[LU-14145] protect cli->cl_import with with_imp_locked()

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Severity: 3
• Assignee: Neil Brown
• Reporter: Jian Yu

Description

Protect cli->cl_import with with_imp_locked():

/* You must use these macros when you want to refer to
 * the import in a client obd_device for a lprocfs entry
 */
#define with_imp_locked(__obd, __imp, __rc)                             \
        for (down_read(&(__obd)->u.cli.cl_sem),                         \
             __imp = (__obd)->u.cli.cl_import,                          \
             __rc = __imp ? 0 : -ENODEV;                                \
             __imp ? 1 : (up_read(&(__obd)->u.cli.cl_sem), 0);          \
             __imp = NULL)

Issue Links

• is related to: LU-18689 recovery-small test 57 crashes in osp and sptlrpc
• is related to: LU-9855 Clean up obdclass preprocessor code
• is related to: LU-12511 Prepare lustre for adoption into the linux kernel
• is related to: LU-13503 allow setting larger max_mod_rpcs_in_flight dynamically

Comments

[James A Simmons]

His patch does improve things including handling nested locking, but I did mention in the patch's review other things that need to be covered such as  imp_connect_data and imp_generation access as well. Also lov_iocontrol() does no locking for cl_import access. So another patch is needed.

[Jian Yu]

Thank you James.
The following code in obd_set_max_mod_rpcs_in_flight() is not covered in the above patch:

        ocd = &cli->cl_import->imp_connect_data;

[James A Simmons]

Note Neil has a patch for this at https://review.whamcloud.com/#/c/39595/