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Commit 62af4f1f authored by Jeff Layton's avatar Jeff Layton
Browse files

locks: add some tracepoints in the lease handling code 



v2: add a __break_lease tracepoint for non-blocking case

Recently, I needed these to help track down a softlockup when recalling a
delegation, but they might be helpful in other situations as well.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: default avatarJeff Layton <jlayton@poochiereds.net>
parent 5315c26a

fs/locks.c

+11 −0
Original line number Diff line number Diff line
@@ -130,6 +130,9 @@ 
#include <linux/percpu.h>

#include <linux/lglock.h>



#define CREATE_TRACE_POINTS

#include <trace/events/filelock.h>



#include <asm/uaccess.h>



#define IS_POSIX(fl)	(fl->fl_flags & FL_POSIX)
@@ -1287,6 +1290,7 @@ static void time_out_leases(struct inode *inode) 


	before = &inode->i_flock;

	while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) {

		trace_time_out_leases(inode, fl);

		if (past_time(fl->fl_downgrade_time))

			lease_modify(before, F_RDLCK);

		if (past_time(fl->fl_break_time))
@@ -1374,6 +1378,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) 
	}



	if (i_have_this_lease || (mode & O_NONBLOCK)) {

		trace_break_lease_noblock(inode, new_fl);

		error = -EWOULDBLOCK;

		goto out;

	}
@@ -1385,10 +1390,12 @@ restart: 
	if (break_time == 0)

		break_time++;

	locks_insert_block(flock, new_fl);

	trace_break_lease_block(inode, new_fl);

	spin_unlock(&inode->i_lock);

	error = wait_event_interruptible_timeout(new_fl->fl_wait,

						!new_fl->fl_next, break_time);

	spin_lock(&inode->i_lock);

	trace_break_lease_unblock(inode, new_fl);

	locks_delete_block(new_fl);

	if (error >= 0) {

		if (error == 0)
@@ -1510,6 +1517,8 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp 
	int error;



	lease = *flp;

	trace_generic_add_lease(inode, lease);



	/*

	 * In the delegation case we need mutual exclusion with

	 * a number of operations that take the i_mutex.  We trylock
@@ -1599,6 +1608,8 @@ static int generic_delete_lease(struct file *filp, struct file_lock **flp) 
	struct dentry *dentry = filp->f_path.dentry;

	struct inode *inode = dentry->d_inode;



	trace_generic_delete_lease(inode, *flp);



	for (before = &inode->i_flock;

			((fl = *before) != NULL) && IS_LEASE(fl);

			before = &fl->fl_next) {

include/trace/events/filelock.h

0 → 100644
+96 −0
Original line number Diff line number Diff line 
/*

 * Events for filesystem locks

 *

 * Copyright 2013 Jeff Layton <jlayton@poochiereds.net>

 */

#undef TRACE_SYSTEM

#define TRACE_SYSTEM filelock



#if !defined(_TRACE_FILELOCK_H) || defined(TRACE_HEADER_MULTI_READ)

#define _TRACE_FILELOCK_H



#include <linux/tracepoint.h>

#include <linux/fs.h>

#include <linux/device.h>

#include <linux/kdev_t.h>



#define show_fl_flags(val)						\

	__print_flags(val, "|", 					\

		{ FL_POSIX,		"FL_POSIX" },			\

		{ FL_FLOCK,		"FL_FLOCK" },			\

		{ FL_DELEG,		"FL_DELEG" },			\

		{ FL_ACCESS,		"FL_ACCESS" },			\

		{ FL_EXISTS,		"FL_EXISTS" },			\

		{ FL_LEASE,		"FL_LEASE" },			\

		{ FL_CLOSE,		"FL_CLOSE" },			\

		{ FL_SLEEP,		"FL_SLEEP" },			\

		{ FL_DOWNGRADE_PENDING,	"FL_DOWNGRADE_PENDING" },	\

		{ FL_UNLOCK_PENDING,	"FL_UNLOCK_PENDING" },		\

		{ FL_OFDLCK,		"FL_OFDLCK" })



#define show_fl_type(val)				\

	__print_symbolic(val,				\

			{ F_RDLCK, "F_RDLCK" },		\

			{ F_WRLCK, "F_WRLCK" },		\

			{ F_UNLCK, "F_UNLCK" })



DECLARE_EVENT_CLASS(filelock_lease,



	TP_PROTO(struct inode *inode, struct file_lock *fl),



	TP_ARGS(inode, fl),



	TP_STRUCT__entry(

		__field(struct file_lock *, fl)

		__field(unsigned long, i_ino)

		__field(dev_t, s_dev)

		__field(struct file_lock *, fl_next)

		__field(fl_owner_t, fl_owner)

		__field(unsigned int, fl_flags)

		__field(unsigned char, fl_type)

		__field(unsigned long, fl_break_time)

		__field(unsigned long, fl_downgrade_time)

	),



	TP_fast_assign(

		__entry->fl = fl;

		__entry->s_dev = inode->i_sb->s_dev;

		__entry->i_ino = inode->i_ino;

		__entry->fl_next = fl->fl_next;

		__entry->fl_owner = fl->fl_owner;

		__entry->fl_flags = fl->fl_flags;

		__entry->fl_type = fl->fl_type;

		__entry->fl_break_time = fl->fl_break_time;

		__entry->fl_downgrade_time = fl->fl_downgrade_time;

	),



	TP_printk("fl=0x%p dev=0x%x:0x%x ino=0x%lx fl_next=0x%p fl_owner=0x%p fl_flags=%s fl_type=%s fl_break_time=%lu fl_downgrade_time=%lu",

		__entry->fl, MAJOR(__entry->s_dev), MINOR(__entry->s_dev),

		__entry->i_ino, __entry->fl_next, __entry->fl_owner,

		show_fl_flags(__entry->fl_flags),

		show_fl_type(__entry->fl_type),

		__entry->fl_break_time, __entry->fl_downgrade_time)

);



DEFINE_EVENT(filelock_lease, break_lease_noblock, TP_PROTO(struct inode *inode, struct file_lock *fl),

		TP_ARGS(inode, fl));



DEFINE_EVENT(filelock_lease, break_lease_block, TP_PROTO(struct inode *inode, struct file_lock *fl),

		TP_ARGS(inode, fl));



DEFINE_EVENT(filelock_lease, break_lease_unblock, TP_PROTO(struct inode *inode, struct file_lock *fl),

		TP_ARGS(inode, fl));



DEFINE_EVENT(filelock_lease, generic_add_lease, TP_PROTO(struct inode *inode, struct file_lock *fl),

		TP_ARGS(inode, fl));



DEFINE_EVENT(filelock_lease, generic_delete_lease, TP_PROTO(struct inode *inode, struct file_lock *fl),

		TP_ARGS(inode, fl));



DEFINE_EVENT(filelock_lease, time_out_leases, TP_PROTO(struct inode *inode, struct file_lock *fl),

		TP_ARGS(inode, fl));



#endif /* _TRACE_FILELOCK_H */



/* This part must be outside protection */

#include <trace/define_trace.h>