Messages in this thread | | | Subject | Re: [linux-lvm] *** ANNOUNCEMENT *** LVM 0.9.1 Beta 7 available at www.sistina.com | From | "Martin K. Petersen" <> | Date | 10 Apr 2001 16:01:04 -0400 |
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>>>>> "Heinz" == Heinz J Mauelshagen <Mauelshagen@sistina.com> writes:
Heinz> a tarball of the Linux Logical Volume Manager 0.9.1 Beta 7 is Heinz> available now at
The following code is baaaad, m'kay...
[...]
down(&_pe_lock); if((pe_lock_req.lock == LOCK_PE) && (rdev_map == pe_lock_req.data.pv_dev) && (rsector_map >= pe_lock_req.data.pv_offset) && (rsector_map < (pe_lock_req.data.pv_offset + vg_this->pe_size)) && ((rw == WRITE) || (rw == WRITEA))) { /* defer this bh until the PE has moved */ if(((int) bh) & 0x3) { printk(KERN_ERR "%s -- bh uses low 2 bits of pointer\n", lvm_name); up(&_pe_lock); goto bad; }
bh->b_reqnext = _pe_requests; _pe_requests = (struct buffer_head *) ((int) bh | rw); up(&_pe_lock); up(&lv->lv_snapshot_sem); return 0; } up(&_pe_lock);
[...]
/* handle all deferred io for this PE */ while(q) { struct buffer_head *d_bh = (struct buffer_head *) (q & ~0x3); int rw = q & 0x3; q = (uint) d_bh->b_reqnext; /* resubmit this buffer head */ d_bh->b_reqnext = 0; generic_make_request(rw, d_bh); }
Not only is this an evil hack from hell, I don't understand why you go through such a huge effort of storing rw in the pointer. Afaict, the only valid value is WRITE. And WRITEA is #defined to WRITE in lvm.c.
-- Martin K. Petersen, Principal Linux Consultant, Linuxcare, Inc. mkp@linuxcare.com, http://www.linuxcare.com/ SGI XFS for Linux Developer, http://oss.sgi.com/projects/xfs/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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