[RFC PATCH 04/16] ext4: count removed reserved blocks for delalloc only es entry

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

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

Current __es_remove_extent() count reserved clusters if the removed es
entry is delalloc only, it's equal to blocks number if the bigalloc
feature is disabled, but we cannot get the blocks number if that feature
is enabled. So add a parameter to count the reserved blocks number, it
is not used in this patch now, it will be used to calculate reserved
meta blocks.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/extents_status.c | 40 ++++++++++++++++++++++++++++------------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 67ac09930541..3a004ed04570 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -141,13 +141,18 @@
  *   -- Extent-level locking
  */
 
+struct rsvd_info {
+	int ndelonly_clu;	/* reserved clusters for delalloc es entry */
+	int ndelonly_blk;	/* 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,
@@ -1050,6 +1055,7 @@ int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
 
 struct rsvd_count {
 	int ndelonly;
+	int ndelonly_blk;
 	bool first_do_lblk_found;
 	ext4_lblk_t first_do_lblk;
 	ext4_lblk_t last_do_lblk;
@@ -1076,6 +1082,7 @@ static void init_rsvd(struct inode *inode, ext4_lblk_t lblk,
 	struct rb_node *node;
 
 	rc->ndelonly = 0;
+	rc->ndelonly_blk = 0;
 
 	/*
 	 * for bigalloc, note the first delonly block in the range has not
@@ -1124,10 +1131,12 @@ static void count_rsvd(struct inode *inode, ext4_lblk_t lblk, long len,
 
 	if (sbi->s_cluster_ratio == 1) {
 		rc->ndelonly += (int) len;
+		rc->ndelonly_blk = rc->ndelonly;
 		return;
 	}
 
 	/* bigalloc */
+	rc->ndelonly_blk += (int)len;
 
 	i = (lblk < es->es_lblk) ? es->es_lblk : lblk;
 	end = lblk + (ext4_lblk_t) len - 1;
@@ -1355,16 +1364,17 @@ 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;
@@ -1374,11 +1384,15 @@ 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->ndelonly_clu = 0;
+		rinfo->ndelonly_blk = 0;
+		if (test_opt(inode->i_sb, DELALLOC))
+			count_reserved = true;
+	}
 
 	es = __es_tree_search(&tree->root, lblk);
 	if (!es)
@@ -1476,8 +1490,10 @@ 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->ndelonly_clu = get_rsvd(inode, end, es, &rc);
+		rinfo->ndelonly_blk = rc.ndelonly_blk;
+	}
 out:
 	return err;
 }
@@ -1496,8 +1512,8 @@ 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)
@@ -1522,7 +1538,7 @@ 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)
@@ -1534,7 +1550,7 @@ 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.ndelonly_clu);
 	return;
 }
 
-- 
2.39.2