llog.c

来自「lustre 1.6.5 source code」· C语言 代码 · 共 425 行 · 第 1/2 页

        int rc = 0, index = 1, last_index;
        int saved_index = 0, last_called_index = 0;
        ENTRY;

        LASSERT(llh);

        OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
        if (!buf)
                RETURN(-ENOMEM);

        if (cd != NULL) {
                last_called_index = cd->first_idx;
                index = cd->first_idx + 1;
        }
        if (cd != NULL && cd->last_idx)
                last_index = cd->last_idx;
        else
                last_index = LLOG_BITMAP_BYTES * 8 - 1;

        while (rc == 0) {
                struct llog_rec_hdr *rec;

                /* skip records not set in bitmap */
                while (index <= last_index &&
                       !ext2_test_bit(index, llh->llh_bitmap))
                        ++index;

                LASSERT(index <= last_index + 1);
                if (index == last_index + 1)
                        break;

                CDEBUG(D_OTHER, "index: %d last_index %d\n",
                       index, last_index);

                /* get the buf with our target record; avoid old garbage */
                last_offset = cur_offset;
                rc = llog_next_block(loghandle, &saved_index, index,
                                     &cur_offset, buf, LLOG_CHUNK_SIZE);
                if (rc)
                        GOTO(out, rc);

                /* NB: when rec->lrh_len is accessed it is already swabbed
                 * since it is used at the "end" of the loop and the rec
                 * swabbing is done at the beginning of the loop. */
                for (rec = (struct llog_rec_hdr *)buf;
                     (char *)rec < buf + LLOG_CHUNK_SIZE;
                     rec = (struct llog_rec_hdr *)((char *)rec + rec->lrh_len)){

                        CDEBUG(D_OTHER, "processing rec 0x%p type %#x\n",
                               rec, rec->lrh_type);

                        if (LLOG_REC_HDR_NEEDS_SWABBING(rec))
                                lustre_swab_llog_rec(rec, NULL);

                        CDEBUG(D_OTHER, "after swabbing, type=%#x idx=%d\n",
                               rec->lrh_type, rec->lrh_index);
                        
                        if (rec->lrh_index == 0)
                                GOTO(out, 0); /* no more records */

                        if (rec->lrh_len == 0 || rec->lrh_len >LLOG_CHUNK_SIZE){
                                CWARN("invalid length %d in llog record for "
                                      "index %d/%d\n", rec->lrh_len,
                                      rec->lrh_index, index);
                                GOTO(out, rc = -EINVAL);
                        }

                        if (rec->lrh_index < index) {
                                CDEBUG(D_OTHER, "skipping lrh_index %d\n",
                                       rec->lrh_index);
                                continue;
                        }

                        CDEBUG(D_OTHER, 
                               "lrh_index: %d lrh_len: %d (%d remains)\n",
                               rec->lrh_index, rec->lrh_len,
                               (int)(buf + LLOG_CHUNK_SIZE - (char *)rec));

                        loghandle->lgh_cur_idx = rec->lrh_index;
                        loghandle->lgh_cur_offset = (char *)rec - (char *)buf +
                                last_offset;

                        /* if set, process the callback on this record */
                        if (ext2_test_bit(index, llh->llh_bitmap)) {
                                rc = cb(loghandle, rec, data);
                                last_called_index = index;
                                if (rc == LLOG_PROC_BREAK) {
                                        CDEBUG(D_HA, "recovery from log: "LPX64
                                               ":%x stopped\n",
                                               loghandle->lgh_id.lgl_oid,
                                               loghandle->lgh_id.lgl_ogen);
                                        GOTO(out, rc);
                                } else if (rc == LLOG_DEL_RECORD) {
                                        llog_cancel_rec(loghandle, rec->lrh_index);
                                        rc = 0;
                                }
                                if (rc)
                                        GOTO(out, rc);
                        } else {
                                CDEBUG(D_OTHER, "Skipped index %d\n", index);
                        }

                        /* next record, still in buffer? */
                        ++index;
                        if (index > last_index)
                                GOTO(out, rc = 0);
                }
        }

 out:
        if (cd != NULL)
                cd->last_idx = last_called_index;
        if (buf)
                OBD_FREE(buf, LLOG_CHUNK_SIZE);
        RETURN(rc);
}
EXPORT_SYMBOL(llog_process);

inline int llog_get_size(struct llog_handle *loghandle)
{
        if (loghandle && loghandle->lgh_hdr)
                return loghandle->lgh_hdr->llh_count;
        return 0;
}
EXPORT_SYMBOL(llog_get_size);

int llog_reverse_process(struct llog_handle *loghandle, llog_cb_t cb,
                         void *data, void *catdata)
{
        struct llog_log_hdr *llh = loghandle->lgh_hdr;
        struct llog_process_cat_data *cd = catdata;
        void *buf;
        int rc = 0, first_index = 1, index, idx;
        ENTRY;

        OBD_ALLOC(buf, LLOG_CHUNK_SIZE);
        if (!buf)
                RETURN(-ENOMEM);

        if (cd != NULL)
                first_index = cd->first_idx + 1;
        if (cd != NULL && cd->last_idx)
                index = cd->last_idx;
        else
                index = LLOG_BITMAP_BYTES * 8 - 1;

        while (rc == 0) {
                struct llog_rec_hdr *rec;
                struct llog_rec_tail *tail;

                /* skip records not set in bitmap */
                while (index >= first_index &&
                       !ext2_test_bit(index, llh->llh_bitmap))
                        --index;

                LASSERT(index >= first_index - 1);
                if (index == first_index - 1)
                        break;

                /* get the buf with our target record; avoid old garbage */
                memset(buf, 0, LLOG_CHUNK_SIZE);
                rc = llog_prev_block(loghandle, index, buf, LLOG_CHUNK_SIZE);
                if (rc)
                        GOTO(out, rc);

                rec = buf;
                idx = le32_to_cpu(rec->lrh_index);
                if (idx < index)
                        CDEBUG(D_RPCTRACE, "index %u : idx %u\n", index, idx);
                while (idx < index) {
                        rec = ((void *)rec + le32_to_cpu(rec->lrh_len));
                        idx ++;
                }
                tail = (void *)rec + le32_to_cpu(rec->lrh_len) - sizeof(*tail);

                /* process records in buffer, starting where we found one */
                while ((void *)tail > buf) {
                        rec = (void *)tail - le32_to_cpu(tail->lrt_len) +
                                sizeof(*tail);

                        if (rec->lrh_index == 0)
                                GOTO(out, 0); /* no more records */

                        /* if set, process the callback on this record */
                        if (ext2_test_bit(index, llh->llh_bitmap)) {
                                rc = cb(loghandle, rec, data);
                                if (rc == LLOG_PROC_BREAK) {
                                        CWARN("recovery from log: "LPX64":%x"
                                              " stopped\n",
                                              loghandle->lgh_id.lgl_oid,
                                              loghandle->lgh_id.lgl_ogen);
                                        GOTO(out, rc);
                                }
                                if (rc)
                                        GOTO(out, rc);
                        }

                        /* previous record, still in buffer? */
                        --index;
                        if (index < first_index)
                                GOTO(out, rc = 0);
                        tail = (void *)rec - sizeof(*tail);
                }
        }

out:
        if (buf)
                OBD_FREE(buf, LLOG_CHUNK_SIZE);
        RETURN(rc);
}
EXPORT_SYMBOL(llog_reverse_process);