• zhangyi (F)'s avatar
    ext4: abort the filesystem if failed to async write metadata buffer · bc71726c
    zhangyi (F) authored
    There is a risk of filesystem inconsistency if we failed to async write
    back metadata buffer in the background. Because of current buffer's end
    io procedure is handled by end_buffer_async_write() in the block layer,
    and it only clear the buffer's uptodate flag and mark the write_io_error
    flag, so ext4 cannot detect such failure immediately. In most cases of
    getting metadata buffer (e.g. ext4_read_inode_bitmap()), although the
    buffer's data is actually uptodate, it may still read data from disk
    because the buffer's uptodate flag has been cleared. Finally, it may
    lead to on-disk filesystem inconsistency if reading old data from the
    disk successfully and write them out again.
    
    This patch detect bdev mapping->wb_err when getting journal's write
    access and mark the filesystem error if bdev's mapping->wb_err was
    increased, this could prevent further writing and potential
    inconsistency.
    Signed-off-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
    Suggested-by: default avatarJan Kara <jack@suse.cz>
    Link: https://lore.kernel.org/r/20200620025427.1756360-2-yi.zhang@huawei.comSigned-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    bc71726c
ext4_jbd2.c 10.2 KB