Messages in this thread | | | Date | Wed, 20 Feb 2008 14:43:39 +0000 | From | Stephane Chazelas <> | Subject | Re: [PATCH 2.6.24] block2mtd: removing a device and typo fixes |
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2008-02-19 23:33:38 +0100, Arnd Bergmann: > On Tuesday 19 February 2008, you wrote: > > > What about having a /dev/block2mtd (with owner/permissions that > > > could allow non-root users to use it), with 2 ioctls: > > > > > > - one to "link" a block dev to a mtd that would take as > > > parameter a fd to an open block dev (again allowing for > > > flexible permissions) and would return the number of the > > > allocated mtd and success/failure in errno. Upon sucess it > > > would increase the refcnt of block2mtd. > > > > > > - and one to "release" the link. That would fail if the mtd is > > > in use and decrease block2mtd's refcnt upon success. > > > > > > A bit like the loop devices (or /dev/ptmx) actually. What do you > > > think? > > > > Could work. Passing the fd raises several alarm bells. Arnd, any > > comments from you? > > Given that loop works in this way, I certainly see that as doable, > but then I'd vote for using the existing ioctl semantics of > LOOP_SET_FD and LOOP_DEL_FD on the mtdchar device, which already > comes with an ioctl interface for mtd devices. > I'd probably also allow the LOOP_{GET,SET}_STATUS{,64} commands, > so you can actually use the existing losetup tool. > That way, we wouldn't have to introduce a new API, just extend > an existing one to work on more things. [...]
Hi Arnd,
note that for "loop", you have /dev/loop0, /dev/loop1... which makes it a pain to handle
For block2mtd, you don't need several device files in /dev, you only need one to pass ioctls down to create mtd devices.
That may end up creating new /dev devices via mtdblock or mtdblock_ro for instance.
So I'm not sure reusing the "loop" ioctls is a good idea.
Cheers, Stephane -- 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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