Re: [PATCH v15 13/22] xfs: Add state machine tracepoints

Allison Henderson <allison.henderson@xxxxxxxxxx> · Fri, 26 Feb 2021 17:57:33 -0700

On 2/25/21 10:06 PM, Darrick J. Wong wrote:
On Thu, Feb 18, 2021 at 09:53:39AM -0700, Allison Henderson wrote:
This is a quick patch to add a new tracepoint: xfs_das_state_return.  We
use this to track when ever a new state is set or -EAGAIN is returned

Signed-off-by: Allison Henderson <allison.henderson@xxxxxxxxxx>

Looks good!
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Cool, thank you!
Allison


--D

---
  fs/xfs/libxfs/xfs_attr.c        | 31 ++++++++++++++++++++++++++++++-
  fs/xfs/libxfs/xfs_attr_remote.c |  1 +
  fs/xfs/xfs_trace.h              | 25 +++++++++++++++++++++++++
  3 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index c7b86d5..ba21475 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -313,6 +313,7 @@ xfs_attr_set_fmt(
  	 * the attr fork to leaf format and will restart with the leaf
  	 * add.
  	 */
+	trace_xfs_attr_set_fmt_return(XFS_DAS_UNINIT, args->dp);
  	dac->flags |= XFS_DAC_DEFER_FINISH;
  	return -EAGAIN;
  }
@@ -378,6 +379,8 @@ xfs_attr_set_iter(
  				 * handling code below
  				 */
  				dac->flags |= XFS_DAC_DEFER_FINISH;
+				trace_xfs_attr_set_iter_return(
+					dac->dela_state, args->dp);
  				return -EAGAIN;
  			}
  			else if (error)
@@ -400,10 +403,13 @@ xfs_attr_set_iter(
  				return error;
  
  			dac->dela_state = XFS_DAS_FOUND_NBLK;
+			trace_xfs_attr_set_iter_return(dac->dela_state,
+						       args->dp);
  			return -EAGAIN;
  		}
  
  		dac->dela_state = XFS_DAS_FOUND_LBLK;
+		trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
  		return -EAGAIN;
  
          case XFS_DAS_FOUND_LBLK:
@@ -433,6 +439,8 @@ xfs_attr_set_iter(
  			if (error)
  				return error;
  
+			trace_xfs_attr_set_iter_return(dac->dela_state,
+						       args->dp);
  			return -EAGAIN;
  		}
  
@@ -469,6 +477,7 @@ xfs_attr_set_iter(
  		 * series.
  		 */
  		dac->dela_state = XFS_DAS_FLIP_LFLAG;
+		trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
  		return -EAGAIN;
  	case XFS_DAS_FLIP_LFLAG:
  		/*
@@ -488,6 +497,9 @@ xfs_attr_set_iter(
  	case XFS_DAS_RM_LBLK:
  		if (args->rmtblkno) {
  			error = __xfs_attr_rmtval_remove(dac);
+			if (error == -EAGAIN)
+				trace_xfs_attr_set_iter_return(
+					dac->dela_state, args->dp);
  			if (error)
  				return error;
  		}
@@ -545,6 +557,8 @@ xfs_attr_set_iter(
  				if (error)
  					return error;
  
+				trace_xfs_attr_set_iter_return(
+					dac->dela_state, args->dp);
  				return -EAGAIN;
  			}
  
@@ -581,6 +595,7 @@ xfs_attr_set_iter(
  		 * series
  		 */
  		dac->dela_state = XFS_DAS_FLIP_NFLAG;
+		trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
  		return -EAGAIN;
  
  	case XFS_DAS_FLIP_NFLAG:
@@ -601,6 +616,10 @@ xfs_attr_set_iter(
  	case XFS_DAS_RM_NBLK:
  		if (args->rmtblkno) {
  			error = __xfs_attr_rmtval_remove(dac);
+			if (error == -EAGAIN)
+				trace_xfs_attr_set_iter_return(
+					dac->dela_state, args->dp);
+
  			if (error)
  				return error;
  		}
@@ -1214,6 +1233,8 @@ xfs_attr_node_addname(
  			 * this point.
  			 */
  			dac->flags |= XFS_DAC_DEFER_FINISH;
+			trace_xfs_attr_node_addname_return(
+					dac->dela_state, args->dp);
  			return -EAGAIN;
  		}
  
@@ -1394,6 +1415,9 @@ xfs_attr_node_remove_rmt (
  	 * May return -EAGAIN to request that the caller recall this function
  	 */
  	error = __xfs_attr_rmtval_remove(dac);
+	if (error == -EAGAIN)
+		trace_xfs_attr_node_remove_rmt_return(dac->dela_state,
+						      dac->da_args->dp);
  	if (error)
  		return error;
  
@@ -1513,6 +1537,8 @@ xfs_attr_node_removename_iter(
  
  			dac->flags |= XFS_DAC_DEFER_FINISH;
  			dac->dela_state = XFS_DAS_RM_SHRINK;
+			trace_xfs_attr_node_removename_iter_return(
+					dac->dela_state, args->dp);
  			return -EAGAIN;
  		}
  
@@ -1531,8 +1557,11 @@ xfs_attr_node_removename_iter(
  		goto out;
  	}
  
-	if (error == -EAGAIN)
+	if (error == -EAGAIN) {
+		trace_xfs_attr_node_removename_iter_return(
+					dac->dela_state, args->dp);
  		return error;
+	}
  out:
  	if (state)
  		xfs_da_state_free(state);
diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
index 6af86bf..b242e1a 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.c
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -763,6 +763,7 @@ __xfs_attr_rmtval_remove(
  	 */
  	if (!done) {
  		dac->flags |= XFS_DAC_DEFER_FINISH;
+		trace_xfs_attr_rmtval_remove_return(dac->dela_state, args->dp);
  		return -EAGAIN;
  	}
  
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 363e1bf..7993f55 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3927,6 +3927,31 @@ DEFINE_EVENT(xfs_eofblocks_class, name,	\
  DEFINE_EOFBLOCKS_EVENT(xfs_ioc_free_eofblocks);
  DEFINE_EOFBLOCKS_EVENT(xfs_blockgc_free_space);
  
+DECLARE_EVENT_CLASS(xfs_das_state_class,
+	TP_PROTO(int das, struct xfs_inode *ip),
+	TP_ARGS(das, ip),
+	TP_STRUCT__entry(
+		__field(int, das)
+		__field(xfs_ino_t, ino)
+	),
+	TP_fast_assign(
+		__entry->das = das;
+		__entry->ino = ip->i_ino;
+	),
+	TP_printk("state change %d ino 0x%llx",
+		  __entry->das, __entry->ino)
+)
+
+#define DEFINE_DAS_STATE_EVENT(name) \
+DEFINE_EVENT(xfs_das_state_class, name, \
+	TP_PROTO(int das, struct xfs_inode *ip), \
+	TP_ARGS(das, ip))
+DEFINE_DAS_STATE_EVENT(xfs_attr_set_fmt_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_set_iter_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_node_addname_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_node_removename_iter_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_node_remove_rmt_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_rmtval_remove_return);
  #endif /* _TRACE_XFS_H */
  
  #undef TRACE_INCLUDE_PATH
--
2.7.4







