On Tue, 26 Oct 2010 16:09:27 +0200, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
On Tue, 26 Oct 2010, Michal Nazarewicz wrote:
This commit fixes some issues with File-backed Storage Gadget
error recovery when registering LUN's devices.
First of all, when device_register() fails the device still
needs to be put. However, because lun_release() decreases
fsg->ref reference counter the counter must be incremented
beforehand.
Correct.
Second of all, after any of the device_create_file()s fails,
device_unregister() is called which in turn (indirectly) calls
lun_release() which decrements fsg->ref. So, again, the
reference counter must be incremented beforehand.
Correct.
Lastly, if the first or the second device_create_file()
succeeds, the files are never removed. To fix it,
device_remove_file() needs to be called. This is done by
simply marking LUN as registered prior to creating files so
that fsg_unbind() can handle removing files.
Correct.
Hope I'm not late for 37?
No doubt it is too late to get into the merge window.
Ah, yes, that what I meant. I was hoping to get the whole set in -rc1, since
some of the patches are purely coding style fixes.
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index d4fdf65..e0504a1 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -3392,21 +3392,19 @@ static int __init fsg_bind(struct usb_gadget *gadget)
dev_set_name(&curlun->dev,"%s-lun%d",
dev_name(&gadget->dev), i);
- if ((rc = device_register(&curlun->dev)) != 0) {
+ kref_get(&fsg->ref);
+ rc = device_register(&curlun->dev);
+ if (rc) {
INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
- goto out;
- }
- if ((rc = device_create_file(&curlun->dev,
- &dev_attr_ro)) != 0 ||
- (rc = device_create_file(&curlun->dev,
- &dev_attr_nofua)) != 0 ||
- (rc = device_create_file(&curlun->dev,
- &dev_attr_file)) != 0) {
- device_unregister(&curlun->dev);
+ put_device(&curlun->dev);
goto out;
}
curlun->registered = 1;
- kref_get(&fsg->ref);
+
+ if ((rc = device_create_file(&curlun->dev, &dev_attr_ro)) ||
+ (rc = device_create_file(&curlun->dev, &dev_attr_nofua)) ||
+ (rc = device_create_file(&curlun->dev, &dev_attr_file)))
+ goto out;
As long as you're changing these anyway, you may as well use the style
most developers seem to prefer:
rc = device_create_file(&curlun->dev, &dev_attr_ro);
if (rc)
goto out;
...
But then it'd be total of 9 lines consisting of three 3-line ifs. I decided
that it would be more readable with a single if even though it is not compliant
with coding style. What do you think? I can just resend it.
After all, you did the same thing in the device_register() call above.
Apart from this small matter, ACK.
Thanks.
--
Best regards, _ _
| Humble Liege of Serenely Enlightened Majesty of o' \,=./ `o
| Computer Science, MichaÅ "mina86" Nazarewicz (o o)
+----[mina86*mina86.com]---[mina86*jabber.org]----ooO--(_)--Ooo--
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