Commit 3e9e3dbe authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
Browse files

[PATCH] knfsd: nfsd4: allow multiple lockowners 



>From the language of rfc3530 section 8.1.3 (e.g., the suggestion that a
"process id" might be a reasonable lockowner value) it's conceivable that a
client might want to use the same lockowner string on multiple files, so we may
as well allow that.  We expect each use of open_to_lockowner to create a
distinct seqid stream, though.

For now we're also allowing multiple uses of open_to_lockowner with the same
open, though it seems unlikely clients would actually do that.

Also add a comment reminding myself of some very non-scalable data structures.

Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: default avatarNeil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ea1da636

fs/nfsd/nfs4state.c

+33 −43
Original line number Diff line number Diff line
@@ -2583,22 +2583,6 @@ nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny) 
		deny->ld_type = NFS4_WRITE_LT;

}



static struct nfs4_stateowner *

find_lockstateowner(struct xdr_netobj *owner, clientid_t *clid)

{

	struct nfs4_stateowner *local = NULL;

	int i;



	for (i = 0; i < LOCK_HASH_SIZE; i++) {

		list_for_each_entry(local, &lock_ownerid_hashtbl[i], so_idhash) {

			if (!cmp_owner_str(local, owner, clid))

				continue;

			return local;

		}

	}

	return NULL;

}



static struct nfs4_stateowner *

find_lockstateowner_str(struct inode *inode, clientid_t *clid,

		struct xdr_netobj *owner)
@@ -2697,7 +2681,7 @@ check_lock_length(u64 offset, u64 length) 
int

nfsd4_lock(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_lock *lock)

{

	struct nfs4_stateowner *lock_sop = NULL, *open_sop = NULL;

	struct nfs4_stateowner *open_sop = NULL;

	struct nfs4_stateid *lock_stp;

	struct file *filp;

	struct file_lock file_lock;
@@ -2756,16 +2740,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_lock 
		strhashval = lock_ownerstr_hashval(fp->fi_inode, 

				open_sop->so_client->cl_clientid.cl_id, 

				&lock->v.new.owner);

		/* 

		 * If we already have this lock owner, the client is in 

		 * error (or our bookeeping is wrong!) 

		 * for asking for a 'new lock'.

		 */

		status = nfserr_bad_stateid;

		lock_sop = find_lockstateowner(&lock->v.new.owner,

						&lock->v.new.clientid);

		if (lock_sop)

			goto out;

		/* XXX: Do we need to check for duplicate stateowners on

		 * the same file, or should they just be allowed (and

		 * create new stateids)? */

		status = nfserr_resource;

		if (!(lock->lk_stateowner = alloc_init_lock_stateowner(strhashval, open_sop->so_client, open_stp, lock)))

			goto out;
@@ -3056,8 +3033,11 @@ int 
nfsd4_release_lockowner(struct svc_rqst *rqstp, struct nfsd4_release_lockowner *rlockowner)

{

	clientid_t *clid = &rlockowner->rl_clientid;

	struct nfs4_stateowner *local = NULL;

	struct nfs4_stateowner *sop;

	struct nfs4_stateid *stp;

	struct xdr_netobj *owner = &rlockowner->rl_owner;

	struct list_head matches;

	int i;

	int status;



	dprintk("nfsd4_release_lockowner clientid: (%08x/%08x):\n",
@@ -3073,22 +3053,32 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp, struct nfsd4_release_lockowner * 


	nfs4_lock_state();



	status = nfs_ok;

	local = find_lockstateowner(owner, clid);

	if (local) {

		struct nfs4_stateid *stp;



		/* check for any locks held by any stateid

		 * associated with the (lock) stateowner */

	status = nfserr_locks_held;

		list_for_each_entry(stp, &local->so_stateids,

	/* XXX: we're doing a linear search through all the lockowners.

	 * Yipes!  For now we'll just hope clients aren't really using

	 * release_lockowner much, but eventually we have to fix these

	 * data structures. */

	INIT_LIST_HEAD(&matches);

	for (i = 0; i < LOCK_HASH_SIZE; i++) {

		list_for_each_entry(sop, &lock_ownerid_hashtbl[i], so_idhash) {

			if (!cmp_owner_str(sop, owner, clid))

				continue;

			list_for_each_entry(stp, &sop->so_stateids,

					st_perstateowner) {

			if (check_for_locks(stp->st_vfs_file, local))

				if (check_for_locks(stp->st_vfs_file, sop))

					goto out;

				/* Note: so_perclient unused for lockowners,

				 * so it's OK to fool with here. */

				list_add(&sop->so_perclient, &matches);

			}

		/* no locks held by (lock) stateowner */

		}

	}

	/* Clients probably won't expect us to return with some (but not all)

	 * of the lockowner state released; so don't release any until all

	 * have been checked. */

	status = nfs_ok;

		release_stateowner(local);

	list_for_each_entry(sop, &matches, so_perclient) {

		release_stateowner(sop);

	}

out:

	nfs4_unlock_state();

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