A problem in LVM1 kernel code lvm.c::lvm_do_vg_create()

"more.zeng" <mzeng@plasmon.cn> · Mon, 25 Sep 2006 18:12:12 +0800

Dear LVM guys,

I find an issue in the LVM1 kernel code for function
lvm.c::lvm_do_vg_create():

In the original code, the vg_count will be increased
only when this function is executed successfully. But I think the vg_count
should be increased after the variable vg[VG_CHR(minor)] is updated. Given the
reason that after the variable vg[VG_CHR(minor)] is updated, for any failure
case, lvm_do_vg_create() will always call lvm_do_vg_remove() that will decrease
the vg_count. So the vg_count should be increased first before any call for
lvm_do_vg_remove().

This issue did exist for our product for our LV sometimes will fail to
start (corrupt snapshot). Please give me the confirmation that the above is
really an issue and the following diff can resolve this issue (from the latest
LVM1 CVS code), thanks.

Best regards,

More

Index: lvm.c

===================================================================

RCS file: /cvs/lvm/LVM/kernel/lvm.c,v

retrieving revision 1.81

diff -c -r1.81 lvm.c

*** lvm.c       5 Mar 2003 11:37:16 -0000       1.81

--- lvm.c       25 Sep 2006 09:57:26 -0000

***************

*** 1802,1807 ****

--- 1802,1809 ----

        vg[VG_CHR(minor)] = vg_ptr;

+       vg_count++;

+ 

        /* get the physical volume structures */

        vg_ptr->pv_act = vg_ptr->pv_cur = 0;

        for (p = 0; p < vg_ptr->pv_max; p++) {

***************

*** 1870,1877 ****

        vfree(snap_lv_ptr);

-       vg_count++;

- 

        MOD_INC_USE_COUNT;

--- 1872,1877 ----

_______________________________________________
linux-lvm mailing list
linux-lvm@redhat.com
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/