Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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10.2.3
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10.2.4-5
Description
The call to srv_latch_meta_destroy() was disabled, because it was dereferencing some freed memory, because some calls to mutex_free() were omitted.
Do call the function on shutdown, and ensure that all mutex_create() is paired with mutex_free().
Attachments
Activity
In 10.1 the code is different. sync_latch_meta_destroy() was introduced in the refactoring in MySQL 5.7.
In 10.1, it looks like forgetting the mutex_free() will leave garbage in mutex_list. While this might not be detected by memory leak tools if the mutex_list is freed at shutdown, it still is a problem to keep a lot of garbage in that list, especially if those garbage pointers can sometimes be dereferenced. So, I will try backporting the fix to 10.1 as well.
10.1 seems to be better in this respect. fil_space_crypt_cleanup() forgot to call mutex_free() for two mutexes and fil_crypt_threads_cleanup() for one, but those are called during shutdown anyway. innobase_shutdown_for_mysql() should possibly shut down the encryption threads even when innodb_read_only_mode. I am testing those changes.
I made a simpler patch for 10.1. Also there we were missing some mutex_free() before sync_close() which does the equivalent of sync_latch_meta_destroy().
ok to push, consider also 10.1