[LU-20035] add dt_device/lu_name/lov_object name extraction helper functions

• Type: Improvement
• Resolution: Unresolved
• Priority: Medium
• Affects Version/s: Lustre 2.18.0
• Labels: easy
• Severity: 3
• Assignee: WC Triage
• Reporter: Andreas Dilger

Description

There are many places in the LOV code where CERROR() messages are printed without any leading OBD device name, when it is actually possible to get the device/filesystem name from a dt_device or lu_device or lu_object in the function.

In general, there are lots of callers that are using the lengthy "dt_dev->dd_lu_dev.ld_obd->obd_name" and similar to extract the device name, when they could be using a more compact form like lu_dev_name(&dt_dev->dd_lu_dev). This can be seen in about 100 places in the code (via "git grep 'ld_obd.*obd_name'").

Many of these callers could use another helper function to extract the device name directly from a dt_device could be used ("git grep 'dd_lu_dev.*obd_name'
shows about 40 uses, though they all overlap with the ld_obd.*obd_name cases):

static inline const char *dt_dev_name(const struct dt_device *dt)
{
          return lu_dev_name(&dt->dd_lu_dev);
}

Similary, extracting the device name from an lu_object would also be useful (13 callers appear in "git grep 'obj.*obd_name'", but I expect there are more CERROR() messages where these could be used:

static inline const char *luobj_dev_name(const struct lu_object *obj)
{
        return lu_dev_name(obj->lo_dev);
}

It also makes sense to add a corresponding helper function in lustre/lov/lov_cl_internal.h to simplify callers in lustre/lov/lov_io.c:

static inline const char *lovobj_dev_name(const struct lov_object *lovobj)
{
        return lu_dev_name(lov2lu(lovobj)->lo_dev);
}

This should also add a regexp to contrib/scripts/spelling.txt to catch these cases:

dd_lu_dev.*obd_name||dt_dev_name()
ld_obd.*obd_name||lu_dev_name()
obj.*obd_name||luobj_dev_name()