Commit 586759f0 authored by Marc Eshel's avatar Marc Eshel Committed by J. Bruce Fields
Browse files

gfs2: nfs lock support for gfs2 



Add NFS lock support to GFS2.

Signed-off-by: default avatarMarc Eshel <eshel@almaden.ibm.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
Acked-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 1a8322b2

fs/gfs2/locking/dlm/plock.c

+99 −10
Original line number Diff line number Diff line
@@ -25,6 +25,15 @@ struct plock_op { 
	struct gdlm_plock_info info;

};



struct plock_xop {

	struct plock_op xop;

	void *callback;

	void *fl;

	void *file;

	struct file_lock flc;

};





static inline void set_version(struct gdlm_plock_info *info)

{

	info->version[0] = GDLM_PLOCK_VERSION_MAJOR;
@@ -64,12 +73,14 @@ int gdlm_plock(void *lockspace, struct lm_lockname *name, 
{

	struct gdlm_ls *ls = lockspace;

	struct plock_op *op;

	struct plock_xop *xop;

	int rv;



	op = kzalloc(sizeof(*op), GFP_KERNEL);

	if (!op)

	xop = kzalloc(sizeof(*xop), GFP_KERNEL);

	if (!xop)

		return -ENOMEM;



	op = &xop->xop;

	op->info.optype		= GDLM_PLOCK_OP_LOCK;

	op->info.pid		= fl->fl_pid;

	op->info.ex		= (fl->fl_type == F_WRLCK);
@@ -79,9 +90,21 @@ int gdlm_plock(void *lockspace, struct lm_lockname *name, 
	op->info.start		= fl->fl_start;

	op->info.end		= fl->fl_end;

	op->info.owner		= (__u64)(long) fl->fl_owner;

	if (fl->fl_lmops && fl->fl_lmops->fl_grant) {

		xop->callback	= fl->fl_lmops->fl_grant;

		locks_init_lock(&xop->flc);

		locks_copy_lock(&xop->flc, fl);

		xop->fl		= fl;

		xop->file	= file;

	} else

		xop->callback	= NULL;



	send_op(op);



	if (xop->callback == NULL)

		wait_event(recv_wq, (op->done != 0));

	else

		return -EINPROGRESS;



	spin_lock(&ops_lock);

	if (!list_empty(&op->list)) {
@@ -99,7 +122,63 @@ int gdlm_plock(void *lockspace, struct lm_lockname *name, 
				  (unsigned long long)name->ln_number);

	}



	kfree(op);

	kfree(xop);

	return rv;

}



/* Returns failure iff a succesful lock operation should be canceled */

static int gdlm_plock_callback(struct plock_op *op)

{

	struct file *file;

	struct file_lock *fl;

	struct file_lock *flc;

	int (*notify)(void *, void *, int) = NULL;

	struct plock_xop *xop = (struct plock_xop *)op;

	int rv = 0;



	spin_lock(&ops_lock);

	if (!list_empty(&op->list)) {

		printk(KERN_INFO "plock op on list\n");

		list_del(&op->list);

	}

	spin_unlock(&ops_lock);



	/* check if the following 2 are still valid or make a copy */

	file = xop->file;

	flc = &xop->flc;

	fl = xop->fl;

	notify = xop->callback;



	if (op->info.rv) {

		notify(flc, NULL, op->info.rv);

		goto out;

	}



	/* got fs lock; bookkeep locally as well: */

	flc->fl_flags &= ~FL_SLEEP;

	if (posix_lock_file(file, flc, NULL)) {

		/*

		 * This can only happen in the case of kmalloc() failure.

		 * The filesystem's own lock is the authoritative lock,

		 * so a failure to get the lock locally is not a disaster.

		 * As long as GFS cannot reliably cancel locks (especially

		 * in a low-memory situation), we're better off ignoring

		 * this failure than trying to recover.

		 */

		log_error("gdlm_plock: vfs lock error file %p fl %p",

				file, fl);

	}



	rv = notify(flc, NULL, 0);

	if (rv) {

		/* XXX: We need to cancel the fs lock here: */

		printk("gfs2 lock granted after lock request failed;"

						" dangling lock!\n");

		goto out;

	}



out:

	kfree(xop);

	return rv;

}
@@ -138,6 +217,9 @@ int gdlm_punlock(void *lockspace, struct lm_lockname *name, 


	rv = op->info.rv;



	if (rv == -ENOENT)

		rv = 0;



	kfree(op);

	return rv;

}
@@ -161,6 +243,7 @@ int gdlm_plock_get(void *lockspace, struct lm_lockname *name, 
	op->info.start		= fl->fl_start;

	op->info.end		= fl->fl_end;





	send_op(op);

	wait_event(recv_wq, (op->done != 0));
@@ -173,9 +256,10 @@ int gdlm_plock_get(void *lockspace, struct lm_lockname *name, 


	rv = op->info.rv;



	if (rv == 0)

	fl->fl_type = F_UNLCK;

	else if (rv > 0) {

	if (rv == -ENOENT)

		rv = 0;

	else if (rv == 0 && op->info.pid != fl->fl_pid) {

		fl->fl_type = (op->info.ex) ? F_WRLCK : F_RDLCK;

		fl->fl_pid = op->info.pid;

		fl->fl_start = op->info.start;
@@ -243,9 +327,14 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count, 
	}

	spin_unlock(&ops_lock);



	if (found)

		wake_up(&recv_wq);

	if (found) {

		struct plock_xop *xop;

		xop = (struct plock_xop *)op;

		if (xop->callback)

			count = gdlm_plock_callback(op);

		else

			wake_up(&recv_wq);

	} else

		printk(KERN_INFO "gdlm dev_write no op %x %llx\n", info.fsid,

			(unsigned long long)info.number);

	return count;

fs/gfs2/ops_file.c

+5 −0
Original line number Diff line number Diff line
@@ -520,6 +520,11 @@ static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl) 
		}

	}



	if (cmd == F_CANCELLK) {

		/* Hack: */

		cmd = F_SETLK;

		fl->fl_type = F_UNLCK;

	}

	if (IS_GETLK(cmd))

		return gfs2_lm_plock_get(sdp, &name, file, fl);

	else if (fl->fl_type == F_UNLCK)