Revision 475049809977bf3975d78f2d2fd992e19ce2d59e authored by Roel Kluin on 10 March 2009, 19:55:45 UTC, committed by Linus Torvalds on 10 March 2009, 22:55:10 UTC
get_nid_for_pfn() returns int
Presumably the (nid < 0) case has never happened.
We do know that it is happening on one system while creating a symlink for
a memory section so it should also happen on the same system if
unregister_mem_sect_under_nodes() were called to remove the same symlink.
The test was actually added in response to a problem with an earlier
version reported by Yasunori Goto where one or more of the leading pages
of a memory section on the 2nd node of one of his systems was
uninitialized because I believe they coincided with a memory hole.
That earlier version did not ignore uninitialized pages and determined
the nid by considering only the 1st page of each memory section. This
caused the symlink to the 1st memory section on the 2nd node to be
incorrectly created in /sys/devices/system/node/node0 instead of
/sys/devices/system/node/node1. The problem was fixed by adding the
test to skip over uninitialized pages.
I suspect we have not seen any reports of the non-removal
of a symlink due to the incorrect declaration of the nid
variable in unregister_mem_sect_under_nodes() because
- systems where a memory section could have an uninitialized
range of leading pages are probably rare.
- memory remove is probably not done very frequently on the
systems that are capable of demonstrating the problem.
- lingering symlink(s) that should have been removed may
have simply gone unnoticed.
[garyhade@us.ibm.com: wrote changelog]
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 1abaf33
ide-scan-pci.c
/*
* support for probing IDE PCI devices in the PCI bus order
*
* Copyright (c) 1998-2000 Andre Hedrick <andre@linux-ide.org>
* Copyright (c) 1995-1998 Mark Lord
*
* May be copied or modified under the terms of the GNU General Public License
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ide.h>
/*
* Module interfaces
*/
static int pre_init = 1; /* Before first ordered IDE scan */
static LIST_HEAD(ide_pci_drivers);
/*
* __ide_pci_register_driver - attach IDE driver
* @driver: pci driver
* @module: owner module of the driver
*
* Registers a driver with the IDE layer. The IDE layer arranges that
* boot time setup is done in the expected device order and then
* hands the controllers off to the core PCI code to do the rest of
* the work.
*
* Returns are the same as for pci_register_driver
*/
int __ide_pci_register_driver(struct pci_driver *driver, struct module *module,
const char *mod_name)
{
if (!pre_init)
return __pci_register_driver(driver, module, mod_name);
driver->driver.owner = module;
list_add_tail(&driver->node, &ide_pci_drivers);
return 0;
}
EXPORT_SYMBOL_GPL(__ide_pci_register_driver);
/**
* ide_scan_pcidev - find an IDE driver for a device
* @dev: PCI device to check
*
* Look for an IDE driver to handle the device we are considering.
* This is only used during boot up to get the ordering correct. After
* boot up the pci layer takes over the job.
*/
static int __init ide_scan_pcidev(struct pci_dev *dev)
{
struct list_head *l;
struct pci_driver *d;
list_for_each(l, &ide_pci_drivers) {
d = list_entry(l, struct pci_driver, node);
if (d->id_table) {
const struct pci_device_id *id =
pci_match_id(d->id_table, dev);
if (id != NULL && d->probe(dev, id) >= 0) {
dev->driver = d;
pci_dev_get(dev);
return 1;
}
}
}
return 0;
}
/**
* ide_scan_pcibus - perform the initial IDE driver scan
*
* Perform the initial bus rather than driver ordered scan of the
* PCI drivers. After this all IDE pci handling becomes standard
* module ordering not traditionally ordered.
*/
static int __init ide_scan_pcibus(void)
{
struct pci_dev *dev = NULL;
struct pci_driver *d;
struct list_head *l, *n;
pre_init = 0;
while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)))
ide_scan_pcidev(dev);
/*
* Hand the drivers over to the PCI layer now we
* are post init.
*/
list_for_each_safe(l, n, &ide_pci_drivers) {
list_del(l);
d = list_entry(l, struct pci_driver, node);
if (__pci_register_driver(d, d->driver.owner,
d->driver.mod_name))
printk(KERN_ERR "%s: failed to register %s driver\n",
__func__, d->driver.mod_name);
}
return 0;
}
module_init(ide_scan_pcibus);
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