On Wed 27-09-23 15:21:19, Christian Brauner wrote:
> The grab_super() helper is now only used by grab_super_dead(). Merge the
> two helpers into one.
>
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Yeah, nice! Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/super.c | 44 +++++++-------------------------------------
> 1 file changed, 7 insertions(+), 37 deletions(-)
>
> diff --git a/fs/super.c b/fs/super.c
> index 181ac8501301..6cdce2b31622 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -517,35 +517,6 @@ void deactivate_super(struct super_block *s)
>
> EXPORT_SYMBOL(deactivate_super);
>
> -/**
> - * grab_super - acquire an active reference
> - * @s: reference we are trying to make active
> - *
> - * Tries to acquire an active reference. grab_super() is used when we
> - * had just found a superblock in super_blocks or fs_type->fs_supers
> - * and want to turn it into a full-blown active reference. grab_super()
> - * is called with sb_lock held and drops it. Returns 1 in case of
> - * success, 0 if we had failed (superblock contents was already dead or
> - * dying when grab_super() had been called). Note that this is only
> - * called for superblocks not in rundown mode (== ones still on ->fs_supers
> - * of their type), so increment of ->s_count is OK here.
> - */
> -static int grab_super(struct super_block *s) __releases(sb_lock)
> -{
> - bool born;
> -
> - s->s_count++;
> - spin_unlock(&sb_lock);
> - born = super_lock_excl(s);
> - if (born && atomic_inc_not_zero(&s->s_active)) {
> - put_super(s);
> - return 1;
> - }
> - super_unlock_excl(s);
> - put_super(s);
> - return 0;
> -}
> -
> static inline bool wait_dead(struct super_block *sb)
> {
> unsigned int flags;
> @@ -559,7 +530,7 @@ static inline bool wait_dead(struct super_block *sb)
> }
>
> /**
> - * grab_super_dead - acquire an active reference to a superblock
> + * grab_super - acquire an active reference to a superblock
> * @sb: superblock to acquire
> *
> * Acquire a temporary reference on a superblock and try to trade it for
> @@ -570,17 +541,16 @@ static inline bool wait_dead(struct super_block *sb)
> * Return: This returns true if an active reference could be acquired,
> * false if not.
> */
> -static bool grab_super_dead(struct super_block *sb)
> +static bool grab_super(struct super_block *sb)
> {
> -
> sb->s_count++;
> - if (grab_super(sb)) {
> + spin_unlock(&sb_lock);
> + if (super_lock_excl(sb) && atomic_inc_not_zero(&sb->s_active)) {
> put_super(sb);
> - lockdep_assert_held(&sb->s_umount);
> return true;
> }
> + super_unlock_excl(sb);
> wait_var_event(&sb->s_flags, wait_dead(sb));
> - lockdep_assert_not_held(&sb->s_umount);
> put_super(sb);
> return false;
> }
> @@ -831,7 +801,7 @@ struct super_block *sget_fc(struct fs_context *fc,
> warnfc(fc, "reusing existing filesystem in another namespace not allowed");
> return ERR_PTR(-EBUSY);
> }
> - if (!grab_super_dead(old))
> + if (!grab_super(old))
> goto retry;
> destroy_unused_super(s);
> return old;
> @@ -875,7 +845,7 @@ struct super_block *sget(struct file_system_type *type,
> destroy_unused_super(s);
> return ERR_PTR(-EBUSY);
> }
> - if (!grab_super_dead(old))
> + if (!grab_super(old))
> goto retry;
> destroy_unused_super(s);
> return old;
>
> --
> 2.34.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
