From patchwork Thu Feb 20 15:18:29 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 3688131 Return-Path: X-Original-To: patchwork-ocfs2-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3E7D29F35F for ; Thu, 20 Feb 2014 15:19:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 37E9420179 for ; Thu, 20 Feb 2014 15:19:36 +0000 (UTC) Received: from aserp1040.oracle.com (aserp1040.oracle.com [141.146.126.69]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0FF2620173 for ; Thu, 20 Feb 2014 15:19:35 +0000 (UTC) Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s1KFJPBA009994 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); 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Thu, 20 Feb 2014 15:18:41 GMT Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id C983C75018; Thu, 20 Feb 2014 15:18:39 +0000 (UTC) Received: by quack.suse.cz (Postfix, from userid 1000) id 9335C80E16; Thu, 20 Feb 2014 16:18:37 +0100 (CET) From: Jan Kara To: Joel Becker Date: Thu, 20 Feb 2014 16:18:29 +0100 Message-Id: <1392909511-2933-5-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1392909511-2933-1-git-send-email-jack@suse.cz> References: <1392909511-2933-1-git-send-email-jack@suse.cz> X-Flow-Control-Info: class=Pass-to-MM reputation=ipRisk-All ip=195.135.220.15 ct-class=T2 ct-vol1=0 ct-vol2=4 ct-vol3=3 ct-risk=59 ct-spam1=75 ct-spam2=44 ct-bulk=37 rcpts=1 size=6539 X-SPF-Info: NONE::cantor2.suse.de X-Sendmail-CM-Score: 0.00% X-Sendmail-CM-Analysis: v=2.1 cv=LvSrlBtc c=1 sm=1 tr=0 a=uEuDQZVrWKuLCe7byFjfVg==:117 a=uEuDQZVrWKuLCe7byFjfVg==:17 a=lZq4grqqF4YA:10 a=CEjYZf1i_7IA:10 a=U6uSX1DrnQiyQb8uEpYA:9 a=VXUOizL7mNhP2n0k:21 a=go4fZuDfNF5W6hy6:21 X-Sendmail-CT-Classification: not spam X-Sendmail-CT-RefID: str=0001.0A020208.53061CD1.02F6:SCFSTAT18040053, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0 Cc: Mark Fasheh , Jan Kara , ocfs2-devel@oss.oracle.com Subject: [Ocfs2-devel] [PATCH 4/6] ocfs2: Implement delayed dropping of last dquot reference X-BeenThere: ocfs2-devel@oss.oracle.com X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ocfs2-devel-bounces@oss.oracle.com Errors-To: ocfs2-devel-bounces@oss.oracle.com X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We cannot drop last dquot reference from downconvert thread as that creates the following deadlock: NODE 1 NODE2 holds dentry lock for 'foo' holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE dquot_initialize(bar) ocfs2_dquot_acquire() ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE) ... downconvert thread (triggered from another node or a different process from NODE2) ocfs2_dentry_post_unlock() ... iput(foo) ocfs2_evict_inode(foo) ocfs2_clear_inode(foo) dquot_drop(inode) ... ocfs2_dquot_release() ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE) - blocks finds we need more space in quota file ... ocfs2_extend_no_holes() ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE) - deadlocks waiting for downconvert thread We solve the problem by postponing dropping of the last dquot reference to a workqueue if it happens from the downconvert thread. Signed-off-by: Jan Kara Reviewed-by: Srinivas Eeda --- fs/ocfs2/ocfs2.h | 5 +++++ fs/ocfs2/quota.h | 2 ++ fs/ocfs2/quota_global.c | 35 +++++++++++++++++++++++++++++++++++ fs/ocfs2/super.c | 8 ++++++++ 4 files changed, 50 insertions(+) diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 553f53cc73ae..64c02239ba46 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -419,6 +420,10 @@ struct ocfs2_super struct ocfs2_dentry_lock *dentry_lock_list; struct work_struct dentry_lock_work; + /* List of dquot structures to drop last reference to */ + struct llist_head dquot_drop_list; + struct work_struct dquot_drop_work; + wait_queue_head_t osb_mount_event; /* Truncate log info */ diff --git a/fs/ocfs2/quota.h b/fs/ocfs2/quota.h index d5ab56cbe5c5..f266d67df3c6 100644 --- a/fs/ocfs2/quota.h +++ b/fs/ocfs2/quota.h @@ -28,6 +28,7 @@ struct ocfs2_dquot { unsigned int dq_use_count; /* Number of nodes having reference to this entry in global quota file */ s64 dq_origspace; /* Last globally synced space usage */ s64 dq_originodes; /* Last globally synced inode usage */ + struct llist_node list; /* Member of list of dquots to drop */ }; /* Description of one chunk to recover in memory */ @@ -110,6 +111,7 @@ int ocfs2_read_quota_phys_block(struct inode *inode, u64 p_block, int ocfs2_create_local_dquot(struct dquot *dquot); int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot); int ocfs2_local_write_dquot(struct dquot *dquot); +void ocfs2_drop_dquot_refs(struct work_struct *work); extern const struct dquot_operations ocfs2_quota_operations; extern struct quota_format_type ocfs2_quota_format; diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c index aaa50611ec66..7921e209c64b 100644 --- a/fs/ocfs2/quota_global.c +++ b/fs/ocfs2/quota_global.c @@ -10,6 +10,7 @@ #include #include #include +#include #include @@ -679,6 +680,27 @@ static int ocfs2_calc_qdel_credits(struct super_block *sb, int type) OCFS2_INODE_UPDATE_CREDITS; } +void ocfs2_drop_dquot_refs(struct work_struct *work) +{ + struct ocfs2_super *osb = container_of(work, struct ocfs2_super, + dquot_drop_work); + struct llist_node *list; + struct ocfs2_dquot *odquot, *next_odquot; + + list = llist_del_all(&osb->dquot_drop_list); + llist_for_each_entry_safe(odquot, next_odquot, list, list) { + /* Drop the reference we acquired in ocfs2_dquot_release() */ + dqput(&odquot->dq_dquot); + } +} + +/* + * Called when the last reference to dquot is dropped. If we are called from + * downconvert thread, we cannot do all the handling here because grabbing + * quota lock could deadlock (the node holding the quota lock could need some + * other cluster lock to proceed but with blocked downconvert thread we cannot + * release any lock). + */ static int ocfs2_release_dquot(struct dquot *dquot) { handle_t *handle; @@ -694,6 +716,19 @@ static int ocfs2_release_dquot(struct dquot *dquot) /* Check whether we are not racing with some other dqget() */ if (atomic_read(&dquot->dq_count) > 1) goto out; + /* Running from downconvert thread? Postpone quota processing to wq */ + if (current == osb->dc_task) { + /* + * Grab our own reference to dquot and queue it for delayed + * dropping. Quota code rechecks after calling + * ->release_dquot() and won't free dquot structure. + */ + dqgrab(dquot); + /* First entry on list -> queue work */ + if (llist_add(&OCFS2_DQUOT(dquot)->list, &osb->dquot_drop_list)) + queue_work(ocfs2_wq, &osb->dquot_drop_work); + goto out; + } status = ocfs2_lock_global_qf(oinfo, 1); if (status < 0) goto out; diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 49d84f80f36c..0a8972deae2b 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -1943,6 +1943,11 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err) ocfs2_disable_quotas(osb); + /* All dquots should be freed by now */ + WARN_ON(!llist_empty(&osb->dquot_drop_list)); + /* Wait for worker to be done with the work structure in osb */ + cancel_work_sync(&osb->dquot_drop_work); + ocfs2_shutdown_local_alloc(osb); /* This will disable recovery and flush any recovery work. */ @@ -2279,6 +2284,9 @@ static int ocfs2_initialize_super(struct super_block *sb, INIT_WORK(&osb->dentry_lock_work, ocfs2_drop_dl_inodes); osb->dentry_lock_list = NULL; + INIT_WORK(&osb->dquot_drop_work, ocfs2_drop_dquot_refs); + init_llist_head(&osb->dquot_drop_list); + /* get some pseudo constants for clustersize bits */ osb->s_clustersize_bits = le32_to_cpu(di->id2.i_super.s_clustersize_bits);