Revert "f2fs: Fix deadlock between f2fs_quota_sync and block_operation"

This reverts commit 26233c1a7e343e010a33310313e6b6067c4249e3. Signed-off-by: engstk <eng.stk@sapo.pt>
engstk · Mar 12, 2021 · 4e42569 · 4e42569
1 parent 2587f9b
commit 4e42569
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Showing 2 changed files with 2 additions and 14 deletions.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
@@ -1369,7 +1369,6 @@ struct f2fs_sb_info {
 	struct inode *meta_inode;		/* cache meta blocks */
 	struct mutex cp_mutex;			/* checkpoint procedure lock */
 	struct rw_semaphore cp_rwsem;		/* blocking FS operations */
-	struct rw_semaphore cp_quota_rwsem;    	/* blocking quota sync operations */
 	struct rw_semaphore node_write;		/* locking node writes */
 	struct rw_semaphore node_change;	/* locking node change */
 	wait_queue_head_t cp_wait;
@@ -1883,14 +1882,12 @@ static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)
 
 static inline void f2fs_lock_all(struct f2fs_sb_info *sbi)
 {
-	down_write(&sbi->cp_quota_rwsem);
 	down_write(&sbi->cp_rwsem);
 }
 
 static inline void f2fs_unlock_all(struct f2fs_sb_info *sbi)
 {
 	up_write(&sbi->cp_rwsem);
-	up_write(&sbi->cp_quota_rwsem);
 }
 
 static inline int __get_cp_reason(struct f2fs_sb_info *sbi)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
@@ -2281,16 +2281,8 @@ int f2fs_quota_sync(struct super_block *sb, int type)
 	 *  f2fs_dquot_commit
 	 *                            block_operation
 	 *                            down_read(quota_sem)
-	 *
-	 * However, we cannot use the cp_rwsem to prevent this
-	 * deadlock, as the cp_rwsem is taken for read inside the
-	 * f2fs_dquot_commit code, and rwsem is not recursive.
-	 *
-	 * We therefore use a special lock to synchronize
-	 * f2fs_quota_sync with block_operations, as this is the only
-	 * place where such recursion occurs.
 	 */
-	down_read(&sbi->cp_quota_rwsem);
+	f2fs_lock_op(sbi);
 
 	down_read(&sbi->quota_sem);
 	ret = dquot_writeback_dquots(sb, type);
@@ -2331,7 +2323,7 @@ int f2fs_quota_sync(struct super_block *sb, int type)
 	if (ret)
 		set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
 	up_read(&sbi->quota_sem);
-	up_read(&sbi->cp_quota_rwsem);
+	f2fs_unlock_op(sbi);
 	return ret;
 }
 
@@ -3711,7 +3703,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 
 	init_rwsem(&sbi->cp_rwsem);
 	init_rwsem(&sbi->quota_sem);
-	init_rwsem(&sbi->cp_quota_rwsem);
 	init_waitqueue_head(&sbi->cp_wait);
 	init_sb_info(sbi);