On Thu, 23 Nov 2017 22:51:34 -0800 Joe Perches <joe@xxxxxxxxxxx> wrote:
> On Fri, 2017-11-24 at 15:07 +0900, OGAWA Hirofumi wrote:
> > Joe Perches <joe@xxxxxxxxxxx> writes:
> >
> > > On Thu, 2017-11-23 at 15:29 +0900, OGAWA Hirofumi wrote:
> > > > Ouch forgot to add stable@
> > > >
> > > > --
> > > > commit bc98a42c1f7d0f886c0c1b75a92a004976a46d9f introduced bug.
> > >
> > > I think your commit message needs a bit more information.
> > >
> > > It'd be useful to describe that the introduction of
> > > sb_rdonly converted the bitwise & to a boolean and so
> > > this conversion and comparison was made defective.
> > >
> > > Are there any other instances of defective comparisons?
> >
> > Please ask to that patch author.
>
> The patch author, David Howells, is on the cc list.
>
> btw:
>
> It seems all the the other uses use a (bool) cast of the
> (*flags & MS_RDONLY) and a comparison of sb_rdonly(sb).
Sentence is hard to understand.
> It would make sense to change the argument type of the
> ext[24]_setup_super int read_only arg to bool to match
> the sb_rdonly() type.
I did this:
: From: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
: Subject: fat: Fix sb_rdonly() change
:
: bc98a42c1f7d0f ("VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)")
: converted fat_remount():new_rdonly from a bool to an int. However
: fat_remount() depends upon the compiler's conversion of a non-zero integer
: into boolean `true'.
:
: Fix it by switching `new_rdonly' back into a bool.
:
: Link: http://lkml.kernel.org/r/87mv3d5x51.fsf@xxxxxxxxxxxxxxxxxx
: Fixes: bc98a42c1f7d0f8 ("VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)")
: Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
: Cc: Joe Perches <joe@xxxxxxxxxxx>
: Cc: David Howells <dhowells@xxxxxxxxxx>
: Cc: <stable@xxxxxxxxxxxxxxx>
: Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
: ---
:
: fs/fat/inode.c | 2 +-
: 1 file changed, 1 insertion(+), 1 deletion(-)
:
: diff -puN fs/fat/inode.c~fat-fix-sb_rdonly-change fs/fat/inode.c
: --- a/fs/fat/inode.c~fat-fix-sb_rdonly-change
: +++ a/fs/fat/inode.c
: @@ -779,7 +779,7 @@ static void __exit fat_destroy_inodecach
:
: static int fat_remount(struct super_block *sb, int *flags, char *data)
: {
: - int new_rdonly;
: + bool new_rdonly;
: struct msdos_sb_info *sbi = MSDOS_SB(sb);
: *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
:
: _
