Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 22 Sep 2010 08:06:40 -0700 | Subject | Re: [GIT PULL] block fixes for 2.6.36-rc5 |
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Gaah. This is just _incredibly_ ugly:
On Wed, Sep 22, 2010 at 12:49 AM, Jens Axboe <jaxboe@fusionio.com> wrote: > > - /* Add group onto cgroup list */ > - sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); > - cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, > + /* > + * Add group onto cgroup list. It might happen that bdi->dev is > + * not initiliazed yet. Initialize this new group without major > + * and minor info and this info will be filled in once a new thread > + * comes for IO. See code above. > + */ > + if (bdi->dev) { > + sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); > + cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, > MKDEV(major, minor)); > + } else > + cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, > + 0); > +
and quite frankly, anything that does that kind of thing is total sh*t. Not only is the sscanf() just broken (really? figuring out things from some internal string? Using dev_t in this time and age for kernel internal stuff?) to begin with, but if you have to then do it conditionally, for chrissake do it _cleanly_.
Make a small helper function that does "get me the dev_t of this 'dev'", and make that one do
static unsigned int device_dev_t(struct device *dev) { unsigned int major = 0, minor = 0;
if (dev) sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
return MKDEV(major, minor); }
and then just have a single 'cfq_blkiocg_add_blkio_group()' there.
But more seriously, why the hell does anything internal to cfq use a 'dev_t' in the first place? Why isn't that 'struct blkio_group' using a pointer to the 'struct device' or something like that instead (or the pointer to the queue, or whatever)? It's just damn wrong to use dev_t in this day and age, and the fact that you need to make it up using sscanf() should have clued people into that fact.
I hate seeing obvious crap-workarounds this late in an -rc.
Linus -- 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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