Commit 9a8db97e authored by Marc Eshel's avatar Marc Eshel Committed by Linus Torvalds
Browse files

knfsd: lockd: nfsd4: use same grace period for lockd and nfsd4 



Both lockd and (in the nfsv4 case) nfsd enforce a "grace period" after reboot,
during which clients may reclaim locks from the previous server instance, but
may not acquire new locks.

Currently the lockd and nfsd enforce grace periods of different lengths.  This
may cause problems when we reboot a server with both v2/v3 and v4 clients.
For example, if the lockd grace period is shorter (as is likely the case),
then a v3 client might acquire a new lock that conflicts with a lock already
held (but not yet reclaimed) by a v4 client.

This patch calculates a lease time that lockd and nfsd can both use.

Signed-off-by: default avatarMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 12127498

fs/lockd/svc.c

+20 −7
Original line number Diff line number Diff line
@@ -76,18 +76,31 @@ static const int nlm_port_min = 0, nlm_port_max = 65535; 


static struct ctl_table_header * nlm_sysctl_table;



static unsigned long set_grace_period(void)

static unsigned long get_lockd_grace_period(void)

{

	unsigned long grace_period;



	/* Note: nlm_timeout should always be nonzero */

	if (nlm_grace_period)

		grace_period = ((nlm_grace_period + nlm_timeout - 1)

				/ nlm_timeout) * nlm_timeout * HZ;

		return roundup(nlm_grace_period, nlm_timeout) * HZ;

	else

		grace_period = nlm_timeout * 5 * HZ;

		return nlm_timeout * 5 * HZ;

}



unsigned long get_nfs_grace_period(void)

{

	unsigned long lockdgrace = get_lockd_grace_period();

	unsigned long nfsdgrace = 0;



	if (nlmsvc_ops)

		nfsdgrace = nlmsvc_ops->get_grace_period();



	return max(lockdgrace, nfsdgrace);

}

EXPORT_SYMBOL(get_nfs_grace_period);



static unsigned long set_grace_period(void)

{

	nlmsvc_grace_period = 1;

	return grace_period + jiffies;

	return get_nfs_grace_period() + jiffies;

}



static inline void clear_grace_period(void)

fs/nfsd/lockd.c

+1 −0
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ nlm_fclose(struct file *filp) 
static struct nlmsvc_binding	nfsd_nlm_ops = {

	.fopen		= nlm_fopen,		/* open file for locking */

	.fclose		= nlm_fclose,		/* close file */

	.get_grace_period = get_nfs4_grace_period,

};



void

fs/nfsd/nfs4state.c

+12 −4
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 
#include <linux/namei.h>

#include <linux/mutex.h>

#include <linux/lockd/bind.h>

#include <linux/module.h>



#define NFSDDBG_FACILITY                NFSDDBG_PROC
@@ -3190,20 +3191,27 @@ nfsd4_load_reboot_recovery_data(void) 
		printk("NFSD: Failure reading reboot recovery data\n");

}



unsigned long

get_nfs4_grace_period(void)

{

	return max(user_lease_time, lease_time) * HZ;

}



/* initialization to perform when the nfsd service is started: */



static void

__nfs4_state_start(void)

{

	time_t grace_time;

	unsigned long grace_time;



	boot_time = get_seconds();

	grace_time = max(user_lease_time, lease_time);

	grace_time = get_nfs_grace_period();

	lease_time = user_lease_time;

	in_grace = 1;

	printk("NFSD: starting %ld-second grace period\n", grace_time);

	printk(KERN_INFO "NFSD: starting %ld-second grace period\n",

	       grace_time/HZ);

	laundry_wq = create_singlethread_workqueue("nfsd4");

	queue_delayed_work(laundry_wq, &laundromat_work, grace_time*HZ);

	queue_delayed_work(laundry_wq, &laundromat_work, grace_time);

}



int

include/linux/lockd/bind.h

+9 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct nlmsvc_binding { 
						struct nfs_fh *,

						struct file **);

	void			(*fclose)(struct file *);

	unsigned long		(*get_grace_period)(void);

};



extern struct nlmsvc_binding *	nlmsvc_ops;
@@ -38,4 +39,12 @@ extern int nlmclnt_proc(struct inode *, int, struct file_lock *); 
extern int	lockd_up(int proto);

extern void	lockd_down(void);



unsigned long get_nfs_grace_period(void);



#ifdef CONFIG_NFSD_V4

unsigned long get_nfs4_grace_period(void);

#else

static inline unsigned long get_nfs4_grace_period(void) {return 0;}

#endif



#endif /* LINUX_LOCKD_BIND_H */

CRA Git | Maintained and supported by SUSTech CRA and CCSE