f2fs: fix to account missing .skipped_gc_rwsem

stable inclusion
from stable-5.10.67
commit 45cb5f86c1c65da62806d0c9618e9351a4025efa
bugzilla: 182619 https://gitee.com/openeuler/kernel/issues/I4EWO7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=45cb5f86c1c65da62806d0c9618e9351a4025efa

--------------------------------

[ Upstream commit ad126ebd ]

There is a missing place we forgot to account .skipped_gc_rwsem, fix it.

Fixes: 6f8d4455 ("f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc")
Signed-off-by: NChao Yu <chao@kernel.org>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/f2fs/gc.c

@@ -1477,8 +1477,10 @@ static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 			int err;
 
 			if (S_ISREG(inode->i_mode)) {
-				if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
+				if (!down_write_trylock(&fi->i_gc_rwsem[READ])) {
+					sbi->skipped_gc_rwsem++;
 					continue;
+				}
 				if (!down_write_trylock(
 						&fi->i_gc_rwsem[WRITE])) {
 					sbi->skipped_gc_rwsem++;