; typedef struct xfs_buf_log_item { diff --git a/libxfs/init.c b/libxfs/init.c index 477487e985c4..fe784940c299 100644 --- a/libxfs/init.c +++ b/libxfs/init.c @@ -683,7 +683,9 @@ libxfs_mount( mp->m_flags = (LIBXFS_MOUNT_32BITINODES|LIBXFS_MOUNT_32BITINOOPT); mp->m_sb = *sb; INIT_RADIX_TREE(&mp->m_perag_tree, GFP_KERNEL); - sbp = &(mp->m_sb); + sbp = &mp->m_sb; + spin_lock_init(&mp->m_sb_lock); + spin_lock_init(&mp->m_agirotor_lock); xfs_sb_mount_common(mp, sb); diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h index 4cce1d680921..e134f65c5dd1 100644 --- a/libxfs/libxfs_priv.h +++ b/libxfs/libxfs_priv.h @@ -48,6 +48,7 @@ #include "kmem.h" #include "libfrog/radix-tree.h" #include "atomic.h" +#include "spinlock.h" #include "xfs_types.h" #include "xfs_arch.h" @@ -189,9 +190,6 @@ enum ce { CE_DEBUG, CE_CONT, CE_NOTE, CE_WARN, CE_ALERT, CE_PANIC }; #endif /* miscellaneous kernel routines not in user space */ -#define spin_lock_init(a) ((void) 0) -#define spin_lock(a) ((void) 0) -#define spin_unlock(a) ((void) 0) #define likely(x) (x) #define unlikely(x) (x) diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c index 174cbcac1250..5ab1987eb0fe 100644 --- a/libxfs/rdwr.c +++ b/libxfs/rdwr.c @@ -1062,6 +1062,8 @@ libxfs_iget( ip->i_ino = ino; ip->i_mount = mp; + spin_lock_init(&VFS_I(ip)->i_lock); + error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, 0); if (error) goto out_destroy;