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Commit 30f4e20a authored by Trond Myklebust's avatar Trond Myklebust Committed by Linus Torvalds
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[PATCH] NLM: Ensure we do not Oops in the case of an unlock 



In theory, NLM specs assure us that the server will only reply LCK_GRANTED or
LCK_DENIED_GRACE_PERIOD to our NLM_UNLOCK request.

In practice, we should not assume this to be the case, and the code will
currently Oops if we do.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e6d83d55

fs/lockd/clntproc.c

+7 −2
Original line number Original line Diff line number Diff line
@@ -662,12 +662,18 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) 
	 * reclaimed while we're stuck in the unlock call. */

	 * reclaimed while we're stuck in the unlock call. */

	fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;

	fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;





	/*

	 * Note: the server is supposed to either grant us the unlock

	 * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either

	 * case, we want to unlock.

	 */

	do_vfs_lock(fl);



	if (req->a_flags & RPC_TASK_ASYNC) {

	if (req->a_flags & RPC_TASK_ASYNC) {

		status = nlmclnt_async_call(req, NLMPROC_UNLOCK,

		status = nlmclnt_async_call(req, NLMPROC_UNLOCK,

					&nlmclnt_unlock_ops);

					&nlmclnt_unlock_ops);

		/* Hrmf... Do the unlock early since locks_remove_posix()

		/* Hrmf... Do the unlock early since locks_remove_posix()

		 * really expects us to free the lock synchronously */

		 * really expects us to free the lock synchronously */

		do_vfs_lock(fl);

		if (status < 0) {

		if (status < 0) {

			nlmclnt_release_lockargs(req);

			nlmclnt_release_lockargs(req);

			kfree(req);

			kfree(req);
@@ -680,7 +686,6 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl) 
	if (status < 0)

	if (status < 0)

		return status;

		return status;





	do_vfs_lock(fl);

	if (resp->status == NLM_LCK_GRANTED)

	if (resp->status == NLM_LCK_GRANTED)

		return 0;

		return 0;