Re: [f2fs-dev] [PATCH 3/4] f2fs: record node block allocation in dnode_of_data

[Jaegeuk Kim <jaegeuk@kernel.org>]

Hi Chao,

On Wed, Dec 23, 2015 at 04:00:36PM +0800, Chao Yu wrote:
> Hi Jaegeuk,
> 
> > -----Original Message-----
> > From: Jaegeuk Kim [mailto:jaegeuk@kernel.org]
> > Sent: Wednesday, December 23, 2015 9:00 AM
> > To: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org;
> > linux-f2fs-devel@lists.sourceforge.net
> > Cc: Jaegeuk Kim
> > Subject: [f2fs-dev] [PATCH 3/4] f2fs: record node block allocation in dnode_of_data
> > 
> > This patch introduces recording node block allocation in dnode_of_data.
> > This information helps to figure out whether any node block is allocated during
> > specific file operations.
> > 
> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> > ---
> >  fs/f2fs/data.c | 1 +
> >  fs/f2fs/f2fs.h | 1 +
> >  fs/f2fs/file.c | 1 +
> >  fs/f2fs/node.c | 4 ++++
> >  4 files changed, 7 insertions(+)
> > 
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index cf0c9dd..a7a9a05 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -226,6 +226,7 @@ void set_data_blkaddr(struct dnode_of_data *dn)
> >  	addr_array = blkaddr_in_node(rn);
> >  	addr_array[ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
> >  	set_page_dirty(node_page);
> > +	dn->node_changed = true;
> >  }
> > 
> >  int reserve_new_block(struct dnode_of_data *dn)
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 90fb970..0f4d329 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -547,6 +547,7 @@ struct dnode_of_data {
> >  	unsigned int ofs_in_node;	/* data offset in the node page */
> >  	bool inode_page_locked;		/* inode page is locked or not */
> 
> Better to add node_changed here to avoid holes generated by compiler due
> to alignment.

Ok.

> 
> >  	block_t	data_blkaddr;		/* block address of the node block */
> > +	bool node_changed;		/* is node block changed */
> 
> How about reset it in set_new_dnode?

In set_new_dnode(), memset() is called.

> 
> >  };
> > 
> >  static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index f2effe1..10ed357 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -484,6 +484,7 @@ int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
> >  		dec_valid_block_count(sbi, dn->inode, nr_free);
> >  		set_page_dirty(dn->node_page);
> >  		sync_inode_page(dn);
> > +		dn->node_changed = true;
> 
> dn->node_changed should have been set in set_data_blkaddr, so no needed to
> set here.

Right. :)

Thanks,

> 
> Thanks,
> 
> >  	}
> >  	dn->ofs_in_node = ofs;
> > 
> > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> > index 6cc8ac7..ff2acb1 100644
> > --- a/fs/f2fs/node.c
> > +++ b/fs/f2fs/node.c
> > @@ -542,6 +542,7 @@ int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
> > 
> >  			set_nid(parent, offset[i - 1], nids[i], i == 1);
> >  			alloc_nid_done(sbi, nids[i]);
> > +			dn->node_changed = true;
> >  			done = true;
> >  		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
> >  			npage[i] = get_node_page_ra(parent, offset[i - 1]);
> > @@ -678,6 +679,7 @@ static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
> >  			if (ret < 0)
> >  				goto out_err;
> >  			set_nid(page, i, 0, false);
> > +			dn->node_changed = true;
> >  		}
> >  	} else {
> >  		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
> > @@ -691,6 +693,7 @@ static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
> >  			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
> >  			if (ret == (NIDS_PER_BLOCK + 1)) {
> >  				set_nid(page, i, 0, false);
> > +				dn->node_changed = true;
> >  				child_nofs += ret;
> >  			} else if (ret < 0 && ret != -ENOENT) {
> >  				goto out_err;
> > @@ -752,6 +755,7 @@ static int truncate_partial_nodes(struct dnode_of_data *dn,
> >  		if (err < 0)
> >  			goto fail;
> >  		set_nid(pages[idx], i, 0, false);
> > +		dn->node_changed = true;
> >  	}
> > 
> >  	if (offset[idx + 1] == 0) {
> > --
> > 2.5.4 (Apple Git-61)
> > 
> > 
> > ------------------------------------------------------------------------------
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