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authorAl Viro <viro@zeniv.linux.org.uk>2019-04-10 21:43:44 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2019-05-02 05:37:39 +0300
commitfdb0da89f4ba0c74d7d3b9e6f471e96a5766820b (patch)
tree3c82eb1fe04568315a76d03ec86617e206b12a41 /fs/inode.c
parentad7999cd701e4e058765d35cf5274ee16801e986 (diff)
downloadlinux-fdb0da89f4ba0c74d7d3b9e6f471e96a5766820b.tar.xz
new inode method: ->free_inode()
A lot of ->destroy_inode() instances end with call_rcu() of a callback that does RCU-delayed part of freeing. Introduce a new method for doing just that, with saner signature. Rules: ->destroy_inode ->free_inode f g immediate call of f(), RCU-delayed call of g() f NULL immediate call of f(), no RCU-delayed calls NULL g RCU-delayed call of g() NULL NULL RCU-delayed default freeing IOW, NULL ->free_inode gives the same behaviour as now. Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could mandate the latter form, but that would have very little benefit beyond making rules a bit more symmetric. It would break backwards compatibility, require extra boilerplate and expected semantics for (NULL, NULL) pair would have no use whatsoever... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c56
1 files changed, 34 insertions, 22 deletions
diff --git a/fs/inode.c b/fs/inode.c
index e9d97add2b36..627e1766503a 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -202,12 +202,28 @@ out:
}
EXPORT_SYMBOL(inode_init_always);
+void free_inode_nonrcu(struct inode *inode)
+{
+ kmem_cache_free(inode_cachep, inode);
+}
+EXPORT_SYMBOL(free_inode_nonrcu);
+
+static void i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ if (inode->free_inode)
+ inode->free_inode(inode);
+ else
+ free_inode_nonrcu(inode);
+}
+
static struct inode *alloc_inode(struct super_block *sb)
{
+ const struct super_operations *ops = sb->s_op;
struct inode *inode;
- if (sb->s_op->alloc_inode)
- inode = sb->s_op->alloc_inode(sb);
+ if (ops->alloc_inode)
+ inode = ops->alloc_inode(sb);
else
inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
@@ -215,22 +231,19 @@ static struct inode *alloc_inode(struct super_block *sb)
return NULL;
if (unlikely(inode_init_always(sb, inode))) {
- if (inode->i_sb->s_op->destroy_inode)
- inode->i_sb->s_op->destroy_inode(inode);
- else
- kmem_cache_free(inode_cachep, inode);
+ if (ops->destroy_inode) {
+ ops->destroy_inode(inode);
+ if (!ops->free_inode)
+ return NULL;
+ }
+ inode->free_inode = ops->free_inode;
+ i_callback(&inode->i_rcu);
return NULL;
}
return inode;
}
-void free_inode_nonrcu(struct inode *inode)
-{
- kmem_cache_free(inode_cachep, inode);
-}
-EXPORT_SYMBOL(free_inode_nonrcu);
-
void __destroy_inode(struct inode *inode)
{
BUG_ON(inode_has_buffers(inode));
@@ -253,20 +266,19 @@ void __destroy_inode(struct inode *inode)
}
EXPORT_SYMBOL(__destroy_inode);
-static void i_callback(struct rcu_head *head)
-{
- struct inode *inode = container_of(head, struct inode, i_rcu);
- kmem_cache_free(inode_cachep, inode);
-}
-
static void destroy_inode(struct inode *inode)
{
+ const struct super_operations *ops = inode->i_sb->s_op;
+
BUG_ON(!list_empty(&inode->i_lru));
__destroy_inode(inode);
- if (inode->i_sb->s_op->destroy_inode)
- inode->i_sb->s_op->destroy_inode(inode);
- else
- call_rcu(&inode->i_rcu, i_callback);
+ if (ops->destroy_inode) {
+ ops->destroy_inode(inode);
+ if (!ops->free_inode)
+ return;
+ }
+ inode->free_inode = ops->free_inode;
+ call_rcu(&inode->i_rcu, i_callback);
}
/**