fs: uninline inode_query_iversion (c5bc1b3f) · Commits · EulixOS / Software / Kernel

fs/libfs.c

+36 −0

Original line number	Diff line number	Diff line
		@@ -1582,3 +1582,39 @@ bool inode_maybe_inc_iversion(struct inode *inode, bool force)
		return true;
		}
		EXPORT_SYMBOL(inode_maybe_inc_iversion);

		/**
		* inode_query_iversion - read i_version for later use
		* @inode: inode from which i_version should be read
		*
		* Read the inode i_version counter. This should be used by callers that wish
		* to store the returned i_version for later comparison. This will guarantee
		* that a later query of the i_version will result in a different value if
		* anything has changed.
		*
		* In this implementation, we fetch the current value, set the QUERIED flag and
		* then try to swap it into place with a cmpxchg, if it wasn't already set. If
		* that fails, we try again with the newly fetched value from the cmpxchg.
		*/
		u64 inode_query_iversion(struct inode *inode)
		{
		u64 cur, new;

		cur = inode_peek_iversion_raw(inode);
		do {
		/* If flag is already set, then no need to swap */
		if (cur & I_VERSION_QUERIED) {
		/*
		* This barrier (and the implicit barrier in the
		* cmpxchg below) pairs with the barrier in
		* inode_maybe_inc_iversion().
		*/
		smp_mb();
		break;
		}

		new = cur \| I_VERSION_QUERIED;
		} while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new));
		return cur >> I_VERSION_QUERIED_SHIFT;
		}
		EXPORT_SYMBOL(inode_query_iversion);

include/linux/iversion.h

+2 −36

Original line number	Diff line number	Diff line
		@@ -234,42 +234,6 @@ inode_peek_iversion(const struct inode *inode)
		return inode_peek_iversion_raw(inode) >> I_VERSION_QUERIED_SHIFT;
		}

		/**
		* inode_query_iversion - read i_version for later use
		* @inode: inode from which i_version should be read
		*
		* Read the inode i_version counter. This should be used by callers that wish
		* to store the returned i_version for later comparison. This will guarantee
		* that a later query of the i_version will result in a different value if
		* anything has changed.
		*
		* In this implementation, we fetch the current value, set the QUERIED flag and
		* then try to swap it into place with a cmpxchg, if it wasn't already set. If
		* that fails, we try again with the newly fetched value from the cmpxchg.
		*/
		static inline u64
		inode_query_iversion(struct inode *inode)
		{
		u64 cur, new;

		cur = inode_peek_iversion_raw(inode);
		do {
		/* If flag is already set, then no need to swap */
		if (cur & I_VERSION_QUERIED) {
		/*
		* This barrier (and the implicit barrier in the
		* cmpxchg below) pairs with the barrier in
		* inode_maybe_inc_iversion().
		*/
		smp_mb();
		break;
		}

		new = cur \| I_VERSION_QUERIED;
		} 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:
		@@ -283,6 +247,8 @@ static inline u64 time_to_chattr(struct timespec64 *t)
		return chattr;
		}

		u64 inode_query_iversion(struct inode *inode);

		/**
		* inode_eq_iversion_raw - check whether the raw i_version counter has changed
		* @inode: inode to check