ext4: remove unused metadata accounting variables

Two variables in ext4_inode_info, i_reserved_meta_blocks and
i_allocated_meta_blocks, are unused.  Removing them saves a little
memory per in-memory inode and cleans up clutter in several tracepoints.
Adjust tracepoint output from ext4_alloc_da_blocks() for consistency
and fix a typo and whitespace near these changes.
Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

fs/ext4/ext4.h

@@ -961,7 +961,7 @@ struct ext4_inode_info {
 	/*
 	 * i_block_group is the number of the block group which contains
 	 * this file's inode.  Constant across the lifetime of the inode,
-	 * it is ued for making block allocation decisions - we try to
+	 * it is used for making block allocation decisions - we try to
 	 * place a file's data blocks near its inode block, and new inodes
 	 * near to their parent directory's inode.
 	 */
@@ -1049,10 +1049,8 @@ struct ext4_inode_info {
 	ext4_group_t	i_last_alloc_group;
 
 	/* allocation reservation info for delalloc */
-	/* In case of bigalloc, these refer to clusters rather than blocks */
+	/* In case of bigalloc, this refer to clusters rather than blocks */
 	unsigned int i_reserved_data_blocks;
-	unsigned int i_reserved_meta_blocks;
-	unsigned int i_allocated_meta_blocks;
 	ext4_lblk_t i_da_metadata_calc_last_lblock;
 	int i_da_metadata_calc_len;
 

fs/ext4/super.c

@@ -978,8 +978,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_es_shk_nr = 0;
 	ei->i_es_shrink_lblk = 0;
 	ei->i_reserved_data_blocks = 0;
-	ei->i_reserved_meta_blocks = 0;
-	ei->i_allocated_meta_blocks = 0;
 	ei->i_da_metadata_calc_len = 0;
 	ei->i_da_metadata_calc_last_lblock = 0;
 	spin_lock_init(&(ei->i_block_reservation_lock));

include/trace/events/ext4.h

@@ -937,21 +937,19 @@ TRACE_EVENT(ext4_alloc_da_blocks,
 	TP_STRUCT__entry(
 		__field(	dev_t,	dev			)
 		__field(	ino_t,	ino			)
-		__field( unsigned int,	data_blocks	)
-		__field( unsigned int,	meta_blocks	)
+		__field( unsigned int,	data_blocks		)
 	),
 
 	TP_fast_assign(
 		__entry->dev	= inode->i_sb->s_dev;
 		__entry->ino	= inode->i_ino;
 		__entry->data_blocks = EXT4_I(inode)->i_reserved_data_blocks;
-		__entry->meta_blocks = EXT4_I(inode)->i_reserved_meta_blocks;
 	),
 
-	TP_printk("dev %d,%d ino %lu data_blocks %u meta_blocks %u",
+	TP_printk("dev %d,%d ino %lu reserved_data_blocks %u",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  (unsigned long) __entry->ino,
-		  __entry->data_blocks, __entry->meta_blocks)
+		  __entry->data_blocks)
 );
 
 TRACE_EVENT(ext4_mballoc_alloc,
@@ -1153,8 +1151,6 @@ TRACE_EVENT(ext4_da_update_reserve_space,
 		__field(	__u64,	i_blocks		)
 		__field(	int,	used_blocks		)
 		__field(	int,	reserved_data_blocks	)
-		__field(	int,	reserved_meta_blocks	)
-		__field(	int,	allocated_meta_blocks	)
 		__field(	int,	quota_claim		)
 		__field(	__u16,	mode			)
 	),
@@ -1166,22 +1162,16 @@ TRACE_EVENT(ext4_da_update_reserve_space,
 		__entry->used_blocks = used_blocks;
 		__entry->reserved_data_blocks =
 				EXT4_I(inode)->i_reserved_data_blocks;
-		__entry->reserved_meta_blocks =
-				EXT4_I(inode)->i_reserved_meta_blocks;
-		__entry->allocated_meta_blocks =
-				EXT4_I(inode)->i_allocated_meta_blocks;
 		__entry->quota_claim = quota_claim;
 		__entry->mode	= inode->i_mode;
 	),
 
 	TP_printk("dev %d,%d ino %lu mode 0%o i_blocks %llu used_blocks %d "
-		  "reserved_data_blocks %d reserved_meta_blocks %d "
-		  "allocated_meta_blocks %d quota_claim %d",
+		  "reserved_data_blocks %d quota_claim %d",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  (unsigned long) __entry->ino,
 		  __entry->mode, __entry->i_blocks,
 		  __entry->used_blocks, __entry->reserved_data_blocks,
-		  __entry->reserved_meta_blocks, __entry->allocated_meta_blocks,
 		  __entry->quota_claim)
 );
 
@@ -1195,7 +1185,6 @@ TRACE_EVENT(ext4_da_reserve_space,
 		__field(	ino_t,	ino			)
 		__field(	__u64,	i_blocks		)
 		__field(	int,	reserved_data_blocks	)
-		__field(	int,	reserved_meta_blocks	)
 		__field(	__u16,  mode			)
 	),
 
@@ -1204,17 +1193,15 @@ TRACE_EVENT(ext4_da_reserve_space,
 		__entry->ino	= inode->i_ino;
 		__entry->i_blocks = inode->i_blocks;
 		__entry->reserved_data_blocks = EXT4_I(inode)->i_reserved_data_blocks;
-		__entry->reserved_meta_blocks = EXT4_I(inode)->i_reserved_meta_blocks;
 		__entry->mode	= inode->i_mode;
 	),
 
 	TP_printk("dev %d,%d ino %lu mode 0%o i_blocks %llu "
-		  "reserved_data_blocks %d reserved_meta_blocks %d",
+		  "reserved_data_blocks %d",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  (unsigned long) __entry->ino,
 		  __entry->mode, __entry->i_blocks,
-		  __entry->reserved_data_blocks,
-		  __entry->reserved_meta_blocks)
+		  __entry->reserved_data_blocks)
 );
 
 TRACE_EVENT(ext4_da_release_space,
@@ -1228,8 +1215,6 @@ TRACE_EVENT(ext4_da_release_space,
 		__field(	__u64,	i_blocks		)
 		__field(	int,	freed_blocks		)
 		__field(	int,	reserved_data_blocks	)
-		__field(	int,	reserved_meta_blocks	)
-		__field(	int,	allocated_meta_blocks	)
 		__field(	__u16,  mode			)
 	),
 
@@ -1239,19 +1224,15 @@ TRACE_EVENT(ext4_da_release_space,
 		__entry->i_blocks = inode->i_blocks;
 		__entry->freed_blocks = freed_blocks;
 		__entry->reserved_data_blocks = EXT4_I(inode)->i_reserved_data_blocks;
-		__entry->reserved_meta_blocks = EXT4_I(inode)->i_reserved_meta_blocks;
-		__entry->allocated_meta_blocks = EXT4_I(inode)->i_allocated_meta_blocks;
 		__entry->mode	= inode->i_mode;
 	),
 
 	TP_printk("dev %d,%d ino %lu mode 0%o i_blocks %llu freed_blocks %d "
-		  "reserved_data_blocks %d reserved_meta_blocks %d "
-		  "allocated_meta_blocks %d",
+		  "reserved_data_blocks %d",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  (unsigned long) __entry->ino,
 		  __entry->mode, __entry->i_blocks,
-		  __entry->freed_blocks, __entry->reserved_data_blocks,
-		  __entry->reserved_meta_blocks, __entry->allocated_meta_blocks)
+		  __entry->freed_blocks, __entry->reserved_data_blocks)
 );
 
 DECLARE_EVENT_CLASS(ext4__bitmap_load,