Commit 3d694271 authored by Dai Ngo's avatar Dai Ngo Committed by Chuck Lever
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NFSD: add support for share reservation conflict to courteous server 



This patch allows expired client with open state to be in COURTESY
state. Share/access conflict with COURTESY client is resolved by
setting COURTESY client to EXPIRABLE state, schedule laundromat
to run and returning nfserr_jukebox to the request client.

Reviewed-by: default avatarJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: default avatarDai Ngo <dai.ngo@oracle.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 66af2579

fs/nfsd/nfs4state.c

+101 −8
Original line number Diff line number Diff line
@@ -694,6 +694,57 @@ static unsigned int file_hashval(struct svc_fh *fh) 


static struct hlist_head file_hashtbl[FILE_HASH_SIZE];



/*

 * Check if courtesy clients have conflicting access and resolve it if possible

 *

 * access:  is op_share_access if share_access is true.

 *	    Check if access mode, op_share_access, would conflict with

 *	    the current deny mode of the file 'fp'.

 * access:  is op_share_deny if share_access is false.

 *	    Check if the deny mode, op_share_deny, would conflict with

 *	    current access of the file 'fp'.

 * stp:     skip checking this entry.

 * new_stp: normal open, not open upgrade.

 *

 * Function returns:

 *	false - access/deny mode conflict with normal client.

 *	true  - no conflict or conflict with courtesy client(s) is resolved.

 */

static bool

nfs4_resolve_deny_conflicts_locked(struct nfs4_file *fp, bool new_stp,

		struct nfs4_ol_stateid *stp, u32 access, bool share_access)

{

	struct nfs4_ol_stateid *st;

	bool resolvable = true;

	unsigned char bmap;

	struct nfsd_net *nn;

	struct nfs4_client *clp;



	lockdep_assert_held(&fp->fi_lock);

	list_for_each_entry(st, &fp->fi_stateids, st_perfile) {

		/* ignore lock stateid */

		if (st->st_openstp)

			continue;

		if (st == stp && new_stp)

			continue;

		/* check file access against deny mode or vice versa */

		bmap = share_access ? st->st_deny_bmap : st->st_access_bmap;

		if (!(access & bmap_to_share_mode(bmap)))

			continue;

		clp = st->st_stid.sc_client;

		if (try_to_expire_client(clp))

			continue;

		resolvable = false;

		break;

	}

	if (resolvable) {

		clp = stp->st_stid.sc_client;

		nn = net_generic(clp->net, nfsd_net_id);

		mod_delayed_work(laundry_wq, &nn->laundromat_work, 0);

	}

	return resolvable;

}



static void

__nfs4_file_get_access(struct nfs4_file *fp, u32 access)

{
@@ -4968,7 +5019,7 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh, 


static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,

		struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,

		struct nfsd4_open *open)

		struct nfsd4_open *open, bool new_stp)

{

	struct nfsd_file *nf = NULL;

	__be32 status;
@@ -4984,6 +5035,13 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, 
	 */

	status = nfs4_file_check_deny(fp, open->op_share_deny);

	if (status != nfs_ok) {

		if (status != nfserr_share_denied) {

			spin_unlock(&fp->fi_lock);

			goto out;

		}

		if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,

				stp, open->op_share_deny, false))

			status = nfserr_jukebox;

		spin_unlock(&fp->fi_lock);

		goto out;

	}
@@ -4991,6 +5049,13 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, 
	/* set access to the file */

	status = nfs4_file_get_access(fp, open->op_share_access);

	if (status != nfs_ok) {

		if (status != nfserr_share_denied) {

			spin_unlock(&fp->fi_lock);

			goto out;

		}

		if (nfs4_resolve_deny_conflicts_locked(fp, new_stp,

				stp, open->op_share_access, true))

			status = nfserr_jukebox;

		spin_unlock(&fp->fi_lock);

		goto out;

	}
@@ -5037,21 +5102,29 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, 
}



static __be32

nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open)

nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp,

		struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,

		struct nfsd4_open *open)

{

	__be32 status;

	unsigned char old_deny_bmap = stp->st_deny_bmap;



	if (!test_access(open->op_share_access, stp))

		return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open);

		return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open, false);



	/* test and set deny mode */

	spin_lock(&fp->fi_lock);

	status = nfs4_file_check_deny(fp, open->op_share_deny);

	if (status == nfs_ok) {

		if (status != nfserr_share_denied) {

			set_deny(open->op_share_deny, stp);

			fp->fi_share_deny |=

				(open->op_share_deny & NFS4_SHARE_DENY_BOTH);

		} else {

			if (nfs4_resolve_deny_conflicts_locked(fp, false,

					stp, open->op_share_deny, false))

				status = nfserr_jukebox;

		}

	}

	spin_unlock(&fp->fi_lock);
@@ -5392,7 +5465,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf 
			goto out;

		}

	} else {

		status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open);

		status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open, true);

		if (status) {

			stp->st_stid.sc_type = NFS4_CLOSED_STID;

			release_open_stateid(stp);
@@ -5626,6 +5699,26 @@ static void nfsd4_ssc_expire_umount(struct nfsd_net *nn) 
}

#endif



static bool

nfs4_has_any_locks(struct nfs4_client *clp)

{

	int i;

	struct nfs4_stateowner *so;



	spin_lock(&clp->cl_lock);

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

		list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[i],

				so_strhash) {

			if (so->so_is_open_owner)

				continue;

			spin_unlock(&clp->cl_lock);

			return true;

		}

	}

	spin_unlock(&clp->cl_lock);

	return false;

}



/*

 * place holder for now, no check for lock blockers yet

 */
@@ -5633,8 +5726,8 @@ static bool 
nfs4_anylock_blockers(struct nfs4_client *clp)

{

	if (atomic_read(&clp->cl_delegs_in_recall) ||

			client_has_openowners(clp)  ||

			!list_empty(&clp->async_copies))

			!list_empty(&clp->async_copies) ||

			nfs4_has_any_locks(clp))

		return true;

	return false;

}