* [PATCH 3/3] fuse: check O_DIRECT
@ 2005-09-23 14:21 Miklos Szeredi
2005-09-23 21:27 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Miklos Szeredi @ 2005-09-23 14:21 UTC (permalink / raw)
To: akpm; +Cc: linux-kernel
Check O_DIRECT and return -EINVAL error in open. dentry_open() also
checks this but only after the open method is called. This patch
optimizes away the unnecessary upcalls in this case.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Index: linux/fs/fuse/file.c
===================================================================
--- linux.orig/fs/fuse/file.c 2005-09-21 11:55:45.000000000 +0200
+++ linux/fs/fuse/file.c 2005-09-23 15:24:23.000000000 +0200
@@ -23,6 +23,10 @@ int fuse_open_common(struct inode *inode
struct fuse_file *ff;
int err;
+ /* VFS checks this, but only _after_ ->open() */
+ if (file->f_flags & O_DIRECT)
+ return -EINVAL;
+
err = generic_file_open(inode, file);
if (err)
return err;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 3/3] fuse: check O_DIRECT
2005-09-23 14:21 [PATCH 3/3] fuse: check O_DIRECT Miklos Szeredi
@ 2005-09-23 21:27 ` Andrew Morton
2005-09-24 5:56 ` Miklos Szeredi
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2005-09-23 21:27 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: linux-kernel
Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> Check O_DIRECT and return -EINVAL error in open. dentry_open() also
> checks this but only after the open method is called. This patch
> optimizes away the unnecessary upcalls in this case.
>
> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
>
> Index: linux/fs/fuse/file.c
> ===================================================================
> --- linux.orig/fs/fuse/file.c 2005-09-21 11:55:45.000000000 +0200
> +++ linux/fs/fuse/file.c 2005-09-23 15:24:23.000000000 +0200
> @@ -23,6 +23,10 @@ int fuse_open_common(struct inode *inode
> struct fuse_file *ff;
> int err;
>
> + /* VFS checks this, but only _after_ ->open() */
> + if (file->f_flags & O_DIRECT)
> + return -EINVAL;
> +
> err = generic_file_open(inode, file);
> if (err)
> return err;
This hardly seems worth optimising for?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 3/3] fuse: check O_DIRECT
2005-09-23 21:27 ` Andrew Morton
@ 2005-09-24 5:56 ` Miklos Szeredi
0 siblings, 0 replies; 3+ messages in thread
From: Miklos Szeredi @ 2005-09-24 5:56 UTC (permalink / raw)
To: akpm; +Cc: linux-kernel
> > + /* VFS checks this, but only _after_ ->open() */
> > + if (file->f_flags & O_DIRECT)
> > + return -EINVAL;
> > +
> > err = generic_file_open(inode, file);
> > if (err)
> > return err;
>
> This hardly seems worth optimising for?
It could be a correctness issue too: if filesystem has open() with
side effect, then it should fail before doing the open, not after.
Not a big deal, but I think it's worth the 3 lines.
Miklos
^ permalink raw reply [flat|nested] 3+ messages in thread
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2005-09-23 14:21 [PATCH 3/3] fuse: check O_DIRECT Miklos Szeredi
2005-09-23 21:27 ` Andrew Morton
2005-09-24 5:56 ` Miklos Szeredi
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