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From: Zhiguo Niu <zhiguo.niu@unisoc.com>
To: <jaegeuk@kernel.org>, <chao@kernel.org>
CC: <linux-f2fs-devel@lists.sourceforge.net>, <linux-kernel@vger.kernel.org>,
        <niuzhiguo84@gmail.com>, <zhiguo.niu@unisoc.com>, <ke.wang@unisoc.com>
Subject: [PATCH V1] f2fs: fix potentail deadloop issue in do_recover_data
Date: Mon, 25 Dec 2023 19:11:55 +0800
Message-ID: <1703502715-11936-1-git-send-email-zhiguo.niu@unisoc.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain

There is a potentail deadloop issue in the corner case of
CONFIG_F2FS_FAULT_INJECTION is enabled and the return value
of f2fs_reserve_new_block is error but not -ENOSPC, such as
this error case:
if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
		return -EPERM;
besides, the mainly error -ENOSPC has been handled as bug on,
so other error cases can be proecssed normally without looping.

Fixes: 956fa1ddc132 ("f2fs: fix to check return value of f2fs_reserve_new_block()")
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
---
 fs/f2fs/recovery.c | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 21381b7..5d658f6 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -710,15 +710,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 		 */
 		if (dest == NEW_ADDR) {
 			f2fs_truncate_data_blocks_range(&dn, 1);
-			do {
-				err = f2fs_reserve_new_block(&dn);
-				if (err == -ENOSPC) {
-					f2fs_bug_on(sbi, 1);
-					break;
-				}
-			} while (err &&
-				IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
-			if (err)
+			err = f2fs_reserve_new_block(&dn);
+			if (err == -ENOSPC)
+				f2fs_bug_on(sbi, 1);
+			else if (err)
 				goto err;
 			continue;
 		}
@@ -727,15 +722,10 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 		if (f2fs_is_valid_blkaddr(sbi, dest, META_POR)) {
 
 			if (src == NULL_ADDR) {
-				do {
-					err = f2fs_reserve_new_block(&dn);
-					if (err == -ENOSPC) {
-						f2fs_bug_on(sbi, 1);
-						break;
-					}
-				} while (err &&
-					IS_ENABLED(CONFIG_F2FS_FAULT_INJECTION));
-				if (err)
+				err = f2fs_reserve_new_block(&dn);
+				if (err == -ENOSPC)
+					f2fs_bug_on(sbi, 1);
+				else if (err)
 					goto err;
 			}
 retry_prev:
-- 
1.9.1