• R
    mm: clear PageError bit in msync & fsync · 212260aa
    Rik van Riel 提交于
    Temporary IO failures, eg.  due to loss of both multipath paths, can
    permanently leave the PageError bit set on a page, resulting in msync or
    fsync returning -EIO over and over again, even if IO is now getting to the
    disk correctly.
    
    We already clear the AS_ENOSPC and AS_IO bits in mapping->flags in the
    filemap_fdatawait_range function.  Also clearing the PageError bit on the
    page allows subsequent msync or fsync calls on this file to return without
    an error, if the subsequent IO succeeds.
    
    Unfortunately data written out in the msync or fsync call that returned
    -EIO can still get lost, because the page dirty bit appears to not get
    restored on IO error.  However, the alternative could be potentially all
    of memory filling up with uncleanable dirty pages, hanging the system, so
    there is no nice choice here...
    Signed-off-by: NRik van Riel <riel@redhat.com>
    Acked-by: NValerie Aurora <vaurora@redhat.com>
    Acked-by: NJeff Layton <jlayton@redhat.com>
    Cc: Theodore Ts'o <tytso@mit.edu>
    Acked-by: NJan Kara <jack@suse.cz>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    212260aa
page-flags.h 13.3 KB