};
/* Generate a list of split position in the BSR to break any cycle
- * returns true if a cycle was detected
+ * return
+ * 0: OK no split needed
+ * 1: OK but some split are required
+ * -1: ERROR We found a cycles inside one job, the code in the SD must
+ * be improved to handle this situation. See last sample at the end of the
+ * comment
*
* When a volume appears multiple time into a BSR, interleaved with other
* volumes, this can be a problem because the SD mount each volume only once and
* As the BSR is written job by job the split is enough, no need to reorganize
* the BSR an move all the parts of the first job before the second one.
*
- * The only case that this function cannot solve is the end of a job is written
- * before the beginning inside the same volume. This could happens in a copy job
- * if not copying the volume in the wrong order.
+ * This function don't work inside a job. If two parts of a job are already
+ * written in reverse order on the same volume (after a copy job) or if a part
+ * between the two are written into another volume. It can detect the problem
+ * but the "split" must be done inside the SD.
*
* It is possible to split the BSR at multiple place, I split it at the beginning
- * of the job where the problem is detected.
+ * of the job where the problem is detected.
*
* For example:
* number are jobs, letters are volumes
* 2 B
* 2 A
* 3 A
- * Here I must split between 1A & 2B to be sure that 2A will be read after 2B
- * else the file that span 2B & 2A will never be fully restored as the blocks
- * should have been read just after 1A and befor 2B by the SD
+ * Normally here the SD will mount A once read blocks 1A, 2A, 3A, then mount
+ * B for 2B. Reading 2B before 2A is a mistake.
+ * Here I must split between 1A & 2B to be sure that 2A will be read after 2B.
*
- * Another example
+ * Another example where offset matter
* 1 A start=0 end=1000
* ---
* 2 A start=0 end=2000
* 4 B start=0 end=2000
* I must split between 3C & 4B to avoid to include blocks of 4B while restoring
* 2B. But this is handled by the 1st example
+ *
+ * In this case the volume 2 was reused for the same job, despite it was already
+ * full. This is a bug, the DIR don't know about the right size of the volume!
+ * The job start writing (with other jobs) on the volume 2, when the Maximum
+ * Size is reached, the SD close the volume and switch to another volume, that
+ * get full quickly and the DIR tell to continue back on volume 2. The SD
+ * notice the differrence in size between the Catalog and the file but still
+ * write on it.
+ * In this situation despite the data are not "corrupted", the SD is unable
+ * to restore the backup and no split can be used inside a job.
+ * +---------+------------+----------+
+ * | MediaId | StartBlock | EndBlock |
+ * +---------+------------+----------+
+ * | 2 | 10028425 | 10355984 |
+ * | 30 | 10201502 | 10267009 |
+ * | 2 | 10421493 | 10471710 |
+ * +---------+------------+----------+
+ *
*/
-bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
+int split_bsr_loop(JCR *jcr, bootstrap_info &info)
{
UAContext *ua = info.ua;
FILE *bs = info.bs;
bool first = true;
bool after_eof = false; // used to handle the after EOF inside the loop
int job_num = 0; // internal job numbering from 0,1..N
- int last_split_job_num = 0; // the volumes that matter in "volumes" have a job_num >= last_split_job_num
+ int last_split_job_num = 1; // the volumes that matter in "volumes" have a job_num >= last_split_job_num
+ bool internal_cycle = false; /* no cycle detecte inside a job */
if (info.split_list == NULL) {
info.split_list = New(alist(100, owned_by_alist));
Dmsg2(120, "BSR: insert volume %s jobnum=%d\n", item->volume, item->job_num);
} else {
/* we already know about this volume, but is it used in the current part of the BSR? */
- if (item->job_num >= last_split_job_num) {
+ if (item->job_num == job_num) {
+ /* the volume is used again in the same job, we have an issue */
+ /* This is would be up to the SD to fix the problem */
+ Dmsg8(1, "BSR: unfixable cycle inside the BSR at off=%lld at the beginning of jobnum=%d sess=%lu:%lu because volume %s is previously used by jobnum=%d sess=%lu:%lu\n",
+ start_job_off, job_num, VolSessionTime, VolSessionId, volume.c_str(), item->job_num, item->VolSessionTime, item->VolSessionId);
+ internal_cycle = true;
+ } else if (item->job_num >= last_split_job_num) {
/* the volume is used again in this part, we need to split the BSR into a new part */
boffset_t *p = (boffset_t *)malloc(sizeof(boffset_t));
*p = start_job_off;
}
fseeko(bs, 0, SEEK_SET);
info.next_split_off = (boffset_t *)info.split_list->first();
- return info.next_split_off != NULL;
+ if (internal_cycle) {
+ return -1; // we have a probleme that we cannot solve
+ } else if (info.next_split_off != NULL) {
+ return 1; // we have detected cycles and added a splits
+ } else {
+ return 0; // no cycle found
+ }
}
projects / thirdparty / bacula.git / commitdiff
