nilfs2: move out mark_inode_dirty calls from bmap routines

Previously, nilfs_bmap_add_blocks() and nilfs_bmap_sub_blocks() called
mark_inode_dirty() after they changed the number of data blocks.

This moves these calls outside bmap outermost functions like
nilfs_bmap_insert() or nilfs_bmap_truncate().

This will mitigate overhead for truncate or delete operation since
they repeatedly remove set of blocks.  Nearly 10 percent improvement
was observed for removal of a large file:

 # dd if=/dev/zero of=/test/aaa bs=1M count=512
 # time rm /test/aaa

  real  2.968s -> 2.705s

Further optimization may be possible by eliminating these
mark_inode_dirty() uses though I avoid mixing separate changes here.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/bmap.c

@@ -402,15 +402,11 @@ int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 void nilfs_bmap_add_blocks(const struct nilfs_bmap *bmap, int n)
 {
 	inode_add_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
-	if (!NILFS_MDT(bmap->b_inode))
-		mark_inode_dirty(bmap->b_inode);
 }
 
 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *bmap, int n)
 {
 	inode_sub_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
-	if (!NILFS_MDT(bmap->b_inode))
-		mark_inode_dirty(bmap->b_inode);
 }
 
 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,

fs/nilfs2/inode.c

@@ -97,6 +97,7 @@ int nilfs_get_block(struct inode *inode, sector_t blkoff,
 			nilfs_transaction_abort(inode->i_sb);
 			goto out;
 		}
+		mark_inode_dirty(inode);
 		nilfs_transaction_commit(inode->i_sb); /* never fails */
 		/* Error handling should be detailed */
 		set_buffer_new(bh_result);
@@ -598,6 +599,7 @@ void nilfs_truncate(struct inode *inode)
 	if (IS_SYNC(inode))
 		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 
+	mark_inode_dirty(inode);
 	nilfs_set_file_dirty(NILFS_SB(sb), inode, 0);
 	nilfs_transaction_commit(sb);
 	/* May construct a logical segment and may fail in sync mode.
@@ -622,6 +624,7 @@ void nilfs_delete_inode(struct inode *inode)
 		truncate_inode_pages(&inode->i_data, 0);
 
 	nilfs_truncate_bmap(ii, 0);
+	mark_inode_dirty(inode);
 	nilfs_free_inode(inode);
 	/* nilfs_free_inode() marks inode buffer dirty */
 	if (IS_SYNC(inode))