ocfs2: Use a separate masklog for AST and BASTs

This patch adds a new masklog and uses it allow tracing ASTs and BASTs
in the dlmglue layer. This has been found to be very useful in debugging
cluster locking issues.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

3 files changed, 67 insertions, 25 deletions

diff --git a/fs/ocfs2/cluster/masklog.c b/fs/ocfs2/cluster/masklog.c
index 1cd2934de615..b39da877b12f 100644
--- a/fs/ocfs2/cluster/masklog.c
+++ b/fs/ocfs2/cluster/masklog.c
@@ -112,6 +112,7 @@ static struct mlog_attribute mlog_attrs[MLOG_MAX_BITS] = {
         define_mask(XATTR),
         define_mask(QUOTA),
         define_mask(REFCOUNT),
+        define_mask(BASTS),
         define_mask(ERROR),
         define_mask(NOTICE),
         define_mask(KTHREAD),
diff --git a/fs/ocfs2/cluster/masklog.h b/fs/ocfs2/cluster/masklog.h
index 0442366b3060..3dfddbec32f2 100644
--- a/fs/ocfs2/cluster/masklog.h
+++ b/fs/ocfs2/cluster/masklog.h
@@ -114,6 +114,7 @@
 #define ML_XATTR        0x0000000020000000ULL /* ocfs2 extended attributes */
 #define ML_QUOTA        0x0000000040000000ULL /* ocfs2 quota operations */
 #define ML_REFCOUNT     0x0000000080000000ULL /* refcount tree operations */
+#define ML_BASTS        0x0000001000000000ULL /* dlmglue asts and basts */
 /* bits that are infrequently given and frequently matched in the high word */
 #define ML_ERROR        0x0000000100000000ULL /* sent to KERN_ERR */
 #define ML_NOTICE       0x0000000200000000ULL /* setn to KERN_NOTICE */
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index d009d7744d63..8298608d4165 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -932,6 +932,10 @@ static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
                 lockres->l_blocking = level;
         }
 
+        mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
+             lockres->l_name, level, lockres->l_level, lockres->l_blocking,
+             needs_downconvert);
+
         if (needs_downconvert)
                 lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
 
@@ -1054,8 +1058,8 @@ static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
 
         BUG_ON(level <= DLM_LOCK_NL);
 
-        mlog(0, "BAST fired for lockres %s, blocking %d, level %d type %s\n",
-             lockres->l_name, level, lockres->l_level,
+        mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
+             "type %s\n", lockres->l_name, level, lockres->l_level,
              ocfs2_lock_type_string(lockres->l_type));
 
         /*
@@ -1099,6 +1103,10 @@ static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
                 return;
         }
 
+        mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
+             "level %d => %d\n", lockres->l_name, lockres->l_action,
+             lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
+
         switch(lockres->l_action) {
         case OCFS2_AST_ATTACH:
                 ocfs2_generic_handle_attach_action(lockres);
@@ -1111,8 +1119,8 @@ static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
                 ocfs2_generic_handle_downconvert_action(lockres);
                 break;
         default:
-                mlog(ML_ERROR, "lockres %s: ast fired with invalid action: %u "
-                     "lockres flags = 0x%lx, unlock action: %u\n",
+                mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
+                     "flags 0x%lx, unlock: %u\n",
                      lockres->l_name, lockres->l_action, lockres->l_flags,
                      lockres->l_unlock_action);
                 BUG();
@@ -1145,8 +1153,8 @@ static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
 
         mlog_entry_void();
 
-        mlog(0, "UNLOCK AST called on lock %s, action = %d\n", lockres->l_name,
-             lockres->l_unlock_action);
+        mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
+             lockres->l_name, lockres->l_unlock_action);
 
         spin_lock_irqsave(&lockres->l_lock, flags);
         if (error) {
@@ -1497,7 +1505,7 @@ again:
                 BUG_ON(level == DLM_LOCK_IV);
                 BUG_ON(level == DLM_LOCK_NL);
 
-                mlog(0, "lock %s, convert from %d to level = %d\n",
+                mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
                      lockres->l_name, lockres->l_level, level);
 
                 /* call dlm_lock to upgrade lock now */
@@ -3314,13 +3322,20 @@ static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
         BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
 
         if (lockres->l_level <= new_level) {
-                mlog(ML_ERROR, "lockres->l_level (%d) <= new_level (%d)\n",
-                     lockres->l_level, new_level);
+                mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
+                     "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
+                     "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
+                     new_level, list_empty(&lockres->l_blocked_list),
+                     list_empty(&lockres->l_mask_waiters), lockres->l_type,
+                     lockres->l_flags, lockres->l_ro_holders,
+                     lockres->l_ex_holders, lockres->l_action,
+                     lockres->l_unlock_action, lockres->l_requested,
+                     lockres->l_blocking, lockres->l_pending_gen);
                 BUG();
         }
 
-        mlog(0, "lock %s, new_level = %d, l_blocking = %d\n",
-             lockres->l_name, new_level, lockres->l_blocking);
+        mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
+             lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
 
         lockres->l_action = OCFS2_AST_DOWNCONVERT;
         lockres->l_requested = new_level;
@@ -3339,6 +3354,9 @@ static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
 
         mlog_entry_void();
 
+        mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
+             lockres->l_level, new_level);
+
         if (lvb)
                 dlm_flags |= DLM_LKF_VALBLK;
 
@@ -3368,14 +3386,12 @@ static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
         assert_spin_locked(&lockres->l_lock);
 
         mlog_entry_void();
-        mlog(0, "lock %s\n", lockres->l_name);
 
         if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
                 /* If we're already trying to cancel a lock conversion
                  * then just drop the spinlock and allow the caller to
                  * requeue this lock. */
-
-                mlog(0, "Lockres %s, skip convert\n", lockres->l_name);
+                mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
                 return 0;
         }
 
@@ -3390,6 +3406,8 @@ static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
                         "lock %s, invalid flags: 0x%lx\n",
                         lockres->l_name, lockres->l_flags);
 
+        mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
+
         return 1;
 }
 
@@ -3399,7 +3417,6 @@ static int ocfs2_cancel_convert(struct ocfs2_super *osb,
         int ret;
 
         mlog_entry_void();
-        mlog(0, "lock %s\n", lockres->l_name);
 
         ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
                                DLM_LKF_CANCEL);
@@ -3408,7 +3425,7 @@ static int ocfs2_cancel_convert(struct ocfs2_super *osb,
                 ocfs2_recover_from_dlm_error(lockres, 0);
         }
 
-        mlog(0, "lock %s return from ocfs2_dlm_unlock\n", lockres->l_name);
+        mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
 
         mlog_exit(ret);
         return ret;
@@ -3465,8 +3482,11 @@ recheck:
                  * at the same time they set OCFS2_DLM_BUSY.  They must
                  * clear OCFS2_DLM_PENDING after dlm_lock() returns.
                  */
-                if (lockres->l_flags & OCFS2_LOCK_PENDING)
+                if (lockres->l_flags & OCFS2_LOCK_PENDING) {
+                        mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
+                             lockres->l_name);
                         goto leave_requeue;
+                }
 
                 ctl->requeue = 1;
                 ret = ocfs2_prepare_cancel_convert(osb, lockres);
@@ -3498,6 +3518,7 @@ recheck:
          */
         if (lockres->l_level == DLM_LOCK_NL) {
                 BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
+                mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
                 lockres->l_blocking = DLM_LOCK_NL;
                 lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
                 spin_unlock_irqrestore(&lockres->l_lock, flags);
@@ -3507,28 +3528,41 @@ recheck:
         /* if we're blocking an exclusive and we have *any* holders,
          * then requeue. */
         if ((lockres->l_blocking == DLM_LOCK_EX)
-            && (lockres->l_ex_holders || lockres->l_ro_holders))
+            && (lockres->l_ex_holders || lockres->l_ro_holders)) {
+                mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
+                     lockres->l_name, lockres->l_ex_holders,
+                     lockres->l_ro_holders);
                 goto leave_requeue;
+        }
 
         /* If it's a PR we're blocking, then only
          * requeue if we've got any EX holders */
         if (lockres->l_blocking == DLM_LOCK_PR &&
-            lockres->l_ex_holders)
+            lockres->l_ex_holders) {
+                mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
+                     lockres->l_name, lockres->l_ex_holders);
                 goto leave_requeue;
+        }
 
         /*
          * Can we get a lock in this state if the holder counts are
          * zero? The meta data unblock code used to check this.
          */
         if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
-            && (lockres->l_flags & OCFS2_LOCK_REFRESHING))
+            && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
+                mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
+                     lockres->l_name);
                 goto leave_requeue;
+        }
 
         new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
 
         if (lockres->l_ops->check_downconvert
-            && !lockres->l_ops->check_downconvert(lockres, new_level))
+            && !lockres->l_ops->check_downconvert(lockres, new_level)) {
+                mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
+                     lockres->l_name);
                 goto leave_requeue;
+        }
 
         /* If we get here, then we know that there are no more
          * incompatible holders (and anyone asking for an incompatible
@@ -3546,13 +3580,19 @@ recheck:
 
         ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
 
-        if (ctl->unblock_action == UNBLOCK_STOP_POST)
+        if (ctl->unblock_action == UNBLOCK_STOP_POST) {
+                mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
+                     lockres->l_name);
                 goto leave;
+        }
 
         spin_lock_irqsave(&lockres->l_lock, flags);
         if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
                 /* If this changed underneath us, then we can't drop
                  * it just yet. */
+                mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
+                     "Recheck\n", lockres->l_name, blocking,
+                     lockres->l_blocking, level, lockres->l_level);
                 goto recheck;
         }
 
@@ -3963,7 +4003,7 @@ static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
         BUG_ON(!lockres);
         BUG_ON(!lockres->l_ops);
 
-        mlog(0, "lockres %s blocked.\n", lockres->l_name);
+        mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
 
         /* Detect whether a lock has been marked as going away while
          * the downconvert thread was processing other things. A lock can
@@ -3986,7 +4026,7 @@ unqueue:
         } else
                 ocfs2_schedule_blocked_lock(osb, lockres);
 
-        mlog(0, "lockres %s, requeue = %s.\n", lockres->l_name,
+        mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
              ctl.requeue ? "yes" : "no");
         spin_unlock_irqrestore(&lockres->l_lock, flags);
 
@@ -4008,7 +4048,7 @@ static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
                 /* Do not schedule a lock for downconvert when it's on
                  * the way to destruction - any nodes wanting access
                  * to the resource will get it soon. */
-                mlog(0, "Lockres %s won't be scheduled: flags 0x%lx\n",
+                mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
                      lockres->l_name, lockres->l_flags);
                 return;
         }