Revert "ext4: fix superblock checksum calculation race" (d196e229) · Commits · 戴 / test

This reverts commit which can result in a ext4_superblock_csum_set() trying to sleep while a spinlock is being held. For more discussion of this issue, please see: https://lore.kernel.org/r/000000000000f50cb705b313ed70@google.com Reported-by:

fs/ext4/super.c

+0 −11

Original line number	Diff line number	Diff line
		@@ -289,18 +289,7 @@ void ext4_superblock_csum_set(struct super_block *sb)
		if (!ext4_has_metadata_csum(sb))
		return;

		/*
		* Locking the superblock prevents the scenario
		* where:
		* 1) a first thread pauses during checksum calculation.
		* 2) a second thread updates the superblock, recalculates
		* the checksum, and updates s_checksum
		* 3) the first thread resumes and finishes its checksum calculation
		* and updates s_checksum with a potentially stale or torn value.
		*/
		lock_buffer(EXT4_SB(sb)->s_sbh);
		es->s_checksum = ext4_superblock_csum(sb, es);
		unlock_buffer(EXT4_SB(sb)->s_sbh);
		}

		ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,