Unverified Commit 97cbed04 authored by Christian Brauner's avatar Christian Brauner
Browse files

fs: remove unused helper 

The grab_super() helper is now only used by grab_super_dead(). Merge the
two helpers into one.

Link: https://lore.kernel.org/r/20231024-vfs-super-freeze-v2-8-599c19f4faac@kernel.org


Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 90f95dc4

fs/super.c

+14 −40
Original line number Diff line number Diff line
@@ -523,37 +523,6 @@ 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 locked;



	s->s_count++;

	spin_unlock(&sb_lock);

	locked = super_lock_excl(s);

	if (locked) {

		if (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;
@@ -567,7 +536,7 @@ 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
@@ -578,16 +547,21 @@ 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)

{

	bool locked;



	sb->s_count++;

	if (grab_super(sb)) {

	spin_unlock(&sb_lock);

	locked = super_lock_excl(sb);

	if (locked) {

		if (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;

}
@@ -838,7 +812,7 @@ 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;
@@ -882,7 +856,7 @@ 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;