Commit 9542e6a6 authored by Trond Myklebust's avatar Trond Myklebust Committed by J. Bruce Fields

nfsd: Containerise filecache laundrette

Ensure that if the filecache laundrette gets stuck, it only affects
the knfsd instances of one container.

The notifier callbacks can be called from various contexts so avoid
using synchonous filesystem operations that might deadlock.
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 36ebbdb9
......@@ -44,6 +44,17 @@ 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;
};
struct workqueue_struct *nfsd_filecache_wq __read_mostly;
static struct kmem_cache *nfsd_file_slab;
static struct kmem_cache *nfsd_file_mark_slab;
static struct nfsd_fcache_bucket *nfsd_file_hashtbl;
......@@ -52,32 +63,21 @@ 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);
enum nfsd_file_laundrette_ctl {
NFSD_FILE_LAUNDRETTE_NOFLUSH = 0,
NFSD_FILE_LAUNDRETTE_MAY_FLUSH
};
static void nfsd_file_gc(void);
static void
nfsd_file_schedule_laundrette(enum nfsd_file_laundrette_ctl ctl)
nfsd_file_schedule_laundrette(void)
{
long count = atomic_long_read(&nfsd_filecache_count);
if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags))
return;
/* Be more aggressive about scanning if over the threshold */
if (count > NFSD_FILE_LRU_THRESHOLD)
mod_delayed_work(system_wq, &nfsd_filecache_laundrette, 0);
else
schedule_delayed_work(&nfsd_filecache_laundrette, NFSD_LAUNDRETTE_DELAY);
if (ctl == NFSD_FILE_LAUNDRETTE_NOFLUSH)
return;
/* ...and don't delay flushing if we're out of control */
if (count >= NFSD_FILE_LRU_LIMIT)
flush_delayed_work(&nfsd_filecache_laundrette);
queue_delayed_work(system_wq, &nfsd_filecache_laundrette,
NFSD_LAUNDRETTE_DELAY);
}
static void
......@@ -312,7 +312,9 @@ nfsd_file_put(struct nfsd_file *nf)
set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
if (nfsd_file_put_noref(nf) == 1 && is_hashed && unused)
nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_MAY_FLUSH);
nfsd_file_schedule_laundrette();
if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT)
nfsd_file_gc();
}
struct nfsd_file *
......@@ -353,6 +355,58 @@ nfsd_file_dispose_list_sync(struct list_head *dispose)
flush_delayed_fput();
}
static void
nfsd_file_list_remove_disposal(struct list_head *dst,
struct nfsd_fcache_disposal *l)
{
spin_lock(&l->lock);
list_splice_init(&l->freeme, dst);
spin_unlock(&l->lock);
}
static void
nfsd_file_list_add_disposal(struct list_head *files, struct net *net)
{
struct nfsd_fcache_disposal *l;
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();
}
static void
nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src,
struct net *net)
{
struct nfsd_file *nf, *tmp;
list_for_each_entry_safe(nf, tmp, src, nf_lru) {
if (nf->nf_net == net)
list_move_tail(&nf->nf_lru, dst);
}
}
static void
nfsd_file_dispose_list_delayed(struct list_head *dispose)
{
LIST_HEAD(list);
struct nfsd_file *nf;
while(!list_empty(dispose)) {
nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
nfsd_file_list_add_pernet(&list, dispose, nf->nf_net);
nfsd_file_list_add_disposal(&list, nf->nf_net);
}
}
/*
* Note this can deadlock with nfsd_file_cache_purge.
*/
......@@ -399,17 +453,40 @@ nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
return LRU_SKIP;
}
static void
nfsd_file_lru_dispose(struct list_head *head)
static unsigned long
nfsd_file_lru_walk_list(struct shrink_control *sc)
{
LIST_HEAD(head);
struct nfsd_file *nf;
unsigned long ret;
list_for_each_entry(nf, head, nf_lru) {
if (sc)
ret = list_lru_shrink_walk(&nfsd_file_lru, sc,
nfsd_file_lru_cb, &head);
else
ret = list_lru_walk(&nfsd_file_lru,
nfsd_file_lru_cb,
&head, LONG_MAX);
list_for_each_entry(nf, &head, nf_lru) {
spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
nfsd_file_do_unhash(nf);
spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
}
nfsd_file_dispose_list(head);
nfsd_file_dispose_list_delayed(&head);
return ret;
}
static void
nfsd_file_gc(void)
{
nfsd_file_lru_walk_list(NULL);
}
static void
nfsd_file_gc_worker(struct work_struct *work)
{
nfsd_file_gc();
nfsd_file_schedule_laundrette();
}
static unsigned long
......@@ -421,12 +498,7 @@ nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc)
static unsigned long
nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc)
{
LIST_HEAD(head);
unsigned long ret;
ret = list_lru_shrink_walk(&nfsd_file_lru, sc, nfsd_file_lru_cb, &head);
nfsd_file_lru_dispose(&head);
return ret;
return nfsd_file_lru_walk_list(sc);
}
static struct shrinker nfsd_file_shrinker = {
......@@ -488,7 +560,7 @@ nfsd_file_close_inode(struct inode *inode)
__nfsd_file_close_inode(inode, hashval, &dispose);
trace_nfsd_file_close_inode(inode, hashval, !list_empty(&dispose));
nfsd_file_dispose_list(&dispose);
nfsd_file_dispose_list_delayed(&dispose);
}
/**
......@@ -504,16 +576,11 @@ static void
nfsd_file_delayed_close(struct work_struct *work)
{
LIST_HEAD(head);
struct nfsd_fcache_disposal *l = container_of(work,
struct nfsd_fcache_disposal, work);
list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, &head, LONG_MAX);
if (test_and_clear_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags))
nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_NOFLUSH);
if (!list_empty(&head)) {
nfsd_file_lru_dispose(&head);
flush_delayed_fput();
}
nfsd_file_list_remove_disposal(&head, l);
nfsd_file_dispose_list(&head);
}
static int
......@@ -574,6 +641,10 @@ nfsd_file_cache_init(void)
if (nfsd_file_hashtbl)
return 0;
nfsd_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0);
if (!nfsd_filecache_wq)
goto out;
nfsd_file_hashtbl = kcalloc(NFSD_FILE_HASH_SIZE,
sizeof(*nfsd_file_hashtbl), GFP_KERNEL);
if (!nfsd_file_hashtbl) {
......@@ -627,7 +698,7 @@ nfsd_file_cache_init(void)
spin_lock_init(&nfsd_file_hashtbl[i].nfb_lock);
}
INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_delayed_close);
INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker);
out:
return ret;
out_notifier:
......@@ -643,6 +714,8 @@ nfsd_file_cache_init(void)
nfsd_file_mark_slab = NULL;
kfree(nfsd_file_hashtbl);
nfsd_file_hashtbl = NULL;
destroy_workqueue(nfsd_filecache_wq);
nfsd_filecache_wq = NULL;
goto out;
}
......@@ -681,6 +754,88 @@ nfsd_file_cache_purge(struct net *net)
}
}
static struct nfsd_fcache_disposal *
nfsd_alloc_fcache_disposal(struct net *net)
{
struct nfsd_fcache_disposal *l;
l = kmalloc(sizeof(*l), GFP_KERNEL);
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;
}
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;
}
static void
nfsd_free_fcache_disposal_net(struct net *net)
{
struct nfsd_fcache_disposal *l;
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();
}
int
nfsd_file_cache_start_net(struct net *net)
{
return nfsd_alloc_fcache_disposal_net(net);
}
void
nfsd_file_cache_shutdown_net(struct net *net)
{
nfsd_file_cache_purge(net);
nfsd_free_fcache_disposal_net(net);
}
void
nfsd_file_cache_shutdown(void)
{
......@@ -705,6 +860,8 @@ nfsd_file_cache_shutdown(void)
nfsd_file_mark_slab = NULL;
kfree(nfsd_file_hashtbl);
nfsd_file_hashtbl = NULL;
destroy_workqueue(nfsd_filecache_wq);
nfsd_filecache_wq = NULL;
}
static bool
......@@ -872,7 +1029,8 @@ nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount,
nfsd_file_hashtbl[hashval].nfb_count);
spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
atomic_long_inc(&nfsd_filecache_count);
if (atomic_long_inc_return(&nfsd_filecache_count) >= NFSD_FILE_LRU_THRESHOLD)
nfsd_file_gc();
nf->nf_mark = nfsd_file_mark_find_or_create(nf);
if (nf->nf_mark)
......
......@@ -51,6 +51,8 @@ struct nfsd_file {
int nfsd_file_cache_init(void);
void nfsd_file_cache_purge(struct net *);
void nfsd_file_cache_shutdown(void);
int nfsd_file_cache_start_net(struct net *net);
void nfsd_file_cache_shutdown_net(struct net *net);
void nfsd_file_put(struct nfsd_file *nf);
struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
void nfsd_file_close_inode_sync(struct inode *inode);
......
......@@ -400,13 +400,18 @@ static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cre
nn->lockd_up = true;
}
ret = nfs4_state_start_net(net);
ret = nfsd_file_cache_start_net(net);
if (ret)
goto out_lockd;
ret = nfs4_state_start_net(net);
if (ret)
goto out_filecache;
nn->nfsd_net_up = true;
return 0;
out_filecache:
nfsd_file_cache_shutdown_net(net);
out_lockd:
if (nn->lockd_up) {
lockd_down(net);
......@@ -421,7 +426,7 @@ static void nfsd_shutdown_net(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
nfsd_file_cache_purge(net);
nfsd_file_cache_shutdown_net(net);
nfs4_state_shutdown_net(net);
if (nn->lockd_up) {
lockd_down(net);
......
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