Hello,
I'm trying to get LVM 0.8 on top of Ingo's 0.9 RAID patches with 2.2.16
(this appears to be the same issue as applying LVM on top of a RedHat
kernel, which came up on the LVM list a few times, but was never answered).
There is a problem with applying the LVM patch to ll_rw_block.c, which
I think I have fixed, but I'm not very certain of the RAID code, so I'd
like some comments on these changes:
2.2.16+LVM looks like :::: drivers/block/ll_rw_blk.c ::::::::::
============================================================================
#ifdef CONFIG_BLK_DEV_MD
if (major==MD_MAJOR &&
/* changed v to allow LVM to remap */
md_map (MINOR(bh[i]->b_rdev), &bh[i]->b_rdev,
&bh[i]->b_rsector, bh[i]->b_size >> 9)) {
printk (KERN_ERR
"Bad md_map in ll_rw_block\n");
goto sorry;
}
#endif
[[[[snip]]]]
/* changed v to allow LVM to remap */
if (MAJOR(bh[i]->b_rdev) == MD_MAJOR) {
/* changed for LVM to remap v */
md_make_request(MINOR (bh[i]->b_rdev), rw, bh[i]);
continue;
}
============================================================================
2.2.16+RAID0.9+LVM looks like this :::: drivers/block/ll_rw_blk.c ::::::::::
============================================================================
#ifdef CONFIG_BLK_DEV_MD
if (major==MD_MAJOR &&
- md_map (bh[i]->b_dev, &bh[i]->b_rdev,
+ /* changed v to allow LVM to remap */
+ md_map (bh[i]->b_rdev, &bh[i]->b_rdev,
&bh[i]->b_rsector, bh[i]->b_size >> 9)) {
printk (KERN_ERR
"Bad md_map in ll_rw_block\n");
goto sorry;
}
#endif
[[[[snip]]]]
- if (MAJOR(bh[i]->b_dev) == MD_MAJOR) {
+ /* changed v to allow LVM to remap */
+ if (MAJOR(bh[i]->b_rdev) == MD_MAJOR) {
md_make_request(bh[i], rw);
continue;
}
:::::::: in drivers/block/md.c ::::::::::
static int md_make_request()
{
- mddev_t *mddev = kdev_to_mddev(bh->b_dev);
+ /* changed v to allow LVM to remap */
+ mddev_t *mddev = kdev_to_mddev(bh->b_rdev);
============================================================================
The md_make_request() uses the same mddev (i.e. uses b_rdev instead of b_dev)
in 2.4-test1, so I think this is correct. I'm not certain of md_map()
because it no longer exists in 2.4. The change looks like it would work
(going from old to new RAID), but I have no idea as I've never set up RAID
before so there could be any number of problems...
Cheers, Andreas
PS - I'm not on the linux-raid list, so please CC any replies to me or
[EMAIL PROTECTED]
--
Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto,
\ would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert
