[RFC PATCH v3 09/26] ext4: allow inserting delalloc extents with multi-blocks

[Zhang Yi <yi.zhang@huaweicloud.com>]

From: Zhang Yi <yi.zhang@huawei.com>

Introduce a new helper ext4_insert_delayed_blocks() to replace
ext4_insert_delayed_block() that we could add multi-delayed blocks into
the extent status tree once a time. But for now, it doesn't support
bigalloc feature yet. Also rename ext4_es_insert_delayed_block() to
ext4_es_insert_delayed_extent(), which matches the name style of other
ext4_es_{insert|remove}_extent() functions.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/extents_status.c    | 26 ++++++++++++++-----------
 fs/ext4/extents_status.h    |  4 ++--
 fs/ext4/inode.c             | 39 ++++++++++++++++++++++---------------
 include/trace/events/ext4.h | 12 +++++++-----
 4 files changed, 47 insertions(+), 34 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 4a00e2f019d9..324a6b0a6283 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -2052,19 +2052,21 @@ bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
 }
 
 /*
- * ext4_es_insert_delayed_block - adds a delayed block to the extents status
- *                                tree, adding a pending reservation where
- *                                needed
+ * ext4_es_insert_delayed_extent - adds delayed blocks to the extents status
+ *                                 tree, adding a pending reservation where
+ *                                 needed
  *
  * @inode - file containing the newly added block
- * @lblk - logical block to be added
+ * @lblk - first logical block to be added
+ * @len - length of blocks to be added
  * @allocated - indicates whether a physical cluster has been allocated for
  *              the logical cluster that contains the block
  */
-void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
-				  bool allocated)
+void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
+				   unsigned int len, bool allocated)
 {
 	struct extent_status newes;
+	ext4_lblk_t end = lblk + len - 1;
 	int err1 = 0, err2 = 0, err3 = 0;
 	struct extent_status *es1 = NULL;
 	struct extent_status *es2 = NULL;
@@ -2073,13 +2075,15 @@ void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
 	if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
 		return;
 
-	es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
-		 lblk, inode->i_ino);
+	es_debug("add [%u/%u) delayed to extent status tree of inode %lu\n",
+		 lblk, len, inode->i_ino);
+	if (!len)
+		return;
 
 	newes.es_lblk = lblk;
-	newes.es_len = 1;
+	newes.es_len = len;
 	ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
-	trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
+	trace_ext4_es_insert_delayed_extent(inode, &newes, allocated);
 
 	ext4_es_insert_extent_check(inode, &newes);
 
@@ -2092,7 +2096,7 @@ void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
 		pr = __alloc_pending(true);
 	write_lock(&EXT4_I(inode)->i_es_lock);
 
-	err1 = __es_remove_extent(inode, lblk, lblk, NULL, es1);
+	err1 = __es_remove_extent(inode, lblk, end, NULL, es1);
 	if (err1 != 0)
 		goto error;
 	/* Free preallocated extent if it didn't get used. */
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index d9847a4a25db..24493e682ab4 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -249,8 +249,8 @@ extern void ext4_exit_pending(void);
 extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
 extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
 extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
-extern void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
-					 bool allocated);
+extern void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
+					  unsigned int len, bool allocated);
 extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
 					ext4_lblk_t len);
 extern void ext4_clear_inode_es(struct inode *inode);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0458d7f0c059..bc29c2e92750 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1452,7 +1452,7 @@ static int ext4_journalled_write_end(struct file *file,
 /*
  * Reserve space for a single cluster
  */
-static int ext4_da_reserve_space(struct inode *inode)
+static int ext4_da_reserve_space(struct inode *inode, unsigned int len)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	struct ext4_inode_info *ei = EXT4_I(inode);
@@ -1463,18 +1463,18 @@ static int ext4_da_reserve_space(struct inode *inode)
 	 * us from metadata over-estimation, though we may go over by
 	 * a small amount in the end.  Here we just reserve for data.
 	 */
-	ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
+	ret = dquot_reserve_block(inode, EXT4_C2B(sbi, len));
 	if (ret)
 		return ret;
 
 	spin_lock(&ei->i_block_reservation_lock);
-	if (ext4_claim_free_clusters(sbi, 1, 0)) {
+	if (ext4_claim_free_clusters(sbi, len, 0)) {
 		spin_unlock(&ei->i_block_reservation_lock);
-		dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
+		dquot_release_reservation_block(inode, EXT4_C2B(sbi, len));
 		return -ENOSPC;
 	}
-	ei->i_reserved_data_blocks++;
-	trace_ext4_da_reserve_space(inode);
+	ei->i_reserved_data_blocks += len;
+	trace_ext4_da_reserve_space(inode, len);
 	spin_unlock(&ei->i_block_reservation_lock);
 
 	return 0;       /* success */
@@ -1620,18 +1620,21 @@ static void ext4_print_free_blocks(struct inode *inode)
 	return;
 }
 
+
 /*
- * ext4_insert_delayed_block - adds a delayed block to the extents status
- *                             tree, incrementing the reserved cluster/block
- *                             count or making a pending reservation
- *                             where needed
+ * ext4_insert_delayed_blocks - adds multi-delayed blocks to the extents
+ *                              status tree, incrementing the reserved
+ *                              cluster/block count or making a pending
+ *                              reservation where needed.
  *
  * @inode - file containing the newly added block
- * @lblk - logical block to be added
+ * @lblk - start logical block to be added
+ * @len - length of blocks to be added
  *
  * Returns 0 on success, negative error code on failure.
  */
-static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
+static int ext4_insert_delayed_blocks(struct inode *inode, ext4_lblk_t lblk,
+				      ext4_lblk_t len)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	int ret;
@@ -1649,10 +1652,14 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
 	 * extents status tree doesn't get a match.
 	 */
 	if (sbi->s_cluster_ratio == 1) {
-		ret = ext4_da_reserve_space(inode);
+		ret = ext4_da_reserve_space(inode, len);
 		if (ret != 0)   /* ENOSPC */
 			return ret;
 	} else {   /* bigalloc */
+		/* TODO: support bigalloc for multi-blocks. */
+		if (len != 1)
+			return -EOPNOTSUPP;
+
 		if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) {
 			if (!ext4_es_scan_clu(inode,
 					      &ext4_es_is_mapped, lblk)) {
@@ -1661,7 +1668,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
 				if (ret < 0)
 					return ret;
 				if (ret == 0) {
-					ret = ext4_da_reserve_space(inode);
+					ret = ext4_da_reserve_space(inode, 1);
 					if (ret != 0)   /* ENOSPC */
 						return ret;
 				} else {
@@ -1673,7 +1680,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
 		}
 	}
 
-	ext4_es_insert_delayed_block(inode, lblk, allocated);
+	ext4_es_insert_delayed_extent(inode, lblk, len, allocated);
 	return 0;
 }
 
@@ -1774,7 +1781,7 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
 
 add_delayed:
 	down_write(&EXT4_I(inode)->i_data_sem);
-	retval = ext4_insert_delayed_block(inode, map->m_lblk);
+	retval = ext4_insert_delayed_blocks(inode, map->m_lblk, map->m_len);
 	up_write(&EXT4_I(inode)->i_data_sem);
 	if (retval)
 		return retval;
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index 65029dfb92fb..53aa7a7fb3be 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -1249,14 +1249,15 @@ TRACE_EVENT(ext4_da_update_reserve_space,
 );
 
 TRACE_EVENT(ext4_da_reserve_space,
-	TP_PROTO(struct inode *inode),
+	TP_PROTO(struct inode *inode, int reserved_blocks),
 
-	TP_ARGS(inode),
+	TP_ARGS(inode, reserved_blocks),
 
 	TP_STRUCT__entry(
 		__field(	dev_t,	dev			)
 		__field(	ino_t,	ino			)
 		__field(	__u64,	i_blocks		)
+		__field(	int,	reserved_blocks		)
 		__field(	int,	reserved_data_blocks	)
 		__field(	__u16,  mode			)
 	),
@@ -1265,16 +1266,17 @@ TRACE_EVENT(ext4_da_reserve_space,
 		__entry->dev	= inode->i_sb->s_dev;
 		__entry->ino	= inode->i_ino;
 		__entry->i_blocks = inode->i_blocks;
+		__entry->reserved_blocks = reserved_blocks;
 		__entry->reserved_data_blocks = EXT4_I(inode)->i_reserved_data_blocks;
 		__entry->mode	= inode->i_mode;
 	),
 
-	TP_printk("dev %d,%d ino %lu mode 0%o i_blocks %llu "
+	TP_printk("dev %d,%d ino %lu mode 0%o i_blocks %llu reserved_blocks %u "
 		  "reserved_data_blocks %d",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  (unsigned long) __entry->ino,
 		  __entry->mode, __entry->i_blocks,
-		  __entry->reserved_data_blocks)
+		  __entry->reserved_blocks, __entry->reserved_data_blocks)
 );
 
 TRACE_EVENT(ext4_da_release_space,
@@ -2481,7 +2483,7 @@ TRACE_EVENT(ext4_es_shrink,
 		  __entry->scan_time, __entry->nr_skipped, __entry->retried)
 );
 
-TRACE_EVENT(ext4_es_insert_delayed_block,
+TRACE_EVENT(ext4_es_insert_delayed_extent,
 	TP_PROTO(struct inode *inode, struct extent_status *es,
 		 bool allocated),
 
-- 
2.39.2