xfs: remove file_path tracepoint data

The xfile/xmbuf shmem file descriptions are no longer as detailed as
they were when online fsck was first merged, because moving to static
strings in commit 6038299 ("xfs: get rid of the
xchk_xfile_*_descr calls") removed a memory allocation and hence a
source of failure.

However this makes encoding the description in the tracepoints sort of a
waste of memory.  David Laight also points out that file_path doesn't
zero the whole buffer which causes exposure of stale trace bytes, and
Steven Rostedt wonders why we're not using a dynamic array for the file
path.

I don't think this is worth fixing, so let's just rip it out.

Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/linux-xfs/[email protected]/
Cc: [email protected] # v6.11
Fixes: 19ebc8f ("xfs: fix file_path handling in tracepoints")
Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Carlos Maiolino <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Carlos Maiolino <[email protected]>

Author: Darrick J. Wong

fs/xfs/scrub/trace.h

@@ -972,20 +972,12 @@ TRACE_EVENT(xfile_create,
 	TP_STRUCT__entry(
 		__field(dev_t, dev)
 		__field(unsigned long, ino)
-		__array(char, pathname, MAXNAMELEN)
 	),
 	TP_fast_assign(
-		char		*path;
-
 		__entry->ino = file_inode(xf->file)->i_ino;
-		path = file_path(xf->file, __entry->pathname, MAXNAMELEN);
-		if (IS_ERR(path))
-			strncpy(__entry->pathname, "(unknown)",
-					sizeof(__entry->pathname));
 	),
-	TP_printk("xfino 0x%lx path '%s'",
-		  __entry->ino,
-		  __entry->pathname)
+	TP_printk("xfino 0x%lx",
+		  __entry->ino)
 );
 
 TRACE_EVENT(xfile_destroy,

fs/xfs/xfs_trace.h

@@ -5119,23 +5119,16 @@ TRACE_EVENT(xmbuf_create,
 	TP_STRUCT__entry(
 		__field(dev_t, dev)
 		__field(unsigned long, ino)
-		__array(char, pathname, MAXNAMELEN)
 	),
 	TP_fast_assign(
-		char		*path;
 		struct file	*file = btp->bt_file;
 
 		__entry->dev = btp->bt_mount->m_super->s_dev;
 		__entry->ino = file_inode(file)->i_ino;
-		path = file_path(file, __entry->pathname, MAXNAMELEN);
-		if (IS_ERR(path))
-			strncpy(__entry->pathname, "(unknown)",
-					sizeof(__entry->pathname));
 	),
-	TP_printk("dev %d:%d xmino 0x%lx path '%s'",
+	TP_printk("dev %d:%d xmino 0x%lx",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
-		  __entry->ino,
-		  __entry->pathname)
+		  __entry->ino)
 );
 
 TRACE_EVENT(xmbuf_free,