Unverified Commit 8b99f6a8 authored by Jeff Layton's avatar Jeff Layton Committed by Christian Brauner
Browse files

nfsd: wire up GET_DIR_DELEGATION handling 



Add a new routine for acquiring a read delegation on a directory. These
are recallable-only delegations with no support for CB_NOTIFY. That will
be added in a later phase.

Since the same CB_RECALL/DELEGRETURN infrastructure is used for regular
and directory delegations, a normal nfs4_delegation is used to represent
a directory delegation.

Reviewed-by: default avatarNeilBrown <neil@brown.name>
Reviewed-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-16-52f3feebb2f2@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 80c8afdd

fs/nfsd/nfs4proc.c

+21 −1
Original line number Diff line number Diff line
@@ -2341,6 +2341,13 @@ nfsd4_get_dir_delegation(struct svc_rqst *rqstp, 
			 union nfsd4_op_u *u)

{

	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;

	struct nfs4_delegation *dd;

	struct nfsd_file *nf;

	__be32 status;



	status = nfsd_file_acquire_dir(rqstp, &cstate->current_fh, &nf);

	if (status != nfs_ok)

		return status;



	/*

	 * RFC 8881, section 18.39.3 says:
@@ -2354,10 +2361,23 @@ nfsd4_get_dir_delegation(struct svc_rqst *rqstp, 
	 * return NFS4_OK with a non-fatal status of GDD4_UNAVAIL in this

	 * situation.

	 */

	dd = nfsd_get_dir_deleg(cstate, gdd, nf);

	nfsd_file_put(nf);

	if (IS_ERR(dd)) {

		int err = PTR_ERR(dd);



		if (err != -EAGAIN)

			return nfserrno(err);

		gdd->gddrnf_status = GDD4_UNAVAIL;

		return nfs_ok;

	}



	gdd->gddrnf_status = GDD4_OK;

	memcpy(&gdd->gddr_stateid, &dd->dl_stid.sc_stateid, sizeof(gdd->gddr_stateid));

	nfs4_put_stid(&dd->dl_stid);

	return nfs_ok;

}



#ifdef CONFIG_NFSD_PNFS

static const struct nfsd4_layout_ops *

nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type)

fs/nfsd/nfs4state.c

+100 −0
Original line number Diff line number Diff line
@@ -9347,3 +9347,103 @@ nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, struct dentry *dentry, 
	nfs4_put_stid(&dp->dl_stid);

	return status;

}



/**

 * nfsd_get_dir_deleg - attempt to get a directory delegation

 * @cstate: compound state

 * @gdd: GET_DIR_DELEGATION arg/resp structure

 * @nf: nfsd_file opened on the directory

 *

 * Given a GET_DIR_DELEGATION request @gdd, attempt to acquire a delegation

 * on the directory to which @nf refers. Note that this does not set up any

 * sort of async notifications for the delegation.

 */

struct nfs4_delegation *

nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,

		   struct nfsd4_get_dir_delegation *gdd,

		   struct nfsd_file *nf)

{

	struct nfs4_client *clp = cstate->clp;

	struct nfs4_delegation *dp;

	struct file_lease *fl;

	struct nfs4_file *fp, *rfp;

	int status = 0;



	fp = nfsd4_alloc_file();

	if (!fp)

		return ERR_PTR(-ENOMEM);



	nfsd4_file_init(&cstate->current_fh, fp);



	rfp = nfsd4_file_hash_insert(fp, &cstate->current_fh);

	if (unlikely(!rfp)) {

		put_nfs4_file(fp);

		return ERR_PTR(-ENOMEM);

	}



	if (rfp != fp) {

		put_nfs4_file(fp);

		fp = rfp;

	}



	/* if this client already has one, return that it's unavailable */

	spin_lock(&state_lock);

	spin_lock(&fp->fi_lock);

	/* existing delegation? */

	if (nfs4_delegation_exists(clp, fp)) {

		status = -EAGAIN;

	} else if (!fp->fi_deleg_file) {

		fp->fi_deleg_file = nfsd_file_get(nf);

		fp->fi_delegees = 1;

	} else {

		++fp->fi_delegees;

	}

	spin_unlock(&fp->fi_lock);

	spin_unlock(&state_lock);



	if (status) {

		put_nfs4_file(fp);

		return ERR_PTR(status);

	}



	/* Try to set up the lease */

	status = -ENOMEM;

	dp = alloc_init_deleg(clp, fp, NULL, NFS4_OPEN_DELEGATE_READ);

	if (!dp)

		goto out_delegees;



	fl = nfs4_alloc_init_lease(dp);

	if (!fl)

		goto out_put_stid;



	status = kernel_setlease(nf->nf_file,

				 fl->c.flc_type, &fl, NULL);

	if (fl)

		locks_free_lease(fl);

	if (status)

		goto out_put_stid;



	/*

	 * Now, try to hash it. This can fail if we race another nfsd task

	 * trying to set a delegation on the same file. If that happens,

	 * then just say UNAVAIL.

	 */

	spin_lock(&state_lock);

	spin_lock(&clp->cl_lock);

	spin_lock(&fp->fi_lock);

	status = hash_delegation_locked(dp, fp);

	spin_unlock(&fp->fi_lock);

	spin_unlock(&clp->cl_lock);

	spin_unlock(&state_lock);



	if (!status)

		return dp;



	/* Something failed. Drop the lease and clean up the stid */

	kernel_setlease(fp->fi_deleg_file->nf_file, F_UNLCK, NULL, (void **)&dp);

out_put_stid:

	nfs4_put_stid(&dp->dl_stid);

out_delegees:

	put_deleg_file(fp);

	return ERR_PTR(status);

}

fs/nfsd/state.h

+5 −0
Original line number Diff line number Diff line
@@ -867,4 +867,9 @@ static inline bool try_to_expire_client(struct nfs4_client *clp) 


extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp,

		struct dentry *dentry, struct nfs4_delegation **pdp);



struct nfsd4_get_dir_delegation;

struct nfs4_delegation *nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,

						struct nfsd4_get_dir_delegation *gdd,

						struct nfsd_file *nf);

#endif   /* NFSD4_STATE_H */