NFS: Convert lookups of the lock context to RCU (1db97eaa) · Commits · 戴 / test

fs/nfs/inode.c

+12 −13

Original line number	Diff line number	Diff line
		@@ -857,15 +857,14 @@ static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)

		static struct nfs_lock_context __nfs_find_lock_context(struct nfs_open_context ctx)
		{
		struct nfs_lock_context *head = &ctx->lock_context;
		struct nfs_lock_context *pos = head;
		struct nfs_lock_context *pos;

		do {
		list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
		if (pos->lockowner != current->files)
		continue;
		refcount_inc(&pos->count);
		if (refcount_inc_not_zero(&pos->count))
		return pos;
		} while ((pos = list_entry(pos->list.next, typeof(*pos), list)) != head);
		}
		return NULL;
		}

		@@ -874,10 +873,10 @@ struct nfs_lock_context nfs_get_lock_context(struct nfs_open_context ctx)
		struct nfs_lock_context res, new = NULL;
		struct inode *inode = d_inode(ctx->dentry);

		spin_lock(&inode->i_lock);
		rcu_read_lock();
		res = __nfs_find_lock_context(ctx);
		rcu_read_unlock();
		if (res == NULL) {
		spin_unlock(&inode->i_lock);
		new = kmalloc(sizeof(*new), GFP_KERNEL);
		if (new == NULL)
		return ERR_PTR(-ENOMEM);
		@@ -885,14 +884,14 @@ struct nfs_lock_context nfs_get_lock_context(struct nfs_open_context ctx)
		spin_lock(&inode->i_lock);
		res = __nfs_find_lock_context(ctx);
		if (res == NULL) {
		list_add_tail(&new->list, &ctx->lock_context.list);
		list_add_tail_rcu(&new->list, &ctx->lock_context.list);
		new->open_context = ctx;
		res = new;
		new = NULL;
		}
		}
		spin_unlock(&inode->i_lock);
		kfree(new);
		}
		return res;
		}
		EXPORT_SYMBOL_GPL(nfs_get_lock_context);
		@@ -904,9 +903,9 @@ void nfs_put_lock_context(struct nfs_lock_context *l_ctx)

		if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
		return;
		list_del(&l_ctx->list);
		list_del_rcu(&l_ctx->list);
		spin_unlock(&inode->i_lock);
		kfree(l_ctx);
		kfree_rcu(l_ctx, rcu_head);
		}
		EXPORT_SYMBOL_GPL(nfs_put_lock_context);

include/linux/nfs_fs.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -62,6 +62,7 @@ struct nfs_lock_context {
		struct nfs_open_context *open_context;
		fl_owner_t lockowner;
		atomic_t io_count;
		struct rcu_head rcu_head;
		};

		struct nfs4_state;

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