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Commit 26bcbf96 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Trond Myklebust
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lockd: stop abusing file_lock_list 



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)

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 04266473

fs/lockd/clntlock.c

+9 −45
Original line number Diff line number Diff line
@@ -154,34 +154,6 @@ u32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock) 
 * server crash.

 */



/*

 * 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.
@@ -194,7 +166,12 @@ void nlmclnt_prepare_reclaim(struct nlm_host *host, u32 newstate) 
	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);

}
@@ -223,9 +200,7 @@ reclaimer(void *ptr) 
{

	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);
@@ -237,20 +212,9 @@ reclaimer(void *ptr) 


	/* 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;

fs/lockd/clntproc.c

+6 −5
Original line number Diff line number Diff line
@@ -465,7 +465,6 @@ static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *ho 
{

	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;

}
@@ -552,8 +551,8 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl) 


	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);
@@ -619,9 +618,11 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) 
	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);



	/*

	 * Note: the server is supposed to either grant us the unlock

fs/lockd/host.c

+2 −0
Original line number Diff line number Diff line
@@ -123,6 +123,8 @@ nlm_lookup_host(int server, struct sockaddr_in *sin, 
	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;

fs/locks.c

+1 −4
Original line number Diff line number Diff line
@@ -139,10 +139,7 @@ int lease_break_time = 45; 
#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;

include/linux/fs.h

+0 −2
Original line number Diff line number Diff line
@@ -730,8 +730,6 @@ struct file_lock { 
#define OFFT_OFFSET_MAX	INT_LIMIT(off_t)

#endif



extern struct list_head file_lock_list;



#include <linux/fcntl.h>



extern int fcntl_getlk(struct file *, struct flock __user *);