xfs_buflock: record line number of trace where we locked the buffer

Enhance the debug output by reporting at which line in the trace output
we locked a particular buffer.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/tools/xfsbuflock.py b/tools/xfsbuflock.py
index cc15f582c4efb87e01ae82b010beeea6e2ba2021..954f0954358297bf2578942fd2ecbc8e5ec69a61 100755 (executable)
--- a/tools/xfsbuflock.py
+++ b/tools/xfsbuflock.py
@@ -85,6 +85,7 @@ class Buffer:
                self.locktime = None
                self.owner = None
                self.waiters = set()
+               self.lockline = 0
 
        def trylock(self, process, time):
                if not self.locked:
@@ -92,7 +93,8 @@ class Buffer:
 
        def lockdone(self, process, time):
                if self.locked:
-                       print('Buffer already locked on line %d?!' % nr)
+                       print('Buffer 0x%x already locked at line %d? (line %d)' % \
+                                       (self.bno, self.lockline, nr))
                #       process.dump()
                #       self.dump()
                #       assert False
@@ -101,6 +103,7 @@ class Buffer:
                self.locked = True
                self.owner = process
                self.locktime = time
+               self.lockline = nr
                process.locked_bufs.add(self)
                process.bufs.add(self)
                locked_buffers.add(self)
@@ -118,7 +121,8 @@ class Buffer:
 
        def dump(self):
                if self.owner is not None:
-                       pid = '%s@%f' % (self.owner.pid, self.locktime)
+                       pid = '%s@%f (line %d)' % \
+                               (self.owner.pid, self.locktime, self.lockline)
                else:
                        pid = ''
                print('dev %s bno 0x%x nblks 0x%x lock %d owner %s' % \