FS-Cache: Clear netfs pointers in cookie after detaching object, not before (7e311a20) · Commits · 戴 / test

Clear the pointers from the fscache_cookie struct to netfs private data after clearing the pointer to the cookie from the fscache_object struct and releasing the object lock, rather than before. This allows the netfs private data pointers to be relied on simply by holding the object lock, rather than having to hold the cookie lock. This is makes things simpler as the cookie lock has to be taken before the object lock, but sometimes the object pointer is all that the code has. Signed-off-by:

David Howells <dhowells@redhat.com>

fs/fscache/cookie.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -437,12 +437,8 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)

		event = retire ? FSCACHE_OBJECT_EV_RETIRE : FSCACHE_OBJECT_EV_RELEASE;

		/* detach pointers back to the netfs */
		spin_lock(&cookie->lock);

		cookie->netfs_data = NULL;
		cookie->def = NULL;

		/* break links with all the active objects */
		while (!hlist_empty(&cookie->backing_objects)) {
		object = hlist_entry(cookie->backing_objects.first,
		@@ -465,6 +461,10 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, int retire)
		BUG();
		}

		/* detach pointers back to the netfs */
		cookie->netfs_data = NULL;
		cookie->def = NULL;

		spin_unlock(&cookie->lock);

		if (cookie->parent) {

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