• Vasil Dimov's avatar
    Fix Bug#11754376 45976: INNODB LOST FILES FOR TEMPORARY TABLES ON · 17afdb90
    Vasil Dimov authored
    GRACEFUL SHUTDOWN
    
    During startup mysql picks up .frm files from the tmpdir directory and
    tries to drop those tables in the storage engine.
    
    The problem is that when tmpdir ends in / then ha_innobase::delete_table()
    is passed a string like "/var/tmp//#sql123", then it wrongly normalizes it
    to "/#sql123" and calls row_drop_table_for_mysql() which of course fails
    to delete the table entry from the InnoDB dictionary cache.
    ha_innobase::delete_table() returns an error but nevertheless mysql wipes
    away the .frm file and the entry in the InnoDB dictionary cache remains
    orphaned with no easy way to remove it.
    
    The "no easy" way to remove it is to create a similar temporary table again,
    copy its .frm file to tmpdir under "#sql123.frm" and restart mysqld with
    tmpdir=/var/tmp (no trailing slash) - this way mysql will pick the .frm file
    after restart and will try to issue drop table for "/var/tmp/#sql123"
    (notice do double slash), ha_innobase::delete_table() will normalize it to
    "tmp/#sql123" and row_drop_table_for_mysql() will successfully remove the
    table entry from the dictionary cache.
    
    The solution is to fix normalize_table_name_low() to normalize things like
    "/var/tmp//table" correctly to "tmp/table".
    
    This patch also adds a test function which invokes
    normalize_table_name_low() with various inputs to make sure it works
    correctly and a mtr test that calls this test function.
    
    Reviewed by:	Marko (http://bur03.no.oracle.com/rb/r/929/)
    17afdb90
ha_innodb.cc 268 KB