[PATCH 05/10] ext4: count removed reserved blocks for delalloc only extent entry

[Zhang Yi]

From: Zhang Yi <yi.zhang@xxxxxxxxxx>

If bigalloc feature is enabled, __es_remove_extent() only counts
reserved clusters when removing delalloc extent entry, it doesn't count
reserved blocks. However, it's useful to distinguish whether we are
allocating blocks that contains a delalloc range in one cluster, so
let's count the reserved blocks number too.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 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 e54e15eb05b9..ced9826682bb 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;
 }
 
-- 
2.31.1