Patch "NFSD: simplify per-net file cache management" has been added to the 5.10-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    NFSD: simplify per-net file cache management

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-simplify-per-net-file-cache-management.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 47410849ed2ffece288a34f43ca867af67cd6983
Author: NeilBrown <neilb@xxxxxxx>
Date:   Wed Dec 1 10:58:14 2021 +1100

    NFSD: simplify per-net file cache management
    
    [ Upstream commit 1463b38e7cf34d4cc60f41daff459ad807b2e408 ]
    
    We currently have a 'laundrette' for closing cached files - a different
    work-item for each network-namespace.
    
    These 'laundrettes' (aka struct nfsd_fcache_disposal) are currently on a
    list, and are freed using rcu.
    
    The list is not necessary as we have a per-namespace structure (struct
    nfsd_net) which can hold a link to the nfsd_fcache_disposal.
    The use of kfree_rcu is also unnecessary as the cache is cleaned of all
    files associated with a given namespace, and no new files can be added,
    before the nfsd_fcache_disposal is freed.
    
    So add a '->fcache_disposal' link to nfsd_net, and discard the list
    management and rcu usage.
    
    Signed-off-by: NeilBrown <neilb@xxxxxxx>
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 8cd7d5d6955a0..b6ef8256c9c64 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -44,12 +44,9 @@ struct nfsd_fcache_bucket {
 static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
 
 struct nfsd_fcache_disposal {
-	struct list_head list;
 	struct work_struct work;
-	struct net *net;
 	spinlock_t lock;
 	struct list_head freeme;
-	struct rcu_head rcu;
 };
 
 static struct workqueue_struct *nfsd_filecache_wq __read_mostly;
@@ -62,8 +59,6 @@ static long				nfsd_file_lru_flags;
 static struct fsnotify_group		*nfsd_file_fsnotify_group;
 static atomic_long_t			nfsd_filecache_count;
 static struct delayed_work		nfsd_filecache_laundrette;
-static DEFINE_SPINLOCK(laundrette_lock);
-static LIST_HEAD(laundrettes);
 
 static void nfsd_file_gc(void);
 
@@ -366,19 +361,13 @@ nfsd_file_list_remove_disposal(struct list_head *dst,
 static void
 nfsd_file_list_add_disposal(struct list_head *files, struct net *net)
 {
-	struct nfsd_fcache_disposal *l;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct nfsd_fcache_disposal *l = nn->fcache_disposal;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(l, &laundrettes, list) {
-		if (l->net == net) {
-			spin_lock(&l->lock);
-			list_splice_tail_init(files, &l->freeme);
-			spin_unlock(&l->lock);
-			queue_work(nfsd_filecache_wq, &l->work);
-			break;
-		}
-	}
-	rcu_read_unlock();
+	spin_lock(&l->lock);
+	list_splice_tail_init(files, &l->freeme);
+	spin_unlock(&l->lock);
+	queue_work(nfsd_filecache_wq, &l->work);
 }
 
 static void
@@ -754,7 +743,7 @@ nfsd_file_cache_purge(struct net *net)
 }
 
 static struct nfsd_fcache_disposal *
-nfsd_alloc_fcache_disposal(struct net *net)
+nfsd_alloc_fcache_disposal(void)
 {
 	struct nfsd_fcache_disposal *l;
 
@@ -762,7 +751,6 @@ nfsd_alloc_fcache_disposal(struct net *net)
 	if (!l)
 		return NULL;
 	INIT_WORK(&l->work, nfsd_file_delayed_close);
-	l->net = net;
 	spin_lock_init(&l->lock);
 	INIT_LIST_HEAD(&l->freeme);
 	return l;
@@ -771,61 +759,27 @@ nfsd_alloc_fcache_disposal(struct net *net)
 static void
 nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l)
 {
-	rcu_assign_pointer(l->net, NULL);
 	cancel_work_sync(&l->work);
 	nfsd_file_dispose_list(&l->freeme);
-	kfree_rcu(l, rcu);
-}
-
-static void
-nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l)
-{
-	spin_lock(&laundrette_lock);
-	list_add_tail_rcu(&l->list, &laundrettes);
-	spin_unlock(&laundrette_lock);
-}
-
-static void
-nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l)
-{
-	spin_lock(&laundrette_lock);
-	list_del_rcu(&l->list);
-	spin_unlock(&laundrette_lock);
-}
-
-static int
-nfsd_alloc_fcache_disposal_net(struct net *net)
-{
-	struct nfsd_fcache_disposal *l;
-
-	l = nfsd_alloc_fcache_disposal(net);
-	if (!l)
-		return -ENOMEM;
-	nfsd_add_fcache_disposal(l);
-	return 0;
+	kfree(l);
 }
 
 static void
 nfsd_free_fcache_disposal_net(struct net *net)
 {
-	struct nfsd_fcache_disposal *l;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct nfsd_fcache_disposal *l = nn->fcache_disposal;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(l, &laundrettes, list) {
-		if (l->net != net)
-			continue;
-		nfsd_del_fcache_disposal(l);
-		rcu_read_unlock();
-		nfsd_free_fcache_disposal(l);
-		return;
-	}
-	rcu_read_unlock();
+	nfsd_free_fcache_disposal(l);
 }
 
 int
 nfsd_file_cache_start_net(struct net *net)
 {
-	return nfsd_alloc_fcache_disposal_net(net);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nn->fcache_disposal = nfsd_alloc_fcache_disposal();
+	return nn->fcache_disposal ? 0 : -ENOMEM;
 }
 
 void
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 021acdc0d03bb..9e8b77d2a3a47 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -185,6 +185,8 @@ struct nfsd_net {
 
 	/* utsname taken from the process that starts the server */
 	char			nfsd_name[UNX_MAXNODENAME+1];
+
+	struct nfsd_fcache_disposal *fcache_disposal;
 };
 
 /* Simple check to find out if a given net was properly initialized */




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux