1 files changed, 83 insertions, 12 deletions

diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c
index 761c79c3a4ba..cc5cffc4a769 100644
--- a/fs/exfat/balloc.c
+++ b/fs/exfat/balloc.c
@@ -141,11 +141,7 @@ void exfat_free_bitmap(struct exfat_sb_info *sbi)
 	kfree(sbi->vol_amap);
 }
 
-/*
- * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
- * the cluster heap.
- */
-int exfat_set_bitmap(struct inode *inode, unsigned int clu)
+int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync)
 {
 	int i, b;
 	unsigned int ent_idx;
@@ -158,14 +154,10 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu)
 	b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
 
 	set_bit_le(b, sbi->vol_amap[i]->b_data);
-	exfat_update_bh(sbi->vol_amap[i], IS_DIRSYNC(inode));
+	exfat_update_bh(sbi->vol_amap[i], sync);
 	return 0;
 }
 
-/*
- * If the value of "clu" is 0, it means cluster 2 which is the first cluster of
- * the cluster heap.
- */
 void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
 {
 	int i, b;
@@ -186,8 +178,7 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync)
 		int ret_discard;
 
 		ret_discard = sb_issue_discard(sb,
-			exfat_cluster_to_sector(sbi, clu +
-						EXFAT_RESERVED_CLUSTERS),
+			exfat_cluster_to_sector(sbi, clu),
 			(1 << sbi->sect_per_clus_bits), GFP_NOFS, 0);
 
 		if (ret_discard == -EOPNOTSUPP) {
@@ -273,3 +264,83 @@ int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count)
 	*ret_count = count;
 	return 0;
 }
+
+int exfat_trim_fs(struct inode *inode, struct fstrim_range *range)
+{
+	unsigned int trim_begin, trim_end, count, next_free_clu;
+	u64 clu_start, clu_end, trim_minlen, trimmed_total = 0;
+	struct super_block *sb = inode->i_sb;
+	struct exfat_sb_info *sbi = EXFAT_SB(sb);
+	int err = 0;
+
+	clu_start = max_t(u64, range->start >> sbi->cluster_size_bits,
+				EXFAT_FIRST_CLUSTER);
+	clu_end = clu_start + (range->len >> sbi->cluster_size_bits) - 1;
+	trim_minlen = range->minlen >> sbi->cluster_size_bits;
+
+	if (clu_start >= sbi->num_clusters || range->len < sbi->cluster_size)
+		return -EINVAL;
+
+	if (clu_end >= sbi->num_clusters)
+		clu_end = sbi->num_clusters - 1;
+
+	mutex_lock(&sbi->bitmap_lock);
+
+	trim_begin = trim_end = exfat_find_free_bitmap(sb, clu_start);
+	if (trim_begin == EXFAT_EOF_CLUSTER)
+		goto unlock;
+
+	next_free_clu = exfat_find_free_bitmap(sb, trim_end + 1);
+	if (next_free_clu == EXFAT_EOF_CLUSTER)
+		goto unlock;
+
+	do {
+		if (next_free_clu == trim_end + 1) {
+			/* extend trim range for continuous free cluster */
+			trim_end++;
+		} else {
+			/* trim current range if it's larger than trim_minlen */
+			count = trim_end - trim_begin + 1;
+			if (count >= trim_minlen) {
+				err = sb_issue_discard(sb,
+					exfat_cluster_to_sector(sbi, trim_begin),
+					count * sbi->sect_per_clus, GFP_NOFS, 0);
+				if (err)
+					goto unlock;
+
+				trimmed_total += count;
+			}
+
+			/* set next start point of the free hole */
+			trim_begin = trim_end = next_free_clu;
+		}
+
+		if (next_free_clu >= clu_end)
+			break;
+
+		if (fatal_signal_pending(current)) {
+			err = -ERESTARTSYS;
+			goto unlock;
+		}
+
+		next_free_clu = exfat_find_free_bitmap(sb, next_free_clu + 1);
+	} while (next_free_clu != EXFAT_EOF_CLUSTER &&
+			next_free_clu > trim_end);
+
+	/* try to trim remainder */
+	count = trim_end - trim_begin + 1;
+	if (count >= trim_minlen) {
+		err = sb_issue_discard(sb, exfat_cluster_to_sector(sbi, trim_begin),
+			count * sbi->sect_per_clus, GFP_NOFS, 0);
+		if (err)
+			goto unlock;
+
+		trimmed_total += count;
+	}
+
+unlock:
+	mutex_unlock(&sbi->bitmap_lock);
+	range->len = trimmed_total << sbi->cluster_size_bits;
+
+	return err;
+}