ext4: Add new ext4 inode tracepoints

Add ext4_evict_inode, ext4_drop_inode, ext4_mark_inode_dirty, and
ext4_begin_ordered_truncate()

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1916164..846e1e9 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -53,6 +53,7 @@
 static inline int ext4_begin_ordered_truncate(struct inode *inode,
 					      loff_t new_size)
 {
+	trace_ext4_begin_ordered_truncate(inode, new_size);
 	return jbd2_journal_begin_ordered_truncate(
 					EXT4_SB(inode->i_sb)->s_journal,
 					&EXT4_I(inode)->jinode,
@@ -178,6 +179,7 @@
 	handle_t *handle;
 	int err;
 
+	trace_ext4_evict_inode(inode);
 	if (inode->i_nlink) {
 		truncate_inode_pages(&inode->i_data, 0);
 		goto no_delete;
@@ -5649,6 +5651,7 @@
 	int err, ret;
 
 	might_sleep();
+	trace_ext4_mark_inode_dirty(inode, _RET_IP_);
 	err = ext4_reserve_inode_write(handle, inode, &iloc);
 	if (ext4_handle_valid(handle) &&
 	    EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ee91e29d..61182fe 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -833,6 +833,14 @@
 	return &ei->vfs_inode;
 }
 
+static int ext4_drop_inode(struct inode *inode)
+{
+	int drop = generic_drop_inode(inode);
+
+	trace_ext4_drop_inode(inode, drop);
+	return drop;
+}
+
 static void ext4_destroy_inode(struct inode *inode)
 {
 	ext4_ioend_wait(inode);
@@ -1175,6 +1183,7 @@
 	.destroy_inode	= ext4_destroy_inode,
 	.write_inode	= ext4_write_inode,
 	.dirty_inode	= ext4_dirty_inode,
+	.drop_inode	= ext4_drop_inode,
 	.evict_inode	= ext4_evict_inode,
 	.put_super	= ext4_put_super,
 	.sync_fs	= ext4_sync_fs,
@@ -1196,6 +1205,7 @@
 	.destroy_inode	= ext4_destroy_inode,
 	.write_inode	= ext4_write_inode,
 	.dirty_inode	= ext4_dirty_inode,
+	.drop_inode	= ext4_drop_inode,
 	.evict_inode	= ext4_evict_inode,
 	.write_super	= ext4_write_super,
 	.put_super	= ext4_put_super,