Commit c035362e authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Add a mechanism to wait for a DELEGRETURN 



Subsequent patches will use this mechanism to wake up an operation
that is waiting for a client to return a delegation.

The new tracepoint records whether the wait timed out or was
properly awoken by the expected DELEGRETURN:

            nfsd-1155  [002] 83799.493199: nfsd_delegret_wakeup: xid=0x14b7d6ef fh_hash=0xf6826792 (timed out)

Suggested-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
parent 1035d654

fs/nfsd/nfs4state.c

+30 −0
Original line number Original line Diff line number Diff line
@@ -4717,6 +4717,35 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type) 
	return ret;

	return ret;

}

}





static bool nfsd4_deleg_present(const struct inode *inode)

{

	struct file_lock_context *ctx = smp_load_acquire(&inode->i_flctx);



	return ctx && !list_empty_careful(&ctx->flc_lease);

}



/**

 * nfsd_wait_for_delegreturn - wait for delegations to be returned

 * @rqstp: the RPC transaction being executed

 * @inode: in-core inode of the file being waited for

 *

 * The timeout prevents deadlock if all nfsd threads happen to be

 * tied up waiting for returning delegations.

 *

 * Return values:

 *   %true: delegation was returned

 *   %false: timed out waiting for delegreturn

 */

bool nfsd_wait_for_delegreturn(struct svc_rqst *rqstp, struct inode *inode)

{

	long __maybe_unused timeo;



	timeo = wait_var_event_timeout(inode, !nfsd4_deleg_present(inode),

				       NFSD_DELEGRETURN_TIMEOUT);

	trace_nfsd_delegret_wakeup(rqstp, inode, timeo);

	return timeo > 0;

}



static void nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)

static void nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)

{

{

	struct nfs4_delegation *dp = cb_to_delegation(cb);

	struct nfs4_delegation *dp = cb_to_delegation(cb);
@@ -6779,6 +6808,7 @@ nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	if (status)

	if (status)

		goto put_stateid;

		goto put_stateid;





	wake_up_var(d_inode(cstate->current_fh.fh_dentry));

	destroy_delegation(dp);

	destroy_delegation(dp);

put_stateid:

put_stateid:

	nfs4_put_stid(&dp->dl_stid);

	nfs4_put_stid(&dp->dl_stid);

fs/nfsd/nfsd.h

+7 −0
Original line number Original line Diff line number Diff line
@@ -164,6 +164,7 @@ char * nfs4_recoverydir(void); 
bool nfsd4_spo_must_allow(struct svc_rqst *rqstp);

bool nfsd4_spo_must_allow(struct svc_rqst *rqstp);

int nfsd4_create_laundry_wq(void);

int nfsd4_create_laundry_wq(void);

void nfsd4_destroy_laundry_wq(void);

void nfsd4_destroy_laundry_wq(void);

bool nfsd_wait_for_delegreturn(struct svc_rqst *rqstp, struct inode *inode);

#else

#else

static inline int nfsd4_init_slabs(void) { return 0; }

static inline int nfsd4_init_slabs(void) { return 0; }

static inline void nfsd4_free_slabs(void) { }

static inline void nfsd4_free_slabs(void) { }
@@ -179,6 +180,11 @@ static inline bool nfsd4_spo_must_allow(struct svc_rqst *rqstp) 
}

}

static inline int nfsd4_create_laundry_wq(void) { return 0; };

static inline int nfsd4_create_laundry_wq(void) { return 0; };

static inline void nfsd4_destroy_laundry_wq(void) {};

static inline void nfsd4_destroy_laundry_wq(void) {};

static inline bool nfsd_wait_for_delegreturn(struct svc_rqst *rqstp,

					      struct inode *inode)

{

	return false;

}

#endif

#endif





/*

/*
@@ -343,6 +349,7 @@ void nfsd_lockd_shutdown(void); 
#define	NFSD_COURTESY_CLIENT_TIMEOUT	(24 * 60 * 60)	/* seconds */

#define	NFSD_COURTESY_CLIENT_TIMEOUT	(24 * 60 * 60)	/* seconds */

#define	NFSD_CLIENT_MAX_TRIM_PER_RUN	128

#define	NFSD_CLIENT_MAX_TRIM_PER_RUN	128

#define	NFS4_CLIENTS_PER_GB		1024

#define	NFS4_CLIENTS_PER_GB		1024

#define NFSD_DELEGRETURN_TIMEOUT	(HZ / 34)	/* 30ms */





/*

/*

 * The following attributes are currently not supported by the NFSv4 server:

 * The following attributes are currently not supported by the NFSv4 server:

fs/nfsd/trace.h

+23 −0
Original line number Original line Diff line number Diff line
@@ -538,6 +538,29 @@ DEFINE_NFSD_COPY_ERR_EVENT(clone_file_range_err); 
#include "filecache.h"

#include "filecache.h"

#include "vfs.h"

#include "vfs.h"





TRACE_EVENT(nfsd_delegret_wakeup,

	TP_PROTO(

		const struct svc_rqst *rqstp,

		const struct inode *inode,

		long timeo

	),

	TP_ARGS(rqstp, inode, timeo),

	TP_STRUCT__entry(

		__field(u32, xid)

		__field(const void *, inode)

		__field(long, timeo)

	),

	TP_fast_assign(

		__entry->xid = be32_to_cpu(rqstp->rq_xid);

		__entry->inode = inode;

		__entry->timeo = timeo;

	),

	TP_printk("xid=0x%08x inode=%p%s",

		  __entry->xid, __entry->inode,

		  __entry->timeo == 0 ? " (timed out)" : ""

	)

);



DECLARE_EVENT_CLASS(nfsd_stateid_class,

DECLARE_EVENT_CLASS(nfsd_stateid_class,

	TP_PROTO(stateid_t *stp),

	TP_PROTO(stateid_t *stp),

	TP_ARGS(stp),

	TP_ARGS(stp),