[LU-15647] "lfs df" should not loop indefinitely for new MDTs/OSTs

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0, Lustre 2.15.1
• Severity: 3
• Assignee: Andreas Dilger
• Reporter: Andreas Dilger

Description

The inner loop in lfs_df->mntdf() iterating over MDTs and OSTs will run forever if ENODEV is not returned, even if other errors are returned:

        for (tp = types; tp->st_name != NULL; tp++) {
                bool have_ost = false;

                if (!(tp->st_op & ops))
                        continue;

                for (index = 0; ; index++) {
                       rc2 = llapi_obd_fstatfs(fd, type, index, &stat_buf, &uuid_buf);
                        if (rc2 == -ENODEV)
                                break;
                        if (rc2 == -EAGAIN)
                                continue;
                        if (rc2 == -ENODATA) { /* Inactive device, OK. */
                                if (!(flags & MNTDF_VERBOSE))
                                        continue;
                        } else if (rc2 < 0 && rc == 0) {
                                rc = rc2;
                        }
                        :
                }
        }

The inner loop should be limited to a maximum index of LOV_ALL_STRIPES (to avoid looping forever) and a maximum of LL_STATFS_MAX actual targets (to avoid overflowing the lsb->sb_buf[] array).