Recover from afs_GetVolSlot errors

[openafs.git] / src / afs / afs_volume.c

diff --git a/src/afs/afs_volume.c b/src/afs/afs_volume.c
index 07c10a7..cdfe174 100644 (file)
--- a/src/afs/afs_volume.c
+++ b/src/afs/afs_volume.c
@@ -113,11 +113,13 @@ afs_int32 afs_FVIndex = -1;
 struct volume *
 afs_UFSGetVolSlot(void)
 {
-    register struct volume *tv, **lv;
+    register struct volume *tv = NULL, **lv;
     struct osi_file *tfile;
-    register afs_int32 i, code;
+    register afs_int32 i = -1, code;
     afs_int32 bestTime;
-    struct volume *bestVp, **bestLp;
+    struct volume *bestVp, *oldLp = NULL, **bestLp = NULL;
+    char *oldname = NULL;
+    afs_int32 oldvtix;
 
     AFS_STATCNT(afs_UFSGetVolSlot);
     if (!afs_freeVolList) {
@@ -137,13 +139,19 @@ afs_UFSGetVolSlot(void)
                }
            }
        }
-       if (!bestVp)
-           osi_Panic("getvolslot none");
+       if (!bestVp) {
+           afs_warn("afs_UFSGetVolSlot: no vol slots available\n");
+           goto error;
+       }
        tv = bestVp;
+
+       oldLp = *bestLp;
        *bestLp = tv->next;
-       if (tv->name)
-           afs_osi_Free(tv->name, strlen(tv->name) + 1);
+
+       oldname = tv->name;
        tv->name = NULL;
+
+       oldvtix = tv->vtix;
        /* now write out volume structure to file */
        if (tv->vtix < 0) {
            tv->vtix = afs_volCounter++;
@@ -161,9 +169,12 @@ afs_UFSGetVolSlot(void)
                code =
                    afs_osi_Read(tfile, sizeof(struct fvolume) * tv->vtix,
                                 &staticFVolume, sizeof(struct fvolume));
-               if (code != sizeof(struct fvolume))
-                   osi_Panic("read volumeinfo");
                osi_UFSClose(tfile);
+               if (code != sizeof(struct fvolume)) {
+                   afs_warn("afs_UFSGetVolSlot: error %d reading volumeinfo\n",
+                            (int)code);
+                   goto error;
+               }
                afs_FVIndex = tv->vtix;
            }
        }
@@ -178,15 +189,41 @@ afs_UFSGetVolSlot(void)
        code =
            afs_osi_Write(tfile, sizeof(struct fvolume) * afs_FVIndex,
                          &staticFVolume, sizeof(struct fvolume));
-       if (code != sizeof(struct fvolume))
-           osi_Panic("write volumeinfo");
        osi_UFSClose(tfile);
+       if (code != sizeof(struct fvolume)) {
+           afs_warn("afs_UFSGetVolSlot: error %d writing volumeinfo\n",
+                    (int)code);
+           goto error;
+       }
+       if (oldname) {
+           afs_osi_Free(oldname, strlen(oldname) + 1);
+           oldname = NULL;
+       }
     } else {
        tv = afs_freeVolList;
        afs_freeVolList = tv->next;
     }
     return tv;
 
+ error:
+    if (tv) {
+       if (oldname) {
+           tv->name = oldname;
+           oldname = NULL;
+       }
+       if (oldvtix < 0) {
+           afs_volCounter--;
+           fvTable[i] = staticFVolume.next;
+       }
+       if (bestLp) {
+           *bestLp = oldLp;
+       }
+       tv->vtix = oldvtix;
+       /* we messed with staticFVolume, so make sure someone else
+        * doesn't think it's fine to use */
+       afs_FVIndex = -1;
+    }
+    return NULL;
 }                              /*afs_UFSGetVolSlot */
 
 
@@ -534,6 +571,10 @@ afs_SetupVolume(afs_int32 volid, char *aname, void *ve, struct cell *tcell,
        struct fvolume *tf = 0;
 
        tv = afs_GetVolSlot();
+       if (!tv) {
+           ReleaseWriteLock(&afs_xvolume);
+           return NULL;
+       }
        memset(tv, 0, sizeof(struct volume));
        tv->cell = tcell->cellNum;
        AFS_RWLOCK_INIT(&tv->lock, "volume lock");
@@ -799,22 +840,26 @@ afs_NewVolumeByName(char *aname, afs_int32 acell, int agood,
     else
        ve = (char *)tve;
     tv = afs_SetupVolume(0, aname, ve, tcell, agood, type, areq);
-    if ((agood == 3) && tv->backVol) {
+    if ((agood == 3) && tv && tv->backVol) {
        /*
         * This means that very soon we'll ask for the BK volume so
         * we'll prefetch it (well we did already.)
         */
        tv1 =
            afs_SetupVolume(tv->backVol, (char *)0, ve, tcell, 0, type, areq);
-       tv1->refCount--;
+       if (tv1) {
+           tv1->refCount--;
+       }
     }
-    if ((agood >= 2) && tv->roVol) {
+    if ((agood >= 2) && tv && tv->roVol) {
        /*
         * This means that very soon we'll ask for the RO volume so
         * we'll prefetch it (well we did already.)
         */
        tv1 = afs_SetupVolume(tv->roVol, NULL, ve, tcell, 0, type, areq);
-       tv1->refCount--;
+       if (tv1) {
+           tv1->refCount--;
+       }
     }
     osi_FreeLargeSpace(tbuffer);
     afs_PutCell(tcell, READ_LOCK);