Re: [f2fs-dev] [PATCH] f2fs: add F2FS_IOC_SEC_TRIM_FILE ioctl

[Daeho Jeong]

Ok, I got it. Thanks for quick response~ :)

2020ë 6ì 11ì (ë) ìì 10:56, Eric Biggers <ebiggers@xxxxxxxxxx>ëì ìì:
>
> On Thu, Jun 11, 2020 at 09:23:23AM +0900, Daeho Jeong wrote:
> > Yes, I saw the implementation in vfs_write().
> > But if we use mnt_want_write_file() here, it'll call mnt_clone_write()
> > internally if the file is already open in write mode.
> > Don't you think the below thing is needed? We can increase the counter
> > each of them, open and ioctl, like other filesystems such as ext4.
> >
> > int mnt_clone_write(struct vfsmount *mnt)
> > {
> >         /* superblock may be r/o */
> >         if (__mnt_is_readonly(mnt))
> >                 return -EROFS;
> >         preempt_disable();
> >         mnt_inc_writers(real_mount(mnt));
> >         preempt_enable();
> >         return 0;
> > }
>
> No, this seems to be left over from when mnt_want_write_file() was paired with
> mnt_drop_write() instead of mnt_drop_write_file().  I sent a patch to remove it:
> https://lkml.kernel.org/r/20200611014945.237210-1-ebiggers@xxxxxxxxxx
>
> - Eric