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Commit b27b7cbc authored by Mark Fasheh's avatar Mark Fasheh
Browse files

ocfs2: support writing of unwritten extents 



Update the write code to detect when the user is asking to write to an
unwritten extent. Like writing to a hole, we must zero the region between
the write and the cluster boundaries. Most of the existing cluster zeroing
logic can be re-used with some additional checks for the unwritten flag on
extent records.

Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
parent 0d172baa

fs/ocfs2/aops.c

+74 −20
Original line number Diff line number Diff line
@@ -782,8 +782,14 @@ struct ocfs2_write_cluster_desc { 
	 * filled.

	 */

	unsigned	c_new;

	unsigned	c_unwritten;

};



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;
@@ -829,6 +835,8 @@ struct ocfs2_write_ctxt { 
	handle_t			*w_handle;



	struct buffer_head		*w_di_bh;



	struct ocfs2_cached_dealloc_ctxt w_dealloc;

};



static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
@@ -868,6 +876,8 @@ static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp, 
	else

		wc->w_large_pages = 0;



	ocfs2_init_dealloc_ctxt(&wc->w_dealloc);



	*wcp = wc;



	return 0;
@@ -1103,16 +1113,19 @@ static int ocfs2_grab_pages_for_write(struct address_space *mapping, 
 * Prepare a single cluster for write one cluster into the file.

 */

static int ocfs2_write_cluster(struct address_space *mapping,

			       u32 phys, struct ocfs2_alloc_context *data_ac,

			       u32 phys, unsigned int unwritten,

			       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;

	int ret, i, new, should_zero = 0;

	u64 v_blkno, p_blkno;

	struct inode *inode = mapping->host;



	new = phys == 0 ? 1 : 0;

	if (new || unwritten)

		should_zero = 1;



	if (new) {

		u32 tmp_pos;
@@ -1142,11 +1155,20 @@ static int ocfs2_write_cluster(struct address_space *mapping, 
			mlog_errno(ret);

			goto out;

		}

	} else if (unwritten) {

		ret = ocfs2_mark_extent_written(inode, wc->w_di_bh,

						wc->w_handle, cpos, 1, phys,

						meta_ac, &wc->w_dealloc);

		if (ret < 0) {

			mlog_errno(ret);

			goto out;

		}

	}



	if (should_zero)

		v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);

	} else {

	else

		v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;

	}



	/*

	 * The only reason this should fail is due to an inability to
@@ -1169,7 +1191,8 @@ static int ocfs2_write_cluster(struct address_space *mapping, 


		tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,

						      wc->w_pages[i], cpos,

						      user_pos, user_len, new);

						      user_pos, user_len,

						      should_zero);

		if (tmpret) {

			mlog_errno(tmpret);

			if (ret == 0)
@@ -1200,8 +1223,9 @@ static int ocfs2_write_cluster_by_desc(struct address_space *mapping, 
	for (i = 0; i < wc->w_clen; i++) {

		desc = &wc->w_desc[i];



		ret = ocfs2_write_cluster(mapping, desc->c_phys, data_ac,

					  meta_ac, wc, desc->c_cpos, pos, len);

		ret = ocfs2_write_cluster(mapping, desc->c_phys,

					  desc->c_unwritten, data_ac, meta_ac,

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

		if (ret) {

			mlog_errno(ret);

			goto out;
@@ -1242,19 +1266,19 @@ static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, 
	if (wc->w_large_pages) {

		/*

		 * We only care about the 1st and last cluster within

		 * our range and whether they are holes or not. Either

		 * our range and whether they should be zero'd or not. Either

		 * value may be extended out to the start/end of a

		 * newly allocated cluster.

		 */

		desc = &wc->w_desc[0];

		if (desc->c_new)

		if (ocfs2_should_zero_cluster(desc))

			ocfs2_figure_cluster_boundaries(osb,

							desc->c_cpos,

							&wc->w_target_from,

							NULL);



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

		if (desc->c_new)

		if (ocfs2_should_zero_cluster(desc))

			ocfs2_figure_cluster_boundaries(osb,

							desc->c_cpos,

							NULL,
@@ -1268,28 +1292,52 @@ static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, 
/*

 * Populate each single-cluster write descriptor in the write context

 * with information about the i/o to be done.

 *

 * Returns the number of clusters that will have to be allocated, as

 * well as a worst case estimate of the number of extent records that

 * would have to be created during a write to an unwritten region.

 */

static int ocfs2_populate_write_desc(struct inode *inode,

				     struct ocfs2_write_ctxt *wc,

				     unsigned int *clusters_to_alloc)

				     unsigned int *clusters_to_alloc,

				     unsigned int *extents_to_split)

{

	int ret;

	struct ocfs2_write_cluster_desc *desc;

	unsigned int num_clusters = 0;

	unsigned int ext_flags = 0;

	u32 phys = 0;

	int i;



	*clusters_to_alloc = 0;

	*extents_to_split = 0;



	for (i = 0; i < wc->w_clen; i++) {

		desc = &wc->w_desc[i];

		desc->c_cpos = wc->w_cpos + i;



		if (num_clusters == 0) {

			/*

			 * Need to look up the next extent record.

			 */

			ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,

						 &num_clusters, NULL);

						 &num_clusters, &ext_flags);

			if (ret) {

				mlog_errno(ret);

				goto out;

			}



			/*

			 * Assume worst case - that we're writing in

			 * the middle of the extent.

			 *

			 * We can assume that the write proceeds from

			 * left to right, in which case the extent

			 * insert code is smart enough to coalesce the

			 * next splits into the previous records created.

			 */

			if (ext_flags & OCFS2_EXT_UNWRITTEN)

				*extents_to_split = *extents_to_split + 2;

		} else if (phys) {

			/*

			 * Only increment phys if it doesn't describe
@@ -1303,6 +1351,8 @@ static int ocfs2_populate_write_desc(struct inode *inode, 
			desc->c_new = 1;

			*clusters_to_alloc = *clusters_to_alloc + 1;

		}

		if (ext_flags & OCFS2_EXT_UNWRITTEN)

			desc->c_unwritten = 1;



		num_clusters--;

	}
@@ -1318,7 +1368,7 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
			     struct buffer_head *di_bh, struct page *mmap_page)

{

	int ret, credits = OCFS2_INODE_UPDATE_CREDITS;

	unsigned int clusters_to_alloc = 0;

	unsigned int clusters_to_alloc, extents_to_split;

	struct ocfs2_write_ctxt *wc;

	struct inode *inode = mapping->host;

	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
@@ -1333,7 +1383,8 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
		return ret;

	}



	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc);

	ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,

					&extents_to_split);

	if (ret) {

		mlog_errno(ret);

		goto out;
@@ -1347,14 +1398,14 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 
	 * write out. An allocation requires that we write the entire

	 * cluster range.

	 */

	if (clusters_to_alloc > 0) {

	if (clusters_to_alloc || extents_to_split) {

		/*

		 * XXX: We are stretching the limits of

		 * ocfs2_lock_allocators(). It greately over-estimates

		 * ocfs2_lock_allocators(). It greatly over-estimates

		 * the work to be done.

		 */

		ret = ocfs2_lock_allocators(inode, di, clusters_to_alloc,

					    &data_ac, &meta_ac);

					    extents_to_split, &data_ac, &meta_ac);

		if (ret) {

			mlog_errno(ret);

			goto out;
@@ -1365,7 +1416,8 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, 


	}



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

	ocfs2_set_target_boundaries(osb, wc, pos, len,

				    clusters_to_alloc + extents_to_split);



	handle = ocfs2_start_trans(osb, credits);

	if (IS_ERR(handle)) {
@@ -1393,7 +1445,8 @@ 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, mmap_page);

					 clusters_to_alloc + extents_to_split,

					 mmap_page);

	if (ret) {

		mlog_errno(ret);

		goto out_commit;
@@ -1538,11 +1591,12 @@ int ocfs2_write_end_nolock(struct address_space *mapping, 
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;

	di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);

	di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);



	ocfs2_journal_dirty(handle, wc->w_di_bh);



	ocfs2_commit_trans(osb, handle);



	ocfs2_run_deallocs(osb, &wc->w_dealloc);



	ocfs2_free_write_ctxt(wc);



	return copied;

fs/ocfs2/file.c

+9 −5
Original line number Diff line number Diff line
@@ -527,20 +527,21 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, 
 * understand sparse inodes.

 */

int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,

			  u32 clusters_to_add,

			  u32 clusters_to_add, u32 extents_to_split,

			  struct ocfs2_alloc_context **data_ac,

			  struct ocfs2_alloc_context **meta_ac)

{

	int ret, num_free_extents;

	unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;

	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);



	*meta_ac = NULL;

	*data_ac = NULL;



	mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u, "

	     "clusters_to_add = %u\n",

	     "clusters_to_add = %u, extents_to_split = %u\n",

	     (unsigned long long)OCFS2_I(inode)->ip_blkno, i_size_read(inode),

	     le32_to_cpu(di->i_clusters), clusters_to_add);

	     le32_to_cpu(di->i_clusters), clusters_to_add, extents_to_split);



	num_free_extents = ocfs2_num_free_extents(osb, inode, di);

	if (num_free_extents < 0) {
@@ -558,9 +559,12 @@ int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di, 
	 *

	 * Most of the time we'll only be seeing this 1 cluster at a time

	 * anyway.

	 *

	 * Always lock for any unwritten extents - we might want to

	 * add blocks during a split.

	 */

	if (!num_free_extents ||

	    (ocfs2_sparse_alloc(osb) && num_free_extents < clusters_to_add)) {

	    (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {

		ret = ocfs2_reserve_new_metadata(osb, di, meta_ac);

		if (ret < 0) {

			if (ret != -ENOSPC)
@@ -641,7 +645,7 @@ static int ocfs2_extend_allocation(struct inode *inode, 
	down_write(&OCFS2_I(inode)->ip_alloc_sem);

	drop_alloc_sem = 1;



	status = ocfs2_lock_allocators(inode, fe, clusters_to_add, &data_ac,

	status = ocfs2_lock_allocators(inode, fe, clusters_to_add, 0, &data_ac,

				       &meta_ac);

	if (status) {

		mlog_errno(status);

fs/ocfs2/file.h

+1 −1
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, 
			       struct ocfs2_alloc_context *meta_ac,

			       enum ocfs2_alloc_restarted *reason);

int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di,

			  u32 clusters_to_add,

			  u32 clusters_to_add, u32 extents_to_split,

			  struct ocfs2_alloc_context **data_ac,

			  struct ocfs2_alloc_context **meta_ac);

int ocfs2_setattr(struct dentry *dentry, struct iattr *attr);