Commit 6aad1c3d authored by Bob Peterson's avatar Bob Peterson Committed by Steven Whitehouse
Browse files

GFS2: Eliminate sd_rindex_mutex 



Over time, we've slowly eliminated the use of sd_rindex_mutex.
Up to this point, it was only used in two places: function
gfs2_ri_total (which totals the file system size by reading
and parsing the rindex file) and function gfs2_rindex_update
which updates the rgrps in memory. Both of these functions have
the rindex glock to protect them, so the rindex is unnecessary.
Since gfs2_grow writes to the rindex via the meta_fs, the mutex
is in the wrong order according to the normal rules. This patch
eliminates the mutex entirely to avoid the problem.

Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent a08fd280

fs/gfs2/incore.h

+0 −1
Original line number Diff line number Diff line
@@ -644,7 +644,6 @@ struct gfs2_sbd { 


	int sd_rindex_uptodate;

	spinlock_t sd_rindex_spin;

	struct mutex sd_rindex_mutex;

	struct rb_root sd_rindex_tree;

	unsigned int sd_rgrps;

	unsigned int sd_max_rg_data;

fs/gfs2/ops_fstype.c

+0 −1
Original line number Diff line number Diff line
@@ -83,7 +83,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb) 
	spin_lock_init(&sdp->sd_statfs_spin);



	spin_lock_init(&sdp->sd_rindex_spin);

	mutex_init(&sdp->sd_rindex_mutex);

	sdp->sd_rindex_tree.rb_node = NULL;



	INIT_LIST_HEAD(&sdp->sd_jindex_list);

fs/gfs2/rgrp.c

+10 −12
Original line number Diff line number Diff line
@@ -540,7 +540,6 @@ u64 gfs2_ri_total(struct gfs2_sbd *sdp) 
	struct file_ra_state ra_state;

	int error, rgrps;



	mutex_lock(&sdp->sd_rindex_mutex);

	file_ra_state_init(&ra_state, inode->i_mapping);

	for (rgrps = 0;; rgrps++) {

		loff_t pos = rgrps * sizeof(struct gfs2_rindex);
@@ -553,11 +552,10 @@ u64 gfs2_ri_total(struct gfs2_sbd *sdp) 
			break;

		total_data += be32_to_cpu(((struct gfs2_rindex *)buf)->ri_data);

	}

	mutex_unlock(&sdp->sd_rindex_mutex);

	return total_data;

}



static void rgd_insert(struct gfs2_rgrpd *rgd)

static int rgd_insert(struct gfs2_rgrpd *rgd)

{

	struct gfs2_sbd *sdp = rgd->rd_sbd;

	struct rb_node **newn = &sdp->sd_rindex_tree.rb_node, *parent = NULL;
@@ -573,11 +571,13 @@ static void rgd_insert(struct gfs2_rgrpd *rgd) 
		else if (rgd->rd_addr > cur->rd_addr)

			newn = &((*newn)->rb_right);

		else

			return;

			return -EEXIST;

	}



	rb_link_node(&rgd->rd_node, parent, newn);

	rb_insert_color(&rgd->rd_node, &sdp->sd_rindex_tree);

	sdp->sd_rgrps++;

	return 0;

}



/**
@@ -631,10 +631,12 @@ static int read_rindex_entry(struct gfs2_inode *ip, 
	if (rgd->rd_data > sdp->sd_max_rg_data)

		sdp->sd_max_rg_data = rgd->rd_data;

	spin_lock(&sdp->sd_rindex_spin);

	rgd_insert(rgd);

	sdp->sd_rgrps++;

	error = rgd_insert(rgd);

	spin_unlock(&sdp->sd_rindex_spin);

	return error;

	if (!error)

		return 0;



	error = 0; /* someone else read in the rgrp; free it and ignore it */



fail:

	kfree(rgd->rd_bits);
@@ -695,22 +697,18 @@ int gfs2_rindex_update(struct gfs2_sbd *sdp) 


	/* Read new copy from disk if we don't have the latest */

	if (!sdp->sd_rindex_uptodate) {

		mutex_lock(&sdp->sd_rindex_mutex);

		if (!gfs2_glock_is_locked_by_me(gl)) {

			error = gfs2_glock_nq_init(gl, LM_ST_SHARED, 0, &ri_gh);

			if (error)

				goto out_unlock;

				return error;

			unlock_required = 1;

		}

		if (!sdp->sd_rindex_uptodate)

			error = gfs2_ri_update(ip);

		if (unlock_required)

			gfs2_glock_dq_uninit(&ri_gh);

out_unlock:

		mutex_unlock(&sdp->sd_rindex_mutex);

	}





	return error;

}

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