On Wed, Jul 24, 2013 at 09:58:45PM +0000, jon ernst wrote: > > My purpose is to trigger this bug and fix it. So I manually define this > > flag for my convenience. > > > >> I saw it has > >> been defined in header file. (fcntl.h) Did I miss anything? > > > > I guess that you might 'include <fcntl.h>' header file, right? But the > > O_TMPFILE is defined in $LINUX/include/uapi/asm-generic/fcntl.h. So > > maybe compiler couldn't find this header file. > > > > Regards, > > - Zheng > -- > Got it. Thank you. BTW, the weird thing is I didn't see any > discussion on ext4 mailing list before Al Viro committed this change. > The first time I heard about this is someone reporting a bug about it. > Document about this FLAG might be necessary. Oh, this flag has been discussed in linux-fsdevel mailing list [1]. Maybe you don't subscribe it. 1. https://lkml.org/lkml/2013/7/3/181 > Also, about this code: > > /* a horrid kludge trying to make sure that this will fail on old kernels */ > #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY) > > why not doing something like this: > > #ifndef O_TMPFILE > /* a horrid kludge trying to make sure that this will fail on old kernels */ > #define O_TMPFILE (__O_TMPFILE | O_DIRECTORY) > #endif Sorry, I don't take a closer look at that thread. I look at the code, and it seems that there is no any rule about adding '#ifndef XXX'. Meanwhile, I notice a comment: /* * When introducing new O_* bits, please check its uniqueness in fcntl_init(). */ But we are missing adding O_TMPFILE flag in fcntl_init(). So I attach a patch below. Al, could you please answer this question? Thanks. Regards, - Zheng Subject: [PATCH] vfs: add missing check for __O_TMPFILE in fcntl_init() From: Zheng Liu <wenqing.lz@xxxxxxxxxx> As comment in include/uapi/asm-generic/fcntl.h described, when introducing new O_* bits, we need to check its uniqueness in fcntl_init(). But __O_TMPFILE bit is missing. So fix it. Signed-off-by: Zheng Liu <wenqing.lz@xxxxxxxxxx> --- *This patch is against ext4/dev tree.* fs/fcntl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/fcntl.c b/fs/fcntl.c index 6599222..65343c3 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -730,14 +730,14 @@ 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(19 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32( + BUILD_BUG_ON(20 - 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 + __FMODE_EXEC | O_PATH | __O_TMPFILE )); fasync_cache = kmem_cache_create("fasync_cache", -- 1.7.9.7 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
