Commit 16feb9fe authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

[GFS2] Use atomic_t rather than kref in glock.c 



Use atomic_t as the ref count in glocks rather than a kref.
This is another step towards using RCU for the glock hash.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 0bc0748d

fs/gfs2/glock.c

+12 −22
Original line number Diff line number Diff line
@@ -15,7 +15,6 @@ 
#include <linux/delay.h>

#include <linux/sort.h>

#include <linux/jhash.h>

#include <linux/kref.h>

#include <linux/kallsyms.h>

#include <linux/gfs2_ondisk.h>

#include <linux/list.h>
@@ -179,23 +178,7 @@ static void glock_free(struct gfs2_glock *gl) 


void gfs2_glock_hold(struct gfs2_glock *gl)

{

	kref_get(&gl->gl_ref);

}



/* All work is done after the return from kref_put() so we

   can release the write_lock before the free. */



static void kill_glock(struct kref *kref)

{

	struct gfs2_glock *gl = container_of(kref, struct gfs2_glock, gl_ref);

	struct gfs2_sbd *sdp = gl->gl_sbd;



	gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);

	gfs2_assert(sdp, list_empty(&gl->gl_reclaim));

	gfs2_assert(sdp, list_empty(&gl->gl_holders));

	gfs2_assert(sdp, list_empty(&gl->gl_waiters1));

	gfs2_assert(sdp, list_empty(&gl->gl_waiters2));

	gfs2_assert(sdp, list_empty(&gl->gl_waiters3));

	atomic_inc(&gl->gl_ref);

}



/**
@@ -207,12 +190,19 @@ static void kill_glock(struct kref *kref) 
int gfs2_glock_put(struct gfs2_glock *gl)

{

	int rv = 0;

	struct gfs2_sbd *sdp = gl->gl_sbd;



	write_lock(gl_lock_addr(gl->gl_hash));

	if (kref_put(&gl->gl_ref, kill_glock)) {

	if (atomic_dec_and_test(&gl->gl_ref)) {

		hlist_del(&gl->gl_list);

		write_unlock(gl_lock_addr(gl->gl_hash));

		BUG_ON(spin_is_locked(&gl->gl_spin));

		gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);

		gfs2_assert(sdp, list_empty(&gl->gl_reclaim));

		gfs2_assert(sdp, list_empty(&gl->gl_holders));

		gfs2_assert(sdp, list_empty(&gl->gl_waiters1));

		gfs2_assert(sdp, list_empty(&gl->gl_waiters2));

		gfs2_assert(sdp, list_empty(&gl->gl_waiters3));

		glock_free(gl);

		rv = 1;

		goto out;
@@ -267,7 +257,7 @@ static struct gfs2_glock *search_bucket(unsigned int hash, 
		if (gl->gl_sbd != sdp)

			continue;



		kref_get(&gl->gl_ref);

		atomic_inc(&gl->gl_ref);



		return gl;

	}
@@ -333,7 +323,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, 


	gl->gl_flags = 0;

	gl->gl_name = name;

	kref_init(&gl->gl_ref);

	atomic_set(&gl->gl_ref, 1);

	gl->gl_state = LM_ST_UNLOCKED;

	gl->gl_hash = hash;

	gl->gl_owner = NULL;
@@ -2124,7 +2114,7 @@ static int dump_glock(struct gfs2_glock *gl) 
			printk(" %u", x);

	}

	printk(" \n");

	printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref.refcount));

	printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref));

	printk(KERN_INFO "  gl_state = %u\n", gl->gl_state);

	printk(KERN_INFO "  gl_owner = %s\n", gl->gl_owner->comm);

	print_symbol(KERN_INFO "  gl_ip = %s\n", gl->gl_ip);

fs/gfs2/incore.h

+1 −1
Original line number Diff line number Diff line
@@ -164,7 +164,7 @@ struct gfs2_glock { 
	struct hlist_node gl_list;

	unsigned long gl_flags;		/* GLF_... */

	struct lm_lockname gl_name;

	struct kref gl_ref;

	atomic_t gl_ref;



	spinlock_t gl_spin;