[PATCH v22 05/16] xfs: Add state machine tracepoints

Allison Henderson
2021-07-27T06:21:17Z

This is a quick patch to add a new xfs_attr_*_return tracepoints. We
use these to track when ever a new state is set or -EAGAIN is returned

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_attr.c | 28 ++++++++++++++++++++++++++--
fs/xfs/libxfs/xfs_attr_remote.c | 1 +
fs/xfs/xfs_trace.h | 24 ++++++++++++++++++++++++
3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 5040fc1..b0c6c62 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -335,6 +335,7 @@ xfs_attr_sf_addname(
* the attr fork to leaf format and will restart with the leaf
* add.
*/
+ trace_xfs_attr_sf_addname_return(XFS_DAS_UNINIT, args->dp);
dac->flags |= XFS_DAC_DEFER_FINISH;
return -EAGAIN;
}
@@ -394,6 +395,8 @@ 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) {
return error;
@@ -418,6 +421,7 @@ xfs_attr_set_iter(

dac->dela_state = XFS_DAS_FOUND_NBLK;
}
+ trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
case XFS_DAS_FOUND_LBLK:
/*
@@ -445,6 +449,8 @@ xfs_attr_set_iter(
error = xfs_attr_rmtval_set_blk(dac);
if (error)
return error;
+ trace_xfs_attr_set_iter_return(dac->dela_state,
+ args->dp);
return -EAGAIN;
}

@@ -479,6 +485,7 @@ 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:
/*
@@ -496,6 +503,9 @@ xfs_attr_set_iter(
dac->dela_state = 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;

@@ -549,6 +559,8 @@ xfs_attr_set_iter(
error = xfs_attr_rmtval_set_blk(dac);
if (error)
return error;
+ trace_xfs_attr_set_iter_return(
+ dac->dela_state, args->dp);
return -EAGAIN;
}

@@ -584,6 +596,7 @@ 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:
@@ -603,6 +616,10 @@ xfs_attr_set_iter(
dac->dela_state = 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;

@@ -1183,6 +1200,8 @@ 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;
}

@@ -1429,10 +1448,13 @@ xfs_attr_remove_iter(
* blocks are removed.
*/
error = __xfs_attr_rmtval_remove(dac);
- if (error == -EAGAIN)
+ if (error == -EAGAIN) {
+ trace_xfs_attr_remove_iter_return(
+ dac->dela_state, args->dp);
return error;
- else if (error)
+ } else if (error) {
goto out;
+ }

/*
* Refill the state structure with buffers (the prior
@@ -1473,6 +1495,8 @@ xfs_attr_remove_iter(

dac->flags |= XFS_DAC_DEFER_FINISH;
dac->dela_state = XFS_DAS_RM_SHRINK;
+ trace_xfs_attr_remove_iter_return(
+ dac->dela_state, args->dp);
return -EAGAIN;
}

diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c
index 0c8bee3..70f880d 100644
--- a/fs/xfs/libxfs/xfs_attr_remote.c
+++ b/fs/xfs/libxfs/xfs_attr_remote.c
@@ -696,6 +696,7 @@ __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 f9d8d60..f9840dd 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3987,6 +3987,30 @@ DEFINE_ICLOG_EVENT(xlog_iclog_want_sync);
DEFINE_ICLOG_EVENT(xlog_iclog_wait_on);
DEFINE_ICLOG_EVENT(xlog_iclog_write);

+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_sf_addname_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_remove_iter_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_rmtval_remove_return);
#endif /* _TRACE_XFS_H */

#undef TRACE_INCLUDE_PATH
--
2.7.4