From patchwork Thu Apr 1 01:09:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 12176673 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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 C9C71C4360C for ; Thu, 1 Apr 2021 01:10:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A160661075 for ; Thu, 1 Apr 2021 01:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232884AbhDABJa (ORCPT ); Wed, 31 Mar 2021 21:09:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:41448 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232601AbhDABJK (ORCPT ); Wed, 31 Mar 2021 21:09:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 240BC61057; Thu, 1 Apr 2021 01:09:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617239350; bh=WO/Ibayp9wD3mpiGOIRPoFx7iqn3Jcwc5oEnEJlemD0=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=GOruQRdJLhSC7e1LN6V1oyNgwCBh++a2movEwr+zcvyGiymEteBw8BTSyv+ZS9hrk EizD7Qwkbc2B1qG4oPNhiruMCaipdb5ayFUBNnfpA7tuaBVjxuUPhWiY23Y73gCwbX /TrJQHUm3lcUgIOqE1YBHQXLE7+E4PF7bybGHmaCRbBafE6Ofj6u7YuhxeZkZ0wLIG q9KVRIxa5ovNL2iHm3T7rMYT6oMXR52appm0kN7lQntPPu1Nzg6n8n+towgR+Z2Zqz XeJ+0VEL0kZndccyUKKpYL35+CH/UsZNvPOCOkbqeqY0foFDs7oJ0dazwJjnXxHOLD PL0eH7LPmGxvA== Subject: [PATCH 04/18] xfs: clear log incompat feature bits when the log is idle From: "Darrick J. Wong" To: djwong@kernel.org Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Date: Wed, 31 Mar 2021 18:09:09 -0700 Message-ID: <161723934912.3149451.16053630119296453937.stgit@magnolia> In-Reply-To: <161723932606.3149451.12366114306150243052.stgit@magnolia> References: <161723932606.3149451.12366114306150243052.stgit@magnolia> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Darrick J. Wong When there are no ongoing transactions and the log contents have been checkpointed back into the filesystem, the log performs 'covering', which is to say that it log a dummy transaction to record the fact that the tail has caught up with the head. This is a good time to clear log incompat feature flags, because they are flags that are temporarily set to limit the range of kernels that can replay a dirty log. Since it's possible that some other higher level thread is about to start logging items protected by a log incompat flag, we create a rwsem so that upper level threads can coordinate this with the log. It would probably be more performant to use a percpu rwsem, but the ability to /try/ taking the write lock during covering is critical, and percpu rwsems do not provide that. Signed-off-by: Darrick J. Wong Reviewed-by: Allison Henderson --- fs/xfs/libxfs/xfs_shared.h | 6 +++++ fs/xfs/xfs_log.c | 49 ++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_log.h | 3 +++ fs/xfs/xfs_log_priv.h | 3 +++ fs/xfs/xfs_trans.c | 14 +++++++++---- 5 files changed, 71 insertions(+), 4 deletions(-) diff --git a/fs/xfs/libxfs/xfs_shared.h b/fs/xfs/libxfs/xfs_shared.h index 8c61a461bf7b..c7c9a0cebb04 100644 --- a/fs/xfs/libxfs/xfs_shared.h +++ b/fs/xfs/libxfs/xfs_shared.h @@ -62,6 +62,12 @@ void xfs_log_get_max_trans_res(struct xfs_mount *mp, #define XFS_TRANS_SB_DIRTY 0x02 /* superblock is modified */ #define XFS_TRANS_PERM_LOG_RES 0x04 /* xact took a permanent log res */ #define XFS_TRANS_SYNC 0x08 /* make commit synchronous */ +/* + * This transaction uses a log incompat feature, which means that we must tell + * the log that we've finished using it at the transaction commit or cancel. + * Callers must call xlog_use_incompat_feat before setting this flag. + */ +#define XFS_TRANS_LOG_INCOMPAT 0x10 #define XFS_TRANS_RESERVE 0x20 /* OK to use reserved data blocks */ #define XFS_TRANS_NO_WRITECOUNT 0x40 /* do not elevate SB writecount */ #define XFS_TRANS_RES_FDBLKS 0x80 /* reserve newly freed blocks */ diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index cf73bc9f4d18..cb72be62da3e 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1335,6 +1335,32 @@ xfs_log_work_queue( msecs_to_jiffies(xfs_syncd_centisecs * 10)); } +/* + * Clear the log incompat flags if we have the opportunity. + * + * This only happens if we're about to log the second dummy transaction as part + * of covering the log and we can get the log incompat feature usage lock. + */ +static inline void +xlog_clear_incompat( + struct xlog *log) +{ + struct xfs_mount *mp = log->l_mp; + + if (!xfs_sb_has_incompat_log_feature(&mp->m_sb, + XFS_SB_FEAT_INCOMPAT_LOG_ALL)) + return; + + if (log->l_covered_state != XLOG_STATE_COVER_DONE2) + return; + + if (!down_write_trylock(&log->l_incompat_users)) + return; + + xfs_clear_incompat_log_features(mp); + up_write(&log->l_incompat_users); +} + /* * Every sync period we need to unpin all items in the AIL and push them to * disk. If there is nothing dirty, then we might need to cover the log to @@ -1361,6 +1387,7 @@ xfs_log_worker( * synchronously log the superblock instead to ensure the * superblock is immediately unpinned and can be written back. */ + xlog_clear_incompat(log); xfs_sync_sb(mp, true); } else xfs_log_force(mp, 0); @@ -1443,6 +1470,8 @@ xlog_alloc_log( } log->l_sectBBsize = 1 << log2_size; + init_rwsem(&log->l_incompat_users); + xlog_get_iclog_buffer_size(mp, log); spin_lock_init(&log->l_icloglock); @@ -3933,3 +3962,23 @@ xfs_log_in_recovery( return log->l_flags & XLOG_ACTIVE_RECOVERY; } + +/* + * Notify the log that we're about to start using a feature that is protected + * by a log incompat feature flag. This will prevent log covering from + * clearing those flags. + */ +void +xlog_use_incompat_feat( + struct xlog *log) +{ + down_read(&log->l_incompat_users); +} + +/* Notify the log that we've finished using log incompat features. */ +void +xlog_drop_incompat_feat( + struct xlog *log) +{ + up_read(&log->l_incompat_users); +} diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h index 044e02cb8921..8b7d0a56cbf1 100644 --- a/fs/xfs/xfs_log.h +++ b/fs/xfs/xfs_log.h @@ -145,4 +145,7 @@ bool xfs_log_in_recovery(struct xfs_mount *); xfs_lsn_t xlog_grant_push_threshold(struct xlog *log, int need_bytes); +void xlog_use_incompat_feat(struct xlog *log); +void xlog_drop_incompat_feat(struct xlog *log); + #endif /* __XFS_LOG_H__ */ diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 1c6fdbf3d506..75702c4fa69c 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -436,6 +436,9 @@ struct xlog { #endif /* log recovery lsn tracking (for buffer submission */ xfs_lsn_t l_recovery_lsn; + + /* Users of log incompat features should take a read lock. */ + struct rw_semaphore l_incompat_users; }; #define XLOG_BUF_CANCEL_BUCKET(log, blkno) \ diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index eb2d8e2e5db6..e548d53c2091 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -71,6 +71,9 @@ xfs_trans_free( xfs_extent_busy_sort(&tp->t_busy); xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false); + if (tp->t_flags & XFS_TRANS_LOG_INCOMPAT) + xlog_drop_incompat_feat(tp->t_mountp->m_log); + trace_xfs_trans_free(tp, _RET_IP_); xfs_trans_clear_context(tp); if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT)) @@ -110,10 +113,13 @@ xfs_trans_dup( ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); ASSERT(tp->t_ticket != NULL); - ntp->t_flags = XFS_TRANS_PERM_LOG_RES | - (tp->t_flags & XFS_TRANS_RESERVE) | - (tp->t_flags & XFS_TRANS_NO_WRITECOUNT) | - (tp->t_flags & XFS_TRANS_RES_FDBLKS); + ntp->t_flags = tp->t_flags & (XFS_TRANS_PERM_LOG_RES | + XFS_TRANS_RESERVE | + XFS_TRANS_NO_WRITECOUNT | + XFS_TRANS_RES_FDBLKS | + XFS_TRANS_LOG_INCOMPAT); + /* Give our LOG_INCOMPAT reference to the new transaction. */ + tp->t_flags &= ~XFS_TRANS_LOG_INCOMPAT; /* We gave our writer reference to the new transaction */ tp->t_flags |= XFS_TRANS_NO_WRITECOUNT; ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);