On Thu, Mar 17, 2022 at 07:34:20PM +1100, Dave Chinner wrote:
> On Wed, Mar 16, 2022 at 10:22:39PM +0900, Naohiro Aota wrote:
> > Add a function sb_write_started() to return if sb_start_write() is
> > properly called. It is used in the next commit.
> >
> > Also, add the similar functions for sb_start_pagefault() and
> > sb_start_intwrite().
> >
> > Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>
> > Signed-off-by: Naohiro Aota <naohiro.aota@xxxxxxx>
> > ---
> > include/linux/fs.h | 20 ++++++++++++++++++++
> > 1 file changed, 20 insertions(+)
> >
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index 27746a3da8fd..0c8714d64169 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -1732,6 +1732,11 @@ static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
> > #define __sb_writers_release(sb, lev) \
> > percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
> >
> > +static inline bool __sb_write_started(struct super_block *sb, int level)
> > +{
> > + return lockdep_is_held_type(sb->s_writers.rw_sem + level - 1, 1);
> > +}
> > +
> > /**
> > * sb_end_write - drop write access to a superblock
> > * @sb: the super we wrote to
> > @@ -1797,6 +1802,11 @@ static inline bool sb_start_write_trylock(struct super_block *sb)
> > return __sb_start_write_trylock(sb, SB_FREEZE_WRITE);
> > }
> >
> > +static inline bool sb_write_started(struct super_block *sb)
> > +{
> > + return __sb_write_started(sb, SB_FREEZE_WRITE);
> > +}
> > +
> > /**
> > * sb_start_pagefault - get write access to a superblock from a page fault
> > * @sb: the super we write to
> > @@ -1821,6 +1831,11 @@ static inline void sb_start_pagefault(struct super_block *sb)
> > __sb_start_write(sb, SB_FREEZE_PAGEFAULT);
> > }
> >
> > +static inline bool sb_pagefault_started(struct super_block *sb)
> > +{
> > + return __sb_write_started(sb, SB_FREEZE_PAGEFAULT);
> > +}
> > +
> > /**
> > * sb_start_intwrite - get write access to a superblock for internal fs purposes
> > * @sb: the super we write to
> > @@ -1844,6 +1859,11 @@ static inline bool sb_start_intwrite_trylock(struct super_block *sb)
> > return __sb_start_write_trylock(sb, SB_FREEZE_FS);
> > }
> >
> > +static inline bool sb_intwrite_started(struct super_block *sb)
> > +{
> > + return __sb_write_started(sb, SB_FREEZE_FS);
> > +}
> > +
> > bool inode_owner_or_capable(struct user_namespace *mnt_userns,
> > const struct inode *inode);
> >
>
> We should not be adding completely unused code to the VFS APIs.
>
> Just rename __sb_write_started() to sb_write_started() and pass
> SB_FREEZE_WRITE directly from the single debug assert that you've
> added that needs this check.
Sure, I will drop them in the next version. I just added them for
completeness.
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
