ocfs2: Write support for inline data

This fixes up write, truncate, mmap, and RESVSP/UNRESVP to understand inline
inode data.

For the most part, the changes to the core write code can be relied on to do
the heavy lifting. Any code calling ocfs2_write_begin (including shared
writeable mmap) can count on it doing the right thing with respect to
growing inline data to an extent tree.

Size reducing truncates, including UNRESVP can simply zero that portion of
the inode block being removed. Size increasing truncatesm, including RESVP
have to be a little bit smarter and grow the inode to an extent tree if
necessary.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/alloc.c

@@ -3726,6 +3726,8 @@ int ocfs2_insert_extent(struct ocfs2_super *osb,
 	struct ocfs2_insert_type insert = {0, };
 	struct ocfs2_extent_rec rec;
 
+	BUG_ON(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL);
+
 	mlog(0, "add %u clusters at position %u to inode %llu\n",
 	     new_clusters, cpos, (unsigned long long)OCFS2_I(inode)->ip_blkno);
 
@@ -5826,6 +5828,174 @@ int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
 	return ret;
 }
 
+static void ocfs2_zero_dinode_id2(struct inode *inode, struct ocfs2_dinode *di)
+{
+	unsigned int blocksize = 1 << inode->i_sb->s_blocksize_bits;
+
+	memset(&di->id2, 0, blocksize - offsetof(struct ocfs2_dinode, id2));
+}
+
+void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di)
+{
+	struct ocfs2_inode_info *oi = OCFS2_I(inode);
+	struct ocfs2_inline_data *idata = &di->id2.i_data;
+
+	spin_lock(&oi->ip_lock);
+	oi->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
+	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
+	spin_unlock(&oi->ip_lock);
+
+	/*
+	 * We clear the entire i_data structure here so that all
+	 * fields can be properly initialized.
+	 */
+	ocfs2_zero_dinode_id2(inode, di);
+
+	idata->id_count = cpu_to_le16(ocfs2_max_inline_data(inode->i_sb));
+}
+
+int ocfs2_convert_inline_data_to_extents(struct inode *inode,
+					 struct buffer_head *di_bh)
+{
+	int ret, i, has_data, num_pages = 0;
+	handle_t *handle;
+	u64 uninitialized_var(block);
+	struct ocfs2_inode_info *oi = OCFS2_I(inode);
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+	struct ocfs2_extent_list *el = &di->id2.i_list;
+	struct ocfs2_alloc_context *data_ac = NULL;
+	struct page **pages = NULL;
+	loff_t end = osb->s_clustersize;
+
+	has_data = i_size_read(inode) ? 1 : 0;
+
+	if (has_data) {
+		pages = kcalloc(ocfs2_pages_per_cluster(osb->sb),
+				sizeof(struct page *), GFP_NOFS);
+		if (pages == NULL) {
+			ret = -ENOMEM;
+			mlog_errno(ret);
+			goto out;
+		}
+
+		ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
+		if (ret) {
+			mlog_errno(ret);
+			goto out;
+		}
+	}
+
+	handle = ocfs2_start_trans(osb, OCFS2_INLINE_TO_EXTENTS_CREDITS);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		mlog_errno(ret);
+		goto out_unlock;
+	}
+
+	ret = ocfs2_journal_access(handle, inode, di_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+
+	if (has_data) {
+		u32 bit_off, num;
+		unsigned int page_end;
+		u64 phys;
+
+		ret = ocfs2_claim_clusters(osb, handle, data_ac, 1, &bit_off,
+					   &num);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		/*
+		 * Save two copies, one for insert, and one that can
+		 * be changed by ocfs2_map_and_dirty_page() below.
+		 */
+		block = phys = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);
+
+		/*
+		 * Non sparse file systems zero on extend, so no need
+		 * to do that now.
+		 */
+		if (!ocfs2_sparse_alloc(osb) &&
+		    PAGE_CACHE_SIZE < osb->s_clustersize)
+			end = PAGE_CACHE_SIZE;
+
+		ret = ocfs2_grab_eof_pages(inode, 0, end, pages, &num_pages);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		/*
+		 * This should populate the 1st page for us and mark
+		 * it up to date.
+		 */
+		ret = ocfs2_read_inline_data(inode, pages[0], di_bh);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		page_end = PAGE_CACHE_SIZE;
+		if (PAGE_CACHE_SIZE > osb->s_clustersize)
+			page_end = osb->s_clustersize;
+
+		for (i = 0; i < num_pages; i++)
+			ocfs2_map_and_dirty_page(inode, handle, 0, page_end,
+						 pages[i], i > 0, &phys);
+	}
+
+	spin_lock(&oi->ip_lock);
+	oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
+	di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
+	spin_unlock(&oi->ip_lock);
+
+	ocfs2_zero_dinode_id2(inode, di);
+
+	el->l_tree_depth = 0;
+	el->l_next_free_rec = 0;
+	el->l_count = cpu_to_le16(ocfs2_extent_recs_per_inode(inode->i_sb));
+
+	ocfs2_journal_dirty(handle, di_bh);
+
+	if (has_data) {
+		/*
+		 * An error at this point should be extremely rare. If
+		 * this proves to be false, we could always re-build
+		 * the in-inode data from our pages.
+		 */
+		ret = ocfs2_insert_extent(osb, handle, inode, di_bh,
+					  0, block, 1, 0, NULL);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		inode->i_blocks = ocfs2_inode_sector_count(inode);
+	}
+
+out_commit:
+	ocfs2_commit_trans(osb, handle);
+
+out_unlock:
+	if (data_ac)
+		ocfs2_free_alloc_context(data_ac);
+
+out:
+	if (pages) {
+		ocfs2_unlock_and_free_pages(pages, num_pages);
+		kfree(pages);
+	}
+
+	return ret;
+}
+
 /*
  * It is expected, that by the time you call this function,
  * inode->i_size and fe->i_size have been adjusted.
@@ -6051,6 +6221,81 @@ int ocfs2_prepare_truncate(struct ocfs2_super *osb,
 	return status;
 }
 
+/*
+ * 'start' is inclusive, 'end' is not.
+ */
+int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
+			  unsigned int start, unsigned int end, int trunc)
+{
+	int ret;
+	unsigned int numbytes;
+	handle_t *handle;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+	struct ocfs2_inline_data *idata = &di->id2.i_data;
+
+	if (end > i_size_read(inode))
+		end = i_size_read(inode);
+
+	BUG_ON(start >= end);
+
+	if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
+	    !(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) ||
+	    !ocfs2_supports_inline_data(osb)) {
+		ocfs2_error(inode->i_sb,
+			    "Inline data flags for inode %llu don't agree! "
+			    "Disk: 0x%x, Memory: 0x%x, Superblock: 0x%x\n",
+			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
+			    le16_to_cpu(di->i_dyn_features),
+			    OCFS2_I(inode)->ip_dyn_features,
+			    osb->s_feature_incompat);
+		ret = -EROFS;
+		goto out;
+	}
+
+	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		mlog_errno(ret);
+		goto out;
+	}
+
+	ret = ocfs2_journal_access(handle, inode, di_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+
+	numbytes = end - start;
+	memset(idata->id_data + start, 0, numbytes);
+
+	/*
+	 * No need to worry about the data page here - it's been
+	 * truncated already and inline data doesn't need it for
+	 * pushing zero's to disk, so we'll let readpage pick it up
+	 * later.
+	 */
+	if (trunc) {
+		i_size_write(inode, start);
+		di->i_size = cpu_to_le64(start);
+	}
+
+	inode->i_blocks = ocfs2_inode_sector_count(inode);
+	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+	di->i_ctime = di->i_mtime = cpu_to_le64(inode->i_ctime.tv_sec);
+	di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+
+	ocfs2_journal_dirty(handle, di_bh);
+
+out_commit:
+	ocfs2_commit_trans(osb, handle);
+
+out:
+	return ret;
+}
+
 static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc)
 {
 	/*

fs/ocfs2/alloc.h

@@ -62,6 +62,10 @@ static inline int ocfs2_extend_meta_needed(struct ocfs2_dinode *fe)
 	return le16_to_cpu(fe->id2.i_list.l_tree_depth) + 2;
 }
 
+void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di);
+int ocfs2_convert_inline_data_to_extents(struct inode *inode,
+					 struct buffer_head *di_bh);
+
 int ocfs2_truncate_log_init(struct ocfs2_super *osb);
 void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb);
 void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
@@ -115,6 +119,8 @@ int ocfs2_commit_truncate(struct ocfs2_super *osb,
 			  struct inode *inode,
 			  struct buffer_head *fe_bh,
 			  struct ocfs2_truncate_context *tc);
+int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
+			  unsigned int start, unsigned int end, int trunc);
 
 int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
 		    u32 cpos, struct buffer_head **leaf_bh);