scst: Use RCU read lock when accessing sess_tgt_dev_list #151
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We must always protect sess_tgt_dev_list during access and modification. There are two mechanisms for that: - tgt_dev_list_mutex for list modifications. - RCU for read-only list accesses. Currently, the codebase doesn't consistently apply protection when accessing the list. Fix this by adding RCU protection. See also commit 3e64094 ("scst_sysfs: Do not suspend I/O for LUN management").
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In the previous commit, we introduced the use of RCU protection when accessing sess_tgt_dev_list in scst_get_max_lun_commands(). As a result, we can now drop the use of scst_mutex when accessing the list.
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We must always protect sess_tgt_dev_list during access and modification.
There are two mechanisms for that:
Currently, the codebase doesn't consistently apply protection when accessing the list. Fix this by adding RCU protection.
See also commit 3e64094 ("scst_sysfs: Do not suspend I/O for LUN management").