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Commit e7432675 authored by Sunil Mushran's avatar Sunil Mushran Committed by Joel Becker
Browse files

ocfs2: Initialize the cluster we're writing to in a non-sparse extend 



In a non-sparse extend, we correctly allocate (and zero) the clusters between
the old_i_size and pos, but we don't zero the portions of the cluster we're
writing to outside of pos<->len.

It handles clustersize > pagesize and blocksize < pagesize.

[Cleaned up by Joel Becker.]

Signed-off-by: default avatarSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
parent ab57a408

fs/ocfs2/aops.c

+47 −19
Original line number Diff line number Diff line
@@ -895,18 +895,17 @@ struct ocfs2_write_cluster_desc { 
	 */

	unsigned	c_new;

	unsigned	c_unwritten;

	unsigned	c_needs_zero;

};



static inline int ocfs2_should_zero_cluster(struct ocfs2_write_cluster_desc *d)

{

	return d->c_new || d->c_unwritten;

}



struct ocfs2_write_ctxt {

	/* Logical cluster position / len of write */

	u32				w_cpos;

	u32				w_clen;



	/* First cluster allocated in a nonsparse extend */

	u32				w_first_new_cpos;



	struct ocfs2_write_cluster_desc	w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];



	/*
@@ -984,6 +983,7 @@ static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp, 
		return -ENOMEM;



	wc->w_cpos = pos >> osb->s_clustersize_bits;

	wc->w_first_new_cpos = UINT_MAX;

	cend = (pos + len - 1) >> osb->s_clustersize_bits;

	wc->w_clen = cend - wc->w_cpos + 1;

	get_bh(di_bh);
@@ -1218,20 +1218,18 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping, 
 */

static int ocfs2_write_cluster(struct address_space *mapping,

			       u32 phys, unsigned int unwritten,

			       unsigned int should_zero,

			       struct ocfs2_alloc_context *data_ac,

			       struct ocfs2_alloc_context *meta_ac,

			       struct ocfs2_write_ctxt *wc, u32 cpos,

			       loff_t user_pos, unsigned user_len)

{

	int ret, i, new, should_zero = 0;

	int ret, i, new;

	u64 v_blkno, p_blkno;

	struct inode *inode = mapping->host;

	struct ocfs2_extent_tree et;



	new = phys == 0 ? 1 : 0;

	if (new || unwritten)

		should_zero = 1;



	if (new) {

		u32 tmp_pos;
@@ -1342,7 +1340,9 @@ static int ocfs2_write_cluster_by_desc(struct address_space *mapping, 
			local_len = osb->s_clustersize - cluster_off;



		ret = ocfs2_write_cluster(mapping, desc->c_phys,

					  desc->c_unwritten, data_ac, meta_ac,

					  desc->c_unwritten,

					  desc->c_needs_zero,

					  data_ac, meta_ac,

					  wc, desc->c_cpos, pos, local_len);

		if (ret) {

			mlog_errno(ret);
@@ -1392,14 +1392,14 @@ static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, 
		 * newly allocated cluster.

		 */

		desc = &wc->w_desc[0];

		if (ocfs2_should_zero_cluster(desc))

		if (desc->c_needs_zero)

			ocfs2_figure_cluster_boundaries(osb,

							desc->c_cpos,

							&wc->w_target_from,

							NULL);



		desc = &wc->w_desc[wc->w_clen - 1];

		if (ocfs2_should_zero_cluster(desc))

		if (desc->c_needs_zero)

			ocfs2_figure_cluster_boundaries(osb,

							desc->c_cpos,

							NULL,
@@ -1467,13 +1467,28 @@ static int ocfs2_populate_write_desc(struct inode *inode, 
			phys++;

		}



		/*

		 * If w_first_new_cpos is < UINT_MAX, we have a non-sparse

		 * file that got extended.  w_first_new_cpos tells us

		 * where the newly allocated clusters are so we can

		 * zero them.

		 */

		if (desc->c_cpos >= wc->w_first_new_cpos) {

			BUG_ON(phys == 0);

			desc->c_needs_zero = 1;

		}



		desc->c_phys = phys;

		if (phys == 0) {

			desc->c_new = 1;

			desc->c_needs_zero = 1;

			*clusters_to_alloc = *clusters_to_alloc + 1;

		}

		if (ext_flags & OCFS2_EXT_UNWRITTEN)



		if (ext_flags & OCFS2_EXT_UNWRITTEN) {

			desc->c_unwritten = 1;

			desc->c_needs_zero = 1;

		}



		num_clusters--;

	}
@@ -1633,10 +1648,13 @@ static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos, 
	if (newsize <= i_size_read(inode))

		return 0;



	ret = ocfs2_extend_no_holes(inode, newsize, newsize - len);

	ret = ocfs2_extend_no_holes(inode, newsize, pos);

	if (ret)

		mlog_errno(ret);



	wc->w_first_new_cpos =

		ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));



	return ret;

}
@@ -1645,7 +1663,7 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
			     struct page **pagep, void **fsdata,

			     struct buffer_head *di_bh, struct page *mmap_page)

{

	int ret, credits = OCFS2_INODE_UPDATE_CREDITS;

	int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;

	unsigned int clusters_to_alloc, extents_to_split;

	struct ocfs2_write_ctxt *wc;

	struct inode *inode = mapping->host;
@@ -1723,8 +1741,19 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 


	}



	ocfs2_set_target_boundaries(osb, wc, pos, len,

				    clusters_to_alloc + extents_to_split);

	/*

	 * We have to zero sparse allocated clusters, unwritten extent clusters,

	 * and non-sparse clusters we just extended.  For non-sparse writes,

	 * we know zeros will only be needed in the first and/or last cluster.

	 */

	if (clusters_to_alloc || extents_to_split ||

	    wc->w_desc[0].c_needs_zero ||

	    wc->w_desc[wc->w_clen - 1].c_needs_zero)

		cluster_of_pages = 1;

	else

		cluster_of_pages = 0;



	ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);



	handle = ocfs2_start_trans(osb, credits);

	if (IS_ERR(handle)) {
@@ -1757,8 +1786,7 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
	 * extent.

	 */

	ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,

					 clusters_to_alloc + extents_to_split,

					 mmap_page);

					 cluster_of_pages, mmap_page);

	if (ret) {

		mlog_errno(ret);

		goto out_quota;