Re: [PATCHv2 1/1] vfs: renumber FMODE_NONOTIFY and add to uniqueness check

[Heinrich Schuchardt]

Hello Andrew,

could you, please, consider the patch proposed in
https://lkml.org/lkml/2014/11/24/196
for inclusion into the mm-tree.

This 2nd version of the patch considers the review comments in the 
thread starting at https://lkml.org/lkml/2014/11/21/141.

Best regards

Heinrich Schuchardt


On 24.11.2014 12:30, Jan Kara wrote:
> On Mon 24-11-14 11:23:19, David Drysdale wrote:
> > Fix clashing values for O_PATH and FMODE_NONOTIFY on sparc.
> > The clashing O_PATH value was added in 5229645bdc35f1cc43eb ("vfs: add
> > nonconflicting values for O_PATH") but this can't be changed as it
> > is user-visible.
> >
> > FMODE_NONOTIFY is only used internally in the kernel, but it is in
> > the same numbering space as the other O_* flags, as indicated by the
> > comment at the top of include/uapi/asm-generic/fcntl.h (and its use
> > in fs/notify/fanotify/fanotify_user.c).  So renumber it to avoid
> > the clash.
> >
> > All of this has happened before (12ed2e36c98aec6c4155, "fanotify:
> > FMODE_NONOTIFY and __O_SYNC in sparc conflict"), and all of this
> > will happen again -- so update the uniqueness check in fcntl_init()
> > to include __FMODE_NONOTIFY.
> >
> > Signed-off-by: David Drysdale <drysdale@xxxxxxxxxx>
> > Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
>    Looks good. You can add:
> Acked-by: Jan Kara <jack@xxxxxxx>
>
> 								Honza
>
> > ---
> >   fs/fcntl.c                       | 5 +++--
> >   include/linux/fs.h               | 2 +-
> >   include/uapi/asm-generic/fcntl.h | 2 +-
> >   3 files changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/fcntl.c b/fs/fcntl.c
> > index 99d440a4a6ba..ee85cd4e136a 100644
> > --- a/fs/fcntl.c
> > +++ b/fs/fcntl.c
> > @@ -740,14 +740,15 @@ static int __init fcntl_init(void)
> >   	 * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY
> >   	 * is defined as O_NONBLOCK on some platforms and not on others.
> >   	 */
> > -	BUILD_BUG_ON(20 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
> > +	BUILD_BUG_ON(21 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
> >   		O_RDONLY	| O_WRONLY	| O_RDWR	|
> >   		O_CREAT		| O_EXCL	| O_NOCTTY	|
> >   		O_TRUNC		| O_APPEND	| /* O_NONBLOCK	| */
> >   		__O_SYNC	| O_DSYNC	| FASYNC	|
> >   		O_DIRECT	| O_LARGEFILE	| O_DIRECTORY	|
> >   		O_NOFOLLOW	| O_NOATIME	| O_CLOEXEC	|
> > -		__FMODE_EXEC	| O_PATH	| __O_TMPFILE
> > +		__FMODE_EXEC	| O_PATH	| __O_TMPFILE	|
> > +		__FMODE_NONOTIFY
> >   		));
> >
> >   	fasync_cache = kmem_cache_create("fasync_cache",
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index 9ab779e8a63c..fc1c2488adbc 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -134,7 +134,7 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
> >   #define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
> >
> >   /* File was opened by fanotify and shouldn't generate fanotify events */
> > -#define FMODE_NONOTIFY		((__force fmode_t)0x1000000)
> > +#define FMODE_NONOTIFY		((__force fmode_t)0x4000000)
> >
> >   /*
> >    * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
> > diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-generic/fcntl.h
> > index 7543b3e51331..e063effe0cc1 100644
> > --- a/include/uapi/asm-generic/fcntl.h
> > +++ b/include/uapi/asm-generic/fcntl.h
> > @@ -5,7 +5,7 @@
> >
> >   /*
> >    * FMODE_EXEC is 0x20
> > - * FMODE_NONOTIFY is 0x1000000
> > + * FMODE_NONOTIFY is 0x4000000
> >    * These cannot be used by userspace O_* until internal and external open
> >    * flags are split.
> >    * -Eric Paris
> > --
> > 2.1.0.rc2.206.gedb03e5

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