fsnotify: fix unlink performance regression (4d8e7055) · Commits · 戴 / test

fs/notify/fsnotify.c

+41 −0

Original line number	Diff line number	Diff line
		@@ -107,6 +107,47 @@ void fsnotify_sb_delete(struct super_block *sb)
		fsnotify_clear_marks_by_sb(sb);
		}

		/*
		* fsnotify_nameremove - a filename was removed from a directory
		*
		* This is mostly called under parent vfs inode lock so name and
		* dentry->d_parent should be stable. However there are some corner cases where
		* inode lock is not held. So to be on the safe side and be reselient to future
		* callers and out of tree users of d_delete(), we do not assume that d_parent
		* and d_name are stable and we use dget_parent() and
		* take_dentry_name_snapshot() to grab stable references.
		*/
		void fsnotify_nameremove(struct dentry *dentry, int isdir)
		{
		struct dentry *parent;
		struct name_snapshot name;
		__u32 mask = FS_DELETE;

		/* d_delete() of pseudo inode? (e.g. __ns_get_path() playing tricks) */
		if (IS_ROOT(dentry))
		return;

		if (isdir)
		mask \|= FS_ISDIR;

		parent = dget_parent(dentry);
		/* Avoid unneeded take_dentry_name_snapshot() */
		if (!(d_inode(parent)->i_fsnotify_mask & FS_DELETE) &&
		!(dentry->d_sb->s_fsnotify_mask & FS_DELETE))
		goto out_dput;

		take_dentry_name_snapshot(&name, dentry);

		fsnotify(d_inode(parent), mask, d_inode(dentry), FSNOTIFY_EVENT_INODE,
		name.name, 0);

		release_dentry_name_snapshot(&name);

		out_dput:
		dput(parent);
		}
		EXPORT_SYMBOL(fsnotify_nameremove);

		/*
		* Given an inode, first check if we care what happens to our children. Inotify
		* and dnotify both tell their parents about events. If we care about any event

+0 −33

Original line number	Diff line number	Diff line
		@@ -151,39 +151,6 @@ static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
		__fsnotify_vfsmount_delete(mnt);
		}

		/*
		* fsnotify_nameremove - a filename was removed from a directory
		*
		* This is mostly called under parent vfs inode lock so name and
		* dentry->d_parent should be stable. However there are some corner cases where
		* inode lock is not held. So to be on the safe side and be reselient to future
		* callers and out of tree users of d_delete(), we do not assume that d_parent
		* and d_name are stable and we use dget_parent() and
		* take_dentry_name_snapshot() to grab stable references.
		*/
		static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
		{
		struct dentry *parent;
		struct name_snapshot name;
		__u32 mask = FS_DELETE;

		/* d_delete() of pseudo inode? (e.g. __ns_get_path() playing tricks) */
		if (IS_ROOT(dentry))
		return;

		if (isdir)
		mask \|= FS_ISDIR;

		parent = dget_parent(dentry);
		take_dentry_name_snapshot(&name, dentry);

		fsnotify(d_inode(parent), mask, d_inode(dentry), FSNOTIFY_EVENT_INODE,
		name.name, 0);

		release_dentry_name_snapshot(&name);
		dput(parent);
		}

		/*
		* fsnotify_inoderemove - an inode is going away
		*/

+4 −0

Original line number	Diff line number	Diff line
		@@ -355,6 +355,7 @@ extern int __fsnotify_parent(const struct path path, struct dentry dentry, __u
		extern void __fsnotify_inode_delete(struct inode *inode);
		extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt);
		extern void fsnotify_sb_delete(struct super_block *sb);
		extern void fsnotify_nameremove(struct dentry *dentry, int isdir);
		extern u32 fsnotify_get_cookie(void);

		static inline int fsnotify_inode_watches_children(struct inode *inode)
		@@ -524,6 +525,9 @@ static inline void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
		static inline void fsnotify_sb_delete(struct super_block *sb)
		{}

		static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
		{}

		static inline void fsnotify_update_flags(struct dentry *dentry)
		{}