Commit 9704a322 authored Sep 27, 2020 by Zhang Xiaoxu Committed by Theodore Ts'o Oct 18, 2020

ext4: fix bdev write error check failed when mount fs with ro



Consider a situation when a filesystem was uncleanly shutdown and the
orphan list is not empty and a read-only mount is attempted. The orphan
list cleanup during mount will fail with:

ext4_check_bdev_write_error:193: comm mount: Error while async write back metadata

This happens because sbi->s_bdev_wb_err is not initialized when mounting
the filesystem in read only mode and so ext4_check_bdev_write_error()
falsely triggers.

Initialize sbi->s_bdev_wb_err unconditionally to avoid this problem.

Fixes: bc71726c ("ext4: abort the filesystem if failed to async write metadata buffer")
Cc: stable@kernel.org
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200928020556.710971-1-zhangxiaoxu5@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent dd0db94f

fs/ext4/super.c

+2 −11

Original line number	Diff line number	Diff line
		@@ -4825,7 +4825,6 @@ no_journal:
		* used to detect the metadata async write error.
		*/
		spin_lock_init(&sbi->s_bdev_wb_lock);
		if (!sb_rdonly(sb))
		errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
		&sbi->s_bdev_wb_err);
		sb->s_bdev->bd_super = sb;
		@@ -5719,14 +5718,6 @@ static int ext4_remount(struct super_block sb, int flags, char *data)
		goto restore_opts;
		}

		/*
		* Update the original bdev mapping's wb_err value
		* which could be used to detect the metadata async
		* write error.
		*/
		errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
		&sbi->s_bdev_wb_err);

		/*
		* Mounting a RDONLY partition read-write, so reread
		* and store the current valid flag. (It may have

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