GFS2: skip dlm_unlock calls in unmount (fb6791d1) · Commits · 戴 / test

When unmounting, gfs2 does a full dlm_unlock operation on every cached lock. This can create a very large amount of work and can take a long time to complete. However, the vast majority of these dlm unlock operations are unnecessary because after all the unlocks are done, gfs2 leaves the dlm lockspace, which automatically clears the locks of the leaving node, without unlocking each one individually. So, gfs2 can skip explicit dlm unlocks, and use dlm_release_lockspace to remove the locks implicitly. The one exception is when the lock's lvb is being used. In this case, dlm_unlock is called because it may update the lvb of the resource. Signed-off-by:

David Teigland <teigland@redhat.com> Signed-off-by:

Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/glock.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1526,6 +1526,7 @@ static void dump_glock_func(struct gfs2_glock *gl)

		void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
		{
		set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags);
		glock_hash_walk(clear_glock, sdp);
		flush_workqueue(glock_workqueue);
		wait_event(sdp->sd_glock_wait, atomic_read(&sdp->sd_glock_disposal) == 0);

fs/gfs2/incore.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -539,6 +539,7 @@ enum {
		SDF_DEMOTE = 5,
		SDF_NOJOURNALID = 6,
		SDF_RORECOVERY = 7, /* read only recovery */
		SDF_SKIP_DLM_UNLOCK = 8,
		};

		#define GFS2_FSNAME_LEN 256

fs/gfs2/lock_dlm.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -289,6 +289,14 @@ static void gdlm_put_lock(struct gfs2_glock *gl)
		gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT);
		gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT);
		gfs2_update_request_times(gl);

		/* don't want to skip dlm_unlock writing the lvb when lock is ex */
		if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) &&
		gl->gl_state != LM_ST_EXCLUSIVE) {
		gfs2_glock_free(gl);
		return;
		}

		error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK,
		NULL, gl);
		if (error) {

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