[RFC PATCH v4 13/34] ext4: let __revise_pending() return newly inserted pendings

[Zhang Yi <yi.zhang@xxxxxxxxxxxxxxx>]

From: Zhang Yi <yi.zhang@xxxxxxxxxx>

Let __insert_pending() return 1 after successfully inserting a new
pending cluster, and also let __revise_pending() to return the number of
of newly inserted pendings.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 fs/ext4/extents_status.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 952a38eaea0f..382a96c1bc5c 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -885,7 +885,7 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 		es1 = __es_alloc_extent(true);
 	if ((err1 || err2) && !es2)
 		es2 = __es_alloc_extent(true);
-	if ((err1 || err2 || err3) && revise_pending && !pr)
+	if ((err1 || err2 || err3 < 0) && revise_pending && !pr)
 		pr = __alloc_pending(true);
 	write_lock(&EXT4_I(inode)->i_es_lock);
 
@@ -913,7 +913,7 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 
 	if (revise_pending) {
 		err3 = __revise_pending(inode, lblk, len, &pr);
-		if (err3 != 0)
+		if (err3 < 0)
 			goto error;
 		if (pr) {
 			__free_pending(pr);
@@ -922,7 +922,7 @@ void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 	}
 error:
 	write_unlock(&EXT4_I(inode)->i_es_lock);
-	if (err1 || err2 || err3)
+	if (err1 || err2 || err3 < 0)
 		goto retry;
 
 	ext4_es_print_tree(inode);
@@ -1931,7 +1931,7 @@ static struct pending_reservation *__get_pending(struct inode *inode,
  * @lblk - logical block in the cluster to be added
  * @prealloc - preallocated pending entry
  *
- * Returns 0 on successful insertion and -ENOMEM on failure.  If the
+ * Returns 1 on successful insertion and -ENOMEM on failure.  If the
  * pending reservation is already in the set, returns successfully.
  */
 static int __insert_pending(struct inode *inode, ext4_lblk_t lblk,
@@ -1975,6 +1975,7 @@ static int __insert_pending(struct inode *inode, ext4_lblk_t lblk,
 
 	rb_link_node(&pr->rb_node, parent, p);
 	rb_insert_color(&pr->rb_node, &tree->root);
+	ret = 1;
 
 out:
 	return ret;
@@ -2089,7 +2090,7 @@ void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
 		es1 = __es_alloc_extent(true);
 	if ((err1 || err2) && !es2)
 		es2 = __es_alloc_extent(true);
-	if (err1 || err2 || err3) {
+	if (err1 || err2 || err3 < 0) {
 		if (lclu_allocated && !pr1)
 			pr1 = __alloc_pending(true);
 		if (end_allocated && !pr2)
@@ -2119,7 +2120,7 @@ void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
 
 	if (lclu_allocated) {
 		err3 = __insert_pending(inode, lblk, &pr1);
-		if (err3 != 0)
+		if (err3 < 0)
 			goto error;
 		if (pr1) {
 			__free_pending(pr1);
@@ -2128,7 +2129,7 @@ void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
 	}
 	if (end_allocated) {
 		err3 = __insert_pending(inode, end, &pr2);
-		if (err3 != 0)
+		if (err3 < 0)
 			goto error;
 		if (pr2) {
 			__free_pending(pr2);
@@ -2137,7 +2138,7 @@ void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
 	}
 error:
 	write_unlock(&EXT4_I(inode)->i_es_lock);
-	if (err1 || err2 || err3)
+	if (err1 || err2 || err3 < 0)
 		goto retry;
 
 	ext4_es_print_tree(inode);
@@ -2247,7 +2248,9 @@ unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
  *
  * Used after a newly allocated extent is added to the extents status tree.
  * Requires that the extents in the range have either written or unwritten
- * status.  Must be called while holding i_es_lock.
+ * status.  Must be called while holding i_es_lock. Returns number of new
+ * inserts pending cluster on insert pendings, returns 0 on remove pendings,
+ * return -ENOMEM on failure.
  */
 static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 			    ext4_lblk_t len,
@@ -2257,6 +2260,7 @@ static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 	ext4_lblk_t end = lblk + len - 1;
 	ext4_lblk_t first, last;
 	bool f_del = false, l_del = false;
+	int pendings = 0;
 	int ret = 0;
 
 	if (len == 0)
@@ -2284,6 +2288,7 @@ static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 			ret = __insert_pending(inode, first, prealloc);
 			if (ret < 0)
 				goto out;
+			pendings += ret;
 		} else {
 			last = EXT4_LBLK_CMASK(sbi, end) +
 			       sbi->s_cluster_ratio - 1;
@@ -2295,6 +2300,7 @@ static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 				ret = __insert_pending(inode, last, prealloc);
 				if (ret < 0)
 					goto out;
+				pendings += ret;
 			} else
 				__remove_pending(inode, last);
 		}
@@ -2307,6 +2313,7 @@ static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 			ret = __insert_pending(inode, first, prealloc);
 			if (ret < 0)
 				goto out;
+			pendings += ret;
 		} else
 			__remove_pending(inode, first);
 
@@ -2318,9 +2325,10 @@ static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 			ret = __insert_pending(inode, last, prealloc);
 			if (ret < 0)
 				goto out;
+			pendings += ret;
 		} else
 			__remove_pending(inode, last);
 	}
 out:
-	return ret;
+	return (ret < 0) ? ret : pendings;
 }
-- 
2.39.2