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: Jeff Layton <jlayton@poochiereds.net>
diff --git a/fs/locks.c b/fs/locks.c
index facf76d..da57c9b 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -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 @@
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 @@
}
if (i_have_this_lease || (mode & O_NONBLOCK)) {
+ trace_break_lease_noblock(inode, new_fl);
error = -EWOULDBLOCK;
goto out;
}
@@ -1385,10 +1390,12 @@
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 @@
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 @@
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) {