On Monday, October 08, 2001 01:05:48 PM -0400 Ed Tomlinson <tomlins@CAM.ORG> wrote:
> On October 8, 2001 12:54 pm, Chris Mason wrote:
>> On Monday, October 08, 2001 11:53:46 AM -0400 Ed Tomlinson
>>
>> <tomlins@CAM.ORG> wrote:
>> > Hi Chris,
>> >
>> > To summerize, with 2.4.11-pre5 and lvm-1.01-rc4 + your test vfslocking
>> > patch for 2.4.11-pre I, unlike you, was able to make snapshots and
>> > reiserfsck them without problems. Then I tried a debench 50 run and got
>> > an oops.
>>
>> Confirmed, similar oops here. Do you get this with rc4 in 2.4.10?
>
> Funny you should ask... Guess what was runing when this email arrived? The
> answer is that with 2.4.10 + lvm 1.01-rc4 the snapshot deactivates correctly -
> I do not see an oops.
Ok, that first patch won't quite fix it, as we can still oops
in lvm_snapshot_COW. This one works better for me:
--- 0.21/drivers/md/lvm.c Sun, 07 Oct 2001 22:15:54 -0400
+++ 0.21(w)/drivers/md/lvm.c Mon, 08 Oct 2001 15:54:42 -0400
@@ -1142,7 +1142,8 @@
/* we must redo lvm_snapshot_remap_block in order to avoid a
race condition in the gap where no lock was held */
- if (!lvm_snapshot_remap_block(&rdev, &rsector, pe_start, lv) &&
+ if (lv->lv_block_exception &&
+ !lvm_snapshot_remap_block(&rdev, &rsector, pe_start, lv) &&
!lvm_snapshot_COW(rdev, rsector, pe_start, rsector, vg, lv))
lvm_write_COW_table_block(vg, lv);
@@ -1151,11 +1152,12 @@
static inline void _remap_snapshot(kdev_t rdev, ulong rsector,
ulong pe_start, lv_t *lv, vg_t *vg) {
- int r;
+ int r = 0;
/* check to see if this chunk is already in the snapshot */
down_read(&lv->lv_lock);
- r = lvm_snapshot_remap_block(&rdev, &rsector, pe_start, lv);
+ if (lv->lv_block_exception)
+ r = lvm_snapshot_remap_block(&rdev, &rsector, pe_start, lv);
up_read(&lv->lv_lock);
if (!r)
Index: 0.21/drivers/md/lvm-snap.c
--- 0.21/drivers/md/lvm-snap.c Sat, 06 Oct 2001 00:07:22 -0400 root (linux/i/c/38_lvm-snap.c 1.1.2.1.2.1 644)
+++ 0.21(w)/drivers/md/lvm-snap.c Mon, 08 Oct 2001 15:13:10 -0400 root (linux/i/c/38_lvm-snap.c 1.1.2.1.2.1 644)
@@ -140,6 +140,8 @@
unsigned long mask = lv->lv_snapshot_hash_mask;
int chunk_size = lv->lv_chunk_size;
+ if (!hash_table)
+ BUG() ;
hash_table = &hash_table[hashfn(org_dev, org_start, mask, chunk_size)];
list_add(&exception->hash, hash_table);
}
