On 06/14/2013 12:28 PM, Marek Skuczynski wrote:
>
>> Values passed to bread are: vol: 0, pxd: len: 1, addr1: 0, addr2: 0
>>
>> The p->header.flag is equal 0 after returning from bread().
>>
>>
>> Any idea how to handle this problem ?
>> It looks like the function needs to do a better job of sanity checking.
>>
>
> I guess that a pxdAddress couldn't be equal to zero.
> If this is the case, rXtree() should return MINOR_ERROR, as in the case
> when bread fails.
> Am I correct?
Something like this would probably fix it. A corrupt node may have
any kind of data, so just keeping it from infinitely recursing
would probably catch any problem where bread() doesn't fail.
Index: libfs/log_map.c
===================================================================
RCS file: /cvsroot/jfs/jfsutils/libfs/log_map.c,v
retrieving revision 1.21
diff -u -p -r1.21 log_map.c
--- libfs/log_map.c 11 May 2012 13:02:04 -0000 1.21
+++ libfs/log_map.c 14 Jun 2013 21:37:56 -0000
@@ -1682,6 +1682,7 @@ int rXtree(int32_t vol, /* index in vop
xtpage_t *p;
caddr_t buf_ptr;
pxd_t pxd;
+ int max_depth;
/* start from root in dinode */
p = (xtpage_t *) & dp->di_btroot;
@@ -1696,6 +1697,13 @@ int rXtree(int32_t vol, /* index in vop
/*
* traverse down leftmost child node to the leftmost leaf of xtree
*/
+
+ /*
+ * Overkill, but I don't know the practical limit for the xtree
+ * depth
+ */
+ max_depth = 100;
+
do {
/* read in the leftmost child page */
if (bread(vol, pxd, (void **) &buf_ptr, PB_READ) != 0) {
@@ -1711,7 +1719,12 @@ int rXtree(int32_t vol, /* index in vop
PXDlength(&pxd, vopen[vol].lbperpage);
PXDaddress(&pxd, addressXAD(&p->xad[XTENTRYSTART]));
}
- } while (!(p->header.flag & BT_LEAF));
+ } while (--max_depth);
+
+ if (!(p->header.flag & BT_LEAF)) {
+ fsck_send_msg(lrdo_RXTREADLFFAIL);
+ return(MINOR_ERROR);
+ }
out:
*first_leaf = p;
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