From 77edfc6e51055b61cae2f54c8e6c3bb7c762e4fe Mon Sep 17 00:00:00 2001

From: Hyeongseok Kim <hyeongseok@gmail.com>

Date: Thu, 4 Mar 2021 09:15:34 +0900

Subject: [Backport 77edfc6e5105] exfat: fix erroneous discard when clear

 cluster bit

If mounted with discard option, exFAT issues discard command when clear

cluster bit to remove file. But the input parameter of cluster-to-sector

calculation is abnormally added by reserved cluster size which is 2,

leading to discard unrelated sectors included in target+2 cluster.

With fixing this, remove the wrong comments in set/clear/find bitmap

functions.

Fixes: 1e49a94cf707 ("exfat: add bitmap operations")

Cc: stable@vger.kernel.org # v5.7+

Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>

Acked-by: Sungjong Seo <sj1557.seo@samsung.com>

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

---

 src/balloc.c | 11 +----------

 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/src/balloc.c b/src/balloc.c

index 761c79c3a4ba262870686608f3619c98312f65cb..411fb0a8da10d40be5610f55f72280d44eb03ee7 100644

--- a/src/balloc.c

+++ b/src/balloc.c

@@ -141,10 +141,6 @@ 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 i, b;

@@ -162,10 +158,6 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu)

 	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) {

-- 

2.31.1