From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH, RFC] lockd: stop abusing file_lock_list Date: Tue, 14 Feb 2006 20:20:51 +0100 Message-ID: <20060214192051.GA20751@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from verein.lst.de ([213.95.11.210]:29905 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S1422673AbWBNTUx (ORCPT ); Tue, 14 Feb 2006 14:20:53 -0500 Received: from verein.lst.de (localhost [127.0.0.1]) by mail.lst.de (8.12.3/8.12.3/Debian-7.1) with ESMTP id k1EJKpRT020856 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Tue, 14 Feb 2006 20:20:51 +0100 Received: (from hch@localhost) by verein.lst.de (8.12.3/8.12.3/Debian-6.6) id k1EJKptm020854 for linux-fsdevel@vger.kernel.org; Tue, 14 Feb 2006 20:20:51 +0100 To: linux-fsdevel@vger.kernel.org Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Currently lockd directly access the file_lock_list from fs/locks.c. It does so to mark locks granted or reclaimable. This is very suboptimal, because a) lockd needs to poke into locks.c internals, and b) it needs to iterate over all locks in the system for marking locks granted or reclaimable. This patch adds lists for granted and reclaimable locks to the nlm_host structure instead, and adds locks to those. nlmclnt_lock: now adds the lock to h_granted instead of setting the NFS_LCK_GRANTED, still O(1) nlmclnt_mark_reclaim: goes away completely, replaced by a list_splice_init. Complexity reduced from O(locks in the system) to O(1) reclaimer: iterates over h_reclaim now, complexity reduced from O(locks in the system) to O(locks per nlm_host) Index: linux-2.6/fs/lockd/clntlock.c =================================================================== --- linux-2.6.orig/fs/lockd/clntlock.c 2006-02-08 21:04:46.000000000 +0100 +++ linux-2.6/fs/lockd/clntlock.c 2006-02-08 21:23:05.000000000 +0100 @@ -140,34 +140,6 @@ */ /* - * Mark the locks for reclaiming. - * FIXME: In 2.5 we don't want to iterate through any global file_lock_list. - * Maintain NLM lock reclaiming lists in the nlm_host instead. - */ -static -void nlmclnt_mark_reclaim(struct nlm_host *host) -{ - struct file_lock *fl; - struct inode *inode; - struct list_head *tmp; - - list_for_each(tmp, &file_lock_list) { - fl = list_entry(tmp, struct file_lock, fl_link); - - inode = fl->fl_file->f_dentry->d_inode; - if (inode->i_sb->s_magic != NFS_SUPER_MAGIC) - continue; - if (fl->fl_u.nfs_fl.owner == NULL) - continue; - if (fl->fl_u.nfs_fl.owner->host != host) - continue; - if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED)) - continue; - fl->fl_u.nfs_fl.flags |= NFS_LCK_RECLAIM; - } -} - -/* * Someone has sent us an SM_NOTIFY. Ensure we bind to the new port number, * that we mark locks for reclaiming, and that we bump the pseudo NSM state. */ @@ -179,7 +151,12 @@ host->h_state++; host->h_nextrebind = 0; nlm_rebind_host(host); - nlmclnt_mark_reclaim(host); + + /* + * Mark the locks for reclaiming. + */ + list_splice_init(&host->h_granted, &host->h_reclaim); + dprintk("NLM: reclaiming locks for host %s", host->h_name); } @@ -208,9 +185,7 @@ { struct nlm_host *host = (struct nlm_host *) ptr; struct nlm_wait *block; - struct list_head *tmp; - struct file_lock *fl; - struct inode *inode; + struct file_lock *fl, *next; daemonize("%s-reclaim", host->h_name); allow_signal(SIGKILL); @@ -222,20 +197,9 @@ /* First, reclaim all locks that have been marked. */ restart: - list_for_each(tmp, &file_lock_list) { - fl = list_entry(tmp, struct file_lock, fl_link); - - inode = fl->fl_file->f_dentry->d_inode; - if (inode->i_sb->s_magic != NFS_SUPER_MAGIC) - continue; - if (fl->fl_u.nfs_fl.owner == NULL) - continue; - if (fl->fl_u.nfs_fl.owner->host != host) - continue; - if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM)) - continue; + list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) { + list_del(&fl->fl_u.nfs_fl.list); - fl->fl_u.nfs_fl.flags &= ~NFS_LCK_RECLAIM; nlmclnt_reclaim(host, fl); if (signalled()) break; Index: linux-2.6/fs/lockd/clntproc.c =================================================================== --- linux-2.6.orig/fs/lockd/clntproc.c 2006-02-08 21:04:46.000000000 +0100 +++ linux-2.6/fs/lockd/clntproc.c 2006-02-08 21:22:17.000000000 +0100 @@ -504,7 +504,6 @@ { BUG_ON(fl->fl_ops != NULL); fl->fl_u.nfs_fl.state = 0; - fl->fl_u.nfs_fl.flags = 0; fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); fl->fl_ops = &nlmclnt_lock_ops; } @@ -591,8 +590,8 @@ if (resp->status == NLM_LCK_GRANTED) { fl->fl_u.nfs_fl.state = host->h_state; - fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED; fl->fl_flags |= FL_SLEEP; + list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted); do_vfs_lock(fl); } status = nlm_stat_to_errno(resp->status); @@ -658,9 +657,11 @@ struct nlm_res *resp = &req->a_res; int status; - /* Clean the GRANTED flag now so the lock doesn't get - * reclaimed while we're stuck in the unlock call. */ - fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED; + /* + * Remove from the granted list now so the lock doesn't get + * reclaimed while we're stuck in the unlock call. + */ + list_del(&fl->fl_u.nfs_fl.list); if (req->a_flags & RPC_TASK_ASYNC) { status = nlmclnt_async_call(req, NLMPROC_UNLOCK, Index: linux-2.6/fs/lockd/host.c =================================================================== --- linux-2.6.orig/fs/lockd/host.c 2006-01-10 13:46:05.000000000 +0100 +++ linux-2.6/fs/lockd/host.c 2006-02-08 21:12:25.000000000 +0100 @@ -123,6 +123,8 @@ nlm_hosts[hash] = host; INIT_LIST_HEAD(&host->h_lockowners); spin_lock_init(&host->h_lock); + INIT_LIST_HEAD(&host->h_granted); + INIT_LIST_HEAD(&host->h_reclaim); if (++nrhosts > NLM_HOST_MAX) next_gc = 0; Index: linux-2.6/include/linux/lockd/lockd.h =================================================================== --- linux-2.6.orig/include/linux/lockd/lockd.h 2006-02-04 13:35:01.000000000 +0100 +++ linux-2.6/include/linux/lockd/lockd.h 2006-02-08 21:11:47.000000000 +0100 @@ -58,6 +58,8 @@ unsigned long h_expires; /* eligible for GC */ struct list_head h_lockowners; /* Lockowners for the client */ spinlock_t h_lock; + struct list_head h_granted; /* Locks in GRANTED state */ + struct list_head h_reclaim; /* Locks in RECLAIM state */ }; /* Index: linux-2.6/include/linux/nfs_fs_i.h =================================================================== --- linux-2.6.orig/include/linux/nfs_fs_i.h 2005-12-27 18:30:35.000000000 +0100 +++ linux-2.6/include/linux/nfs_fs_i.h 2006-02-08 21:18:38.000000000 +0100 @@ -12,8 +12,8 @@ */ struct nfs_lock_info { u32 state; - u32 flags; struct nlm_lockowner *owner; + struct list_head list; }; struct nfs4_lock_state; @@ -21,10 +21,4 @@ struct nfs4_lock_state *owner; }; -/* - * Lock flag values - */ -#define NFS_LCK_GRANTED 0x0001 /* lock has been granted */ -#define NFS_LCK_RECLAIM 0x0002 /* lock marked for reclaiming */ - #endif Index: linux-2.6/fs/locks.c =================================================================== --- linux-2.6.orig/fs/locks.c 2006-01-10 13:46:05.000000000 +0100 +++ linux-2.6/fs/locks.c 2006-02-08 21:24:27.000000000 +0100 @@ -139,10 +139,7 @@ #define for_each_lock(inode, lockp) \ for (lockp = &inode->i_flock; *lockp != NULL; lockp = &(*lockp)->fl_next) -LIST_HEAD(file_lock_list); - -EXPORT_SYMBOL(file_lock_list); - +static LIST_HEAD(file_lock_list); static LIST_HEAD(blocked_list); static kmem_cache_t *filelock_cache; Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2006-02-08 20:49:43.000000000 +0100 +++ linux-2.6/include/linux/fs.h 2006-02-08 21:24:03.000000000 +0100 @@ -730,8 +730,6 @@ #define OFFT_OFFSET_MAX INT_LIMIT(off_t) #endif -extern struct list_head file_lock_list; - #include extern int fcntl_getlk(struct file *, struct flock __user *);