ext4: add ext4-specific kludge to avoid an oops after the disk disappears (7c2e7087) · Commits · 戴 / test

fs/ext4/super.c

+17 −1

Original line number	Diff line number	Diff line
		@@ -414,6 +414,22 @@ static void save_error_info(struct super_block sb, const char func,
		ext4_commit_super(sb, 1);
		}

		/*
		* The del_gendisk() function uninitializes the disk-specific data
		* structures, including the bdi structure, without telling anyone
		* else. Once this happens, any attempt to call mark_buffer_dirty()
		* (for example, by ext4_commit_super), will cause a kernel OOPS.
		* This is a kludge to prevent these oops until we can put in a proper
		* hook in del_gendisk() to inform the VFS and file system layers.
		*/
		static int block_device_ejected(struct super_block *sb)
		{
		struct inode *bd_inode = sb->s_bdev->bd_inode;
		struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;

		return bdi->dev == NULL;
		}


		/* Deal with the reporting of failure conditions on a filesystem such as
		* inconsistencies detected or read IO failures.
		@@ -4072,7 +4088,7 @@ static int ext4_commit_super(struct super_block *sb, int sync)
		struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
		int error = 0;

		if (!sbh)
		if (!sbh \|\| block_device_ejected(sb))
		return error;
		if (buffer_write_io_error(sbh)) {
		/*