lvm in 2.5.1

andersg@0x63.nu
Thu, 27 Dec 2001 09:43:04 +0100


Hi Jens and other kernelhackers,

I'm now running 2.5.1 with lvm. The following patch makes some minor changes
for bio-support and removes allocation of a lv_t on the stack, which made
the stack overflow and gave me something to spend my last 24 hours
debugging.

I dont garantee that this will trash your disks, but probably it will.
It works for me, running my /var and /home on lvm.

Merry Christmas and A Happy New Year

//anders/g

diff -ru linux-2.5.1-vanilj/drivers/md/lvm.c linux-2.5.1/drivers/md/lvm.c
--- linux-2.5.1-vanilj/drivers/md/lvm.c Thu Dec 27 08:28:39 2001
+++ linux-2.5.1/drivers/md/lvm.c Thu Dec 27 08:03:10 2001
@@ -179,6 +179,9 @@
* (Jens Axboe)
* - Defer writes to an extent that is being moved [JT + AD]
* 28/05/2001 - implemented missing BLKSSZGET ioctl [AD]
+ * 28/12/2001 - buffer_head -> bio
+ * removed huge allocation of a lv_t on stack
+ * (Anders Gusafsson)
*
*/

@@ -731,7 +734,7 @@

case PV_FLUSH:
/* physical volume buffer flush/invalidate */
- return lvm_do_pv_flush(arg);
+ return lvm_do_pv_flush(arg);


default:
@@ -1043,7 +1046,7 @@

memset(&bio,0,sizeof(bio));
bio.bi_dev = inode->i_rdev;
- bio.bi_io_vec.bv_len = lvm_get_blksize(bio.bi_dev);
+ bio.bi_size = lvm_get_blksize(bio.bi_dev); /* NEEDED by bio_sectors */
bio.bi_sector = block * bio_sectors(&bio);
bio.bi_rw = READ;
if ((err=lvm_map(&bio)) < 0) {
@@ -1119,18 +1122,18 @@
return 0;
}

-static int lvm_map(struct bio *bh)
+static int lvm_map(struct bio *bi)
{
- int minor = MINOR(bh->bi_dev);
+ int minor = MINOR(bi->bi_dev);
ulong index;
ulong pe_start;
- ulong size = bio_sectors(bh);
- ulong rsector_org = bh->bi_sector;
+ ulong size = bio_sectors(bi);
+ ulong rsector_org = bi->bi_sector;
ulong rsector_map;
kdev_t rdev_map;
vg_t *vg_this = vg[VG_BLK(minor)];
lv_t *lv = vg_this->lv[LV_BLK(minor)];
- int rw = bio_data_dir(bh);
+ int rw = bio_data_dir(bi);


down_read(&lv->lv_lock);
@@ -1151,7 +1154,7 @@

P_MAP("%s - lvm_map minor: %d *rdev: %s *rsector: %lu size:%lu\n",
lvm_name, minor,
- kdevname(bh->bi_dev),
+ kdevname(bi->bi_dev),
rsector_org, size);

if (rsector_org + size > lv->lv_size) {
@@ -1205,7 +1208,7 @@
* we need to queue this request, because this is in the fast path.
*/
if (rw == WRITE || rw == WRITEA) {
- if(_defer_extent(bh, rw, rdev_map,
+ if(_defer_extent(bi, rw, rdev_map,
rsector_map, vg_this->pe_size)) {

up_read(&lv->lv_lock);
@@ -1246,13 +1249,13 @@
}

out:
- bh->bi_dev = rdev_map;
- bh->bi_sector = rsector_map;
+ bi->bi_dev = rdev_map;
+ bi->bi_sector = rsector_map;
up_read(&lv->lv_lock);
return 1;

bad:
- bio_io_error(bh);
+ bio_io_error(bi);
up_read(&lv->lv_lock);
return -1;
} /* lvm_map() */
@@ -1436,9 +1439,9 @@
{
int ret = 0;
ulong l, ls = 0, p, size;
- lv_t lv;
vg_t *vg_ptr;
lv_t **snap_lv_ptr;
+ lv_t *tmplv;

if ((vg_ptr = kmalloc(sizeof(vg_t),GFP_KERNEL)) == NULL) {
printk(KERN_CRIT
@@ -1446,6 +1449,7 @@
lvm_name, __LINE__);
return -ENOMEM;
}
+
/* get the volume group structure */
if (copy_from_user(vg_ptr, arg, sizeof(vg_t)) != 0) {
P_IOCTL("lvm_do_vg_create ERROR: copy VG ptr %p (%d bytes)\n",
@@ -1454,6 +1458,8 @@
return -EFAULT;
}

+
+
/* VG_CREATE now uses minor number in VG structure */
if (minor == -1) minor = vg_ptr->vg_number;

@@ -1513,19 +1519,27 @@
}
memset(snap_lv_ptr, 0, size);

+ if ((tmplv = kmalloc(sizeof(lv_t),GFP_KERNEL)) == NULL) {
+ printk(KERN_CRIT
+ "%s -- VG_CREATE: kmalloc error LV at line %d\n",
+ lvm_name, __LINE__);
+ return -ENOMEM;
+ }
+
/* get the logical volume structures */
vg_ptr->lv_cur = 0;
for (l = 0; l < vg_ptr->lv_max; l++) {
lv_t *lvp;
+
/* user space address */
if ((lvp = vg_ptr->lv[l]) != NULL) {
- if (copy_from_user(&lv, lvp, sizeof(lv_t)) != 0) {
+ if (copy_from_user(tmplv, lvp, sizeof(lv_t)) != 0) {
P_IOCTL("ERROR: copying LV ptr %p (%d bytes)\n",
lvp, sizeof(lv_t));
lvm_do_vg_remove(minor);
return -EFAULT;
}
- if ( lv.lv_access & LV_SNAPSHOT) {
+ if ( tmplv->lv_access & LV_SNAPSHOT) {
snap_lv_ptr[ls] = lvp;
vg_ptr->lv[l] = NULL;
ls++;
@@ -1533,7 +1547,7 @@
}
vg_ptr->lv[l] = NULL;
/* only create original logical volumes for now */
- if (lvm_do_lv_create(minor, lv.lv_name, &lv) != 0) {
+ if (lvm_do_lv_create(minor, tmplv->lv_name, tmplv) != 0) {
lvm_do_vg_remove(minor);
return -EFAULT;
}
@@ -1544,18 +1558,18 @@
in place during first path above */
for (l = 0; l < ls; l++) {
lv_t *lvp = snap_lv_ptr[l];
- if (copy_from_user(&lv, lvp, sizeof(lv_t)) != 0) {
+ if (copy_from_user(tmplv, lvp, sizeof(lv_t)) != 0) {
lvm_do_vg_remove(minor);
return -EFAULT;
}
- if (lvm_do_lv_create(minor, lv.lv_name, &lv) != 0) {
+ if (lvm_do_lv_create(minor, tmplv->lv_name, tmplv) != 0) {
lvm_do_vg_remove(minor);
return -EFAULT;
}
}

vfree(snap_lv_ptr);
-
+ kfree(tmplv);
vg_count++;


@@ -1566,7 +1580,6 @@

return 0;
} /* lvm_do_vg_create() */
-

/*
* character device support function VGDA extend
-
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