[GFS2] Don't do recursive locking in glock layer

This patch changes the last user of recursive locking so that
it no longer needs this feature and removes it from the glock
layer. This makes the glock code a lot simpler and easier to
understand. Its also a prerequsite to adding support for the
AOP_TRUNCATED_PAGE return code (or at least it is if you don't
want your brain to melt in the process)

I've left in a couple of checks just in case there is some place
else in the code which is still using this feature that I didn't
spot yet, but they can probably be removed long term.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 40 insertions, 39 deletions

diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index e91c2bd..7d46796 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -436,30 +436,35 @@ int gfs2_recover_journal(struct gfs2_jdesc *jd)
 	unsigned int pass;
 	int error;
 
-	fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n", jd->jd_jid);
-
-	/* Aquire the journal lock so we can do recovery */
-
-	error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
-				  LM_ST_EXCLUSIVE,
-				  LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
-				  &j_gh);
-	switch (error) {
-	case 0:
-		break;
+	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
+		fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
+			jd->jd_jid);
 
-	case GLR_TRYFAILED:
-		fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
-		error = 0;
+		/* Aquire the journal lock so we can do recovery */
 
-	default:
-		goto fail;
-	};
+		error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
+					  LM_ST_EXCLUSIVE,
+					  LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
+					  &j_gh);
+		switch (error) {
+		case 0:
+			break;
+	
+		case GLR_TRYFAILED:
+			fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
+			error = 0;
+	
+		default:
+			goto fail;
+		};
 
-	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
-				   LM_FLAG_NOEXP, &ji_gh);
-	if (error)
-		goto fail_gunlock_j;
+		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
+					   LM_FLAG_NOEXP, &ji_gh);
+		if (error)
+			goto fail_gunlock_j;
+	} else {
+		fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
+	}
 
 	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
 
@@ -481,10 +486,8 @@ int gfs2_recover_journal(struct gfs2_jdesc *jd)
 
 		error = gfs2_glock_nq_init(sdp->sd_trans_gl,
 					   LM_ST_SHARED,
-					   LM_FLAG_NOEXP |
-					   LM_FLAG_PRIORITY |
-					   GL_NEVER_RECURSE |
-					   GL_NOCANCEL |
+					   LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
+					   GL_NEVER_RECURSE | GL_NOCANCEL |
 					   GL_NOCACHE,
 					   &t_gh);
 		if (error)
@@ -521,37 +524,35 @@ int gfs2_recover_journal(struct gfs2_jdesc *jd)
 			goto fail_gunlock_tr;
 
 		gfs2_glock_dq_uninit(&t_gh);
-
 		t = DIV_ROUND_UP(jiffies - t, HZ);
-		
 		fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
 			jd->jd_jid, t);
 	}
 
-	gfs2_glock_dq_uninit(&ji_gh);
+	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
+		gfs2_glock_dq_uninit(&ji_gh);
 
 	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
 
-	gfs2_glock_dq_uninit(&j_gh);
+	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
+		gfs2_glock_dq_uninit(&j_gh);
 
 	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
-
 	return 0;
 
- fail_gunlock_tr:
+fail_gunlock_tr:
 	gfs2_glock_dq_uninit(&t_gh);
-
- fail_gunlock_ji:
-	gfs2_glock_dq_uninit(&ji_gh);
-
- fail_gunlock_j:
-	gfs2_glock_dq_uninit(&j_gh);
+fail_gunlock_ji:
+	if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
+		gfs2_glock_dq_uninit(&ji_gh);
+fail_gunlock_j:
+		gfs2_glock_dq_uninit(&j_gh);
+	}
 
 	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
 
- fail:
+fail:
 	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
-
 	return error;
 }