Commit 2b36f412 authored by Marc Eshel's avatar Marc Eshel Committed by J. Bruce Fields
Browse files

lockd: save lock state on deferral 



We need to keep some state for a pending asynchronous lock request, so this
patch adds that state to struct nlm_block.

This also adds a function which defers the request, by calling
rqstp->rq_chandle.defer and storing the resulting deferred request in a
nlm_block structure which we insert into lockd's global block list.  That
new function isn't called yet, so it's dead code until a later patch.

Signed-off-by: default avatarMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 2beb6614

fs/lockd/svclock.c

+25 −0
Original line number Diff line number Diff line
@@ -330,6 +330,31 @@ static void nlmsvc_freegrantargs(struct nlm_rqst *call) 
		kfree(call->a_args.lock.oh.data);

}



/*

 * Deferred lock request handling for non-blocking lock

 */

static u32

nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block)

{

	u32 status = nlm_lck_denied_nolocks;



	block->b_flags |= B_QUEUED;



	nlmsvc_insert_block(block, NLM_TIMEOUT);



	block->b_cache_req = &rqstp->rq_chandle;

	if (rqstp->rq_chandle.defer) {

		block->b_deferred_req =

			rqstp->rq_chandle.defer(block->b_cache_req);

		if (block->b_deferred_req != NULL)

			status = nlm_drop_reply;

	}

	dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n",

		block, block->b_flags, status);



	return status;

}



/*

 * Attempt to establish a lock, and if it can't be granted, block it

 * if required.

include/linux/lockd/lockd.h

+10 −0
Original line number Diff line number Diff line
@@ -119,6 +119,9 @@ struct nlm_file { 
 * couldn't be granted because of a conflicting lock).

 */

#define NLM_NEVER		(~(unsigned long) 0)

/* timeout on non-blocking call: */

#define NLM_TIMEOUT		(7 * HZ)



struct nlm_block {

	struct kref		b_count;	/* Reference count */

	struct list_head	b_list;		/* linked list of all blocks */
@@ -130,6 +133,13 @@ struct nlm_block { 
	unsigned int		b_id;		/* block id */

	unsigned char		b_granted;	/* VFS granted lock */

	struct nlm_file *	b_file;		/* file in question */

	struct cache_req *	b_cache_req;	/* deferred request handling */

	struct file_lock *	b_fl;		/* set for GETLK */

	struct cache_deferred_req * b_deferred_req;

	unsigned int		b_flags;	/* block flags */

#define B_QUEUED		1	/* lock queued */

#define B_GOT_CALLBACK		2	/* got lock or conflicting lock */

#define B_TIMED_OUT		4	/* filesystem too slow to respond */

};



/*

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