Merge tag 'v4.19.50-rt22' into toradex_4.19.y-rt

Linux 4.19.50-rt22

1 files changed, 58 insertions, 31 deletions

diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 367b39fe46e5..58d8cbc3f921 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -39,7 +39,7 @@
 #define debugln(x, ...)         ((void)0)
 
 #define dbg_might_sleep()       ((void)0)
-#define DBG_BUGON(...)          ((void)0)
+#define DBG_BUGON(x)            ((void)(x))
 #endif
 
 #ifdef CONFIG_EROFS_FAULT_INJECTION
@@ -184,50 +184,70 @@ struct erofs_workgroup {
 
 #define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
 
-static inline bool erofs_workgroup_try_to_freeze(
-	struct erofs_workgroup *grp, int v)
+#if defined(CONFIG_SMP)
+static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
+						 int val)
 {
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-	if (v != atomic_cmpxchg(&grp->refcount,
-		v, EROFS_LOCKED_MAGIC))
-		return false;
 	preempt_disable();
+	if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
+		preempt_enable();
+		return false;
+	}
+	return true;
+}
+
+static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
+					    int orig_val)
+{
+	/*
+	 * other observers should notice all modifications
+	 * in the freezing period.
+	 */
+	smp_mb();
+	atomic_set(&grp->refcount, orig_val);
+	preempt_enable();
+}
+
+static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
+{
+	return atomic_cond_read_relaxed(&grp->refcount,
+					VAL != EROFS_LOCKED_MAGIC);
+}
 #else
+static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
+						 int val)
+{
 	preempt_disable();
-	if (atomic_read(&grp->refcount) != v) {
+	/* no need to spin on UP platforms, let's just disable preemption. */
+	if (val != atomic_read(&grp->refcount)) {
 		preempt_enable();
 		return false;
 	}
-#endif
 	return true;
 }
 
-static inline void erofs_workgroup_unfreeze(
-	struct erofs_workgroup *grp, int v)
+static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
+					    int orig_val)
 {
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-	atomic_set(&grp->refcount, v);
-#endif
 	preempt_enable();
 }
 
+static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
+{
+	int v = atomic_read(&grp->refcount);
+
+	/* workgroup is never freezed on uniprocessor systems */
+	DBG_BUGON(v == EROFS_LOCKED_MAGIC);
+	return v;
+}
+#endif
+
 static inline bool erofs_workgroup_get(struct erofs_workgroup *grp, int *ocnt)
 {
-	const int locked = (int)EROFS_LOCKED_MAGIC;
 	int o;
 
 repeat:
-	o = atomic_read(&grp->refcount);
-
-	/* spin if it is temporarily locked at the reclaim path */
-	if (unlikely(o == locked)) {
-#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
-		do
-			cpu_relax();
-		while (atomic_read(&grp->refcount) == locked);
-#endif
-		goto repeat;
-	}
+	o = erofs_wait_on_workgroup_freezed(grp);
 
 	if (unlikely(o <= 0))
 		return -1;
@@ -240,6 +260,7 @@ repeat:
 }
 
 #define __erofs_workgroup_get(grp)	atomic_inc(&(grp)->refcount)
+#define __erofs_workgroup_put(grp)	atomic_dec(&(grp)->refcount)
 
 extern int erofs_workgroup_put(struct erofs_workgroup *grp);
 
@@ -307,12 +328,17 @@ static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
 	return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
 }
 
-#define inode_set_inited_xattr(inode)   (EROFS_V(inode)->flags |= 1)
-#define inode_has_inited_xattr(inode)   (EROFS_V(inode)->flags & 1)
+/* atomic flag definitions */
+#define EROFS_V_EA_INITED_BIT	0
+
+/* bitlock definitions (arranged in reverse order) */
+#define EROFS_V_BL_XATTR_BIT	(BITS_PER_LONG - 1)
 
 struct erofs_vnode {
 	erofs_nid_t nid;
-	unsigned int flags;
+
+	/* atomic flags (including bitlocks) */
+	unsigned long flags;
 
 	unsigned char data_mapping_mode;
 	/* inline size in bytes */
@@ -465,8 +491,9 @@ struct erofs_map_blocks_iter {
 };
 
 
-static inline struct page *erofs_get_inline_page(struct inode *inode,
-	erofs_blk_t blkaddr)
+static inline struct page *
+erofs_get_inline_page(struct inode *inode,
+		      erofs_blk_t blkaddr)
 {
 	return erofs_get_meta_page(inode->i_sb,
 		blkaddr, S_ISDIR(inode->i_mode));