Re: [patch 4/5] mtd: Remove BKL and convert to unlocked_ioctl

From: Thomas Gleixner
Date: Tue Oct 20 2009 - 01:28:09 EST


On Fri, 16 Oct 2009, Artem Bityutskiy wrote:
> On Thu, 2009-10-15 at 20:28 +0000, Thomas Gleixner wrote:
> > plain text document attachment
> > (mtd-remove-bkl-and-convert-to-unlocked-ioctl.patch)
> > mtd_open() got lock/unlock kernel from the big BKL push down, but it
> > never relied on the BKL serialization as get_mtd_device() takes care
> > of serialization vs. device init/teardown.
> >
> > mtd_ioctl() is safe w/o the BKL as well. The data which is copied from
> > the mtd data structure is either set up during device initialization
> > or statistics which have never been protected by the BKL against
> > concurrent modification. The mtd functions which are called from
> > various ioctl commands are safe as well.
> >
> > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
> > Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
> > ---
> > drivers/mtd/mtdchar.c | 30 ++++++++----------------------
> > 1 file changed, 8 insertions(+), 22 deletions(-)
>
> [dedekind@eru l2-mtd-2.6.git]$ make -j8
> CHK include/linux/version.h
> CHK include/linux/utsrelease.h
> SYMLINK include/asm -> include/asm-x86
> CALL scripts/checksyscalls.sh
> CHK include/linux/compile.h
> CC [M] drivers/mtd/mtdchar.o
> drivers/mtd/mtdchar.c: In function âmtd_compat_ioctlâ:
> drivers/mtd/mtdchar.c:865: warning: passing argument 1 of âmtd_ioctlâ from incompatible pointer type
> drivers/mtd/mtdchar.c:444: note: expected âstruct file *â but argument is of type âstruct inode *â
> drivers/mtd/mtdchar.c:865: warning: passing argument 2 of âmtd_ioctlâ makes integer from pointer without a cast
> drivers/mtd/mtdchar.c:444: note: expected âu_intâ but argument is of type âstruct file *â
> drivers/mtd/mtdchar.c:865: error: too many arguments to function âmtd_ioctlâ

Yeah, found and fixed that already.

tglx