Linux 4.19.76

[platform/kernel/linux-rpi.git] / fs / dcache.c

diff --git a/fs/dcache.c b/fs/dcache.c
index 2e7e8d8..6e00223 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -344,7 +344,7 @@ static void dentry_free(struct dentry *dentry)
                }
        }
        /* if dentry was never visible to RCU, immediate free is OK */
-       if (!(dentry->d_flags & DCACHE_RCUACCESS))
+       if (dentry->d_flags & DCACHE_NORCU)
                __d_free(&dentry->d_u.d_rcu);
        else
                call_rcu(&dentry->d_u.d_rcu, __d_free);
@@ -1202,15 +1202,11 @@ static enum lru_status dentry_lru_isolate_shrink(struct list_head *item,
  */
 void shrink_dcache_sb(struct super_block *sb)
 {
-       long freed;
-
        do {
                LIST_HEAD(dispose);
 
-               freed = list_lru_walk(&sb->s_dentry_lru,
+               list_lru_walk(&sb->s_dentry_lru,
                        dentry_lru_isolate_shrink, &dispose, 1024);
-
-               this_cpu_sub(nr_dentry_unused, freed);
                shrink_dentry_list(&dispose);
        } while (list_lru_count(&sb->s_dentry_lru) > 0);
 }
@@ -1698,7 +1694,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
        struct dentry *dentry = __d_alloc(parent->d_sb, name);
        if (!dentry)
                return NULL;
-       dentry->d_flags |= DCACHE_RCUACCESS;
        spin_lock(&parent->d_lock);
        /*
         * don't need child lock because it is not subject
@@ -1723,7 +1718,7 @@ struct dentry *d_alloc_cursor(struct dentry * parent)
 {
        struct dentry *dentry = d_alloc_anon(parent->d_sb);
        if (dentry) {
-               dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR;
+               dentry->d_flags |= DCACHE_DENTRY_CURSOR;
                dentry->d_parent = dget(parent);
        }
        return dentry;
@@ -1736,10 +1731,17 @@ struct dentry *d_alloc_cursor(struct dentry * parent)
  *
  * For a filesystem that just pins its dentries in memory and never
  * performs lookups at all, return an unhashed IS_ROOT dentry.
+ * This is used for pipes, sockets et.al. - the stuff that should
+ * never be anyone's children or parents.  Unlike all other
+ * dentries, these will not have RCU delay between dropping the
+ * last reference and freeing them.
  */
 struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
 {
-       return __d_alloc(sb, name);
+       struct dentry *dentry = __d_alloc(sb, name);
+       if (likely(dentry))
+               dentry->d_flags |= DCACHE_NORCU;
+       return dentry;
 }
 EXPORT_SYMBOL(d_alloc_pseudo);
 
@@ -1903,12 +1905,10 @@ struct dentry *d_make_root(struct inode *root_inode)
 
        if (root_inode) {
                res = d_alloc_anon(root_inode->i_sb);
-               if (res) {
-                       res->d_flags |= DCACHE_RCUACCESS;
+               if (res)
                        d_instantiate(res, root_inode);
-               } else {
+               else
                        iput(root_inode);
-               }
        }
        return res;
 }
@@ -2773,9 +2773,7 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
                copy_name(dentry, target);
                target->d_hash.pprev = NULL;
                dentry->d_parent->d_lockref.count++;
-               if (dentry == old_parent)
-                       dentry->d_flags |= DCACHE_RCUACCESS;
-               else
+               if (dentry != old_parent) /* wasn't IS_ROOT */
                        WARN_ON(!--old_parent->d_lockref.count);
        } else {
                target->d_parent = old_parent;