| Message ID | 87ine15wzx.fsf@mail.parknet.co.jp (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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?
Joe Perches <joe@perches.com> 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.
On Fri, 2017-11-24 at 15:07 +0900, OGAWA Hirofumi wrote: > Joe Perches <joe@perches.com> 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). 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.
On Thu, 23 Nov 2017 22:51:34 -0800 Joe Perches <joe@perches.com> wrote: > On Fri, 2017-11-24 at 15:07 +0900, OGAWA Hirofumi wrote: > > Joe Perches <joe@perches.com> 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@mail.parknet.co.jp> : 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@mail.parknet.co.jp : Fixes: bc98a42c1f7d0f8 ("VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)") : Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> : Cc: Joe Perches <joe@perches.com> : Cc: David Howells <dhowells@redhat.com> : Cc: <stable@vger.kernel.org> : Signed-off-by: Andrew Morton <akpm@linux-foundation.org> : --- : : 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); : : _
diff -puN fs/fat/inode.c~fat-fix-sb_rdonly-fix fs/fat/inode.c --- linux/fs/fat/inode.c~fat-fix-sb_rdonly-fix 2017-11-23 15:03:47.371667601 +0900 +++ linux-hirofumi/fs/fat/inode.c 2017-11-23 15:04:07.654616440 +0900 @@ -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 |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);