| Message ID | 4DC86BF1.6050302@kernel.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Mon, May 09, 2011 at 03:34:25PM -0700, Yinghai Lu wrote: > [PATCH -v2 1/3] pci: add rescan to /sys/.../pci_bus/.../ > > After remove the device from /sys, we have to rescan all or > find out the bridge and access /sys../device/rescan there. > > this patch add /sys/.../pci_bus/.../rescan. So user can rescan more easy. > that is more clean and easy to understand. > > like after remove 0000:c4:00.0, you can rescan 0000:c4 directly. > > -v2: According to Jesse, use function instead of exposing attr, so could hide > #ifdef in header file. > also add code to remove rescan file in remove path. > > Signed-off-by: Yinghai Lu <yinghai@kernel.org> > > --- > Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++ > drivers/pci/bus.c | 4 ++++ > drivers/pci/pci-sysfs.c | 31 +++++++++++++++++++++++++++++++ > drivers/pci/pci.h | 10 ++++++++++ > drivers/pci/probe.c | 5 +++++ > drivers/pci/remove.c | 1 + > 6 files changed, 60 insertions(+) > > Index: linux-2.6/drivers/pci/pci-sysfs.c > =================================================================== > --- linux-2.6.orig/drivers/pci/pci-sysfs.c > +++ linux-2.6/drivers/pci/pci-sysfs.c > @@ -318,6 +318,37 @@ remove_store(struct device *dev, struct > count = ret; > return count; > } > + > +static ssize_t > +dev_bus_rescan_store(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + unsigned long val; > + struct pci_bus *bus = to_pci_bus(dev); > + > + if (strict_strtoul(buf, 0, &val) < 0) > + return -EINVAL; > + > + if (val) { > + mutex_lock(&pci_remove_rescan_mutex); > + pci_rescan_bus(bus); > + mutex_unlock(&pci_remove_rescan_mutex); > + } > + return count; > +} > + > +DEVICE_ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_bus_rescan_store); > + > +int pci_bus_create_rescan_file(struct pci_bus *bus) > +{ > + return device_create_file(&bus->dev, &dev_attr_rescan); > +} > + > +void pci_bus_remove_rescan_file(struct pci_bus *bus) > +{ > + device_remove_file(&bus->dev, &dev_attr_rescan); > +} No, please make it part of the attribute for this device type, otherwise you will race with userspace trying to create the file after it has been announced that the device is present. > + > #endif > > struct device_attribute pci_dev_attrs[] = { > Index: linux-2.6/drivers/pci/bus.c > =================================================================== > --- linux-2.6.orig/drivers/pci/bus.c > +++ linux-2.6/drivers/pci/bus.c > @@ -163,6 +163,10 @@ int pci_bus_add_child(struct pci_bus *bu > > bus->is_added = 1; > > + retval = pci_bus_create_rescan_file(bus); > + if (retval) > + return retval; > + See, you just raced. > retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity); > if (retval) > return retval; Look this file, and the one after it are also incorrect, don't continue to add broken code to the kernel please. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-2.6/drivers/pci/pci-sysfs.c =================================================================== --- linux-2.6.orig/drivers/pci/pci-sysfs.c +++ linux-2.6/drivers/pci/pci-sysfs.c @@ -318,6 +318,37 @@ remove_store(struct device *dev, struct count = ret; return count; } + +static ssize_t +dev_bus_rescan_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned long val; + struct pci_bus *bus = to_pci_bus(dev); + + if (strict_strtoul(buf, 0, &val) < 0) + return -EINVAL; + + if (val) { + mutex_lock(&pci_remove_rescan_mutex); + pci_rescan_bus(bus); + mutex_unlock(&pci_remove_rescan_mutex); + } + return count; +} + +DEVICE_ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_bus_rescan_store); + +int pci_bus_create_rescan_file(struct pci_bus *bus) +{ + return device_create_file(&bus->dev, &dev_attr_rescan); +} + +void pci_bus_remove_rescan_file(struct pci_bus *bus) +{ + device_remove_file(&bus->dev, &dev_attr_rescan); +} + #endif struct device_attribute pci_dev_attrs[] = { Index: linux-2.6/drivers/pci/bus.c =================================================================== --- linux-2.6.orig/drivers/pci/bus.c +++ linux-2.6/drivers/pci/bus.c @@ -163,6 +163,10 @@ int pci_bus_add_child(struct pci_bus *bu bus->is_added = 1; + retval = pci_bus_create_rescan_file(bus); + if (retval) + return retval; + retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity); if (retval) return retval; Index: linux-2.6/drivers/pci/pci.h =================================================================== --- linux-2.6.orig/drivers/pci/pci.h +++ linux-2.6/drivers/pci/pci.h @@ -159,9 +159,19 @@ extern struct device_attribute pci_dev_a extern struct device_attribute dev_attr_cpuaffinity; extern struct device_attribute dev_attr_cpulistaffinity; #ifdef CONFIG_HOTPLUG +int pci_bus_create_rescan_file(struct pci_bus *bus); +void pci_bus_remove_rescan_file(struct pci_bus *bus); +extern struct device_attribute dev_attr_rescan; extern struct bus_attribute pci_bus_attrs[]; #else #define pci_bus_attrs NULL +static inline int pci_bus_create_rescan_file(struct device *dev) +{ + return 0; +} +static inline void pci_bus_remove_rescan_file(struct device *dev) +{ +} #endif Index: linux-2.6/drivers/pci/probe.c =================================================================== --- linux-2.6.orig/drivers/pci/probe.c +++ linux-2.6/drivers/pci/probe.c @@ -1471,6 +1471,9 @@ struct pci_bus * pci_create_bus(struct d error = device_create_file(&b->dev, &dev_attr_cpuaffinity); if (error) goto dev_create_file_err; + error = pci_bus_create_rescan_file(b); + if (error) + goto dev_create_bus_rescan_err; /* Create legacy_io and legacy_mem files for this bus */ pci_create_legacy_files(b); @@ -1481,6 +1484,8 @@ struct pci_bus * pci_create_bus(struct d return b; +dev_create_bus_rescan_err: + device_remove_file(&b->dev, &dev_attr_cpuaffinity); dev_create_file_err: device_unregister(&b->dev); class_dev_reg_err: Index: linux-2.6/Documentation/ABI/testing/sysfs-bus-pci =================================================================== --- linux-2.6.orig/Documentation/ABI/testing/sysfs-bus-pci +++ linux-2.6/Documentation/ABI/testing/sysfs-bus-pci @@ -74,6 +74,15 @@ Description: hot-remove the PCI device and any of its children. Depends on CONFIG_HOTPLUG. +What: /sys/bus/pci/devices/.../pci_bus/.../rescan +Date: May 2011 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + force a rescan of the bus and all child buses, + and re-discover devices removed earlier from this + part of the device tree. Depends on CONFIG_HOTPLUG. + What: /sys/bus/pci/devices/.../rescan Date: January 2009 Contact: Linux PCI developers <linux-pci@vger.kernel.org> Index: linux-2.6/drivers/pci/remove.c =================================================================== --- linux-2.6.orig/drivers/pci/remove.c +++ linux-2.6/drivers/pci/remove.c @@ -73,6 +73,7 @@ void pci_remove_bus(struct pci_bus *pci_ return; pci_remove_legacy_files(pci_bus); + pci_bus_remove_rescan_file(pci_bus); device_remove_file(&pci_bus->dev, &dev_attr_cpuaffinity); device_remove_file(&pci_bus->dev, &dev_attr_cpulistaffinity); device_unregister(&pci_bus->dev);
[PATCH -v2 1/3] pci: add rescan to /sys/.../pci_bus/.../ After remove the device from /sys, we have to rescan all or find out the bridge and access /sys../device/rescan there. this patch add /sys/.../pci_bus/.../rescan. So user can rescan more easy. that is more clean and easy to understand. like after remove 0000:c4:00.0, you can rescan 0000:c4 directly. -v2: According to Jesse, use function instead of exposing attr, so could hide #ifdef in header file. also add code to remove rescan file in remove path. Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++ drivers/pci/bus.c | 4 ++++ drivers/pci/pci-sysfs.c | 31 +++++++++++++++++++++++++++++++ drivers/pci/pci.h | 10 ++++++++++ drivers/pci/probe.c | 5 +++++ drivers/pci/remove.c | 1 + 6 files changed, 60 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html