Fix #10086: Going backward in BSR because of 2 jobs running in //

- modify the split_bsr_loop() code to handle this situation:
  This can happens when two incremental jobs run in //
  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

diff --git a/bacula/src/dird/bsr.c b/bacula/src/dird/bsr.c
index d577bdf5adcef3451c1bdecbe829c6ee76ad4ac2..cb82eeda2a56ce3747a837905cffe8519897d9db 100644 (file)
--- a/bacula/src/dird/bsr.c
+++ b/bacula/src/dird/bsr.c
@@ -856,6 +856,11 @@ struct bsr_vol_list {
  * seen for the last time (the job_num) and to know if a volume matter
  * we compare it with the last_split_job_num that is the first job_num
  * in the new list
+ *
+ * Since #10086 the code also detect when the BSR is going backward in the same volume
+ * This can happens when two incremental jobs run in //
+ * 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.
  */
 bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
 {
@@ -869,6 +874,8 @@ bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
 
    uint32_t VolSessionId, VolSessionTime;
    uint32_t prevVolSessionId = 0, prevVolSessionTime = 0;
+   uint64_t VolAddrStart, VolAddrEnd;
+   uint64_t prevVolAddrStart = 0, prevVolAddrEnd = 0;
 
    boffset_t start_section_offset; // the offset of the beginning of the section
    boffset_t start_job_off; // the offset of the first section of the job
@@ -894,8 +901,9 @@ bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
          if (first) {
             first = false;
          } else {
-            // This was the last part or we have reached the end of the file
-            if (strcmp(last_volume.c_str(), volume.c_str()) != 0) {
+            /* We have reached the end of a part or the end of the BSR file */
+            bool same_volume = (strcmp(last_volume.c_str(), volume.c_str()) == 0);
+            if (!same_volume) {
                /* look if the volume has already been used before */
                bsr_vol_list *item = (bsr_vol_list *)volumes.lookup(volume.c_str());
                if (item == NULL) {
@@ -906,9 +914,9 @@ bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
                   volumes.insert(item->volume, item);
 
                } else {
-                  /* we already know about this volume, but is it used in current part ? */
+                  /* 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) {
-                     /* the volume is used in this part, we need to split */
+                     /* the volume is used 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;
                      info.split_list->append(p);
@@ -917,14 +925,35 @@ bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
                   item->job_num = job_num; /* remember when the volume was used */
                }
             }
-            last_volume.strcpy(volume.c_str());
-            if (prevVolSessionTime != VolSessionTime || prevVolSessionId != VolSessionId) {
+            bool is_new_job = (prevVolSessionTime != VolSessionTime || prevVolSessionId != VolSessionId);
+            /* check if we are going backward on the same volume */
+            if (same_volume && VolAddrStart < prevVolAddrEnd) {
+               if (is_new_job) {
+                  /* this is a new job, then we expect that 2 jobs (probably 2 incremental ones)
+                   * ran at the same time on the same Device and wrote on the same volume
+                   * The user should avoid that!
+                   */
+               } else {
+                  /* This is unexpected */
+                  Dmsg3(0, "Error BSR going backward on the Volume=%s on the Session=%lu:%lu\n", volume.c_str(), VolSessionTime, VolSessionId);
+               }
+               /* we need to split the BSR into a new part */
+               boffset_t *p = (boffset_t *)malloc(sizeof(boffset_t));
+               *p = start_job_off;
+               info.split_list->append(p);
+               last_split_job_num = job_num; /* ignore volumes too old */
+            }
+            if (is_new_job) {
                /* This is a new job */
                job_num++;
                start_job_off = start_section_offset;
                prevVolSessionId = VolSessionId;
                prevVolSessionTime = VolSessionTime;
             }
+            last_volume.strcpy(volume.c_str());
+            prevVolAddrStart = VolAddrStart;
+            prevVolAddrEnd = VolAddrEnd;
+            (void) prevVolAddrStart; // not used
             start_section_offset = cur_off;
          }
          if (after_eof) {
@@ -941,6 +970,22 @@ bool split_bsr_loop(JCR *jcr, bootstrap_info &info)
       if (strcasecmp(ua->argk[0], "VolSessionTime") == 0) {
          VolSessionTime = str_to_uint64(ua->argv[0]);
       }
+      if (strcasecmp(ua->argk[0], "VolAddr") == 0) {
+         /* parse something like this: VolAddr=18773542405-24142224724 */
+         char *p = strchr(ua->argv[0], '-');
+         if (p == NULL) {
+            /* error */
+            Dmsg1(0, "Error VolAddr is expected to be a range: \"%s\"\n", ua->argv[0]);
+            VolAddrStart = str_to_uint64(ua->argv[0]);
+            VolAddrEnd = VolAddrStart;
+         } else {
+            char save = *p;
+            *p = '\0';
+            VolAddrStart = str_to_uint64(ua->argv[0]);
+            VolAddrEnd = str_to_uint64(p+1);
+            *p = save;
+         }
+      }
    }
    fseeko(bs, 0, SEEK_SET);
    info.next_split_off = (boffset_t *)info.split_list->first();