[LU-18231] Change all obd_device flags to use atomic set/create/test_bit operations

• Type: Task
• Resolution: Unresolved
• Priority: Minor
• Severity: 3
• Assignee: Ronnie Sahlberg
• Reporter: Ronnie Sahlberg

Description

struct obd_device has a number of bitfields that are supposed to be protected by a spinlock.
Implementation of this spinlock is very inconsistent and as updating a bitfield is not atomic this can lead to bitfields being involuntarily modified when two different fields are updated concurrently.

Migrate all of the bitfields in obd_device into a DECLARE_BITMAP and use atomic set/clear/test functions to access them.
Leave the locking as-is for now to reduce risk as that will require careful audit of where it is safe to remove and where it is not.

Issue Links

• is related to: LU-17022 Clean up flags and locking in struct obd_device