Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

NFS: Enforce an upper limit on the number of cached access call

Browse source 
This may be used to limit the number of cached credentials building up
inside the access cache.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2014-07-21 13:53:48 -04:00
parent bae6746ff3
commit 3a505845cd
1 changed files with 35 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

42
fs/nfs/dir.c
View file

@ -2028,6 +2028,10 @@ static DEFINE_SPINLOCK(nfs_access_lru_lock);
static LIST_HEAD(nfs_access_lru_list);
static atomic_long_t nfs_access_nr_entries;
static unsigned long nfs_access_max_cachesize = ULONG_MAX;
module_param(nfs_access_max_cachesize, ulong, 0644);
MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length");
static void nfs_access_free_entry(struct nfs_access_entry *entry)
{
put_rpccred(entry->cred);
@ -2048,19 +2052,14 @@ static void nfs_access_free_list(struct list_head *head)
}
}
unsigned long
nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
static unsigned long
nfs_do_access_cache_scan(unsigned int nr_to_scan)
{
LIST_HEAD(head);
struct nfs_inode *nfsi, *next;
struct nfs_access_entry *cache;
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
long freed = 0;
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
return SHRINK_STOP;
spin_lock(&nfs_access_lru_lock);
list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
struct inode *inode;
@ -2093,12 +2092,40 @@ nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
return freed;
}
unsigned long
nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
{
int nr_to_scan = sc->nr_to_scan;
gfp_t gfp_mask = sc->gfp_mask;
if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
return SHRINK_STOP;
return nfs_do_access_cache_scan(nr_to_scan);
}
unsigned long
nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc)
{
return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
}
static void
nfs_access_cache_enforce_limit(void)
{
long nr_entries = atomic_long_read(&nfs_access_nr_entries);
unsigned long diff;
unsigned int nr_to_scan;
if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize)
return;
nr_to_scan = 100;
diff = nr_entries - nfs_access_max_cachesize;
if (diff < nr_to_scan)
nr_to_scan = diff;
nfs_do_access_cache_scan(nr_to_scan);
}
static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
{
struct rb_root *root_node = &nfsi->access_cache;
@ -2244,6 +2271,7 @@ void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
&nfs_access_lru_list);
spin_unlock(&nfs_access_lru_lock);
}
nfs_access_cache_enforce_limit();
}
EXPORT_SYMBOL_GPL(nfs_access_add_cache);