From: Chao Yu <chao@kernel.org>
Date: Mon, 10 Apr 2023 02:11:40 +0000 (+0800)
Subject: f2fs: fix to keep consistent i_gc_rwsem lock order
X-Git-Tag: v6.6.17~5024^2~20
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6fd257cb35e8478ed551324ccf7c13723e654fcc;p=platform%2Fkernel%2Flinux-rpi.git

f2fs: fix to keep consistent i_gc_rwsem lock order

i_gc_rwsem[WRITE] and i_gc_rwsem[READ] lock order is reversed
in gc_data_segment() and f2fs_dio_write_iter(), fix to keep
consistent lock order as below:
1. lock i_gc_rwsem[WRITE]
2. lock i_gc_rwsem[READ]

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 56c53db..c748cdf 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1616,14 +1616,14 @@ next_step:
 			int err;
 
 			if (S_ISREG(inode->i_mode)) {
-				if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[READ])) {
+				if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[WRITE])) {
 					sbi->skipped_gc_rwsem++;
 					continue;
 				}
 				if (!f2fs_down_write_trylock(
-						&fi->i_gc_rwsem[WRITE])) {
+						&fi->i_gc_rwsem[READ])) {
 					sbi->skipped_gc_rwsem++;
-					f2fs_up_write(&fi->i_gc_rwsem[READ]);
+					f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
 					continue;
 				}
 				locked = true;
@@ -1646,8 +1646,8 @@ next_step:
 				submitted++;
 
 			if (locked) {
-				f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
 				f2fs_up_write(&fi->i_gc_rwsem[READ]);
+				f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
 			}
 
 			stat_inc_data_blk_count(sbi, 1, gc_type);