1 files changed, 20 insertions, 65 deletions

diff --git a/include/linux/iversion.h b/include/linux/iversion.h
index 2917ef990d43..e27bd4f55d84 100644
--- a/include/linux/iversion.h
+++ b/include/linux/iversion.h
@@ -123,17 +123,12 @@ inode_peek_iversion_raw(const struct inode *inode)
 static inline void
 inode_set_max_iversion_raw(struct inode *inode, u64 val)
 {
-	u64 cur, old;
+	u64 cur = inode_peek_iversion_raw(inode);
 
-	cur = inode_peek_iversion_raw(inode);
-	for (;;) {
+	do {
 		if (cur > val)
 			break;
-		old = atomic64_cmpxchg(&inode->i_version, cur, val);
-		if (likely(old == cur))
-			break;
-		cur = old;
-	}
+	} while (!atomic64_try_cmpxchg(&inode->i_version, &cur, val));
 }
 
 /**
@@ -177,56 +172,7 @@ inode_set_iversion_queried(struct inode *inode, u64 val)
 				I_VERSION_QUERIED);
 }
 
-/**
- * inode_maybe_inc_iversion - increments i_version
- * @inode: inode with the i_version that should be updated
- * @force: increment the counter even if it's not necessary?
- *
- * Every time the inode is modified, the i_version field must be seen to have
- * changed by any observer.
- *
- * If "force" is set or the QUERIED flag is set, then ensure that we increment
- * the value, and clear the queried flag.
- *
- * In the common case where neither is set, then we can return "false" without
- * updating i_version.
- *
- * If this function returns false, and no other metadata has changed, then we
- * can avoid logging the metadata.
- */
-static inline bool
-inode_maybe_inc_iversion(struct inode *inode, bool force)
-{
-	u64 cur, old, new;
-
-	/*
-	 * The i_version field is not strictly ordered with any other inode
-	 * information, but the legacy inode_inc_iversion code used a spinlock
-	 * to serialize increments.
-	 *
-	 * Here, we add full memory barriers to ensure that any de-facto
-	 * ordering with other info is preserved.
-	 *
-	 * This barrier pairs with the barrier in inode_query_iversion()
-	 */
-	smp_mb();
-	cur = inode_peek_iversion_raw(inode);
-	for (;;) {
-		/* If flag is clear then we needn't do anything */
-		if (!force && !(cur & I_VERSION_QUERIED))
-			return false;
-
-		/* Since lowest bit is flag, add 2 to avoid it */
-		new = (cur & ~I_VERSION_QUERIED) + I_VERSION_INCREMENT;
-
-		old = atomic64_cmpxchg(&inode->i_version, cur, new);
-		if (likely(old == cur))
-			break;
-		cur = old;
-	}
-	return true;
-}
-
+bool inode_maybe_inc_iversion(struct inode *inode, bool force);
 
 /**
  * inode_inc_iversion - forcibly increment i_version
@@ -304,10 +250,10 @@ inode_peek_iversion(const struct inode *inode)
 static inline u64
 inode_query_iversion(struct inode *inode)
 {
-	u64 cur, old, new;
+	u64 cur, new;
 
 	cur = inode_peek_iversion_raw(inode);
-	for (;;) {
+	do {
 		/* If flag is already set, then no need to swap */
 		if (cur & I_VERSION_QUERIED) {
 			/*
@@ -320,14 +266,23 @@ inode_query_iversion(struct inode *inode)
 		}
 
 		new = cur | I_VERSION_QUERIED;
-		old = atomic64_cmpxchg(&inode->i_version, cur, new);
-		if (likely(old == cur))
-			break;
-		cur = old;
-	}
+	} while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new));
 	return cur >> I_VERSION_QUERIED_SHIFT;
 }
 
+/*
+ * For filesystems without any sort of change attribute, the best we can
+ * do is fake one up from the ctime:
+ */
+static inline u64 time_to_chattr(struct timespec64 *t)
+{
+	u64 chattr = t->tv_sec;
+
+	chattr <<= 32;
+	chattr += t->tv_nsec;
+	return chattr;
+}
+
 /**
  * inode_eq_iversion_raw - check whether the raw i_version counter has changed
  * @inode: inode to check