Re: [PATCH 2.6.20] kobject net ifindex + rename
On Thu, Mar 01, 2007 at 11:27:34AM -0800, Jean Tourrilhes wrote: > On Thu, Mar 01, 2007 at 08:42:09AM +0100, Jarek Poplawski wrote: > > On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote: > > > > > + > > > > > + if ((size <= 0) || (i >= num_envp)) > > > > > > > > Btw.: > > > > 1. if size == 10 and snprintf returns 9 (without NULL) > > > >then n == 10 (with NULL), so isn't it enough (here and above): > > > > > > > > if ((size < 0) || (i >= num_envp)) > > > > > > I just cut'n'pasted the code a few line above. If the original > > > code is incorrect, it need fixing. And it will need fixing in probably > > > a lot of places. > > > > I think you're kind of responsible for your part, at least. > > I personally don't go fixing stuff without having a full > undersunding of the context and why it was done this way. To me it > look this test was intentionally done this way, so there may be > something I don't know about. I guess I would need to double check > more closely what weid calculation the caller does with the buffer > size. > That's why I would prefer a separate patch about those issues > that give the opportunity for the stakeholder to really talk about > this, rather than slipping it under the carpet. Sure, but adding a functionality is a kind of fixing, too. I don't blame you - I simply think that the patch like yours is an occasion for people reading this list to look at the adjacent code too. So I wrote about my doubts here hoping somebody with a better knowledge of this place could verify them. > In the worse case, this is not a bug, this just means that we > may not use the last char of the buffer. Sorry, I can't agree with this. > > > > > 2. shouldn't there be (here and above): > > > > > > > > envp[--i] = NULL; > > > > > > > > > > No, envp is local, so who cares. > > > > But envp[i] isn't (at least here). So, I guess, a caller > > of this function could care. > > Check the full source code of the caller, and you will see > that the caller does not care (and it's local to the caller). I can't agree with this, too. There is no reason to leave a bad pointer there - you need to analyze more than one caller to verify this now, and any changes in the future are endangered, too. > > > > > > + if ((size <= 0) || (i >= num_envp)) > > > > > + return -ENOMEM; > > > > And one more thing (not necessarily for you): > > ENOBUFS is probably more adequate here. > > This error should never happen. If it happens, the caller need > to be fixed. Yes, but an error handling should be correct or removed, if unnecessary. ... > Note that there are various other things that are puzzling in > this function. The internal object name and the symlinks are changed > even if the kcore rename returns an error. That does not seem right. > But, this is separate from this patch... So, I hope somebody will help to make this code perfect! Best regards, Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Thu, Mar 01, 2007 at 11:27:34AM -0800, Jean Tourrilhes wrote: On Thu, Mar 01, 2007 at 08:42:09AM +0100, Jarek Poplawski wrote: On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote: + + if ((size = 0) || (i = num_envp)) Btw.: 1. if size == 10 and snprintf returns 9 (without NULL) then n == 10 (with NULL), so isn't it enough (here and above): if ((size 0) || (i = num_envp)) I just cut'n'pasted the code a few line above. If the original code is incorrect, it need fixing. And it will need fixing in probably a lot of places. I think you're kind of responsible for your part, at least. I personally don't go fixing stuff without having a full undersunding of the context and why it was done this way. To me it look this test was intentionally done this way, so there may be something I don't know about. I guess I would need to double check more closely what weid calculation the caller does with the buffer size. That's why I would prefer a separate patch about those issues that give the opportunity for the stakeholder to really talk about this, rather than slipping it under the carpet. Sure, but adding a functionality is a kind of fixing, too. I don't blame you - I simply think that the patch like yours is an occasion for people reading this list to look at the adjacent code too. So I wrote about my doubts here hoping somebody with a better knowledge of this place could verify them. In the worse case, this is not a bug, this just means that we may not use the last char of the buffer. Sorry, I can't agree with this. 2. shouldn't there be (here and above): envp[--i] = NULL; No, envp is local, so who cares. But envp[i] isn't (at least here). So, I guess, a caller of this function could care. Check the full source code of the caller, and you will see that the caller does not care (and it's local to the caller). I can't agree with this, too. There is no reason to leave a bad pointer there - you need to analyze more than one caller to verify this now, and any changes in the future are endangered, too. + if ((size = 0) || (i = num_envp)) + return -ENOMEM; And one more thing (not necessarily for you): ENOBUFS is probably more adequate here. This error should never happen. If it happens, the caller need to be fixed. Yes, but an error handling should be correct or removed, if unnecessary. ... Note that there are various other things that are puzzling in this function. The internal object name and the symlinks are changed even if the kcore rename returns an error. That does not seem right. But, this is separate from this patch... So, I hope somebody will help to make this code perfect! Best regards, Jarek P. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Thu, Mar 01, 2007 at 08:42:09AM +0100, Jarek Poplawski wrote: > On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote: > > > > + > > > > + if ((size <= 0) || (i >= num_envp)) > > > > > > Btw.: > > > 1. if size == 10 and snprintf returns 9 (without NULL) > > >then n == 10 (with NULL), so isn't it enough (here and above): > > > > > > if ((size < 0) || (i >= num_envp)) > > > > I just cut'n'pasted the code a few line above. If the original > > code is incorrect, it need fixing. And it will need fixing in probably > > a lot of places. > > I think you're kind of responsible for your part, at least. I personally don't go fixing stuff without having a full undersunding of the context and why it was done this way. To me it look this test was intentionally done this way, so there may be something I don't know about. I guess I would need to double check more closely what weid calculation the caller does with the buffer size. That's why I would prefer a separate patch about those issues that give the opportunity for the stakeholder to really talk about this, rather than slipping it under the carpet. In the worse case, this is not a bug, this just means that we may not use the last char of the buffer. > > > 2. shouldn't there be (here and above): > > > > > > envp[--i] = NULL; > > > > > > > No, envp is local, so who cares. > > But envp[i] isn't (at least here). So, I guess, a caller > of this function could care. Check the full source code of the caller, and you will see that the caller does not care (and it's local to the caller). > > > > + if ((size <= 0) || (i >= num_envp)) > > > > + return -ENOMEM; > > And one more thing (not necessarily for you): > ENOBUFS is probably more adequate here. This error should never happen. If it happens, the caller need to be fixed. > Cheers, > Jarek P. Note that there are various other things that are puzzling in this function. The internal object name and the symlinks are changed even if the kcore rename returns an error. That does not seem right. But, this is separate from this patch... Have fun... Jean - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Thu, Mar 01, 2007 at 08:42:09AM +0100, Jarek Poplawski wrote: On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote: + + if ((size = 0) || (i = num_envp)) Btw.: 1. if size == 10 and snprintf returns 9 (without NULL) then n == 10 (with NULL), so isn't it enough (here and above): if ((size 0) || (i = num_envp)) I just cut'n'pasted the code a few line above. If the original code is incorrect, it need fixing. And it will need fixing in probably a lot of places. I think you're kind of responsible for your part, at least. I personally don't go fixing stuff without having a full undersunding of the context and why it was done this way. To me it look this test was intentionally done this way, so there may be something I don't know about. I guess I would need to double check more closely what weid calculation the caller does with the buffer size. That's why I would prefer a separate patch about those issues that give the opportunity for the stakeholder to really talk about this, rather than slipping it under the carpet. In the worse case, this is not a bug, this just means that we may not use the last char of the buffer. 2. shouldn't there be (here and above): envp[--i] = NULL; No, envp is local, so who cares. But envp[i] isn't (at least here). So, I guess, a caller of this function could care. Check the full source code of the caller, and you will see that the caller does not care (and it's local to the caller). + if ((size = 0) || (i = num_envp)) + return -ENOMEM; And one more thing (not necessarily for you): ENOBUFS is probably more adequate here. This error should never happen. If it happens, the caller need to be fixed. Cheers, Jarek P. Note that there are various other things that are puzzling in this function. The internal object name and the symlinks are changed even if the kcore rename returns an error. That does not seem right. But, this is separate from this patch... Have fun... Jean - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote: > On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote: > > On 28-02-2007 02:27, Jean Tourrilhes wrote: > > > Hi all, > > ... > > > Patch for 2.6.20 is attached. The patch was tested on a system > > > running the hotplug scripts, and on another system running udev. > > > > > > Have fun... > > > > > > Jean > > > > > > Signed-off-by: Jean Tourrilhes <[EMAIL PROTECTED]> > > > > > > - > > ... > > > diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c > > > --- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800 > > > +++ linux/net/core/net-sysfs.c2007-02-27 15:06:49.0 -0800 > > > @@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de > > > if ((size <= 0) || (i >= num_envp)) > > > return -ENOMEM; > > > > > > + /* pass ifindex to uevent. > > > + * ifindex is useful as it won't change (interface name may change) > > > + * and is what RtNetlink uses natively. */ > > > + envp[i++] = buf; > > > + n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1; > > > + buf += n; > > > + size -= n; > > > + > > > + if ((size <= 0) || (i >= num_envp)) > > > > Btw.: > > 1. if size == 10 and snprintf returns 9 (without NULL) > >then n == 10 (with NULL), so isn't it enough (here and above): > > > > if ((size < 0) || (i >= num_envp)) > > I just cut'n'pasted the code a few line above. If the original > code is incorrect, it need fixing. And it will need fixing in probably > a lot of places. I think you're kind of responsible for your part, at least. > > > 2. shouldn't there be (here and above): > > > > envp[--i] = NULL; > > > > No, envp is local, so who cares. But envp[i] isn't (at least here). So, I guess, a caller of this function could care. > > > + if ((size <= 0) || (i >= num_envp)) > > > + return -ENOMEM; And one more thing (not necessarily for you): ENOBUFS is probably more adequate here. Cheers, Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, 2007-02-28 at 16:51 -0800, Jean Tourrilhes wrote: > I would prefer to fix the comment when this change actually > happens. I prefer comments to refer to the current reality, rather > than past/future situation. Uh, no. device_rename is perfectly fine, even other people may use it in the future. > When you introduce wireless renaming, you > will need to verify the whole chain anyway, so you might as well fix > the comment while merging wireless renaming. No again, device_rename is perfectly fine API, I shouldn't have to look at it's internals to see if it's broken in my use case. Even if it's only a broken comment. I'm not going to respin your patches though, if this doesn't make it in I don't care. johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Thu, Mar 01, 2007 at 01:37:46AM +0100, Johannes Berg wrote: > On Wed, 2007-02-28 at 16:26 -0800, Jean Tourrilhes wrote: > > > + /* This function is only used for network interface. > > +* Some hotplug package track interfaces by their name and > > +* therefore want to know when the name is changed by the user. */ > > Right now, that's true, but wireless is going to start using > device_rename pretty soon as well. Could you rephrase this comment? > > johannes I would prefer to fix the comment when this change actually happens. I prefer comments to refer to the current reality, rather than past/future situation. When you introduce wireless renaming, you will need to verify the whole chain anyway, so you might as well fix the comment while merging wireless renaming. Note also that my comment is technically correct. I did not say 'netdev' but the more generic term 'network interface', and I believe your wireless interface is a 'network interface', even if it's not a netdev ;-) But if this really bugs you, please feel free to respin my patch. Have fun... Jean - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, 2007-02-28 at 16:26 -0800, Jean Tourrilhes wrote: > + /* This function is only used for network interface. > + * Some hotplug package track interfaces by their name and > + * therefore want to know when the name is changed by the user. */ Right now, that's true, but wireless is going to start using device_rename pretty soon as well. Could you rephrase this comment? johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 07:36:17AM -0800, Greg KH wrote:
> On Tue, Feb 27, 2007 at 05:27:41PM -0800, Jean Tourrilhes wrote:
> > diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
> > --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800
> > +++ linux/drivers/base/class.c 2007-02-27 15:52:37.0 -0800
> > @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
>
> This function is not in the 2.6.21-rc2 kernel, so you might want to
> rework this patch a bit :)
Thanks for all you good comments. I ported my patch to
2.6.21-rc2, and tested it both on a hotplug and a udev system. Patch
is attached, I would be glad if you could push that through the usual
channels.
Also, I realised that I forgot to say in my original e-mail
that migrating udev to use ifindex instead of ifname would fix the
remove/add race condition for network devices. But that's not going to
happen overnight...
Have fun...
Jean
Signed-off-by: Jean Tourrilhes <[EMAIL PROTECTED]>
-
diff -u -p linux/include/linux/kobject.j1.h linux/include/linux/kobject.h
--- linux/include/linux/kobject.j1.h2007-02-28 14:26:29.0 -0800
+++ linux/include/linux/kobject.h 2007-02-28 14:27:54.0 -0800
@@ -48,6 +48,7 @@ enum kobject_action {
KOBJ_OFFLINE= (__force kobject_action_t) 0x06, /* device
offline */
KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device
online */
KOBJ_MOVE = (__force kobject_action_t) 0x08, /* device move
*/
+ KOBJ_RENAME = (__force kobject_action_t) 0x09, /* device
renamed */
};
struct kobject {
diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
--- linux/net/core/net-sysfs.j1.c 2007-02-28 14:26:45.0 -0800
+++ linux/net/core/net-sysfs.c 2007-02-28 14:27:54.0 -0800
@@ -424,6 +424,17 @@ static int netdev_uevent(struct device *
if ((size <= 0) || (i >= num_envp))
return -ENOMEM;
+ /* pass ifindex to uevent.
+* ifindex is useful as it won't change (interface name may change)
+* and is what RtNetlink uses natively. */
+ envp[i++] = buf;
+ n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1;
+ buf += n;
+ size -= n;
+
+ if ((size <= 0) || (i >= num_envp))
+ return -ENOMEM;
+
envp[i] = NULL;
return 0;
}
diff -u -p linux/lib/kobject_uevent.j1.c linux/lib/kobject_uevent.c
--- linux/lib/kobject_uevent.j1.c 2007-02-28 14:26:58.0 -0800
+++ linux/lib/kobject_uevent.c 2007-02-28 14:27:54.0 -0800
@@ -52,6 +52,8 @@ static char *action_to_string(enum kobje
return "online";
case KOBJ_MOVE:
return "move";
+ case KOBJ_RENAME:
+ return "rename";
default:
return NULL;
}
diff -u -p linux/drivers/base/core.j1.c linux/drivers/base/core.c
--- linux/drivers/base/core.j1.c2007-02-28 15:45:45.0 -0800
+++ linux/drivers/base/core.c 2007-02-28 15:47:30.0 -0800
@@ -1007,6 +1007,8 @@ int device_rename(struct device *dev, ch
char *new_class_name = NULL;
char *old_symlink_name = NULL;
int error;
+ char *devname_string = NULL;
+ char *envp[2];
dev = get_device(dev);
if (!dev)
@@ -1014,6 +1016,15 @@ int device_rename(struct device *dev, ch
pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
+ devname_string = kmalloc(strlen(dev->bus_id) + 15, GFP_KERNEL);
+ if (!devname_string) {
+ put_device(dev);
+ return -ENOMEM;
+ }
+ sprintf(devname_string, "INTERFACE_OLD=%s", dev->bus_id);
+ envp[0] = devname_string;
+ envp[1] = NULL;
+
#ifdef CONFIG_SYSFS_DEPRECATED
if ((dev->class) && (dev->parent))
old_class_name = make_class_name(dev->class->name, >kobj);
@@ -1049,12 +1060,20 @@ int device_rename(struct device *dev, ch
sysfs_create_link(>class->subsys.kset.kobj, >kobj,
dev->bus_id);
}
+
+ /* This function is only used for network interface.
+* Some hotplug package track interfaces by their name and
+* therefore want to know when the name is changed by the user. */
+ if(!error)
+ kobject_uevent_env(>kobj, KOBJ_RENAME, envp);
+
put_device(dev);
kfree(new_class_name);
kfree(old_symlink_name);
out_free_old_class:
kfree(old_class_name);
+ kfree(devname_string);
return error;
}
-
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Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, 2007-02-28 at 10:51 -0800, Jean Tourrilhes wrote: > That's why I always specify the kernel version. I'll look into > that, I'm sure it's not the end of the world ;-) Sure, just wanted to point it out. > In which sense ? Wireless interface are regular netdevices. Yeah but in mac80211 we have the wiphy concept since multiple virtual interfaces can be associated to one hardware, and that is where QoS is done, not the netdevs. Of course, those interested can just listen to nl80211 events to figure out if someone renamed a 802.11 phy, but things like hal would probably not want to and still know about the name change. > I'm just trying to follow the established pattern. Both > class_device_add() and class_device_del() are generating the > event. Also, I'm not sure if other subsystem would benefit from it, I > don't want to generate too many useless events. I don't think many other subsystems (can) rename things ;) johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:16:05AM +0100, Johannes Berg wrote: > Hi, > > > Patch for 2.6.20 is attached. > > ... and in the meantime netdevices aren't class_device any more :) IOW, > your patch isn't going to work any more. That's why I always specify the kernel version. I'll look into that, I'm sure it's not the end of the world ;-) > Also, I think wireless could benefit from this as well. In which sense ? Wireless interface are regular netdevices. > > The kobject framework is well designed, so adding these > > features is trivial change and won't run the risk of breaking anything > > (famous last words). Obviously, hotplug apps are free to ignore those > > additional features. > > Why not just add this to base kobject_rename instead? That way, > userspace is notified for all renames in sysfs. > The patch then collapses down to the change in net's sysfs code to add > the ifindex to the environment, and another change in kobject to invoke > a new event when a name changes and show the old name. I'm just trying to follow the established pattern. Both class_device_add() and class_device_del() are generating the event. Also, I'm not sure if other subsystem would benefit from it, I don't want to generate too many useless events. > johannes Thanks ! Jean - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote: > On 28-02-2007 02:27, Jean Tourrilhes wrote: > > Hi all, > ... > > Patch for 2.6.20 is attached. The patch was tested on a system > > running the hotplug scripts, and on another system running udev. > > > > Have fun... > > > > Jean > > > > Signed-off-by: Jean Tourrilhes <[EMAIL PROTECTED]> > > > > - > ... > > diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c > > --- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800 > > +++ linux/net/core/net-sysfs.c 2007-02-27 15:06:49.0 -0800 > > @@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de > > if ((size <= 0) || (i >= num_envp)) > > return -ENOMEM; > > > > + /* pass ifindex to uevent. > > +* ifindex is useful as it won't change (interface name may change) > > +* and is what RtNetlink uses natively. */ > > + envp[i++] = buf; > > + n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1; > > + buf += n; > > + size -= n; > > + > > + if ((size <= 0) || (i >= num_envp)) > > Btw.: > 1. if size == 10 and snprintf returns 9 (without NULL) >then n == 10 (with NULL), so isn't it enough (here and above): > > if ((size < 0) || (i >= num_envp)) I just cut'n'pasted the code a few line above. If the original code is incorrect, it need fixing. And it will need fixing in probably a lot of places. > 2. shouldn't there be (here and above): > > envp[--i] = NULL; > No, envp is local, so who cares. Thanks. Jean - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 07:36:17AM -0800, Greg KH wrote: > On Tue, Feb 27, 2007 at 05:27:41PM -0800, Jean Tourrilhes wrote: > > diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c > > --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800 > > +++ linux/drivers/base/class.c 2007-02-27 15:52:37.0 -0800 > > @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev > > This function is not in the 2.6.21-rc2 kernel, so you might want to > rework this patch a bit :) It was a trial balloon to gather feedback. I will do. > Also, it's userspace that causes the rename to happen, so it knows it > did it, why should the kernel have to emit a message to tell userspace > again what just happened? Username is not one big program, but a collection of program, and one program does not know what another program do. In particular, udev does not know when people are using iproute2 to rename interface and loose its marbles. We don't really want to ban iproute2 or udev ;-) > thanks, > > greg k-h Have fun... Jean - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Tue, Feb 27, 2007 at 05:27:41PM -0800, Jean Tourrilhes wrote: > diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c > --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800 > +++ linux/drivers/base/class.c2007-02-27 15:52:37.0 -0800 > @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev This function is not in the 2.6.21-rc2 kernel, so you might want to rework this patch a bit :) Also, it's userspace that causes the rename to happen, so it knows it did it, why should the kernel have to emit a message to tell userspace again what just happened? thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote: > On 28-02-2007 02:27, Jean Tourrilhes wrote: ... > > + /* This function is only used for network interface. > > +* Some hotplug package track interfaces by their name and > > +* therefore want to know when the name is changed by the user. */ > > + if(!error) > > + kobject_uevent_env(_dev->kobj, KOBJ_RENAME, envp); > > + > > class_device_put(class_dev); > > > > + kfree(devname_string); > > Maybe I miss something, but it seems kobject_uevent_env copies > pointers from envp instead of buffers' contents. And it's enough - sorry. Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On 28-02-2007 02:27, Jean Tourrilhes wrote:
> Hi all,
...
> Patch for 2.6.20 is attached. The patch was tested on a system
> running the hotplug scripts, and on another system running udev.
>
> Have fun...
>
> Jean
>
> Signed-off-by: Jean Tourrilhes <[EMAIL PROTECTED]>
>
> -
...
> diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
> --- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800
> +++ linux/net/core/net-sysfs.c2007-02-27 15:06:49.0 -0800
> @@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de
> if ((size <= 0) || (i >= num_envp))
> return -ENOMEM;
>
> + /* pass ifindex to uevent.
> + * ifindex is useful as it won't change (interface name may change)
> + * and is what RtNetlink uses natively. */
> + envp[i++] = buf;
> + n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1;
> + buf += n;
> + size -= n;
> +
> + if ((size <= 0) || (i >= num_envp))
Btw.:
1. if size == 10 and snprintf returns 9 (without NULL)
then n == 10 (with NULL), so isn't it enough (here and above):
if ((size < 0) || (i >= num_envp))
2. shouldn't there be (here and above):
envp[--i] = NULL;
> + return -ENOMEM;
> +
> envp[i] = NULL;
> return 0;
> }
...
> diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
> --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800
> +++ linux/drivers/base/class.c2007-02-27 15:52:37.0 -0800
> @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
> {
> int error = 0;
> char *old_class_name = NULL, *new_class_name = NULL;
> + char *devname_string = NULL;
> + char *envp[2];
>
> class_dev = class_device_get(class_dev);
> if (!class_dev)
> @@ -849,6 +851,15 @@ int class_device_rename(struct class_dev
> pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
>new_name);
>
> + devname_string = kmalloc(strlen(class_dev->class_id) + 15, GFP_KERNEL);
> + if (!devname_string) {
> + class_device_put(class_dev);
> + return -ENOMEM;
> + }
> + sprintf(devname_string, "INTERFACE_OLD=%s", class_dev->class_id);
> + envp[0] = devname_string;
> + envp[1] = NULL;
> +
> #ifdef CONFIG_SYSFS_DEPRECATED
> if (class_dev->dev)
> old_class_name = make_class_name(class_dev->class->name,
> @@ -868,8 +879,16 @@ int class_device_rename(struct class_dev
> sysfs_remove_link(_dev->dev->kobj, old_class_name);
> }
> #endif
> +
> + /* This function is only used for network interface.
> + * Some hotplug package track interfaces by their name and
> + * therefore want to know when the name is changed by the user. */
> + if(!error)
> + kobject_uevent_env(_dev->kobj, KOBJ_RENAME, envp);
> +
> class_device_put(class_dev);
>
> + kfree(devname_string);
Maybe I miss something, but it seems kobject_uevent_env copies
pointers from envp instead of buffers' contents.
Regards,
Jarek P.
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Re: [PATCH 2.6.20] kobject net ifindex + rename
Hi, > Patch for 2.6.20 is attached. ... and in the meantime netdevices aren't class_device any more :) IOW, your patch isn't going to work any more. Also, I think wireless could benefit from this as well. > The kobject framework is well designed, so adding these > features is trivial change and won't run the risk of breaking anything > (famous last words). Obviously, hotplug apps are free to ignore those > additional features. Why not just add this to base kobject_rename instead? That way, userspace is notified for all renames in sysfs. The patch then collapses down to the change in net's sysfs code to add the ifindex to the environment, and another change in kobject to invoke a new event when a name changes and show the old name. johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
Hi, Patch for 2.6.20 is attached. ... and in the meantime netdevices aren't class_device any more :) IOW, your patch isn't going to work any more. Also, I think wireless could benefit from this as well. The kobject framework is well designed, so adding these features is trivial change and won't run the risk of breaking anything (famous last words). Obviously, hotplug apps are free to ignore those additional features. Why not just add this to base kobject_rename instead? That way, userspace is notified for all renames in sysfs. The patch then collapses down to the change in net's sysfs code to add the ifindex to the environment, and another change in kobject to invoke a new event when a name changes and show the old name. johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On 28-02-2007 02:27, Jean Tourrilhes wrote:
Hi all,
...
Patch for 2.6.20 is attached. The patch was tested on a system
running the hotplug scripts, and on another system running udev.
Have fun...
Jean
Signed-off-by: Jean Tourrilhes [EMAIL PROTECTED]
-
...
diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
--- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800
+++ linux/net/core/net-sysfs.c2007-02-27 15:06:49.0 -0800
@@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de
if ((size = 0) || (i = num_envp))
return -ENOMEM;
+ /* pass ifindex to uevent.
+ * ifindex is useful as it won't change (interface name may change)
+ * and is what RtNetlink uses natively. */
+ envp[i++] = buf;
+ n = snprintf(buf, size, IFINDEX=%d, dev-ifindex) + 1;
+ buf += n;
+ size -= n;
+
+ if ((size = 0) || (i = num_envp))
Btw.:
1. if size == 10 and snprintf returns 9 (without NULL)
then n == 10 (with NULL), so isn't it enough (here and above):
if ((size 0) || (i = num_envp))
2. shouldn't there be (here and above):
envp[--i] = NULL;
+ return -ENOMEM;
+
envp[i] = NULL;
return 0;
}
...
diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
--- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800
+++ linux/drivers/base/class.c2007-02-27 15:52:37.0 -0800
@@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
{
int error = 0;
char *old_class_name = NULL, *new_class_name = NULL;
+ char *devname_string = NULL;
+ char *envp[2];
class_dev = class_device_get(class_dev);
if (!class_dev)
@@ -849,6 +851,15 @@ int class_device_rename(struct class_dev
pr_debug(CLASS: renaming '%s' to '%s'\n, class_dev-class_id,
new_name);
+ devname_string = kmalloc(strlen(class_dev-class_id) + 15, GFP_KERNEL);
+ if (!devname_string) {
+ class_device_put(class_dev);
+ return -ENOMEM;
+ }
+ sprintf(devname_string, INTERFACE_OLD=%s, class_dev-class_id);
+ envp[0] = devname_string;
+ envp[1] = NULL;
+
#ifdef CONFIG_SYSFS_DEPRECATED
if (class_dev-dev)
old_class_name = make_class_name(class_dev-class-name,
@@ -868,8 +879,16 @@ int class_device_rename(struct class_dev
sysfs_remove_link(class_dev-dev-kobj, old_class_name);
}
#endif
+
+ /* This function is only used for network interface.
+ * Some hotplug package track interfaces by their name and
+ * therefore want to know when the name is changed by the user. */
+ if(!error)
+ kobject_uevent_env(class_dev-kobj, KOBJ_RENAME, envp);
+
class_device_put(class_dev);
+ kfree(devname_string);
Maybe I miss something, but it seems kobject_uevent_env copies
pointers from envp instead of buffers' contents.
Regards,
Jarek P.
-
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Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote: On 28-02-2007 02:27, Jean Tourrilhes wrote: ... + /* This function is only used for network interface. +* Some hotplug package track interfaces by their name and +* therefore want to know when the name is changed by the user. */ + if(!error) + kobject_uevent_env(class_dev-kobj, KOBJ_RENAME, envp); + class_device_put(class_dev); + kfree(devname_string); Maybe I miss something, but it seems kobject_uevent_env copies pointers from envp instead of buffers' contents. And it's enough - sorry. Jarek P. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Tue, Feb 27, 2007 at 05:27:41PM -0800, Jean Tourrilhes wrote: diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800 +++ linux/drivers/base/class.c2007-02-27 15:52:37.0 -0800 @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev This function is not in the 2.6.21-rc2 kernel, so you might want to rework this patch a bit :) Also, it's userspace that causes the rename to happen, so it knows it did it, why should the kernel have to emit a message to tell userspace again what just happened? thanks, greg k-h - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 07:36:17AM -0800, Greg KH wrote: On Tue, Feb 27, 2007 at 05:27:41PM -0800, Jean Tourrilhes wrote: diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800 +++ linux/drivers/base/class.c 2007-02-27 15:52:37.0 -0800 @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev This function is not in the 2.6.21-rc2 kernel, so you might want to rework this patch a bit :) It was a trial balloon to gather feedback. I will do. Also, it's userspace that causes the rename to happen, so it knows it did it, why should the kernel have to emit a message to tell userspace again what just happened? Username is not one big program, but a collection of program, and one program does not know what another program do. In particular, udev does not know when people are using iproute2 to rename interface and loose its marbles. We don't really want to ban iproute2 or udev ;-) thanks, greg k-h Have fun... Jean - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote: On 28-02-2007 02:27, Jean Tourrilhes wrote: Hi all, ... Patch for 2.6.20 is attached. The patch was tested on a system running the hotplug scripts, and on another system running udev. Have fun... Jean Signed-off-by: Jean Tourrilhes [EMAIL PROTECTED] - ... diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c --- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800 +++ linux/net/core/net-sysfs.c 2007-02-27 15:06:49.0 -0800 @@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de if ((size = 0) || (i = num_envp)) return -ENOMEM; + /* pass ifindex to uevent. +* ifindex is useful as it won't change (interface name may change) +* and is what RtNetlink uses natively. */ + envp[i++] = buf; + n = snprintf(buf, size, IFINDEX=%d, dev-ifindex) + 1; + buf += n; + size -= n; + + if ((size = 0) || (i = num_envp)) Btw.: 1. if size == 10 and snprintf returns 9 (without NULL) then n == 10 (with NULL), so isn't it enough (here and above): if ((size 0) || (i = num_envp)) I just cut'n'pasted the code a few line above. If the original code is incorrect, it need fixing. And it will need fixing in probably a lot of places. 2. shouldn't there be (here and above): envp[--i] = NULL; No, envp is local, so who cares. Thanks. Jean - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:16:05AM +0100, Johannes Berg wrote: Hi, Patch for 2.6.20 is attached. ... and in the meantime netdevices aren't class_device any more :) IOW, your patch isn't going to work any more. That's why I always specify the kernel version. I'll look into that, I'm sure it's not the end of the world ;-) Also, I think wireless could benefit from this as well. In which sense ? Wireless interface are regular netdevices. The kobject framework is well designed, so adding these features is trivial change and won't run the risk of breaking anything (famous last words). Obviously, hotplug apps are free to ignore those additional features. Why not just add this to base kobject_rename instead? That way, userspace is notified for all renames in sysfs. The patch then collapses down to the change in net's sysfs code to add the ifindex to the environment, and another change in kobject to invoke a new event when a name changes and show the old name. I'm just trying to follow the established pattern. Both class_device_add() and class_device_del() are generating the event. Also, I'm not sure if other subsystem would benefit from it, I don't want to generate too many useless events. johannes Thanks ! Jean - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, 2007-02-28 at 10:51 -0800, Jean Tourrilhes wrote: That's why I always specify the kernel version. I'll look into that, I'm sure it's not the end of the world ;-) Sure, just wanted to point it out. In which sense ? Wireless interface are regular netdevices. Yeah but in mac80211 we have the wiphy concept since multiple virtual interfaces can be associated to one hardware, and that is where QoS is done, not the netdevs. Of course, those interested can just listen to nl80211 events to figure out if someone renamed a 802.11 phy, but things like hal would probably not want to and still know about the name change. I'm just trying to follow the established pattern. Both class_device_add() and class_device_del() are generating the event. Also, I'm not sure if other subsystem would benefit from it, I don't want to generate too many useless events. I don't think many other subsystems (can) rename things ;) johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 07:36:17AM -0800, Greg KH wrote:
On Tue, Feb 27, 2007 at 05:27:41PM -0800, Jean Tourrilhes wrote:
diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
--- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800
+++ linux/drivers/base/class.c 2007-02-27 15:52:37.0 -0800
@@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
This function is not in the 2.6.21-rc2 kernel, so you might want to
rework this patch a bit :)
Thanks for all you good comments. I ported my patch to
2.6.21-rc2, and tested it both on a hotplug and a udev system. Patch
is attached, I would be glad if you could push that through the usual
channels.
Also, I realised that I forgot to say in my original e-mail
that migrating udev to use ifindex instead of ifname would fix the
remove/add race condition for network devices. But that's not going to
happen overnight...
Have fun...
Jean
Signed-off-by: Jean Tourrilhes [EMAIL PROTECTED]
-
diff -u -p linux/include/linux/kobject.j1.h linux/include/linux/kobject.h
--- linux/include/linux/kobject.j1.h2007-02-28 14:26:29.0 -0800
+++ linux/include/linux/kobject.h 2007-02-28 14:27:54.0 -0800
@@ -48,6 +48,7 @@ enum kobject_action {
KOBJ_OFFLINE= (__force kobject_action_t) 0x06, /* device
offline */
KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device
online */
KOBJ_MOVE = (__force kobject_action_t) 0x08, /* device move
*/
+ KOBJ_RENAME = (__force kobject_action_t) 0x09, /* device
renamed */
};
struct kobject {
diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
--- linux/net/core/net-sysfs.j1.c 2007-02-28 14:26:45.0 -0800
+++ linux/net/core/net-sysfs.c 2007-02-28 14:27:54.0 -0800
@@ -424,6 +424,17 @@ static int netdev_uevent(struct device *
if ((size = 0) || (i = num_envp))
return -ENOMEM;
+ /* pass ifindex to uevent.
+* ifindex is useful as it won't change (interface name may change)
+* and is what RtNetlink uses natively. */
+ envp[i++] = buf;
+ n = snprintf(buf, size, IFINDEX=%d, dev-ifindex) + 1;
+ buf += n;
+ size -= n;
+
+ if ((size = 0) || (i = num_envp))
+ return -ENOMEM;
+
envp[i] = NULL;
return 0;
}
diff -u -p linux/lib/kobject_uevent.j1.c linux/lib/kobject_uevent.c
--- linux/lib/kobject_uevent.j1.c 2007-02-28 14:26:58.0 -0800
+++ linux/lib/kobject_uevent.c 2007-02-28 14:27:54.0 -0800
@@ -52,6 +52,8 @@ static char *action_to_string(enum kobje
return online;
case KOBJ_MOVE:
return move;
+ case KOBJ_RENAME:
+ return rename;
default:
return NULL;
}
diff -u -p linux/drivers/base/core.j1.c linux/drivers/base/core.c
--- linux/drivers/base/core.j1.c2007-02-28 15:45:45.0 -0800
+++ linux/drivers/base/core.c 2007-02-28 15:47:30.0 -0800
@@ -1007,6 +1007,8 @@ int device_rename(struct device *dev, ch
char *new_class_name = NULL;
char *old_symlink_name = NULL;
int error;
+ char *devname_string = NULL;
+ char *envp[2];
dev = get_device(dev);
if (!dev)
@@ -1014,6 +1016,15 @@ int device_rename(struct device *dev, ch
pr_debug(DEVICE: renaming '%s' to '%s'\n, dev-bus_id, new_name);
+ devname_string = kmalloc(strlen(dev-bus_id) + 15, GFP_KERNEL);
+ if (!devname_string) {
+ put_device(dev);
+ return -ENOMEM;
+ }
+ sprintf(devname_string, INTERFACE_OLD=%s, dev-bus_id);
+ envp[0] = devname_string;
+ envp[1] = NULL;
+
#ifdef CONFIG_SYSFS_DEPRECATED
if ((dev-class) (dev-parent))
old_class_name = make_class_name(dev-class-name, dev-kobj);
@@ -1049,12 +1060,20 @@ int device_rename(struct device *dev, ch
sysfs_create_link(dev-class-subsys.kset.kobj, dev-kobj,
dev-bus_id);
}
+
+ /* This function is only used for network interface.
+* Some hotplug package track interfaces by their name and
+* therefore want to know when the name is changed by the user. */
+ if(!error)
+ kobject_uevent_env(dev-kobj, KOBJ_RENAME, envp);
+
put_device(dev);
kfree(new_class_name);
kfree(old_symlink_name);
out_free_old_class:
kfree(old_class_name);
+ kfree(devname_string);
return error;
}
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Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, 2007-02-28 at 16:26 -0800, Jean Tourrilhes wrote: + /* This function is only used for network interface. + * Some hotplug package track interfaces by their name and + * therefore want to know when the name is changed by the user. */ Right now, that's true, but wireless is going to start using device_rename pretty soon as well. Could you rephrase this comment? johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Thu, Mar 01, 2007 at 01:37:46AM +0100, Johannes Berg wrote: On Wed, 2007-02-28 at 16:26 -0800, Jean Tourrilhes wrote: + /* This function is only used for network interface. +* Some hotplug package track interfaces by their name and +* therefore want to know when the name is changed by the user. */ Right now, that's true, but wireless is going to start using device_rename pretty soon as well. Could you rephrase this comment? johannes I would prefer to fix the comment when this change actually happens. I prefer comments to refer to the current reality, rather than past/future situation. When you introduce wireless renaming, you will need to verify the whole chain anyway, so you might as well fix the comment while merging wireless renaming. Note also that my comment is technically correct. I did not say 'netdev' but the more generic term 'network interface', and I believe your wireless interface is a 'network interface', even if it's not a netdev ;-) But if this really bugs you, please feel free to respin my patch. Have fun... Jean - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, 2007-02-28 at 16:51 -0800, Jean Tourrilhes wrote: I would prefer to fix the comment when this change actually happens. I prefer comments to refer to the current reality, rather than past/future situation. Uh, no. device_rename is perfectly fine, even other people may use it in the future. When you introduce wireless renaming, you will need to verify the whole chain anyway, so you might as well fix the comment while merging wireless renaming. No again, device_rename is perfectly fine API, I shouldn't have to look at it's internals to see if it's broken in my use case. Even if it's only a broken comment. I'm not going to respin your patches though, if this doesn't make it in I don't care. johannes signature.asc Description: This is a digitally signed message part
Re: [PATCH 2.6.20] kobject net ifindex + rename
On Wed, Feb 28, 2007 at 10:45:41AM -0800, Jean Tourrilhes wrote: On Wed, Feb 28, 2007 at 10:34:37AM +0100, Jarek Poplawski wrote: On 28-02-2007 02:27, Jean Tourrilhes wrote: Hi all, ... Patch for 2.6.20 is attached. The patch was tested on a system running the hotplug scripts, and on another system running udev. Have fun... Jean Signed-off-by: Jean Tourrilhes [EMAIL PROTECTED] - ... diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c --- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800 +++ linux/net/core/net-sysfs.c2007-02-27 15:06:49.0 -0800 @@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de if ((size = 0) || (i = num_envp)) return -ENOMEM; + /* pass ifindex to uevent. + * ifindex is useful as it won't change (interface name may change) + * and is what RtNetlink uses natively. */ + envp[i++] = buf; + n = snprintf(buf, size, IFINDEX=%d, dev-ifindex) + 1; + buf += n; + size -= n; + + if ((size = 0) || (i = num_envp)) Btw.: 1. if size == 10 and snprintf returns 9 (without NULL) then n == 10 (with NULL), so isn't it enough (here and above): if ((size 0) || (i = num_envp)) I just cut'n'pasted the code a few line above. If the original code is incorrect, it need fixing. And it will need fixing in probably a lot of places. I think you're kind of responsible for your part, at least. 2. shouldn't there be (here and above): envp[--i] = NULL; No, envp is local, so who cares. But envp[i] isn't (at least here). So, I guess, a caller of this function could care. + if ((size = 0) || (i = num_envp)) + return -ENOMEM; And one more thing (not necessarily for you): ENOBUFS is probably more adequate here. Cheers, Jarek P. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 2.6.20] kobject net ifindex + rename
Hi all,
Various hotplug packages have had trouble dealing with network
interface being renamed. I've decided to tackle this issue from two
angles :
o export ifindex to those apps, as ifindex is persistent.
o expose interface renaming as a hotplug event.
Those two changes are complementary, even an application that
would track interface by ifindex would sometime needs to know about
ifname change. My assumption is that most apps would still use ifname
for a long while to be backward compatible with older kernels.
The kobject framework is well designed, so adding these
features is trivial change and won't run the risk of breaking anything
(famous last words). Obviously, hotplug apps are free to ignore those
additional features.
Patch for 2.6.20 is attached. The patch was tested on a system
running the hotplug scripts, and on another system running udev.
Have fun...
Jean
Signed-off-by: Jean Tourrilhes <[EMAIL PROTECTED]>
-
diff -u -p linux/include/linux/kobject.j1.h linux/include/linux/kobject.h
--- linux/include/linux/kobject.j1.h2007-02-26 18:37:55.0 -0800
+++ linux/include/linux/kobject.h 2007-02-26 18:38:42.0 -0800
@@ -48,6 +48,7 @@ enum kobject_action {
KOBJ_OFFLINE= (__force kobject_action_t) 0x06, /* device
offline */
KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device
online */
KOBJ_MOVE = (__force kobject_action_t) 0x08, /* device move
*/
+ KOBJ_RENAME = (__force kobject_action_t) 0x09, /* device
renamed */
};
struct kobject {
diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
--- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800
+++ linux/net/core/net-sysfs.c 2007-02-27 15:06:49.0 -0800
@@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de
if ((size <= 0) || (i >= num_envp))
return -ENOMEM;
+ /* pass ifindex to uevent.
+* ifindex is useful as it won't change (interface name may change)
+* and is what RtNetlink uses natively. */
+ envp[i++] = buf;
+ n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1;
+ buf += n;
+ size -= n;
+
+ if ((size <= 0) || (i >= num_envp))
+ return -ENOMEM;
+
envp[i] = NULL;
return 0;
}
diff -u -p linux/lib/kobject_uevent.j1.c linux/lib/kobject_uevent.c
--- linux/lib/kobject_uevent.j1.c 2007-02-26 18:38:02.0 -0800
+++ linux/lib/kobject_uevent.c 2007-02-26 18:38:42.0 -0800
@@ -52,6 +52,8 @@ static char *action_to_string(enum kobje
return "online";
case KOBJ_MOVE:
return "move";
+ case KOBJ_RENAME:
+ return "rename";
default:
return NULL;
}
diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
--- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800
+++ linux/drivers/base/class.c 2007-02-27 15:52:37.0 -0800
@@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
{
int error = 0;
char *old_class_name = NULL, *new_class_name = NULL;
+ char *devname_string = NULL;
+ char *envp[2];
class_dev = class_device_get(class_dev);
if (!class_dev)
@@ -849,6 +851,15 @@ int class_device_rename(struct class_dev
pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
new_name);
+ devname_string = kmalloc(strlen(class_dev->class_id) + 15, GFP_KERNEL);
+ if (!devname_string) {
+ class_device_put(class_dev);
+ return -ENOMEM;
+ }
+ sprintf(devname_string, "INTERFACE_OLD=%s", class_dev->class_id);
+ envp[0] = devname_string;
+ envp[1] = NULL;
+
#ifdef CONFIG_SYSFS_DEPRECATED
if (class_dev->dev)
old_class_name = make_class_name(class_dev->class->name,
@@ -868,8 +879,16 @@ int class_device_rename(struct class_dev
sysfs_remove_link(_dev->dev->kobj, old_class_name);
}
#endif
+
+ /* This function is only used for network interface.
+* Some hotplug package track interfaces by their name and
+* therefore want to know when the name is changed by the user. */
+ if(!error)
+ kobject_uevent_env(_dev->kobj, KOBJ_RENAME, envp);
+
class_device_put(class_dev);
+ kfree(devname_string);
kfree(old_class_name);
kfree(new_class_name);
-
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More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH 2.6.20] kobject net ifindex + rename
Hi all,
Various hotplug packages have had trouble dealing with network
interface being renamed. I've decided to tackle this issue from two
angles :
o export ifindex to those apps, as ifindex is persistent.
o expose interface renaming as a hotplug event.
Those two changes are complementary, even an application that
would track interface by ifindex would sometime needs to know about
ifname change. My assumption is that most apps would still use ifname
for a long while to be backward compatible with older kernels.
The kobject framework is well designed, so adding these
features is trivial change and won't run the risk of breaking anything
(famous last words). Obviously, hotplug apps are free to ignore those
additional features.
Patch for 2.6.20 is attached. The patch was tested on a system
running the hotplug scripts, and on another system running udev.
Have fun...
Jean
Signed-off-by: Jean Tourrilhes [EMAIL PROTECTED]
-
diff -u -p linux/include/linux/kobject.j1.h linux/include/linux/kobject.h
--- linux/include/linux/kobject.j1.h2007-02-26 18:37:55.0 -0800
+++ linux/include/linux/kobject.h 2007-02-26 18:38:42.0 -0800
@@ -48,6 +48,7 @@ enum kobject_action {
KOBJ_OFFLINE= (__force kobject_action_t) 0x06, /* device
offline */
KOBJ_ONLINE = (__force kobject_action_t) 0x07, /* device
online */
KOBJ_MOVE = (__force kobject_action_t) 0x08, /* device move
*/
+ KOBJ_RENAME = (__force kobject_action_t) 0x09, /* device
renamed */
};
struct kobject {
diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
--- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.0 -0800
+++ linux/net/core/net-sysfs.c 2007-02-27 15:06:49.0 -0800
@@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de
if ((size = 0) || (i = num_envp))
return -ENOMEM;
+ /* pass ifindex to uevent.
+* ifindex is useful as it won't change (interface name may change)
+* and is what RtNetlink uses natively. */
+ envp[i++] = buf;
+ n = snprintf(buf, size, IFINDEX=%d, dev-ifindex) + 1;
+ buf += n;
+ size -= n;
+
+ if ((size = 0) || (i = num_envp))
+ return -ENOMEM;
+
envp[i] = NULL;
return 0;
}
diff -u -p linux/lib/kobject_uevent.j1.c linux/lib/kobject_uevent.c
--- linux/lib/kobject_uevent.j1.c 2007-02-26 18:38:02.0 -0800
+++ linux/lib/kobject_uevent.c 2007-02-26 18:38:42.0 -0800
@@ -52,6 +52,8 @@ static char *action_to_string(enum kobje
return online;
case KOBJ_MOVE:
return move;
+ case KOBJ_RENAME:
+ return rename;
default:
return NULL;
}
diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
--- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.0 -0800
+++ linux/drivers/base/class.c 2007-02-27 15:52:37.0 -0800
@@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
{
int error = 0;
char *old_class_name = NULL, *new_class_name = NULL;
+ char *devname_string = NULL;
+ char *envp[2];
class_dev = class_device_get(class_dev);
if (!class_dev)
@@ -849,6 +851,15 @@ int class_device_rename(struct class_dev
pr_debug(CLASS: renaming '%s' to '%s'\n, class_dev-class_id,
new_name);
+ devname_string = kmalloc(strlen(class_dev-class_id) + 15, GFP_KERNEL);
+ if (!devname_string) {
+ class_device_put(class_dev);
+ return -ENOMEM;
+ }
+ sprintf(devname_string, INTERFACE_OLD=%s, class_dev-class_id);
+ envp[0] = devname_string;
+ envp[1] = NULL;
+
#ifdef CONFIG_SYSFS_DEPRECATED
if (class_dev-dev)
old_class_name = make_class_name(class_dev-class-name,
@@ -868,8 +879,16 @@ int class_device_rename(struct class_dev
sysfs_remove_link(class_dev-dev-kobj, old_class_name);
}
#endif
+
+ /* This function is only used for network interface.
+* Some hotplug package track interfaces by their name and
+* therefore want to know when the name is changed by the user. */
+ if(!error)
+ kobject_uevent_env(class_dev-kobj, KOBJ_RENAME, envp);
+
class_device_put(class_dev);
+ kfree(devname_string);
kfree(old_class_name);
kfree(new_class_name);
-
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