Unverified Commit c859df52 authored by Christian Brauner's avatar Christian Brauner
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Merge patch series "lockref cleanups" 

Christoph Hellwig <hch@lst.de> says:

This series has a bunch of cosmetic cleanups for the lockref code I came up
with when reading the code in preparation of adding a new user of it.

* patches from https://lore.kernel.org/r/20250115094702.504610-1-hch@lst.de:
  gfs2: use lockref_init for qd_lockref
  erofs: use lockref_init for pcl->lockref
  dcache: use lockref_init for d_lockref
  lockref: add a lockref_init helper
  lockref: drop superfluous externs
  lockref: use bool for false/true returns
  lockref: improve the lockref_get_not_zero description
  lockref: remove lockref_put_not_zero

Link: https://lore.kernel.org/r/20250115094702.504610-1-hch@lst.de


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parents 4f3b63e8 3e652eba

fs/dcache.c

+1 −2
Original line number Diff line number Diff line
@@ -1681,9 +1681,8 @@ static struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) 
	/* Make sure we always see the terminating NUL character */

	smp_store_release(&dentry->d_name.name, dname); /* ^^^ */



	dentry->d_lockref.count = 1;

	dentry->d_flags = 0;

	spin_lock_init(&dentry->d_lock);

	lockref_init(&dentry->d_lockref, 1);

	seqcount_spinlock_init(&dentry->d_seq, &dentry->d_lock);

	dentry->d_inode = NULL;

	dentry->d_parent = dentry;

fs/erofs/zdata.c

+1 −2
Original line number Diff line number Diff line
@@ -747,8 +747,7 @@ static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe) 
	if (IS_ERR(pcl))

		return PTR_ERR(pcl);



	spin_lock_init(&pcl->lockref.lock);

	pcl->lockref.count = 1;		/* one ref for this request */

	lockref_init(&pcl->lockref, 1); /* one ref for this request */

	pcl->algorithmformat = map->m_algorithmformat;

	pcl->length = 0;

	pcl->partial = true;

fs/gfs2/quota.c

+1 −2
Original line number Diff line number Diff line
@@ -236,8 +236,7 @@ static struct gfs2_quota_data *qd_alloc(unsigned hash, struct gfs2_sbd *sdp, str 
		return NULL;



	qd->qd_sbd = sdp;

	qd->qd_lockref.count = 0;

	spin_lock_init(&qd->qd_lockref.lock);

	lockref_init(&qd->qd_lockref, 0);

	qd->qd_id = qid;

	qd->qd_slot = -1;

	INIT_LIST_HEAD(&qd->qd_lru);

include/linux/lockref.h

+18 −8
Original line number Diff line number Diff line
@@ -34,14 +34,24 @@ struct lockref { 
	};

};



extern void lockref_get(struct lockref *);

extern int lockref_put_return(struct lockref *);

extern int lockref_get_not_zero(struct lockref *);

extern int lockref_put_not_zero(struct lockref *);

extern int lockref_put_or_lock(struct lockref *);



extern void lockref_mark_dead(struct lockref *);

extern int lockref_get_not_dead(struct lockref *);

/**

 * lockref_init - Initialize a lockref

 * @lockref: pointer to lockref structure

 * @count: initial count

 */

static inline void lockref_init(struct lockref *lockref, unsigned int count)

{

	spin_lock_init(&lockref->lock);

	lockref->count = count;

}



void lockref_get(struct lockref *lockref);

int lockref_put_return(struct lockref *lockref);

bool lockref_get_not_zero(struct lockref *lockref);

bool lockref_put_or_lock(struct lockref *lockref);



void lockref_mark_dead(struct lockref *lockref);

bool lockref_get_not_dead(struct lockref *lockref);



/* Must be called under spinlock for reliable results */

static inline bool __lockref_is_dead(const struct lockref *l)

lib/lockref.c

+15 −45
Original line number Diff line number Diff line
@@ -58,63 +58,34 @@ EXPORT_SYMBOL(lockref_get); 
 * @lockref: pointer to lockref structure

 * Return: 1 if count updated successfully or 0 if count was zero

 */

int lockref_get_not_zero(struct lockref *lockref)

bool lockref_get_not_zero(struct lockref *lockref)

{

	int retval;

	bool retval = false;



	CMPXCHG_LOOP(

		new.count++;

		if (old.count <= 0)

			return 0;

			return false;

	,

		return 1;

		return true;

	);



	spin_lock(&lockref->lock);

	retval = 0;

	if (lockref->count > 0) {

		lockref->count++;

		retval = 1;

		retval = true;

	}

	spin_unlock(&lockref->lock);

	return retval;

}

EXPORT_SYMBOL(lockref_get_not_zero);



/**

 * lockref_put_not_zero - Decrements count unless count <= 1 before decrement

 * @lockref: pointer to lockref structure

 * Return: 1 if count updated successfully or 0 if count would become zero

 */

int lockref_put_not_zero(struct lockref *lockref)

{

	int retval;



	CMPXCHG_LOOP(

		new.count--;

		if (old.count <= 1)

			return 0;

	,

		return 1;

	);



	spin_lock(&lockref->lock);

	retval = 0;

	if (lockref->count > 1) {

		lockref->count--;

		retval = 1;

	}

	spin_unlock(&lockref->lock);

	return retval;

}

EXPORT_SYMBOL(lockref_put_not_zero);



/**

 * lockref_put_return - Decrement reference count if possible

 * @lockref: pointer to lockref structure

 *

 * Decrement the reference count and return the new value.

 * If the lockref was dead or locked, return an error.

 * If the lockref was dead or locked, return -1.

 */

int lockref_put_return(struct lockref *lockref)

{
@@ -134,22 +105,22 @@ EXPORT_SYMBOL(lockref_put_return); 
 * @lockref: pointer to lockref structure

 * Return: 1 if count updated successfully or 0 if count <= 1 and lock taken

 */

int lockref_put_or_lock(struct lockref *lockref)

bool lockref_put_or_lock(struct lockref *lockref)

{

	CMPXCHG_LOOP(

		new.count--;

		if (old.count <= 1)

			break;

	,

		return 1;

		return true;

	);



	spin_lock(&lockref->lock);

	if (lockref->count <= 1)

		return 0;

		return false;

	lockref->count--;

	spin_unlock(&lockref->lock);

	return 1;

	return true;

}

EXPORT_SYMBOL(lockref_put_or_lock);
@@ -169,23 +140,22 @@ EXPORT_SYMBOL(lockref_mark_dead); 
 * @lockref: pointer to lockref structure

 * Return: 1 if count updated successfully or 0 if lockref was dead

 */

int lockref_get_not_dead(struct lockref *lockref)

bool lockref_get_not_dead(struct lockref *lockref)

{

	int retval;

	bool retval = false;



	CMPXCHG_LOOP(

		new.count++;

		if (old.count < 0)

			return 0;

			return false;

	,

		return 1;

		return true;

	);



	spin_lock(&lockref->lock);

	retval = 0;

	if (lockref->count >= 0) {

		lockref->count++;

		retval = 1;

		retval = true;

	}

	spin_unlock(&lockref->lock);

	return retval;