Commit 39be4502 authored by Olaf Kirch's avatar Olaf Kirch Committed by Linus Torvalds
Browse files

[PATCH] knfsd: match GRANTED_RES replies using cookies 



When we send a GRANTED_MSG call, we current copy the NLM cookie provided in
the original LOCK call - because in 1996, some broken clients seemed to rely
on this bug.  However, this means the cookies are not unique, so that when the
client's GRANTED_RES message comes back, we cannot simply match it based on
the cookie, but have to use the client's IP address in addition.  Which breaks
when you have a multi-homed NFS client.

The X/Open spec explicitly mentions that clients should not expect the same
cookie; so one may hope that any clients that were broken in 1996 have either
been fixed or rendered obsolete.

Signed-off-by: default avatarOlaf Kirch <okir@suse.de>
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 031d869d

fs/lockd/svc4proc.c

+1 −1
Original line number Diff line number Diff line
@@ -455,7 +455,7 @@ nlm4svc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res *argp, 


        dprintk("lockd: GRANTED_RES   called\n");



        nlmsvc_grant_reply(rqstp, &argp->cookie, argp->status);

        nlmsvc_grant_reply(&argp->cookie, argp->status);

        return rpc_success;

}

fs/lockd/svclock.c

+13 −11
Original line number Diff line number Diff line
@@ -139,19 +139,19 @@ static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b) 
 * Find a block with a given NLM cookie.

 */

static inline struct nlm_block *

nlmsvc_find_block(struct nlm_cookie *cookie,  struct sockaddr_in *sin)

nlmsvc_find_block(struct nlm_cookie *cookie)

{

	struct nlm_block *block;



	list_for_each_entry(block, &nlm_blocked, b_list) {

		if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie)

				&& nlm_cmp_addr(sin, &block->b_host->h_addr))

		if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie))

			goto found;

	}



	return NULL;



found:

	dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block);

	kref_get(&block->b_count);

	return block;

}
@@ -165,6 +165,11 @@ found: 
 * request, but (as I found out later) that's because some implementations

 * do just this. Never mind the standards comittees, they support our

 * logging industries.

 *

 * 10 years later: I hope we can safely ignore these old and broken

 * clients by now. Let's fix this so we can uniquely identify an incoming

 * GRANTED_RES message by cookie, without having to rely on the client's IP

 * address. --okir

 */

static inline struct nlm_block *

nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
@@ -197,7 +202,7 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file, 
	/* Set notifier function for VFS, and init args */

	call->a_args.lock.fl.fl_flags |= FL_SLEEP;

	call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;

	call->a_args.cookie = *cookie;	/* see above */

	nlmclnt_next_cookie(&call->a_args.cookie);



	dprintk("lockd: created block %p...\n", block);
@@ -640,17 +645,14 @@ static const struct rpc_call_ops nlmsvc_grant_ops = { 
 * block.

 */

void

nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status)

nlmsvc_grant_reply(struct nlm_cookie *cookie, u32 status)

{

	struct nlm_block	*block;

	struct nlm_file		*file;



	dprintk("grant_reply: looking for cookie %x, host (%08x), s=%d \n", 

		*(unsigned int *)(cookie->data), 

		ntohl(rqstp->rq_addr.sin_addr.s_addr), status);

	if (!(block = nlmsvc_find_block(cookie, &rqstp->rq_addr)))

	dprintk("grant_reply: looking for cookie %x, s=%d \n",

		*(unsigned int *)(cookie->data), status);

	if (!(block = nlmsvc_find_block(cookie)))

		return;

	file = block->b_file;



	if (block) {

		if (status == NLM_LCK_DENIED_GRACE_PERIOD) {

fs/lockd/svcproc.c

+1 −1
Original line number Diff line number Diff line
@@ -484,7 +484,7 @@ nlmsvc_proc_granted_res(struct svc_rqst *rqstp, struct nlm_res *argp, 


	dprintk("lockd: GRANTED_RES   called\n");



	nlmsvc_grant_reply(rqstp, &argp->cookie, argp->status);

	nlmsvc_grant_reply(&argp->cookie, argp->status);

	return rpc_success;

}

include/linux/lockd/lockd.h

+1 −1
Original line number Diff line number Diff line
@@ -193,7 +193,7 @@ u32 nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *); 
unsigned long	  nlmsvc_retry_blocked(void);

void		  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,

					nlm_host_match_fn_t match);

void	  nlmsvc_grant_reply(struct svc_rqst *, struct nlm_cookie *, u32);

void		  nlmsvc_grant_reply(struct nlm_cookie *, u32);



/*

 * File handling for the server personality

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