[RFC PATCH v4 14/34] ext4: count removed reserved blocks for delalloc only extent entry

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

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

Current __es_remove_extent() only count reserved clusters if the removed
extent entry is delalloc, it doesn't count reserved blocks if the
bigalloc feature is enabled, so we can't get reserved block number.
However, it's useful to distinguish whether we are allocating delalloc
range in one cluster, so add a parameter to count the reserved blocks
number too.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/extents_status.c | 64 +++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 24 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 382a96c1bc5c..38ec2cc5ae3b 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -141,13 +141,18 @@
  *   -- Extent-level locking
  */
 
+struct rsvd_info {
+	int delonly_cluster;	/* reserved clusters for delalloc es entry */
+	int delonly_block;	/* reserved blocks for delalloc es entry */
+};
+
 static struct kmem_cache *ext4_es_cachep;
 static struct kmem_cache *ext4_pending_cachep;
 
 static int __es_insert_extent(struct inode *inode, struct extent_status *newes,
 			      struct extent_status *prealloc);
 static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
-			      ext4_lblk_t end, int *reserved,
+			      ext4_lblk_t end, struct rsvd_info *rinfo,
 			      struct extent_status *prealloc);
 static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
 static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
@@ -1042,7 +1047,8 @@ int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
 }
 
 struct rsvd_count {
-	int ndelonly;
+	int ndelonly_cluster;
+	int ndelonly_block;
 	bool first_do_lblk_found;
 	ext4_lblk_t first_do_lblk;
 	ext4_lblk_t last_do_lblk;
@@ -1068,7 +1074,8 @@ static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	struct rb_node *node;
 
-	rc->ndelonly = 0;
+	rc->ndelonly_cluster = 0;
+	rc->ndelonly_block = 0;
 
 	/*
 	 * for bigalloc, note the first delonly block in the range has not
@@ -1116,11 +1123,13 @@ static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
 	WARN_ON(len <= 0);
 
 	if (sbi->s_cluster_ratio == 1) {
-		rc->ndelonly += (int) len;
+		rc->ndelonly_cluster += (int) len;
+		rc->ndelonly_block = rc->ndelonly_cluster;
 		return;
 	}
 
 	/* bigalloc */
+	rc->ndelonly_block += (int)len;
 
 	i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
 	end = lblk + (ext4_lblk_t) len - 1;
@@ -1140,7 +1149,7 @@ static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
 	 * doesn't start with it, count it and stop tracking
 	 */
 	if (rc->partial && (rc->lclu != EXT4_B2C(sbi, i))) {
-		rc->ndelonly++;
+		rc->ndelonly_cluster++;
 		rc->partial = false;
 	}
 
@@ -1150,7 +1159,7 @@ static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
 	 */
 	if (EXT4_LBLK_COFF(sbi, i) != 0) {
 		if (end >= EXT4_LBLK_CFILL(sbi, i)) {
-			rc->ndelonly++;
+			rc->ndelonly_cluster++;
 			rc->partial = false;
 			i = EXT4_LBLK_CFILL(sbi, i) + 1;
 		}
@@ -1162,7 +1171,7 @@ static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
 	 */
 	if ((i + sbi->s_cluster_ratio - 1) <= end) {
 		nclu = (end - i + 1) >> sbi->s_cluster_bits;
-		rc->ndelonly += nclu;
+		rc->ndelonly_cluster += nclu;
 		i += nclu << sbi->s_cluster_bits;
 	}
 
@@ -1242,9 +1251,9 @@ static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
 	if (sbi->s_cluster_ratio > 1) {
 		/* count any remaining partial cluster */
 		if (rc->partial)
-			rc->ndelonly++;
+			rc->ndelonly_cluster++;
 
-		if (rc->ndelonly == 0)
+		if (rc->ndelonly_cluster == 0)
 			return 0;
 
 		first_lclu = EXT4_B2C(sbi, rc->first_do_lblk);
@@ -1261,7 +1270,7 @@ static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
 		while (es && ext4_es_end(es) >=
 		       EXT4_LBLK_CMASK(sbi, rc->first_do_lblk)) {
 			if (ext4_es_is_delonly(es)) {
-				rc->ndelonly--;
+				rc->ndelonly_cluster--;
 				left_delonly = true;
 				break;
 			}
@@ -1281,7 +1290,7 @@ static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
 			while (es && es->es_lblk <=
 			       EXT4_LBLK_CFILL(sbi, rc->last_do_lblk)) {
 				if (ext4_es_is_delonly(es)) {
-					rc->ndelonly--;
+					rc->ndelonly_cluster--;
 					right_delonly = true;
 					break;
 				}
@@ -1327,7 +1336,7 @@ static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
 		if (count_pending) {
 			pr = __pr_tree_search(&tree->root, first_lclu);
 			while (pr && pr->lclu <= last_lclu) {
-				rc->ndelonly--;
+				rc->ndelonly_cluster--;
 				node = rb_next(&pr->rb_node);
 				rb_erase(&pr->rb_node, &tree->root);
 				__free_pending(pr);
@@ -1338,7 +1347,7 @@ static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
 			}
 		}
 	}
-	return rc->ndelonly;
+	return rc->ndelonly_cluster;
 }
 
 
@@ -1348,16 +1357,17 @@ static unsigned int get_rsvd(struct inode *inode, ext4_lblk_t end,
  * @inode - file containing range
  * @lblk - first block in range
  * @end - last block in range
- * @reserved - number of cluster reservations released
+ * @rinfo - reserved information collected, includes number of
+ *          block/cluster reservations released
  * @prealloc - pre-allocated es to avoid memory allocation failures
  *
- * If @reserved is not NULL and delayed allocation is enabled, counts
+ * If @rinfo is not NULL and delayed allocation is enabled, counts
  * block/cluster reservations freed by removing range and if bigalloc
  * enabled cancels pending reservations as needed. Returns 0 on success,
  * error code on failure.
  */
 static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
-			      ext4_lblk_t end, int *reserved,
+			      ext4_lblk_t end, struct rsvd_info *rinfo,
 			      struct extent_status *prealloc)
 {
 	struct ext4_es_tree *tree = &EXT4_I(inode)->i_es_tree;
@@ -1367,11 +1377,15 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	ext4_lblk_t len1, len2;
 	ext4_fsblk_t block;
 	int err = 0;
-	bool count_reserved = true;
+	bool count_reserved = false;
 	struct rsvd_count rc;
 
-	if (reserved == NULL || !test_opt(inode->i_sb, DELALLOC))
-		count_reserved = false;
+	if (rinfo) {
+		rinfo->delonly_cluster = 0;
+		rinfo->delonly_block = 0;
+		if (test_opt(inode->i_sb, DELALLOC))
+			count_reserved = true;
+	}
 
 	es = __es_tree_search(&tree->root, lblk);
 	if (!es)
@@ -1469,8 +1483,10 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	}
 
 out_get_reserved:
-	if (count_reserved)
-		*reserved = get_rsvd(inode, end, es, &rc);
+	if (count_reserved) {
+		rinfo->delonly_cluster = get_rsvd(inode, end, es, &rc);
+		rinfo->delonly_block = rc.ndelonly_block;
+	}
 out:
 	return err;
 }
@@ -1489,8 +1505,8 @@ void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 			   ext4_lblk_t len)
 {
 	ext4_lblk_t end;
+	struct rsvd_info rinfo;
 	int err = 0;
-	int reserved = 0;
 	struct extent_status *es = NULL;
 
 	if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
@@ -1515,7 +1531,7 @@ void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	 * is reclaimed.
 	 */
 	write_lock(&EXT4_I(inode)->i_es_lock);
-	err = __es_remove_extent(inode, lblk, end, &reserved, es);
+	err = __es_remove_extent(inode, lblk, end, &rinfo, es);
 	/* Free preallocated extent if it didn't get used. */
 	if (es) {
 		if (!es->es_len)
@@ -1527,7 +1543,7 @@ void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 		goto retry;
 
 	ext4_es_print_tree(inode);
-	ext4_da_release_space(inode, reserved);
+	ext4_da_release_space(inode, rinfo.delonly_cluster);
 	return;
 }
 
-- 
2.39.2